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[PATCH][4/4][v2] RPO-style value-numbering for FRE/PRE
- From: Richard Biener <rguenther at suse dot de>
- To: gcc-patches at gcc dot gnu dot org
- Date: Fri, 24 Aug 2018 13:24:10 +0200 (CEST)
- Subject: [PATCH][4/4][v2] RPO-style value-numbering for FRE/PRE
As indicated I have committed 1/4 of the series.
Changes from v1 are mostly cleanups that were indicated by ??? comments
and that I did by reviewing the patch myself again. I have changed
the cut-off paramter to seven, up from three even though I know that
that will cause gamess to be slower to compile. We can play with this
parameter more once the patch is on trunk and/or devise other
cut-off mechanisms for the iteration.
Comments are still welcome - I've re-bootstrapped and tested the series
on x86_64-unknown-linux-gnu for all languages and will talk about
this work at the Cauldron in more detail.
I plan to install this version on Monday (together with 2/4 and 3/4).
Richard.
>From 147e732b44ad929aff6cf891c0edfde4333434d7 Mon Sep 17 00:00:00 2001
From: Richard Guenther <rguenther@suse.de>
Date: Wed, 4 Jul 2018 11:15:20 +0200
Subject: [PATCH] RPO-vn-merged-final
This rewrites the value-numbering algorithm used for FRE and PRE from
SSA SCC based to RPO based, thus switching from an algorithm that
handles SSA SCCs optimistically to one that handles CFG SCCs optimistically.
The main motivation for this besides being more optimistic was that
adding CFG context sensitive info is easier in RPO style. Also
tracking availability and thus making expression simplification not
based on values like with SCCVN is possible which allows us to remove
all the warts that scrap side-info we store on SSA names. It also
fixes PR86554 which is another manifestation of the same issue.
Another motivation was that we're in the need of applying value-numbering
on regions like when unrolling loops or as part of cleanup on code
generated by other passes like the vectorizer. Thus this rewrite
makes sure that the value-numbering works efficiently on regions
(though in a non-iterative mode), avoiding work and space that is
on the order of the function size rather than the region size to work on.
Sofar the GIMPLE unroller makes use of this, scrapping its own
simple constant propagation engine. I expect that DOM could get rid of
its value-numbering and instead use a non-iterative RPO-VN run as well.
The patch adds something called predication but it just implements
what I put on top of SCCVN to not regress in that area.
With more optimistic handling comes compile-time regressions and
without limiting I can observe for example a 8% compile-time regression
on 416.gamess which contains loop depths exceeding 8. The patch now
contains heuristics to selectively value-number backedges optimistically
or not and chooses to do so for the innermost 7 and the outermost loop
of a nest (controlled by --param rpo-vn-max-loop-depth).
* tree-ssa-sccvn.h (struct vn_pval): New structure.
(struct vn_nary_op_s): Add unwind_to member. Add
predicated_values flag and put result into a union together
with a linked list of vn_pval.
(struct vn_ssa_aux): Add name member to make maintaining
a map of SSA name to vn_ssa_aux possible. Remove no longer
needed info, dfsnum, low, visited, on_sccstack, use_processed
and range_info_anti_range_p members.
(run_scc_vn, vn_eliminate, free_scc_vn, vn_valueize): Remove.
(do_rpo_vn, run_rpo_vn, eliminate_with_rpo_vn, free_rpo_vn):
New functions.
(vn_valueize): New global.
(vn_context_bb): Likewise.
(VN_INFO_RANGE_INFO, VN_INFO_ANTI_RANGE_P, VN_INFO_RANGE_TYPE,
VN_INFO_PTR_INFO): Remove.
* tree-ssa-sccvn.c: ... (rewrite)
(pass_fre::execute): For -O2+ initialize loops and run
RPO VN in optimistic mode (iterating). For -O1 and -Og
run RPO VN in non-optimistic mode.
* params.def (PARAM_SCCVN_MAX_SCC_SIZE): Remove.
(PARAM_RPO_VN_MAX_LOOP_DEPTH): Add.
* doc/invoke.texi (sccvn-max-scc-size): Remove.
(rpo-vn-max-loop-depth): Document.
* tree-ssa-alias.c (walk_non_aliased_vuses): Stop walking
when valuezing the VUSE signals we walked out of the region.
* tree-ssa-pre.c (phi_translate_1): Ignore predicated values.
(phi_translate): Set VN context block to use for availability
lookup.
(compute_avail): Likewise.
(pre_valueize): New function.
(pass_pre::execute): Adjust to the RPO VN API.
* g++.dg/torture/20180705-1.C: New testcase.
* gcc.dg/tree-ssa/ssa-fre-67.c: Likewise.
* gcc.dg/tree-ssa/ssa-ccp-14.c: Scan FRE dump.
* gcc.dg/tree-ssa/ssa-fre-46.c: Use -O2.
* gcc.dg/tree-ssa/vrp92.c: Disable FRE.
* gcc.dg/pr83666.c: Drop --param=sccvn-max-scc-size option.
* gcc.dg/pr85195.c: Likewise.
* gcc.dg/pr85467.c: Likewise.
* gcc.dg/torture/pr81790.c: Likewise.
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index e4148297a87..2ceb755edf6 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -11032,11 +11032,12 @@ parameter sets a limit on the length of the sets that are computed,
which prevents the runaway behavior. Setting a value of 0 for
this parameter allows an unlimited set length.
-@item sccvn-max-scc-size
-Maximum size of a strongly connected component (SCC) during SCCVN
-processing. If this limit is hit, SCCVN processing for the whole
-function is not done and optimizations depending on it are
-disabled. The default maximum SCC size is 10000.
+@item rpo-vn-max-loop-depth
+Maximum loop depth that is value-numbered optimistically. The default
+maximum loop depth is three. When the limit hits the innermost
+@var{rpo-vn-max-loop-depth} loops and the outermost loop in the
+loop nest are value-numbered optimistically and the remaining ones not.
+The default maximum loop depth is seven.
@item sccvn-max-alias-queries-per-access
Maximum number of alias-oracle queries we perform when looking for
diff --git a/gcc/params.def b/gcc/params.def
index a09785d4e07..a0ad3ecdad6 100644
--- a/gcc/params.def
+++ b/gcc/params.def
@@ -847,15 +847,15 @@ DEFPARAM (PARAM_MAX_PARTIAL_ANTIC_LENGTH,
"Maximum length of partial antic set when performing tree pre optimization.",
100, 0, 0)
-/* The following is used as a stop-gap limit for cases where really huge
- SCCs blow up memory and compile-time use too much. If we hit this limit,
- SCCVN and such FRE and PRE will be not done at all for the current
- function. */
-
-DEFPARAM (PARAM_SCCVN_MAX_SCC_SIZE,
- "sccvn-max-scc-size",
- "Maximum size of a SCC before SCCVN stops processing a function.",
- 10000, 10, 0)
+/* The following is used as a stop-gap limit for cases where really deep
+ loop nests cause compile-time to blow up. If we hit this limit,
+ FRE and PRE will value-number outer loops (but the outermost) in a
+ loop nest non-optimistically. */
+
+DEFPARAM (PARAM_RPO_VN_MAX_LOOP_DEPTH,
+ "rpo-vn-max-loop-depth",
+ "Maximum depth of a loop nest to fully value-number optimistically.",
+ 7, 2, 0)
/* The following is used as a stop-gap limit for cases where really huge
functions blow up compile-time use too much. It limits the number of
diff --git a/gcc/testsuite/g++.dg/torture/20180705-1.C b/gcc/testsuite/g++.dg/torture/20180705-1.C
new file mode 100644
index 00000000000..8460473bee8
--- /dev/null
+++ b/gcc/testsuite/g++.dg/torture/20180705-1.C
@@ -0,0 +1,30 @@
+// { dg-do compile }
+
+typedef long unsigned int size_t;
+extern void fancy_abort () __attribute__ ((__noreturn__));
+class cpp_string_location_reader { };
+class cpp_substring_ranges {
+public:
+ void add_range ();
+};
+typedef unsigned char uchar;
+void
+cpp_interpret_string_1 (size_t count, cpp_string_location_reader *loc_readers, cpp_substring_ranges *ranges, uchar c, const uchar *p)
+{
+ size_t i;
+ ((void)(!((loc_readers != __null ) == (ranges != __null )) ? fancy_abort (), 0 : 0));
+ cpp_string_location_reader *loc_reader = __null;
+ for (i = 0; i < count; i++)
+ {
+ if (loc_readers) loc_reader = &loc_readers[i];
+ if (*p == 'R') continue;
+ for (;;)
+ {
+ switch (c) {
+ case 'x': if (ranges) ranges->add_range (); break;
+ case '7': ((void)(!((loc_reader != __null ) == (ranges != __null )) ? fancy_abort (), 0 : 0)); break;
+ }
+ p = 0;
+ }
+ }
+}
diff --git a/gcc/testsuite/gcc.dg/pr83666.c b/gcc/testsuite/gcc.dg/pr83666.c
index 7bd1ed3ceb2..1c43c438544 100644
--- a/gcc/testsuite/gcc.dg/pr83666.c
+++ b/gcc/testsuite/gcc.dg/pr83666.c
@@ -1,6 +1,6 @@
/* PR debug/83666 */
/* { dg-do compile } */
-/* { dg-options "-O2 -g --param=sccvn-max-scc-size=10 -Wno-psabi" } */
+/* { dg-options "-O2 -g -Wno-psabi" } */
/* { dg-additional-options "-fno-common" { target hppa*-*-hpux* } } */
typedef int __attribute__ ((vector_size (64))) V;
diff --git a/gcc/testsuite/gcc.dg/pr85195.c b/gcc/testsuite/gcc.dg/pr85195.c
index 0cc696ba6ee..fb21ee97c5c 100644
--- a/gcc/testsuite/gcc.dg/pr85195.c
+++ b/gcc/testsuite/gcc.dg/pr85195.c
@@ -1,6 +1,6 @@
/* PR middle-end/85195 */
/* { dg-do compile { target int128 } } */
-/* { dg-options "-Wno-psabi -O -fno-tree-ccp --param=sccvn-max-scc-size=10" } */
+/* { dg-options "-Wno-psabi -O -fno-tree-ccp" } */
typedef __int128 V __attribute__ ((vector_size (16)));
diff --git a/gcc/testsuite/gcc.dg/pr85467.c b/gcc/testsuite/gcc.dg/pr85467.c
index 4895e37d0f9..fad94fcd83e 100644
--- a/gcc/testsuite/gcc.dg/pr85467.c
+++ b/gcc/testsuite/gcc.dg/pr85467.c
@@ -1,6 +1,6 @@
/* PR tree-optimization/85467 */
/* { dg-do compile } */
-/* { dg-options "-O2 -fno-tree-ccp --param=sccvn-max-scc-size=10" } */
+/* { dg-options "-O2 -fno-tree-ccp" } */
#define TEST(N, T) \
typedef T V##N __attribute__ ((__vector_size__ (sizeof (T)))); \
diff --git a/gcc/testsuite/gcc.dg/torture/pr81790.c b/gcc/testsuite/gcc.dg/torture/pr81790.c
index b5e02f6c1dd..b69946f9d10 100644
--- a/gcc/testsuite/gcc.dg/torture/pr81790.c
+++ b/gcc/testsuite/gcc.dg/torture/pr81790.c
@@ -1,5 +1,4 @@
/* { dg-do compile } */
-/* { dg-additional-options "--param sccvn-max-scc-size=10" } */
typedef int a __attribute__ ((__vector_size__ (16)));
typedef struct
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-ccp-14.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-ccp-14.c
index 3955bddcf59..65e2d5a664b 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/ssa-ccp-14.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-ccp-14.c
@@ -1,8 +1,5 @@
-/* PR tree-optimization/29738. We used not to realize that "i" can never
- become nonzero. */
-
/* { dg-do compile } */
-/* { dg-options "-O2 -fdump-tree-optimized" } */
+/* { dg-options "-O2 -fdump-tree-fre1 -fdump-tree-optimized" } */
int i;
@@ -16,5 +13,7 @@ void bar (void)
foo ();
}
-/* Everything except for the "i = 0" assignment should get removed. */
-/* { dg-final { scan-tree-dump-times "if" 0 "optimized" { xfail *-*-* } } } */
+/* Everything except for the "i = 0" assignment should get removed. Value
+ numbering already figures out the if in the loop is never true. */
+/* { dg-final { scan-tree-dump-times "foo" 0 "fre1" } } */
+/* { dg-final { scan-tree-dump-times "if" 0 "optimized" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-46.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-46.c
index d6e63518e9f..8d6eaa3ada0 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-46.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-46.c
@@ -1,5 +1,5 @@
/* { dg-do compile } */
-/* { dg-options "-O -fdump-tree-fre1-details" } */
+/* { dg-options "-O2 -fdump-tree-fre1-details" } */
int x[1024];
int foo (int a, int s, unsigned int k)
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-67.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-67.c
new file mode 100644
index 00000000000..fab1e599b81
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-67.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fno-tree-ccp -fdump-tree-fre1-stats" } */
+
+int foo()
+{
+ int i = 0;
+ do
+ {
+ i++;
+ }
+ while (i != 1);
+ return i;
+}
+
+/* { dg-final { scan-tree-dump "RPO iteration over 3 blocks visited 3 blocks" "fre1" } } */
+/* { dg-final { scan-tree-dump "return 1;" "fre1" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/vrp92.c b/gcc/testsuite/gcc.dg/tree-ssa/vrp92.c
index 213aa47609a..5a2dbf0108a 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/vrp92.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/vrp92.c
@@ -1,5 +1,5 @@
/* { dg-do compile } */
-/* { dg-options "-O2 -fdisable-tree-evrp -fdump-tree-vrp1-details -fdisable-tree-ethread" } */
+/* { dg-options "-O2 -fdisable-tree-evrp -fno-tree-fre -fdump-tree-vrp1-details -fdisable-tree-ethread" } */
void bar (void);
int foo (int i, int j)
diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c
index 7b25778307f..e6e21e8773c 100644
--- a/gcc/tree-ssa-alias.c
+++ b/gcc/tree-ssa-alias.c
@@ -2783,7 +2783,14 @@ walk_non_aliased_vuses (ao_ref *ref, tree vuse,
break;
if (valueize)
- vuse = valueize (vuse);
+ {
+ vuse = valueize (vuse);
+ if (!vuse)
+ {
+ res = NULL;
+ break;
+ }
+ }
def_stmt = SSA_NAME_DEF_STMT (vuse);
if (gimple_nop_p (def_stmt))
break;
diff --git a/gcc/tree-ssa-pre.c b/gcc/tree-ssa-pre.c
index 144902d15dc..b9e93188a98 100644
--- a/gcc/tree-ssa-pre.c
+++ b/gcc/tree-ssa-pre.c
@@ -677,10 +677,10 @@ get_expr_value_id (pre_expr expr)
return id;
}
-/* Return a SCCVN valnum (SSA name or constant) for the PRE value-id VAL. */
+/* Return a VN valnum (SSA name or constant) for the PRE value-id VAL. */
static tree
-sccvn_valnum_from_value_id (unsigned int val)
+vn_valnum_from_value_id (unsigned int val)
{
bitmap_iterator bi;
unsigned int i;
@@ -1308,9 +1308,9 @@ get_representative_for (const pre_expr e, basic_block b = NULL)
??? We should be able to re-use this when we insert the statement
to compute it. */
name = make_temp_ssa_name (get_expr_type (e), gimple_build_nop (), "pretmp");
- VN_INFO_GET (name)->value_id = value_id;
+ VN_INFO (name)->value_id = value_id;
VN_INFO (name)->valnum = valnum ? valnum : name;
- /* ??? For now mark this SSA name for release by SCCVN. */
+ /* ??? For now mark this SSA name for release by VN. */
VN_INFO (name)->needs_insertion = true;
add_to_value (value_id, get_or_alloc_expr_for_name (name));
if (dump_file && (dump_flags & TDF_DETAILS))
@@ -1404,7 +1404,22 @@ phi_translate_1 (bitmap_set_t dest,
constant = find_leader_in_sets (value_id, dest,
AVAIL_OUT (pred));
if (constant)
- return constant;
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "simplifying ");
+ print_pre_expr (dump_file, expr);
+ fprintf (dump_file, " translated %d -> %d to ",
+ phiblock->index, pred->index);
+ PRE_EXPR_NARY (expr) = newnary;
+ print_pre_expr (dump_file, expr);
+ PRE_EXPR_NARY (expr) = nary;
+ fprintf (dump_file, " to ");
+ print_pre_expr (dump_file, constant);
+ fprintf (dump_file, "\n");
+ }
+ return constant;
+ }
}
}
else
@@ -1426,7 +1441,7 @@ phi_translate_1 (bitmap_set_t dest,
expr = pre_expr_pool.allocate ();
expr->kind = NARY;
expr->id = 0;
- if (nary)
+ if (nary && !nary->predicated_values)
{
PRE_EXPR_NARY (expr) = nary;
new_val_id = nary->value_id;
@@ -1664,7 +1679,10 @@ phi_translate (bitmap_set_t dest, pre_expr expr,
}
/* Translate. */
+ basic_block saved_valueize_bb = vn_context_bb;
+ vn_context_bb = e->src;
phitrans = phi_translate_1 (dest, expr, set1, set2, e);
+ vn_context_bb = saved_valueize_bb;
if (slot)
{
@@ -2925,7 +2943,7 @@ create_expression_by_pieces (basic_block block, pre_expr expr,
if (forcedname != folded)
{
- VN_INFO_GET (forcedname)->valnum = forcedname;
+ VN_INFO (forcedname)->valnum = forcedname;
VN_INFO (forcedname)->value_id = get_next_value_id ();
nameexpr = get_or_alloc_expr_for_name (forcedname);
add_to_value (VN_INFO (forcedname)->value_id, nameexpr);
@@ -2951,8 +2969,8 @@ create_expression_by_pieces (basic_block block, pre_expr expr,
the expression may have been represented. There is no harm in replacing
here. */
value_id = get_expr_value_id (expr);
- VN_INFO_GET (name)->value_id = value_id;
- VN_INFO (name)->valnum = sccvn_valnum_from_value_id (value_id);
+ VN_INFO (name)->value_id = value_id;
+ VN_INFO (name)->valnum = vn_valnum_from_value_id (value_id);
if (VN_INFO (name)->valnum == NULL_TREE)
VN_INFO (name)->valnum = name;
gcc_assert (VN_INFO (name)->valnum != NULL_TREE);
@@ -3057,8 +3075,8 @@ insert_into_preds_of_block (basic_block block, unsigned int exprnum,
temp = make_temp_ssa_name (type, NULL, "prephitmp");
phi = create_phi_node (temp, block);
- VN_INFO_GET (temp)->value_id = val;
- VN_INFO (temp)->valnum = sccvn_valnum_from_value_id (val);
+ VN_INFO (temp)->value_id = val;
+ VN_INFO (temp)->valnum = vn_valnum_from_value_id (val);
if (VN_INFO (temp)->valnum == NULL_TREE)
VN_INFO (temp)->valnum = temp;
bitmap_set_bit (inserted_exprs, SSA_NAME_VERSION (temp));
@@ -3302,8 +3320,8 @@ do_pre_regular_insertion (basic_block block, basic_block dom)
gimple_stmt_iterator gsi = gsi_after_labels (block);
gsi_insert_before (&gsi, assign, GSI_NEW_STMT);
- VN_INFO_GET (temp)->value_id = val;
- VN_INFO (temp)->valnum = sccvn_valnum_from_value_id (val);
+ VN_INFO (temp)->value_id = val;
+ VN_INFO (temp)->valnum = vn_valnum_from_value_id (val);
if (VN_INFO (temp)->valnum == NULL_TREE)
VN_INFO (temp)->valnum = temp;
bitmap_set_bit (inserted_exprs, SSA_NAME_VERSION (temp));
@@ -3744,6 +3762,7 @@ compute_avail (void)
/* Pick a block from the worklist. */
block = worklist[--sp];
+ vn_context_bb = block;
/* Initially, the set of available values in BLOCK is that of
its immediate dominator. */
@@ -4045,6 +4064,7 @@ compute_avail (void)
son = next_dom_son (CDI_DOMINATORS, son))
worklist[sp++] = son;
}
+ vn_context_bb = NULL;
free (worklist);
}
@@ -4135,6 +4155,34 @@ public:
}; // class pass_pre
+/* Valueization hook for RPO VN when we are calling back to it
+ at ANTIC compute time. */
+
+static tree
+pre_valueize (tree name)
+{
+ if (TREE_CODE (name) == SSA_NAME)
+ {
+ tree tem = VN_INFO (name)->valnum;
+ if (tem != VN_TOP && tem != name)
+ {
+ if (TREE_CODE (tem) != SSA_NAME
+ || SSA_NAME_IS_DEFAULT_DEF (tem))
+ return tem;
+ /* We create temporary SSA names for representatives that
+ do not have a definition (yet) but are not default defs either
+ assume they are fine to use. */
+ basic_block def_bb = gimple_bb (SSA_NAME_DEF_STMT (tem));
+ if (! def_bb
+ || dominated_by_p (CDI_DOMINATORS, vn_context_bb, def_bb))
+ return tem;
+ /* ??? Now we could look for a leader. Ideally we'd somehow
+ expose RPO VN leaders and get rid of AVAIL_OUT as well... */
+ }
+ }
+ return name;
+}
+
unsigned int
pass_pre::execute (function *fun)
{
@@ -4143,16 +4191,18 @@ pass_pre::execute (function *fun)
do_partial_partial =
flag_tree_partial_pre && optimize_function_for_speed_p (fun);
- /* This has to happen before SCCVN runs because
+ /* This has to happen before VN runs because
loop_optimizer_init may create new phis, etc. */
loop_optimizer_init (LOOPS_NORMAL);
split_critical_edges ();
scev_initialize ();
- run_scc_vn (VN_WALK);
+ run_rpo_vn (VN_WALK);
init_pre ();
+ vn_valueize = pre_valueize;
+
/* Insert can get quite slow on an incredibly large number of basic
blocks due to some quadratic behavior. Until this behavior is
fixed, don't run it when he have an incredibly large number of
@@ -4181,8 +4231,9 @@ pass_pre::execute (function *fun)
statistics_counter_event (fun, "HOIST inserted", pre_stats.hoist_insert);
statistics_counter_event (fun, "New PHIs", pre_stats.phis);
- /* Remove all the redundant expressions. */
- todo |= vn_eliminate (inserted_exprs);
+ todo |= eliminate_with_rpo_vn (inserted_exprs);
+
+ vn_valueize = NULL;
/* Because we don't follow exactly the standard PRE algorithm, and decide not
to insert PHI nodes sometimes, and because value numbering of casts isn't
@@ -4195,9 +4246,6 @@ pass_pre::execute (function *fun)
scev_finalize ();
loop_optimizer_finalize ();
- /* Restore SSA info before tail-merging as that resets it as well. */
- scc_vn_restore_ssa_info ();
-
/* TODO: tail_merge_optimize may merge all predecessors of a block, in which
case we can merge the block with the remaining predecessor of the block.
It should either:
@@ -4207,7 +4255,7 @@ pass_pre::execute (function *fun)
- share the cfg cleanup with fini_pre. */
todo |= tail_merge_optimize (todo);
- free_scc_vn ();
+ free_rpo_vn ();
/* Tail merging invalidates the virtual SSA web, together with
cfg-cleanup opportunities exposed by PRE this will wreck the
diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c
index 43f3313911f..c927cb8078f 100644
--- a/gcc/tree-ssa-sccvn.c
+++ b/gcc/tree-ssa-sccvn.c
@@ -127,6 +127,8 @@ along with GCC; see the file COPYING3. If not see
structure copies.
*/
+/* There's no BB_EXECUTABLE but we can use BB_VISITED. */
+#define BB_EXECUTABLE BB_VISITED
static tree *last_vuse_ptr;
static vn_lookup_kind vn_walk_kind;
@@ -304,34 +306,10 @@ static vn_nary_op_t last_inserted_nary;
static vn_tables_t valid_info;
-/* Reverse post order index for each basic block. */
-static int *rpo_numbers;
+/* Valueization hook. Valueize NAME if it is an SSA name, otherwise
+ just return it. */
+tree (*vn_valueize) (tree);
-#define SSA_VAL(x) (VN_INFO ((x))->valnum)
-
-/* Return the SSA value of the VUSE x, supporting released VDEFs
- during elimination which will value-number the VDEF to the
- associated VUSE (but not substitute in the whole lattice). */
-
-static inline tree
-vuse_ssa_val (tree x)
-{
- if (!x)
- return NULL_TREE;
-
- do
- {
- tree tem = SSA_VAL (x);
- /* stmt walking can walk over a backedge and reach code we didn't
- value-number yet. */
- if (tem == VN_TOP)
- return x;
- x = tem;
- }
- while (SSA_NAME_IN_FREE_LIST (x));
-
- return x;
-}
/* This represents the top of the VN lattice, which is the universal
value. */
@@ -342,66 +320,171 @@ tree VN_TOP;
static unsigned int next_value_id;
-/* Next DFS number and the stack for strongly connected component
- detection. */
-
-static unsigned int next_dfs_num;
-static vec<tree> sccstack;
-
-
/* Table of vn_ssa_aux_t's, one per ssa_name. The vn_ssa_aux_t objects
are allocated on an obstack for locality reasons, and to free them
without looping over the vec. */
-static vec<vn_ssa_aux_t> vn_ssa_aux_table;
+struct vn_ssa_aux_hasher : typed_noop_remove <vn_ssa_aux_t>
+{
+ typedef vn_ssa_aux_t value_type;
+ typedef tree compare_type;
+ static inline hashval_t hash (const value_type &);
+ static inline bool equal (const value_type &, const compare_type &);
+ static inline void mark_deleted (value_type &) {}
+ static inline void mark_empty (value_type &e) { e = NULL; }
+ static inline bool is_deleted (value_type &) { return false; }
+ static inline bool is_empty (value_type &e) { return e == NULL; }
+};
+
+hashval_t
+vn_ssa_aux_hasher::hash (const value_type &entry)
+{
+ return SSA_NAME_VERSION (entry->name);
+}
+
+bool
+vn_ssa_aux_hasher::equal (const value_type &entry, const compare_type &name)
+{
+ return name == entry->name;
+}
+
+static hash_table<vn_ssa_aux_hasher> *vn_ssa_aux_hash;
+typedef hash_table<vn_ssa_aux_hasher>::iterator vn_ssa_aux_iterator_type;
static struct obstack vn_ssa_aux_obstack;
+static vn_nary_op_t vn_nary_op_insert_stmt (gimple *, tree);
+static unsigned int vn_nary_length_from_stmt (gimple *);
+static vn_nary_op_t alloc_vn_nary_op_noinit (unsigned int, obstack *);
+static vn_nary_op_t vn_nary_op_insert_into (vn_nary_op_t,
+ vn_nary_op_table_type *, bool);
+static void init_vn_nary_op_from_stmt (vn_nary_op_t, gimple *);
+static void init_vn_nary_op_from_pieces (vn_nary_op_t, unsigned int,
+ enum tree_code, tree, tree *);
+static tree vn_lookup_simplify_result (gimple_match_op *);
+
/* Return whether there is value numbering information for a given SSA name. */
bool
has_VN_INFO (tree name)
{
- if (SSA_NAME_VERSION (name) < vn_ssa_aux_table.length ())
- return vn_ssa_aux_table[SSA_NAME_VERSION (name)] != NULL;
- return false;
+ return vn_ssa_aux_hash->find_with_hash (name, SSA_NAME_VERSION (name));
}
-/* Return the value numbering information for a given SSA name. */
-
vn_ssa_aux_t
VN_INFO (tree name)
{
- vn_ssa_aux_t res = vn_ssa_aux_table[SSA_NAME_VERSION (name)];
- gcc_checking_assert (res);
- return res;
+ vn_ssa_aux_t *res
+ = vn_ssa_aux_hash->find_slot_with_hash (name, SSA_NAME_VERSION (name),
+ INSERT);
+ if (*res != NULL)
+ return *res;
+
+ vn_ssa_aux_t newinfo = *res = XOBNEW (&vn_ssa_aux_obstack, struct vn_ssa_aux);
+ memset (newinfo, 0, sizeof (struct vn_ssa_aux));
+ newinfo->name = name;
+ newinfo->valnum = VN_TOP;
+ /* We are using the visited flag to handle uses with defs not within the
+ region being value-numbered. */
+ newinfo->visited = false;
+
+ /* Given we create the VN_INFOs on-demand now we have to do initialization
+ different than VN_TOP here. */
+ if (SSA_NAME_IS_DEFAULT_DEF (name))
+ switch (TREE_CODE (SSA_NAME_VAR (name)))
+ {
+ case VAR_DECL:
+ /* All undefined vars are VARYING. */
+ newinfo->valnum = name;
+ newinfo->visited = true;
+ break;
+
+ case PARM_DECL:
+ /* Parameters are VARYING but we can record a condition
+ if we know it is a non-NULL pointer. */
+ newinfo->visited = true;
+ newinfo->valnum = name;
+ if (POINTER_TYPE_P (TREE_TYPE (name))
+ && nonnull_arg_p (SSA_NAME_VAR (name)))
+ {
+ tree ops[2];
+ ops[0] = name;
+ ops[1] = build_int_cst (TREE_TYPE (name), 0);
+ vn_nary_op_t nary;
+ /* Allocate from non-unwinding stack. */
+ nary = alloc_vn_nary_op_noinit (2, &vn_tables_insert_obstack);
+ init_vn_nary_op_from_pieces (nary, 2, NE_EXPR,
+ boolean_type_node, ops);
+ nary->predicated_values = 0;
+ nary->u.result = boolean_true_node;
+ vn_nary_op_insert_into (nary, valid_info->nary, true);
+ gcc_assert (nary->unwind_to == NULL);
+ /* Also do not link it into the undo chain. */
+ last_inserted_nary = nary->next;
+ nary->next = (vn_nary_op_t)(void *)-1;
+ nary = alloc_vn_nary_op_noinit (2, &vn_tables_insert_obstack);
+ init_vn_nary_op_from_pieces (nary, 2, EQ_EXPR,
+ boolean_type_node, ops);
+ nary->predicated_values = 0;
+ nary->u.result = boolean_false_node;
+ vn_nary_op_insert_into (nary, valid_info->nary, true);
+ gcc_assert (nary->unwind_to == NULL);
+ last_inserted_nary = nary->next;
+ nary->next = (vn_nary_op_t)(void *)-1;
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Recording ");
+ print_generic_expr (dump_file, name, TDF_SLIM);
+ fprintf (dump_file, " != 0\n");
+ }
+ }
+ break;
+
+ case RESULT_DECL:
+ /* If the result is passed by invisible reference the default
+ def is initialized, otherwise it's uninitialized. Still
+ undefined is varying. */
+ newinfo->visited = true;
+ newinfo->valnum = name;
+ break;
+
+ default:
+ gcc_unreachable ();
+ }
+ return newinfo;
}
-/* Set the value numbering info for a given SSA name to a given
- value. */
+/* Return the SSA value of X. */
-static inline void
-VN_INFO_SET (tree name, vn_ssa_aux_t value)
+inline tree
+SSA_VAL (tree x)
{
- vn_ssa_aux_table[SSA_NAME_VERSION (name)] = value;
+ vn_ssa_aux_t tem = vn_ssa_aux_hash->find_with_hash (x, SSA_NAME_VERSION (x));
+ return tem && tem->visited ? tem->valnum : x;
}
-/* Initialize the value numbering info for a given SSA name.
- This should be called just once for every SSA name. */
+/* Return the SSA value of the VUSE x, supporting released VDEFs
+ during elimination which will value-number the VDEF to the
+ associated VUSE (but not substitute in the whole lattice). */
-vn_ssa_aux_t
-VN_INFO_GET (tree name)
+static inline tree
+vuse_ssa_val (tree x)
{
- vn_ssa_aux_t newinfo;
+ if (!x)
+ return NULL_TREE;
- gcc_assert (SSA_NAME_VERSION (name) >= vn_ssa_aux_table.length ()
- || vn_ssa_aux_table[SSA_NAME_VERSION (name)] == NULL);
- newinfo = XOBNEW (&vn_ssa_aux_obstack, struct vn_ssa_aux);
- memset (newinfo, 0, sizeof (struct vn_ssa_aux));
- if (SSA_NAME_VERSION (name) >= vn_ssa_aux_table.length ())
- vn_ssa_aux_table.safe_grow_cleared (SSA_NAME_VERSION (name) + 1);
- vn_ssa_aux_table[SSA_NAME_VERSION (name)] = newinfo;
- return newinfo;
+ do
+ {
+ tree tem = SSA_VAL (x);
+ /* stmt walking can walk over a backedge and reach code we didn't
+ value-number yet. */
+ if (tem == VN_TOP)
+ return x;
+ x = tem;
+ }
+ while (SSA_NAME_IN_FREE_LIST (x));
+
+ return x;
}
@@ -490,6 +573,11 @@ get_or_alloc_constant_value_id (tree constant)
struct vn_constant_s vc;
vn_constant_t vcp;
+ /* If the hashtable isn't initialized we're not running from PRE and thus
+ do not need value-ids. */
+ if (!constant_to_value_id)
+ return 0;
+
vc.hashcode = vn_hash_constant_with_type (constant);
vc.constant = constant;
slot = constant_to_value_id->find_slot (&vc, INSERT);
@@ -1239,6 +1327,10 @@ vn_reference_maybe_forwprop_address (vec<vn_reference_op_s> *ops,
ptroff = gimple_assign_rhs2 (def_stmt);
if (TREE_CODE (ptr) != SSA_NAME
|| SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ptr)
+ /* Make sure to not endlessly recurse.
+ See gcc.dg/tree-ssa/20040408-1.c for an example. Can easily
+ happen when we value-number a PHI to its backedge value. */
+ || SSA_VAL (ptr) == op->op0
|| !poly_int_tree_p (ptroff))
return false;
@@ -1251,6 +1343,8 @@ vn_reference_maybe_forwprop_address (vec<vn_reference_op_s> *ops,
mem_op->off = tree_to_shwi (mem_op->op0);
else
mem_op->off = -1;
+ /* ??? Can end up with endless recursion here!?
+ gcc.c-torture/execute/strcmp-1.c */
if (TREE_CODE (op->op0) == SSA_NAME)
op->op0 = SSA_VAL (op->op0);
if (TREE_CODE (op->op0) != SSA_NAME)
@@ -1413,7 +1507,8 @@ contains_storage_order_barrier_p (vec<vn_reference_op_s> ops)
whether any operands were valueized. */
static vec<vn_reference_op_s>
-valueize_refs_1 (vec<vn_reference_op_s> orig, bool *valueized_anything)
+valueize_refs_1 (vec<vn_reference_op_s> orig, bool *valueized_anything,
+ bool with_avail = false)
{
vn_reference_op_t vro;
unsigned int i;
@@ -1425,7 +1520,7 @@ valueize_refs_1 (vec<vn_reference_op_s> orig, bool *valueized_anything)
if (vro->opcode == SSA_NAME
|| (vro->op0 && TREE_CODE (vro->op0) == SSA_NAME))
{
- tree tem = SSA_VAL (vro->op0);
+ tree tem = with_avail ? vn_valueize (vro->op0) : SSA_VAL (vro->op0);
if (tem != vro->op0)
{
*valueized_anything = true;
@@ -1438,7 +1533,7 @@ valueize_refs_1 (vec<vn_reference_op_s> orig, bool *valueized_anything)
}
if (vro->op1 && TREE_CODE (vro->op1) == SSA_NAME)
{
- tree tem = SSA_VAL (vro->op1);
+ tree tem = with_avail ? vn_valueize (vro->op1) : SSA_VAL (vro->op1);
if (tem != vro->op1)
{
*valueized_anything = true;
@@ -1447,7 +1542,7 @@ valueize_refs_1 (vec<vn_reference_op_s> orig, bool *valueized_anything)
}
if (vro->op2 && TREE_CODE (vro->op2) == SSA_NAME)
{
- tree tem = SSA_VAL (vro->op2);
+ tree tem = with_avail ? vn_valueize (vro->op2) : SSA_VAL (vro->op2);
if (tem != vro->op2)
{
*valueized_anything = true;
@@ -1619,37 +1714,6 @@ vn_reference_lookup_or_insert_for_pieces (tree vuse,
operands.copy (), value, value_id);
}
-static vn_nary_op_t vn_nary_op_insert_stmt (gimple *, tree);
-static unsigned int vn_nary_length_from_stmt (gimple *);
-static vn_nary_op_t alloc_vn_nary_op_noinit (unsigned int, obstack *);
-static vn_nary_op_t vn_nary_op_insert_into (vn_nary_op_t,
- vn_nary_op_table_type *, bool);
-static void init_vn_nary_op_from_stmt (vn_nary_op_t, gimple *);
-
-/* Hook for maybe_push_res_to_seq, lookup the expression in the VN tables. */
-
-static tree
-vn_lookup_simplify_result (gimple_match_op *res_op)
-{
- if (!res_op->code.is_tree_code ())
- return NULL_TREE;
- tree *ops = res_op->ops;
- unsigned int length = res_op->num_ops;
- if (res_op->code == CONSTRUCTOR
- /* ??? We're arriving here with SCCVNs view, decomposed CONSTRUCTOR
- and GIMPLEs / match-and-simplifies, CONSTRUCTOR as GENERIC tree. */
- && TREE_CODE (res_op->ops[0]) == CONSTRUCTOR)
- {
- length = CONSTRUCTOR_NELTS (res_op->ops[0]);
- ops = XALLOCAVEC (tree, length);
- for (unsigned i = 0; i < length; ++i)
- ops[i] = CONSTRUCTOR_ELT (res_op->ops[0], i)->value;
- }
- vn_nary_op_t vnresult = NULL;
- return vn_nary_op_lookup_pieces (length, (tree_code) res_op->code,
- res_op->type, ops, &vnresult);
-}
-
/* Return a value-number for RCODE OPS... either by looking up an existing
value-number for the simplified result or by inserting the operation if
INSERT is true. */
@@ -1704,7 +1768,7 @@ vn_nary_build_or_lookup_1 (gimple_match_op *res_op, bool insert)
/* The expression is not yet available, value-number lhs to
the new SSA_NAME we created. */
/* Initialize value-number information properly. */
- VN_INFO_GET (result)->valnum = result;
+ VN_INFO (result)->valnum = result;
VN_INFO (result)->value_id = get_next_value_id ();
gimple_seq_add_stmt_without_update (&VN_INFO (result)->expr,
new_stmt);
@@ -1716,8 +1780,8 @@ vn_nary_build_or_lookup_1 (gimple_match_op *res_op, bool insert)
vn_nary_op_lookup_stmt (new_stmt, &nary);
if (nary)
{
- gcc_assert (nary->result == NULL_TREE);
- nary->result = gimple_assign_lhs (new_stmt);
+ gcc_assert (! nary->predicated_values && nary->u.result == NULL_TREE);
+ nary->u.result = gimple_assign_lhs (new_stmt);
}
/* As all "inserted" statements are singleton SCCs, insert
to the valid table. This is strictly needed to
@@ -1733,7 +1797,8 @@ vn_nary_build_or_lookup_1 (gimple_match_op *res_op, bool insert)
= alloc_vn_nary_op_noinit (length, &vn_tables_insert_obstack);
vno1->value_id = VN_INFO (result)->value_id;
vno1->length = length;
- vno1->result = result;
+ vno1->predicated_values = 0;
+ vno1->u.result = result;
init_vn_nary_op_from_stmt (vno1, new_stmt);
vn_nary_op_insert_into (vno1, valid_info->nary, true);
/* Also do not link it into the undo chain. */
@@ -1775,6 +1840,7 @@ vn_nary_simplify (vn_nary_op_t nary)
return vn_nary_build_or_lookup_1 (&op, false);
}
+basic_block vn_context_bb;
/* Callback for walk_non_aliased_vuses. Tries to perform a lookup
from the statement defining VUSE and if not successful tries to
@@ -1815,8 +1881,11 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *vr_,
bool valueized_anything = false;
/* Avoid re-allocation overhead. */
lhs_ops.truncate (0);
+ basic_block saved_rpo_bb = vn_context_bb;
+ vn_context_bb = gimple_bb (def_stmt);
copy_reference_ops_from_ref (lhs, &lhs_ops);
- lhs_ops = valueize_refs_1 (lhs_ops, &valueized_anything);
+ lhs_ops = valueize_refs_1 (lhs_ops, &valueized_anything, true);
+ vn_context_bb = saved_rpo_bb;
if (valueized_anything)
{
lhs_ref_ok = ao_ref_init_from_vn_reference (&lhs_ref,
@@ -2141,7 +2210,7 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *vr_,
{
gimple_match_op op (gimple_match_cond::UNCOND,
BIT_FIELD_REF, vr->type,
- SSA_VAL (gimple_assign_rhs1 (def_stmt)),
+ vn_valueize (gimple_assign_rhs1 (def_stmt)),
bitsize_int (ref->size),
bitsize_int (offset - offset2));
tree val = vn_nary_build_or_lookup (&op);
@@ -2316,7 +2385,7 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *vr_,
lhs_offset = 0;
if (TREE_CODE (lhs) == SSA_NAME)
{
- lhs = SSA_VAL (lhs);
+ lhs = vn_valueize (lhs);
if (TREE_CODE (lhs) == SSA_NAME)
{
gimple *def_stmt = SSA_NAME_DEF_STMT (lhs);
@@ -2336,7 +2405,7 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *vr_,
{
lhs = TREE_OPERAND (tem, 0);
if (TREE_CODE (lhs) == SSA_NAME)
- lhs = SSA_VAL (lhs);
+ lhs = vn_valueize (lhs);
lhs_offset += mem_offset;
}
else if (DECL_P (tem))
@@ -2352,7 +2421,7 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *vr_,
rhs = gimple_call_arg (def_stmt, 1);
rhs_offset = 0;
if (TREE_CODE (rhs) == SSA_NAME)
- rhs = SSA_VAL (rhs);
+ rhs = vn_valueize (rhs);
if (TREE_CODE (rhs) == ADDR_EXPR)
{
tree tem = get_addr_base_and_unit_offset (TREE_OPERAND (rhs, 0),
@@ -2593,10 +2662,9 @@ vn_reference_lookup_call (gcall *call, vn_reference_t *vnresult,
vn_reference_lookup_1 (vr, vnresult);
}
-/* Insert OP into the current hash table with a value number of
- RESULT, and return the resulting reference structure we created. */
+/* Insert OP into the current hash table with a value number of RESULT. */
-static vn_reference_t
+static void
vn_reference_insert (tree op, tree result, tree vuse, tree vdef)
{
vn_reference_s **slot;
@@ -2608,7 +2676,7 @@ vn_reference_insert (tree op, tree result, tree vuse, tree vdef)
vr1->value_id = VN_INFO (result)->value_id;
else
vr1->value_id = get_or_alloc_constant_value_id (result);
- vr1->vuse = vuse ? SSA_VAL (vuse) : NULL_TREE;
+ vr1->vuse = vuse_ssa_val (vuse);
vr1->operands = valueize_shared_reference_ops_from_ref (op, &tem).copy ();
vr1->type = TREE_TYPE (op);
vr1->set = get_alias_set (op);
@@ -2617,24 +2685,25 @@ vn_reference_insert (tree op, tree result, tree vuse, tree vdef)
vr1->result_vdef = vdef;
slot = valid_info->references->find_slot_with_hash (vr1, vr1->hashcode,
- INSERT);
-
- /* Because we lookup stores using vuses, and value number failures
- using the vdefs (see visit_reference_op_store for how and why),
- it's possible that on failure we may try to insert an already
- inserted store. This is not wrong, there is no ssa name for a
- store that we could use as a differentiator anyway. Thus, unlike
- the other lookup functions, you cannot gcc_assert (!*slot)
- here. */
-
- /* But free the old slot in case of a collision. */
+ INSERT);
+
+ /* Because IL walking on reference lookup can end up visiting
+ a def that is only to be visited later in iteration order
+ when we are about to make an irreducible region reducible
+ the def can be effectively processed and its ref being inserted
+ by vn_reference_lookup_3 already. So we cannot assert (!*slot)
+ but save a lookup if we deal with already inserted refs here. */
if (*slot)
- free_reference (*slot);
+ {
+ gcc_assert (operand_equal_p ((*slot)->result, vr1->result, 0));
+ free_reference (vr1);
+ obstack_free (&vn_tables_obstack, vr1);
+ return;
+ }
*slot = vr1;
vr1->next = last_inserted_ref;
last_inserted_ref = vr1;
- return vr1;
}
/* Insert a reference by it's pieces into the current hash table with
@@ -2652,7 +2721,7 @@ vn_reference_insert_pieces (tree vuse, alias_set_type set, tree type,
vr1 = XOBNEW (&vn_tables_obstack, vn_reference_s);
vr1->value_id = value_id;
- vr1->vuse = vuse ? SSA_VAL (vuse) : NULL_TREE;
+ vr1->vuse = vuse_ssa_val (vuse);
vr1->operands = valueize_refs (operands);
vr1->type = type;
vr1->set = set;
@@ -2662,14 +2731,12 @@ vn_reference_insert_pieces (tree vuse, alias_set_type set, tree type,
vr1->result = result;
slot = valid_info->references->find_slot_with_hash (vr1, vr1->hashcode,
- INSERT);
+ INSERT);
/* At this point we should have all the things inserted that we have
seen before, and we should never try inserting something that
already exists. */
gcc_assert (!*slot);
- if (*slot)
- free_reference (*slot);
*slot = vr1;
vr1->next = last_inserted_ref;
@@ -2845,13 +2912,12 @@ vn_nary_op_lookup_1 (vn_nary_op_t vno, vn_nary_op_t *vnresult)
*vnresult = NULL;
vno->hashcode = vn_nary_op_compute_hash (vno);
- slot = valid_info->nary->find_slot_with_hash (vno, vno->hashcode,
- NO_INSERT);
+ slot = valid_info->nary->find_slot_with_hash (vno, vno->hashcode, NO_INSERT);
if (!slot)
return NULL_TREE;
if (vnresult)
*vnresult = *slot;
- return (*slot)->result;
+ return (*slot)->predicated_values ? NULL_TREE : (*slot)->u.result;
}
/* Lookup a n-ary operation by its pieces and return the resulting value
@@ -2919,7 +2985,8 @@ alloc_vn_nary_op (unsigned int length, tree result, unsigned int value_id)
vno1->value_id = value_id;
vno1->length = length;
- vno1->result = result;
+ vno1->predicated_values = 0;
+ vno1->u.result = result;
return vno1;
}
@@ -2934,18 +3001,125 @@ vn_nary_op_insert_into (vn_nary_op_t vno, vn_nary_op_table_type *table,
vn_nary_op_s **slot;
if (compute_hash)
- vno->hashcode = vn_nary_op_compute_hash (vno);
+ {
+ vno->hashcode = vn_nary_op_compute_hash (vno);
+ gcc_assert (! vno->predicated_values
+ || (! vno->u.values->next
+ && vno->u.values->valid_dominated_by_p[0] != EXIT_BLOCK
+ && vno->u.values->valid_dominated_by_p[1] == EXIT_BLOCK));
+ }
slot = table->find_slot_with_hash (vno, vno->hashcode, INSERT);
- /* While we do not want to insert things twice it's awkward to
- avoid it in the case where visit_nary_op pattern-matches stuff
- and ends up simplifying the replacement to itself. We then
- get two inserts, one from visit_nary_op and one from
- vn_nary_build_or_lookup.
- So allow inserts with the same value number. */
- if (*slot && (*slot)->result == vno->result)
- return *slot;
+ vno->unwind_to = *slot;
+ if (*slot)
+ {
+ /* Prefer non-predicated values.
+ ??? Only if those are constant, otherwise, with constant predicated
+ value, turn them into predicated values with entry-block validity
+ (??? but we always find the first valid result currently). */
+ if ((*slot)->predicated_values
+ && ! vno->predicated_values)
+ {
+ /* ??? We cannot remove *slot from the unwind stack list.
+ For the moment we deal with this by skipping not found
+ entries but this isn't ideal ... */
+ *slot = vno;
+ /* ??? Maintain a stack of states we can unwind in
+ vn_nary_op_s? But how far do we unwind? In reality
+ we need to push change records somewhere... Or not
+ unwind vn_nary_op_s and linking them but instead
+ unwind the results "list", linking that, which also
+ doesn't move on hashtable resize. */
+ /* We can also have a ->unwind_to recording *slot there.
+ That way we can make u.values a fixed size array with
+ recording the number of entries but of course we then
+ have always N copies for each unwind_to-state. Or we
+ make sure to only ever append and each unwinding will
+ pop off one entry (but how to deal with predicated
+ replaced with non-predicated here?) */
+ vno->next = last_inserted_nary;
+ last_inserted_nary = vno;
+ return vno;
+ }
+ else if (vno->predicated_values
+ && ! (*slot)->predicated_values)
+ return *slot;
+ else if (vno->predicated_values
+ && (*slot)->predicated_values)
+ {
+ /* ??? Factor this all into a insert_single_predicated_value
+ routine. */
+ gcc_assert (!vno->u.values->next && vno->u.values->n == 1);
+ basic_block vno_bb
+ = BASIC_BLOCK_FOR_FN (cfun, vno->u.values->valid_dominated_by_p[0]);
+ vn_pval *nval = vno->u.values;
+ vn_pval **next = &vno->u.values;
+ bool found = false;
+ for (vn_pval *val = (*slot)->u.values; val; val = val->next)
+ {
+ if (expressions_equal_p (val->result, vno->u.values->result))
+ {
+ found = true;
+ for (unsigned i = 0; i < val->n; ++i)
+ {
+ basic_block val_bb
+ = BASIC_BLOCK_FOR_FN (cfun,
+ val->valid_dominated_by_p[i]);
+ if (dominated_by_p (CDI_DOMINATORS, vno_bb, val_bb))
+ /* Value registered with more generic predicate. */
+ return *slot;
+ else if (dominated_by_p (CDI_DOMINATORS, val_bb, vno_bb))
+ /* Shouldn't happen, we insert in RPO order. */
+ gcc_unreachable ();
+ }
+ /* Append value. */
+ *next = (vn_pval *) obstack_alloc (&vn_tables_obstack,
+ sizeof (vn_pval)
+ + val->n * sizeof (int));
+ (*next)->next = NULL;
+ (*next)->result = val->result;
+ (*next)->n = val->n + 1;
+ memcpy ((*next)->valid_dominated_by_p,
+ val->valid_dominated_by_p,
+ val->n * sizeof (int));
+ (*next)->valid_dominated_by_p[val->n] = vno_bb->index;
+ next = &(*next)->next;
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Appending predicate to value.\n");
+ continue;
+ }
+ /* Copy other predicated values. */
+ *next = (vn_pval *) obstack_alloc (&vn_tables_obstack,
+ sizeof (vn_pval)
+ + (val->n-1) * sizeof (int));
+ memcpy (*next, val, sizeof (vn_pval) + (val->n-1) * sizeof (int));
+ (*next)->next = NULL;
+ next = &(*next)->next;
+ }
+ if (!found)
+ *next = nval;
+
+ *slot = vno;
+ vno->next = last_inserted_nary;
+ last_inserted_nary = vno;
+ return vno;
+ }
+
+ /* While we do not want to insert things twice it's awkward to
+ avoid it in the case where visit_nary_op pattern-matches stuff
+ and ends up simplifying the replacement to itself. We then
+ get two inserts, one from visit_nary_op and one from
+ vn_nary_build_or_lookup.
+ So allow inserts with the same value number. */
+ if ((*slot)->u.result == vno->u.result)
+ return *slot;
+ }
+
+ /* ??? There's also optimistic vs. previous commited state merging
+ that is problematic for the case of unwinding. */
+ /* ??? We should return NULL if we do not use 'vno' and have the
+ caller release it. */
gcc_assert (!*slot);
*slot = vno;
@@ -2968,6 +3142,70 @@ vn_nary_op_insert_pieces (unsigned int length, enum tree_code code,
return vn_nary_op_insert_into (vno1, valid_info->nary, true);
}
+static vn_nary_op_t
+vn_nary_op_insert_pieces_predicated (unsigned int length, enum tree_code code,
+ tree type, tree *ops,
+ tree result, unsigned int value_id,
+ edge pred_e)
+{
+ /* ??? Currently tracking BBs. */
+ if (! single_pred_p (pred_e->dest))
+ {
+ /* Never record for backedges. */
+ if (pred_e->flags & EDGE_DFS_BACK)
+ return NULL;
+ edge_iterator ei;
+ edge e;
+ int cnt = 0;
+ /* Ignore backedges. */
+ FOR_EACH_EDGE (e, ei, pred_e->dest->preds)
+ if (! dominated_by_p (CDI_DOMINATORS, e->src, e->dest))
+ cnt++;
+ if (cnt != 1)
+ return NULL;
+ }
+ if (dump_file && (dump_flags & TDF_DETAILS)
+ /* ??? Fix dumping, but currently we only get comparisons. */
+ && TREE_CODE_CLASS (code) == tcc_comparison)
+ {
+ fprintf (dump_file, "Recording on edge %d->%d ", pred_e->src->index,
+ pred_e->dest->index);
+ print_generic_expr (dump_file, ops[0], TDF_SLIM);
+ fprintf (dump_file, " %s ", get_tree_code_name (code));
+ print_generic_expr (dump_file, ops[1], TDF_SLIM);
+ fprintf (dump_file, " == %s\n",
+ integer_zerop (result) ? "false" : "true");
+ }
+ vn_nary_op_t vno1 = alloc_vn_nary_op (length, NULL_TREE, value_id);
+ init_vn_nary_op_from_pieces (vno1, length, code, type, ops);
+ vno1->predicated_values = 1;
+ vno1->u.values = (vn_pval *) obstack_alloc (&vn_tables_obstack,
+ sizeof (vn_pval));
+ vno1->u.values->next = NULL;
+ vno1->u.values->result = result;
+ vno1->u.values->n = 1;
+ vno1->u.values->valid_dominated_by_p[0] = pred_e->dest->index;
+ vno1->u.values->valid_dominated_by_p[1] = EXIT_BLOCK;
+ return vn_nary_op_insert_into (vno1, valid_info->nary, true);
+}
+
+static bool
+dominated_by_p_w_unex (basic_block bb1, basic_block bb2);
+
+static tree
+vn_nary_op_get_predicated_value (vn_nary_op_t vno, basic_block bb)
+{
+ if (! vno->predicated_values)
+ return vno->u.result;
+ for (vn_pval *val = vno->u.values; val; val = val->next)
+ for (unsigned i = 0; i < val->n; ++i)
+ if (dominated_by_p_w_unex (bb,
+ BASIC_BLOCK_FOR_FN
+ (cfun, val->valid_dominated_by_p[i])))
+ return val->result;
+ return NULL_TREE;
+}
+
/* Insert OP into the current hash table with a value number of
RESULT. Return the vn_nary_op_t structure we created and put in
the hashtable. */
@@ -3170,7 +3408,7 @@ vn_phi_eq (const_vn_phi_t const vp1, const_vn_phi_t const vp2)
it does not exist in the hash table. */
static tree
-vn_phi_lookup (gimple *phi)
+vn_phi_lookup (gimple *phi, bool backedges_varying_p)
{
vn_phi_s **slot;
struct vn_phi_s *vp1;
@@ -3185,7 +3423,9 @@ vn_phi_lookup (gimple *phi)
FOR_EACH_EDGE (e, ei, gimple_bb (phi)->preds)
{
tree def = PHI_ARG_DEF_FROM_EDGE (phi, e);
- def = TREE_CODE (def) == SSA_NAME ? SSA_VAL (def) : def;
+ if (TREE_CODE (def) == SSA_NAME
+ && (!backedges_varying_p || !(e->flags & EDGE_DFS_BACK)))
+ def = SSA_VAL (def);
vp1->phiargs[e->dest_idx] = def;
}
vp1->type = TREE_TYPE (gimple_phi_result (phi));
@@ -3197,12 +3437,13 @@ vn_phi_lookup (gimple *phi)
if (EDGE_COUNT (idom1->succs) == 2)
if (gcond *last1 = safe_dyn_cast <gcond *> (last_stmt (idom1)))
{
+ /* ??? We want to use SSA_VAL here. But possibly not
+ allow VN_TOP. */
vp1->cclhs = vn_valueize (gimple_cond_lhs (last1));
vp1->ccrhs = vn_valueize (gimple_cond_rhs (last1));
}
vp1->hashcode = vn_phi_compute_hash (vp1);
- slot = valid_info->phis->find_slot_with_hash (vp1, vp1->hashcode,
- NO_INSERT);
+ slot = valid_info->phis->find_slot_with_hash (vp1, vp1->hashcode, NO_INSERT);
if (!slot)
return NULL_TREE;
return (*slot)->result;
@@ -3212,7 +3453,7 @@ vn_phi_lookup (gimple *phi)
RESULT. */
static vn_phi_t
-vn_phi_insert (gimple *phi, tree result)
+vn_phi_insert (gimple *phi, tree result, bool backedges_varying_p)
{
vn_phi_s **slot;
vn_phi_t vp1 = (vn_phi_t) obstack_alloc (&vn_tables_obstack,
@@ -3226,7 +3467,9 @@ vn_phi_insert (gimple *phi, tree result)
FOR_EACH_EDGE (e, ei, gimple_bb (phi)->preds)
{
tree def = PHI_ARG_DEF_FROM_EDGE (phi, e);
- def = TREE_CODE (def) == SSA_NAME ? SSA_VAL (def) : def;
+ if (TREE_CODE (def) == SSA_NAME
+ && (!backedges_varying_p || !(e->flags & EDGE_DFS_BACK)))
+ def = SSA_VAL (def);
vp1->phiargs[e->dest_idx] = def;
}
vp1->value_id = VN_INFO (result)->value_id;
@@ -3239,6 +3482,8 @@ vn_phi_insert (gimple *phi, tree result)
if (EDGE_COUNT (idom1->succs) == 2)
if (gcond *last1 = safe_dyn_cast <gcond *> (last_stmt (idom1)))
{
+ /* ??? We want to use SSA_VAL here. But possibly not
+ allow VN_TOP. */
vp1->cclhs = vn_valueize (gimple_cond_lhs (last1));
vp1->ccrhs = vn_valueize (gimple_cond_rhs (last1));
}
@@ -3246,9 +3491,8 @@ vn_phi_insert (gimple *phi, tree result)
vp1->hashcode = vn_phi_compute_hash (vp1);
slot = valid_info->phis->find_slot_with_hash (vp1, vp1->hashcode, INSERT);
+ gcc_assert (!*slot);
- /* Because we iterate over phi operations more than once, it's
- possible the slot might already exist here, hence no assert.*/
*slot = vp1;
vp1->next = last_inserted_phi;
last_inserted_phi = vp1;
@@ -3256,23 +3500,6 @@ vn_phi_insert (gimple *phi, tree result)
}
-/* Print set of components in strongly connected component SCC to OUT. */
-
-static void
-print_scc (FILE *out, vec<tree> scc)
-{
- tree var;
- unsigned int i;
-
- fprintf (out, "SCC consists of %u:", scc.length ());
- FOR_EACH_VEC_ELT (scc, i, var)
- {
- fprintf (out, " ");
- print_generic_expr (out, var);
- }
- fprintf (out, "\n");
-}
-
/* Return true if BB1 is dominated by BB2 taking into account edges
that are not executable. */
@@ -3360,7 +3587,8 @@ dominated_by_p_w_unex (basic_block bb1, basic_block bb2)
static inline bool
set_ssa_val_to (tree from, tree to)
{
- tree currval = SSA_VAL (from);
+ vn_ssa_aux_t from_info = VN_INFO (from);
+ tree currval = from_info->valnum; // SSA_VAL (from)
poly_int64 toff, coff;
/* The only thing we allow as value numbers are ssa_names
@@ -3372,16 +3600,23 @@ set_ssa_val_to (tree from, tree to)
get VN_TOP on valueization. */
if (to == VN_TOP)
{
+ /* ??? When iterating and visiting PHI <undef, backedge-value>
+ for the first time we rightfully get VN_TOP and we need to
+ preserve that to optimize for example gcc.dg/tree-ssa/ssa-sccvn-2.c.
+ With SCCVN we were simply lucky we iterated the other PHI
+ cycles first and thus visited the backedge-value DEF. */
+ if (currval == VN_TOP)
+ goto set_and_exit;
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "Forcing value number to varying on "
"receiving VN_TOP\n");
to = from;
}
- gcc_assert (to != NULL_TREE
- && ((TREE_CODE (to) == SSA_NAME
- && (to == from || SSA_VAL (to) == to))
- || is_gimple_min_invariant (to)));
+ gcc_checking_assert (to != NULL_TREE
+ && ((TREE_CODE (to) == SSA_NAME
+ && (to == from || SSA_VAL (to) == to))
+ || is_gimple_min_invariant (to)));
if (from != to)
{
@@ -3399,6 +3634,7 @@ set_ssa_val_to (tree from, tree to)
}
else if (currval != VN_TOP
&& ! is_gimple_min_invariant (currval)
+ && ! ssa_undefined_value_p (currval, false)
&& is_gimple_min_invariant (to))
{
if (dump_file && (dump_flags & TDF_DETAILS))
@@ -3419,6 +3655,7 @@ set_ssa_val_to (tree from, tree to)
to = from;
}
+set_and_exit:
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, "Setting value number of ");
@@ -3447,73 +3684,7 @@ set_ssa_val_to (tree from, tree to)
{
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, " (changed)\n");
-
- /* If we equate two SSA names we have to make the side-band info
- of the leader conservative (and remember whatever original value
- was present). */
- if (TREE_CODE (to) == SSA_NAME)
- {
- if (INTEGRAL_TYPE_P (TREE_TYPE (to))
- && SSA_NAME_RANGE_INFO (to))
- {
- if (SSA_NAME_IS_DEFAULT_DEF (to)
- || dominated_by_p_w_unex
- (gimple_bb (SSA_NAME_DEF_STMT (from)),
- gimple_bb (SSA_NAME_DEF_STMT (to))))
- /* Keep the info from the dominator. */
- ;
- else
- {
- /* Save old info. */
- if (! VN_INFO (to)->info.range_info)
- {
- VN_INFO (to)->info.range_info = SSA_NAME_RANGE_INFO (to);
- VN_INFO (to)->range_info_anti_range_p
- = SSA_NAME_ANTI_RANGE_P (to);
- }
- /* Rather than allocating memory and unioning the info
- just clear it. */
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "clearing range info of ");
- print_generic_expr (dump_file, to);
- fprintf (dump_file, "\n");
- }
- SSA_NAME_RANGE_INFO (to) = NULL;
- }
- }
- else if (POINTER_TYPE_P (TREE_TYPE (to))
- && SSA_NAME_PTR_INFO (to))
- {
- if (SSA_NAME_IS_DEFAULT_DEF (to)
- || dominated_by_p_w_unex
- (gimple_bb (SSA_NAME_DEF_STMT (from)),
- gimple_bb (SSA_NAME_DEF_STMT (to))))
- /* Keep the info from the dominator. */
- ;
- else if (! SSA_NAME_PTR_INFO (from)
- /* Handle the case of trivially equivalent info. */
- || memcmp (SSA_NAME_PTR_INFO (to),
- SSA_NAME_PTR_INFO (from),
- sizeof (ptr_info_def)) != 0)
- {
- /* Save old info. */
- if (! VN_INFO (to)->info.ptr_info)
- VN_INFO (to)->info.ptr_info = SSA_NAME_PTR_INFO (to);
- /* Rather than allocating memory and unioning the info
- just clear it. */
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "clearing points-to info of ");
- print_generic_expr (dump_file, to);
- fprintf (dump_file, "\n");
- }
- SSA_NAME_PTR_INFO (to) = NULL;
- }
- }
- }
-
- VN_INFO (from)->valnum = to;
+ from_info->valnum = to;
return true;
}
if (dump_file && (dump_flags & TDF_DETAILS))
@@ -3521,30 +3692,6 @@ set_ssa_val_to (tree from, tree to)
return false;
}
-/* Mark as processed all the definitions in the defining stmt of USE, or
- the USE itself. */
-
-static void
-mark_use_processed (tree use)
-{
- ssa_op_iter iter;
- def_operand_p defp;
- gimple *stmt = SSA_NAME_DEF_STMT (use);
-
- if (SSA_NAME_IS_DEFAULT_DEF (use) || gimple_code (stmt) == GIMPLE_PHI)
- {
- VN_INFO (use)->use_processed = true;
- return;
- }
-
- FOR_EACH_SSA_DEF_OPERAND (defp, stmt, iter, SSA_OP_ALL_DEFS)
- {
- tree def = DEF_FROM_PTR (defp);
-
- VN_INFO (def)->use_processed = true;
- }
-}
-
/* Set all definitions in STMT to value number to themselves.
Return true if a value number changed. */
@@ -3582,7 +3729,7 @@ static tree
valueized_wider_op (tree wide_type, tree op)
{
if (TREE_CODE (op) == SSA_NAME)
- op = SSA_VAL (op);
+ op = vn_valueize (op);
/* Either we have the op widened available. */
tree ops[3] = {};
@@ -3603,7 +3750,7 @@ valueized_wider_op (tree wide_type, tree op)
if (useless_type_conversion_p (wide_type, TREE_TYPE (tem)))
{
if (TREE_CODE (tem) == SSA_NAME)
- tem = SSA_VAL (tem);
+ tem = vn_valueize (tem);
return tem;
}
}
@@ -3622,7 +3769,10 @@ valueized_wider_op (tree wide_type, tree op)
static bool
visit_nary_op (tree lhs, gassign *stmt)
{
- tree result = vn_nary_op_lookup_stmt (stmt, NULL);
+ vn_nary_op_t vnresult;
+ tree result = vn_nary_op_lookup_stmt (stmt, &vnresult);
+ if (! result && vnresult)
+ result = vn_nary_op_get_predicated_value (vnresult, gimple_bb (stmt));
if (result)
return set_ssa_val_to (lhs, result);
@@ -3773,7 +3923,7 @@ visit_reference_op_call (tree lhs, gcall *stmt)
vr2->result = lhs;
vr2->result_vdef = vdef_val;
slot = valid_info->references->find_slot_with_hash (vr2, vr2->hashcode,
- INSERT);
+ INSERT);
gcc_assert (!*slot);
*slot = vr2;
vr2->next = last_inserted_ref;
@@ -3812,6 +3962,10 @@ visit_reference_op_load (tree lhs, tree op, gimple *stmt)
gimple_match_op res_op (gimple_match_cond::UNCOND,
VIEW_CONVERT_EXPR, TREE_TYPE (op), result);
result = vn_nary_build_or_lookup (&res_op);
+ /* When building the conversion fails avoid inserting the reference
+ again. */
+ if (!result)
+ return set_ssa_val_to (lhs, lhs);
}
if (result)
@@ -3863,8 +4017,8 @@ visit_reference_op_store (tree lhs, tree op, gimple *stmt)
&& vnresult->result)
{
tree result = vnresult->result;
- if (TREE_CODE (result) == SSA_NAME)
- result = SSA_VAL (result);
+ gcc_checking_assert (TREE_CODE (result) != SSA_NAME
+ || result == SSA_VAL (result));
resultsame = expressions_equal_p (result, op);
if (resultsame)
{
@@ -3887,7 +4041,7 @@ visit_reference_op_store (tree lhs, tree op, gimple *stmt)
vn_reference_lookup (assign, vuse, VN_NOWALK, &vnresult, false);
if (vnresult)
{
- VN_INFO (vdef)->use_processed = true;
+ VN_INFO (vdef)->visited = true;
return set_ssa_val_to (vdef, vnresult->result_vdef);
}
}
@@ -3935,10 +4089,13 @@ visit_reference_op_store (tree lhs, tree op, gimple *stmt)
}
/* Visit and value number PHI, return true if the value number
- changed. */
+ changed. When BACKEDGES_VARYING_P is true then assume all
+ backedge values are varying. When INSERTED is not NULL then
+ this is just a ahead query for a possible iteration, set INSERTED
+ to true if we'd insert into the hashtable. */
static bool
-visit_phi (gimple *phi)
+visit_phi (gimple *phi, bool *inserted, bool backedges_varying_p)
{
tree result, sameval = VN_TOP, seen_undef = NULL_TREE;
tree sameval_base = NULL_TREE;
@@ -3948,11 +4105,17 @@ visit_phi (gimple *phi)
edge_iterator ei;
edge e;
- /* TODO: We could check for this in init_sccvn, and replace this
+ /* TODO: We could check for this in initialization, and replace this
with a gcc_assert. */
if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (PHI_RESULT (phi)))
return set_ssa_val_to (PHI_RESULT (phi), PHI_RESULT (phi));
+ /* We track whether a PHI was CSEd to to avoid excessive iterations
+ that would be necessary only because the PHI changed arguments
+ but not value. */
+ if (!inserted)
+ gimple_set_plf (phi, GF_PLF_1, false);
+
/* See if all non-TOP arguments have the same value. TOP is
equivalent to everything, so we can ignore it. */
FOR_EACH_EDGE (e, ei, gimple_bb (phi)->preds)
@@ -3961,12 +4124,14 @@ visit_phi (gimple *phi)
tree def = PHI_ARG_DEF_FROM_EDGE (phi, e);
++n_executable;
- if (TREE_CODE (def) == SSA_NAME)
+ if (TREE_CODE (def) == SSA_NAME
+ && (!backedges_varying_p || !(e->flags & EDGE_DFS_BACK)))
def = SSA_VAL (def);
if (def == VN_TOP)
;
/* Ignore undefined defs for sameval but record one. */
else if (TREE_CODE (def) == SSA_NAME
+ && ! virtual_operand_p (def)
&& ssa_undefined_value_p (def, false))
seen_undef = def;
else if (sameval == VN_TOP)
@@ -4006,8 +4171,22 @@ visit_phi (gimple *phi)
result = seen_undef ? seen_undef : sameval;
/* First see if it is equivalent to a phi node in this block. We prefer
this as it allows IV elimination - see PRs 66502 and 67167. */
- else if ((result = vn_phi_lookup (phi)))
- ;
+ else if ((result = vn_phi_lookup (phi, backedges_varying_p)))
+ {
+ if (!inserted
+ && TREE_CODE (result) == SSA_NAME
+ && gimple_code (SSA_NAME_DEF_STMT (result)) == GIMPLE_PHI)
+ {
+ gimple_set_plf (SSA_NAME_DEF_STMT (result), GF_PLF_1, true);
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Marking CSEd to PHI node ");
+ print_gimple_expr (dump_file, SSA_NAME_DEF_STMT (result),
+ 0, TDF_SLIM);
+ fprintf (dump_file, "\n");
+ }
+ }
+ }
/* If all values are the same use that, unless we've seen undefined
values as well and the value isn't constant.
CCP/copyprop have the same restriction to not remove uninit warnings. */
@@ -4020,7 +4199,9 @@ visit_phi (gimple *phi)
/* Only insert PHIs that are varying, for constant value numbers
we mess up equivalences otherwise as we are only comparing
the immediate controlling predicates. */
- vn_phi_insert (phi, result);
+ vn_phi_insert (phi, result, backedges_varying_p);
+ if (inserted)
+ *inserted = true;
}
return set_ssa_val_to (PHI_RESULT (phi), result);
@@ -4051,30 +4232,22 @@ try_to_simplify (gassign *stmt)
return NULL_TREE;
}
-/* Visit and value number USE, return true if the value number
- changed. */
+/* Visit and value number STMT, return true if the value number
+ changed. */
static bool
-visit_use (tree use)
+visit_stmt (gimple *stmt, bool backedges_varying_p = false)
{
bool changed = false;
- gimple *stmt = SSA_NAME_DEF_STMT (use);
-
- mark_use_processed (use);
-
- gcc_assert (!SSA_NAME_IN_FREE_LIST (use)
- && !SSA_NAME_IS_DEFAULT_DEF (use));
if (dump_file && (dump_flags & TDF_DETAILS))
{
- fprintf (dump_file, "Value numbering ");
- print_generic_expr (dump_file, use);
- fprintf (dump_file, " stmt = ");
+ fprintf (dump_file, "Value numbering stmt = ");
print_gimple_stmt (dump_file, stmt, 0);
}
if (gimple_code (stmt) == GIMPLE_PHI)
- changed = visit_phi (stmt);
+ changed = visit_phi (stmt, NULL, backedges_varying_p);
else if (gimple_has_volatile_ops (stmt))
changed = defs_to_varying (stmt);
else if (gassign *ass = dyn_cast <gassign *> (stmt))
@@ -4261,319 +4434,21 @@ visit_use (tree use)
return changed;
}
-/* Compare two operands by reverse postorder index */
-
-static int
-compare_ops (const void *pa, const void *pb)
-{
- const tree opa = *((const tree *)pa);
- const tree opb = *((const tree *)pb);
- gimple *opstmta = SSA_NAME_DEF_STMT (opa);
- gimple *opstmtb = SSA_NAME_DEF_STMT (opb);
- basic_block bba;
- basic_block bbb;
-
- if (gimple_nop_p (opstmta) && gimple_nop_p (opstmtb))
- return SSA_NAME_VERSION (opa) - SSA_NAME_VERSION (opb);
- else if (gimple_nop_p (opstmta))
- return -1;
- else if (gimple_nop_p (opstmtb))
- return 1;
-
- bba = gimple_bb (opstmta);
- bbb = gimple_bb (opstmtb);
-
- if (!bba && !bbb)
- return SSA_NAME_VERSION (opa) - SSA_NAME_VERSION (opb);
- else if (!bba)
- return -1;
- else if (!bbb)
- return 1;
-
- if (bba == bbb)
- {
- if (gimple_code (opstmta) == GIMPLE_PHI
- && gimple_code (opstmtb) == GIMPLE_PHI)
- return SSA_NAME_VERSION (opa) - SSA_NAME_VERSION (opb);
- else if (gimple_code (opstmta) == GIMPLE_PHI)
- return -1;
- else if (gimple_code (opstmtb) == GIMPLE_PHI)
- return 1;
- else if (gimple_uid (opstmta) != gimple_uid (opstmtb))
- return gimple_uid (opstmta) - gimple_uid (opstmtb);
- else
- return SSA_NAME_VERSION (opa) - SSA_NAME_VERSION (opb);
- }
- return rpo_numbers[bba->index] - rpo_numbers[bbb->index];
-}
-/* Sort an array containing members of a strongly connected component
- SCC so that the members are ordered by RPO number.
- This means that when the sort is complete, iterating through the
- array will give you the members in RPO order. */
+/* Allocate a value number table. */
static void
-sort_scc (vec<tree> scc)
+allocate_vn_table (vn_tables_t table, unsigned size)
{
- scc.qsort (compare_ops);
+ table->phis = new vn_phi_table_type (size);
+ table->nary = new vn_nary_op_table_type (size);
+ table->references = new vn_reference_table_type (size);
}
-/* Process a strongly connected component in the SSA graph. */
+/* Free a value number table. */
static void
-process_scc (vec<tree> scc)
-{
- tree var;
- unsigned int i;
- unsigned int iterations = 0;
- bool changed = true;
-
- /* If the SCC has a single member, just visit it. */
- if (scc.length () == 1)
- {
- tree use = scc[0];
- if (VN_INFO (use)->use_processed)
- return;
- /* We need to make sure it doesn't form a cycle itself, which can
- happen for self-referential PHI nodes. In that case we would
- end up inserting an expression with VN_TOP operands into the
- valid table which makes us derive bogus equivalences later.
- The cheapest way to check this is to assume it for all PHI nodes. */
- if (gimple_code (SSA_NAME_DEF_STMT (use)) == GIMPLE_PHI)
- /* Fallthru to iteration. */ ;
- else
- {
- visit_use (use);
- return;
- }
- }
-
- if (dump_file && (dump_flags & TDF_DETAILS))
- print_scc (dump_file, scc);
-
- /* Iterate over the SCC with the optimistic table until it stops
- changing. */
- while (changed)
- {
- changed = false;
- iterations++;
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, "Starting iteration %d\n", iterations);
- /* As we are value-numbering optimistically we have to
- clear the expression tables and the simplified expressions
- in each iteration until we converge. */
- void *ob_top = obstack_alloc (&vn_tables_obstack, 0);
- vn_reference_t ref_top = last_inserted_ref;
- vn_phi_t phi_top = last_inserted_phi;
- vn_nary_op_t nary_top = last_inserted_nary;
- FOR_EACH_VEC_ELT (scc, i, var)
- gcc_assert (!VN_INFO (var)->needs_insertion
- && VN_INFO (var)->expr == NULL);
- FOR_EACH_VEC_ELT (scc, i, var)
- changed |= visit_use (var);
- if (changed)
- {
- for (; last_inserted_nary != nary_top;
- last_inserted_nary = last_inserted_nary->next)
- {
- vn_nary_op_t *slot;
- slot = valid_info->nary->find_slot_with_hash (last_inserted_nary,
- last_inserted_nary->hashcode,
- NO_INSERT);
- gcc_assert (slot);
- valid_info->nary->clear_slot (slot);
- }
- for (; last_inserted_phi != phi_top;
- last_inserted_phi = last_inserted_phi->next)
- {
- vn_phi_t *slot;
- slot = valid_info->phis->find_slot_with_hash (last_inserted_phi,
- last_inserted_phi->hashcode,
- NO_INSERT);
- gcc_assert (slot);
- valid_info->phis->clear_slot (slot);
- }
- for (; last_inserted_ref != ref_top;
- last_inserted_ref = last_inserted_ref->next)
- {
- vn_reference_t *slot;
- slot = valid_info->references->find_slot_with_hash (last_inserted_ref,
- last_inserted_ref->hashcode,
- NO_INSERT);
- gcc_assert (slot);
- (*slot)->operands.release ();
- valid_info->references->clear_slot (slot);
- }
- obstack_free (&vn_tables_obstack, ob_top);
- }
- }
-
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, "Processing SCC needed %d iterations\n", iterations);
- statistics_histogram_event (cfun, "SCC iterations", iterations);
-}
-
-
-/* Pop the components of the found SCC for NAME off the SCC stack
- and process them. Returns true if all went well, false if
- we run into resource limits. */
-
-static void
-extract_and_process_scc_for_name (tree name)
-{
- auto_vec<tree> scc;
- tree x;
-
- /* Found an SCC, pop the components off the SCC stack and
- process them. */
- do
- {
- x = sccstack.pop ();
-
- VN_INFO (x)->on_sccstack = false;
- scc.safe_push (x);
- } while (x != name);
-
- /* Drop all defs in the SCC to varying in case a SCC turns out to be
- incredibly large.
- ??? Just switch to a non-optimistic mode that avoids any iteration. */
- if (scc.length () > (unsigned)PARAM_VALUE (PARAM_SCCVN_MAX_SCC_SIZE))
- {
- if (dump_file)
- {
- print_scc (dump_file, scc);
- fprintf (dump_file, "WARNING: Giving up value-numbering SCC due to "
- "size %u exceeding %u\n", scc.length (),
- (unsigned)PARAM_VALUE (PARAM_SCCVN_MAX_SCC_SIZE));
- }
- tree var;
- unsigned i;
- FOR_EACH_VEC_ELT (scc, i, var)
- {
- gimple *def = SSA_NAME_DEF_STMT (var);
- mark_use_processed (var);
- if (SSA_NAME_IS_DEFAULT_DEF (var)
- || gimple_code (def) == GIMPLE_PHI)
- set_ssa_val_to (var, var);
- else
- defs_to_varying (def);
- }
- return;
- }
-
- if (scc.length () > 1)
- sort_scc (scc);
-
- process_scc (scc);
-}
-
-/* Depth first search on NAME to discover and process SCC's in the SSA
- graph.
- Execution of this algorithm relies on the fact that the SCC's are
- popped off the stack in topological order.
- Returns true if successful, false if we stopped processing SCC's due
- to resource constraints. */
-
-static void
-DFS (tree name)
-{
- auto_vec<ssa_op_iter> itervec;
- auto_vec<tree> namevec;
- use_operand_p usep = NULL;
- gimple *defstmt;
- tree use;
- ssa_op_iter iter;
-
-start_over:
- /* SCC info */
- VN_INFO (name)->dfsnum = next_dfs_num++;
- VN_INFO (name)->visited = true;
- VN_INFO (name)->low = VN_INFO (name)->dfsnum;
-
- sccstack.safe_push (name);
- VN_INFO (name)->on_sccstack = true;
- defstmt = SSA_NAME_DEF_STMT (name);
-
- /* Recursively DFS on our operands, looking for SCC's. */
- if (!gimple_nop_p (defstmt))
- {
- /* Push a new iterator. */
- if (gphi *phi = dyn_cast <gphi *> (defstmt))
- usep = op_iter_init_phiuse (&iter, phi, SSA_OP_ALL_USES);
- else
- usep = op_iter_init_use (&iter, defstmt, SSA_OP_ALL_USES);
- }
- else
- clear_and_done_ssa_iter (&iter);
-
- while (1)
- {
- /* If we are done processing uses of a name, go up the stack
- of iterators and process SCCs as we found them. */
- if (op_iter_done (&iter))
- {
- /* See if we found an SCC. */
- if (VN_INFO (name)->low == VN_INFO (name)->dfsnum)
- extract_and_process_scc_for_name (name);
-
- /* Check if we are done. */
- if (namevec.is_empty ())
- return;
-
- /* Restore the last use walker and continue walking there. */
- use = name;
- name = namevec.pop ();
- memcpy (&iter, &itervec.last (),
- sizeof (ssa_op_iter));
- itervec.pop ();
- goto continue_walking;
- }
-
- use = USE_FROM_PTR (usep);
-
- /* Since we handle phi nodes, we will sometimes get
- invariants in the use expression. */
- if (TREE_CODE (use) == SSA_NAME)
- {
- if (! (VN_INFO (use)->visited))
- {
- /* Recurse by pushing the current use walking state on
- the stack and starting over. */
- itervec.safe_push (iter);
- namevec.safe_push (name);
- name = use;
- goto start_over;
-
-continue_walking:
- VN_INFO (name)->low = MIN (VN_INFO (name)->low,
- VN_INFO (use)->low);
- }
- if (VN_INFO (use)->dfsnum < VN_INFO (name)->dfsnum
- && VN_INFO (use)->on_sccstack)
- {
- VN_INFO (name)->low = MIN (VN_INFO (use)->dfsnum,
- VN_INFO (name)->low);
- }
- }
-
- usep = op_iter_next_use (&iter);
- }
-}
-
-/* Allocate a value number table. */
-
-static void
-allocate_vn_table (vn_tables_t table)
-{
- table->phis = new vn_phi_table_type (23);
- table->nary = new vn_nary_op_table_type (23);
- table->references = new vn_reference_table_type (23);
-}
-
-/* Free a value number table. */
-
-static void
-free_vn_table (vn_tables_t table)
+free_vn_table (vn_tables_t table)
{
/* Walk over elements and release vectors. */
vn_reference_iterator_type hir;
@@ -4588,174 +4463,6 @@ free_vn_table (vn_tables_t table)
table->references = NULL;
}
-static void
-init_scc_vn (void)
-{
- int j;
- int *rpo_numbers_temp;
-
- calculate_dominance_info (CDI_DOMINATORS);
- mark_dfs_back_edges ();
-
- sccstack.create (0);
- constant_to_value_id = new hash_table<vn_constant_hasher> (23);
-
- constant_value_ids = BITMAP_ALLOC (NULL);
-
- next_dfs_num = 1;
- next_value_id = 1;
-
- vn_ssa_aux_table.create (num_ssa_names + 1);
- /* VEC_alloc doesn't actually grow it to the right size, it just
- preallocates the space to do so. */
- vn_ssa_aux_table.safe_grow_cleared (num_ssa_names + 1);
- gcc_obstack_init (&vn_ssa_aux_obstack);
-
- shared_lookup_references.create (0);
- rpo_numbers = XNEWVEC (int, last_basic_block_for_fn (cfun));
- rpo_numbers_temp =
- XNEWVEC (int, n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS);
- pre_and_rev_post_order_compute (NULL, rpo_numbers_temp, false);
-
- /* RPO numbers is an array of rpo ordering, rpo[i] = bb means that
- the i'th block in RPO order is bb. We want to map bb's to RPO
- numbers, so we need to rearrange this array. */
- for (j = 0; j < n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS; j++)
- rpo_numbers[rpo_numbers_temp[j]] = j;
-
- XDELETE (rpo_numbers_temp);
-
- VN_TOP = build_decl (UNKNOWN_LOCATION, VAR_DECL,
- get_identifier ("VN_TOP"), error_mark_node);
-
- renumber_gimple_stmt_uids ();
-
- /* Create the valid and optimistic value numbering tables. */
- gcc_obstack_init (&vn_tables_obstack);
- gcc_obstack_init (&vn_tables_insert_obstack);
- valid_info = XCNEW (struct vn_tables_s);
- allocate_vn_table (valid_info);
- last_inserted_ref = NULL;
- last_inserted_phi = NULL;
- last_inserted_nary = NULL;
-
- /* Create the VN_INFO structures, and initialize value numbers to
- TOP or VARYING for parameters. */
- size_t i;
- tree name;
-
- FOR_EACH_SSA_NAME (i, name, cfun)
- {
- VN_INFO_GET (name)->valnum = VN_TOP;
- VN_INFO (name)->needs_insertion = false;
- VN_INFO (name)->expr = NULL;
- VN_INFO (name)->value_id = 0;
-
- if (!SSA_NAME_IS_DEFAULT_DEF (name))
- continue;
-
- switch (TREE_CODE (SSA_NAME_VAR (name)))
- {
- case VAR_DECL:
- /* All undefined vars are VARYING. */
- VN_INFO (name)->valnum = name;
- VN_INFO (name)->visited = true;
- break;
-
- case PARM_DECL:
- /* Parameters are VARYING but we can record a condition
- if we know it is a non-NULL pointer. */
- VN_INFO (name)->visited = true;
- VN_INFO (name)->valnum = name;
- if (POINTER_TYPE_P (TREE_TYPE (name))
- && nonnull_arg_p (SSA_NAME_VAR (name)))
- {
- tree ops[2];
- ops[0] = name;
- ops[1] = build_int_cst (TREE_TYPE (name), 0);
- vn_nary_op_insert_pieces (2, NE_EXPR, boolean_type_node, ops,
- boolean_true_node, 0);
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "Recording ");
- print_generic_expr (dump_file, name, TDF_SLIM);
- fprintf (dump_file, " != 0\n");
- }
- }
- break;
-
- case RESULT_DECL:
- /* If the result is passed by invisible reference the default
- def is initialized, otherwise it's uninitialized. Still
- undefined is varying. */
- VN_INFO (name)->visited = true;
- VN_INFO (name)->valnum = name;
- break;
-
- default:
- gcc_unreachable ();
- }
- }
-}
-
-/* Restore SSA info that has been reset on value leaders. */
-
-void
-scc_vn_restore_ssa_info (void)
-{
- unsigned i;
- tree name;
-
- FOR_EACH_SSA_NAME (i, name, cfun)
- {
- if (has_VN_INFO (name))
- {
- if (VN_INFO (name)->needs_insertion)
- ;
- else if (POINTER_TYPE_P (TREE_TYPE (name))
- && VN_INFO (name)->info.ptr_info)
- SSA_NAME_PTR_INFO (name) = VN_INFO (name)->info.ptr_info;
- else if (INTEGRAL_TYPE_P (TREE_TYPE (name))
- && VN_INFO (name)->info.range_info)
- {
- SSA_NAME_RANGE_INFO (name) = VN_INFO (name)->info.range_info;
- SSA_NAME_ANTI_RANGE_P (name)
- = VN_INFO (name)->range_info_anti_range_p;
- }
- }
- }
-}
-
-void
-free_scc_vn (void)
-{
- size_t i;
- tree name;
-
- delete constant_to_value_id;
- constant_to_value_id = NULL;
- BITMAP_FREE (constant_value_ids);
- shared_lookup_references.release ();
- XDELETEVEC (rpo_numbers);
-
- FOR_EACH_SSA_NAME (i, name, cfun)
- {
- if (has_VN_INFO (name)
- && VN_INFO (name)->needs_insertion)
- release_ssa_name (name);
- }
- obstack_free (&vn_ssa_aux_obstack, NULL);
- vn_ssa_aux_table.release ();
-
- sccstack.release ();
- free_vn_table (valid_info);
- XDELETE (valid_info);
- obstack_free (&vn_tables_obstack, NULL);
- obstack_free (&vn_tables_insert_obstack, NULL);
-
- BITMAP_FREE (const_parms);
-}
-
/* Set *ID according to RESULT. */
static void
@@ -4785,7 +4492,8 @@ set_hashtable_value_ids (void)
table. */
FOR_EACH_HASH_TABLE_ELEMENT (*valid_info->nary, vno, vn_nary_op_t, hin)
- set_value_id_for_result (vno->result, &vno->value_id);
+ if (! vno->predicated_values)
+ set_value_id_for_result (vno->u.result, &vno->value_id);
FOR_EACH_HASH_TABLE_ELEMENT (*valid_info->phis, vp, vn_phi_t, hip)
set_value_id_for_result (vp->result, &vp->value_id);
@@ -4795,355 +4503,75 @@ set_hashtable_value_ids (void)
set_value_id_for_result (vr->result, &vr->value_id);
}
-class sccvn_dom_walker : public dom_walker
-{
-public:
- sccvn_dom_walker ()
- : dom_walker (CDI_DOMINATORS, REACHABLE_BLOCKS), cond_stack (0) {}
-
- virtual edge before_dom_children (basic_block);
- virtual void after_dom_children (basic_block);
-
- void record_cond (basic_block,
- enum tree_code code, tree lhs, tree rhs, bool value);
- void record_conds (basic_block,
- enum tree_code code, tree lhs, tree rhs, bool value);
-
- auto_vec<std::pair <basic_block, std::pair <vn_nary_op_t, vn_nary_op_t> > >
- cond_stack;
-};
-/* Record a temporary condition for the BB and its dominated blocks. */
+/* Allocate and initialize CONST_PARAMS, a bitmap of parameter default defs
+ we know point to readonly memory. */
-void
-sccvn_dom_walker::record_cond (basic_block bb,
- enum tree_code code, tree lhs, tree rhs,
- bool value)
+static void
+init_const_parms ()
{
- tree ops[2] = { lhs, rhs };
- vn_nary_op_t old = NULL;
- if (vn_nary_op_lookup_pieces (2, code, boolean_type_node, ops, &old))
- valid_info->nary->remove_elt_with_hash (old, old->hashcode);
- vn_nary_op_t cond
- = vn_nary_op_insert_pieces (2, code, boolean_type_node, ops,
- value
- ? boolean_true_node
- : boolean_false_node, 0);
- if (dump_file && (dump_flags & TDF_DETAILS))
+ /* Collect pointers we know point to readonly memory. */
+ const_parms = BITMAP_ALLOC (NULL);
+ tree fnspec = lookup_attribute ("fn spec",
+ TYPE_ATTRIBUTES (TREE_TYPE (cfun->decl)));
+ if (fnspec)
{
- fprintf (dump_file, "Recording temporarily ");
- print_generic_expr (dump_file, ops[0], TDF_SLIM);
- fprintf (dump_file, " %s ", get_tree_code_name (code));
- print_generic_expr (dump_file, ops[1], TDF_SLIM);
- fprintf (dump_file, " == %s%s\n",
- value ? "true" : "false",
- old ? " (old entry saved)" : "");
+ fnspec = TREE_VALUE (TREE_VALUE (fnspec));
+ unsigned i = 1;
+ for (tree arg = DECL_ARGUMENTS (cfun->decl);
+ arg; arg = DECL_CHAIN (arg), ++i)
+ {
+ if (i >= (unsigned) TREE_STRING_LENGTH (fnspec))
+ break;
+ if (TREE_STRING_POINTER (fnspec)[i] == 'R'
+ || TREE_STRING_POINTER (fnspec)[i] == 'r')
+ {
+ tree name = ssa_default_def (cfun, arg);
+ if (name)
+ bitmap_set_bit (const_parms, SSA_NAME_VERSION (name));
+ }
+ }
}
- cond_stack.safe_push (std::make_pair (bb, std::make_pair (cond, old)));
}
-/* Record temporary conditions for the BB and its dominated blocks
- according to LHS CODE RHS == VALUE and its dominated conditions. */
+/* Return the maximum value id we have ever seen. */
-void
-sccvn_dom_walker::record_conds (basic_block bb,
- enum tree_code code, tree lhs, tree rhs,
- bool value)
+unsigned int
+get_max_value_id (void)
{
- /* Record the original condition. */
- record_cond (bb, code, lhs, rhs, value);
+ return next_value_id;
+}
- if (!value)
- return;
+/* Return the next unique value id. */
- /* Record dominated conditions if the condition is true. Note that
- the inversion is already recorded. */
- switch (code)
- {
- case LT_EXPR:
- case GT_EXPR:
- record_cond (bb, code == LT_EXPR ? LE_EXPR : GE_EXPR, lhs, rhs, true);
- record_cond (bb, NE_EXPR, lhs, rhs, true);
- record_cond (bb, EQ_EXPR, lhs, rhs, false);
- break;
+unsigned int
+get_next_value_id (void)
+{
+ return next_value_id++;
+}
- case EQ_EXPR:
- record_cond (bb, LE_EXPR, lhs, rhs, true);
- record_cond (bb, GE_EXPR, lhs, rhs, true);
- record_cond (bb, LT_EXPR, lhs, rhs, false);
- record_cond (bb, GT_EXPR, lhs, rhs, false);
- break;
- default:
- break;
- }
-}
-
-/* Restore expressions and values derived from conditionals. */
+/* Compare two expressions E1 and E2 and return true if they are equal. */
-void
-sccvn_dom_walker::after_dom_children (basic_block bb)
+bool
+expressions_equal_p (tree e1, tree e2)
{
- while (!cond_stack.is_empty ()
- && cond_stack.last ().first == bb)
- {
- vn_nary_op_t cond = cond_stack.last ().second.first;
- vn_nary_op_t old = cond_stack.last ().second.second;
- valid_info->nary->remove_elt_with_hash (cond, cond->hashcode);
- if (old)
- vn_nary_op_insert_into (old, valid_info->nary, false);
- cond_stack.pop ();
- }
-}
+ /* The obvious case. */
+ if (e1 == e2)
+ return true;
-/* Value number all statements in BB. */
+ /* If either one is VN_TOP consider them equal. */
+ if (e1 == VN_TOP || e2 == VN_TOP)
+ return true;
-edge
-sccvn_dom_walker::before_dom_children (basic_block bb)
-{
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, "Visiting BB %d\n", bb->index);
+ /* If only one of them is null, they cannot be equal. */
+ if (!e1 || !e2)
+ return false;
- /* If we have a single predecessor record the equivalence from a
- possible condition on the predecessor edge. */
- edge pred_e = single_pred_edge_ignoring_loop_edges (bb, false);
- if (pred_e)
- {
- /* Check if there are multiple executable successor edges in
- the source block. Otherwise there is no additional info
- to be recorded. */
- edge_iterator ei;
- edge e2;
- FOR_EACH_EDGE (e2, ei, pred_e->src->succs)
- if (e2 != pred_e
- && e2->flags & EDGE_EXECUTABLE)
- break;
- if (e2 && (e2->flags & EDGE_EXECUTABLE))
- {
- gimple *stmt = last_stmt (pred_e->src);
- if (stmt
- && gimple_code (stmt) == GIMPLE_COND)
- {
- enum tree_code code = gimple_cond_code (stmt);
- tree lhs = gimple_cond_lhs (stmt);
- tree rhs = gimple_cond_rhs (stmt);
- record_conds (bb, code, lhs, rhs,
- (pred_e->flags & EDGE_TRUE_VALUE) != 0);
- code = invert_tree_comparison (code, HONOR_NANS (lhs));
- if (code != ERROR_MARK)
- record_conds (bb, code, lhs, rhs,
- (pred_e->flags & EDGE_TRUE_VALUE) == 0);
- }
- }
- }
-
- /* Value-number all defs in the basic-block. */
- for (gphi_iterator gsi = gsi_start_phis (bb);
- !gsi_end_p (gsi); gsi_next (&gsi))
- {
- gphi *phi = gsi.phi ();
- tree res = PHI_RESULT (phi);
- if (!VN_INFO (res)->visited)
- DFS (res);
- }
- for (gimple_stmt_iterator gsi = gsi_start_bb (bb);
- !gsi_end_p (gsi); gsi_next (&gsi))
- {
- ssa_op_iter i;
- tree op;
- FOR_EACH_SSA_TREE_OPERAND (op, gsi_stmt (gsi), i, SSA_OP_ALL_DEFS)
- if (!VN_INFO (op)->visited)
- DFS (op);
- }
-
- /* Finally look at the last stmt. */
- gimple *stmt = last_stmt (bb);
- if (!stmt)
- return NULL;
-
- enum gimple_code code = gimple_code (stmt);
- if (code != GIMPLE_COND
- && code != GIMPLE_SWITCH
- && code != GIMPLE_GOTO)
- return NULL;
-
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "Visiting control stmt ending BB %d: ", bb->index);
- print_gimple_stmt (dump_file, stmt, 0);
- }
-
- /* ??? We can even handle stmts with outgoing EH or ABNORMAL edges
- if value-numbering can prove they are not reachable. Handling
- computed gotos is also possible. */
- tree val;
- switch (code)
- {
- case GIMPLE_COND:
- {
- tree lhs = vn_valueize (gimple_cond_lhs (stmt));
- tree rhs = vn_valueize (gimple_cond_rhs (stmt));
- val = gimple_simplify (gimple_cond_code (stmt),
- boolean_type_node, lhs, rhs,
- NULL, vn_valueize);
- /* If that didn't simplify to a constant see if we have recorded
- temporary expressions from taken edges. */
- if (!val || TREE_CODE (val) != INTEGER_CST)
- {
- tree ops[2];
- ops[0] = lhs;
- ops[1] = rhs;
- val = vn_nary_op_lookup_pieces (2, gimple_cond_code (stmt),
- boolean_type_node, ops, NULL);
- }
- break;
- }
- case GIMPLE_SWITCH:
- val = gimple_switch_index (as_a <gswitch *> (stmt));
- break;
- case GIMPLE_GOTO:
- val = gimple_goto_dest (stmt);
- break;
- default:
- gcc_unreachable ();
- }
- if (!val)
- return NULL;
-
- edge taken = find_taken_edge (bb, vn_valueize (val));
- if (!taken)
- return NULL;
-
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, "Marking all edges out of BB %d but (%d -> %d) as "
- "not executable\n", bb->index, bb->index, taken->dest->index);
-
- return taken;
-}
-
-/* Do SCCVN. Returns true if it finished, false if we bailed out
- due to resource constraints. DEFAULT_VN_WALK_KIND_ specifies
- how we use the alias oracle walking during the VN process. */
-
-void
-run_scc_vn (vn_lookup_kind default_vn_walk_kind_)
-{
- size_t i;
-
- default_vn_walk_kind = default_vn_walk_kind_;
-
- init_scc_vn ();
-
- /* Collect pointers we know point to readonly memory. */
- const_parms = BITMAP_ALLOC (NULL);
- tree fnspec = lookup_attribute ("fn spec",
- TYPE_ATTRIBUTES (TREE_TYPE (cfun->decl)));
- if (fnspec)
- {
- fnspec = TREE_VALUE (TREE_VALUE (fnspec));
- i = 1;
- for (tree arg = DECL_ARGUMENTS (cfun->decl);
- arg; arg = DECL_CHAIN (arg), ++i)
- {
- if (i >= (unsigned) TREE_STRING_LENGTH (fnspec))
- break;
- if (TREE_STRING_POINTER (fnspec)[i] == 'R'
- || TREE_STRING_POINTER (fnspec)[i] == 'r')
- {
- tree name = ssa_default_def (cfun, arg);
- if (name)
- bitmap_set_bit (const_parms, SSA_NAME_VERSION (name));
- }
- }
- }
-
- /* Walk all blocks in dominator order, value-numbering stmts
- SSA defs and decide whether outgoing edges are not executable. */
- sccvn_dom_walker walker;
- walker.walk (ENTRY_BLOCK_PTR_FOR_FN (cfun));
-
- /* Initialize the value ids and prune out remaining VN_TOPs
- from dead code. */
- tree name;
- FOR_EACH_SSA_NAME (i, name, cfun)
- {
- vn_ssa_aux_t info = VN_INFO (name);
- if (!info->visited
- || info->valnum == VN_TOP)
- info->valnum = name;
- if (info->valnum == name)
- info->value_id = get_next_value_id ();
- else if (is_gimple_min_invariant (info->valnum))
- info->value_id = get_or_alloc_constant_value_id (info->valnum);
- }
-
- /* Propagate. */
- FOR_EACH_SSA_NAME (i, name, cfun)
- {
- vn_ssa_aux_t info = VN_INFO (name);
- if (TREE_CODE (info->valnum) == SSA_NAME
- && info->valnum != name
- && info->value_id != VN_INFO (info->valnum)->value_id)
- info->value_id = VN_INFO (info->valnum)->value_id;
- }
-
- set_hashtable_value_ids ();
-
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "Value numbers:\n");
- FOR_EACH_SSA_NAME (i, name, cfun)
- {
- if (VN_INFO (name)->visited
- && SSA_VAL (name) != name)
- {
- print_generic_expr (dump_file, name);
- fprintf (dump_file, " = ");
- print_generic_expr (dump_file, SSA_VAL (name));
- fprintf (dump_file, "\n");
- }
- }
- }
-}
-
-/* Return the maximum value id we have ever seen. */
-
-unsigned int
-get_max_value_id (void)
-{
- return next_value_id;
-}
-
-/* Return the next unique value id. */
-
-unsigned int
-get_next_value_id (void)
-{
- return next_value_id++;
-}
-
-
-/* Compare two expressions E1 and E2 and return true if they are equal. */
-
-bool
-expressions_equal_p (tree e1, tree e2)
-{
- /* The obvious case. */
- if (e1 == e2)
- return true;
-
- /* If either one is VN_TOP consider them equal. */
- if (e1 == VN_TOP || e2 == VN_TOP)
- return true;
-
- /* If only one of them is null, they cannot be equal. */
- if (!e1 || !e2)
- return false;
-
- /* Now perform the actual comparison. */
- if (TREE_CODE (e1) == TREE_CODE (e2)
- && operand_equal_p (e1, e2, OEP_PURE_SAME))
- return true;
+ /* Now perform the actual comparison. */
+ if (TREE_CODE (e1) == TREE_CODE (e2)
+ && operand_equal_p (e1, e2, OEP_PURE_SAME))
+ return true;
return false;
}
@@ -5206,9 +4634,13 @@ public:
virtual edge before_dom_children (basic_block);
virtual void after_dom_children (basic_block);
- tree eliminate_avail (tree op);
- void eliminate_push_avail (tree op);
- tree eliminate_insert (gimple_stmt_iterator *gsi, tree val);
+ virtual tree eliminate_avail (basic_block, tree op);
+ virtual void eliminate_push_avail (basic_block, tree op);
+ tree eliminate_insert (basic_block, gimple_stmt_iterator *gsi, tree val);
+
+ void eliminate_stmt (basic_block, gimple_stmt_iterator *);
+
+ unsigned eliminate_cleanup (bool region_p = false);
bool do_pre;
unsigned int el_todo;
@@ -5224,6 +4656,7 @@ public:
/* Blocks with statements that have had their AB properties changed. */
bitmap need_ab_cleanup;
+ /* Local state for the eliminate domwalk. */
auto_vec<gimple *> to_remove;
auto_vec<gimple *> to_fixup;
auto_vec<tree> avail;
@@ -5250,7 +4683,7 @@ eliminate_dom_walker::~eliminate_dom_walker ()
eliminate domwalk. */
tree
-eliminate_dom_walker::eliminate_avail (tree op)
+eliminate_dom_walker::eliminate_avail (basic_block, tree op)
{
tree valnum = VN_INFO (op)->valnum;
if (TREE_CODE (valnum) == SSA_NAME)
@@ -5268,7 +4701,7 @@ eliminate_dom_walker::eliminate_avail (tree op)
/* At the current point of the eliminate domwalk make OP available. */
void
-eliminate_dom_walker::eliminate_push_avail (tree op)
+eliminate_dom_walker::eliminate_push_avail (basic_block, tree op)
{
tree valnum = VN_INFO (op)->valnum;
if (TREE_CODE (valnum) == SSA_NAME)
@@ -5287,7 +4720,8 @@ eliminate_dom_walker::eliminate_push_avail (tree op)
the leader for the expression if insertion was successful. */
tree
-eliminate_dom_walker::eliminate_insert (gimple_stmt_iterator *gsi, tree val)
+eliminate_dom_walker::eliminate_insert (basic_block bb,
+ gimple_stmt_iterator *gsi, tree val)
{
/* We can insert a sequence with a single assignment only. */
gimple_seq stmts = VN_INFO (val)->expr;
@@ -5306,7 +4740,7 @@ eliminate_dom_walker::eliminate_insert (gimple_stmt_iterator *gsi, tree val)
if (gimple_assign_rhs_code (stmt) == VIEW_CONVERT_EXPR
|| gimple_assign_rhs_code (stmt) == BIT_FIELD_REF)
op = TREE_OPERAND (op, 0);
- tree leader = TREE_CODE (op) == SSA_NAME ? eliminate_avail (op) : op;
+ tree leader = TREE_CODE (op) == SSA_NAME ? eliminate_avail (bb, op) : op;
if (!leader)
return NULL_TREE;
@@ -5338,7 +4772,7 @@ eliminate_dom_walker::eliminate_insert (gimple_stmt_iterator *gsi, tree val)
if (dump_file && (dump_flags & TDF_DETAILS))
{
if (TREE_CODE (res) == SSA_NAME)
- res = eliminate_avail (res);
+ res = eliminate_avail (bb, res);
if (res)
{
fprintf (dump_file, "Failed to insert expression for value ");
@@ -5354,7 +4788,8 @@ eliminate_dom_walker::eliminate_insert (gimple_stmt_iterator *gsi, tree val)
else
{
gsi_insert_seq_before (gsi, stmts, GSI_SAME_STMT);
- VN_INFO_GET (res)->valnum = val;
+ VN_INFO (res)->valnum = val;
+ VN_INFO (res)->visited = true;
}
insertions++;
@@ -5367,536 +4802,1335 @@ eliminate_dom_walker::eliminate_insert (gimple_stmt_iterator *gsi, tree val)
return res;
}
-
-
-/* Perform elimination for the basic-block B during the domwalk. */
-
-edge
-eliminate_dom_walker::before_dom_children (basic_block b)
+void
+eliminate_dom_walker::eliminate_stmt (basic_block b, gimple_stmt_iterator *gsi)
{
- /* Mark new bb. */
- avail_stack.safe_push (NULL_TREE);
-
- /* Skip unreachable blocks marked unreachable during the SCCVN domwalk. */
- edge_iterator ei;
- edge e;
- FOR_EACH_EDGE (e, ei, b->preds)
- if (e->flags & EDGE_EXECUTABLE)
- break;
- if (! e)
- return NULL;
-
- for (gphi_iterator gsi = gsi_start_phis (b); !gsi_end_p (gsi);)
+ tree sprime = NULL_TREE;
+ gimple *stmt = gsi_stmt (*gsi);
+ tree lhs = gimple_get_lhs (stmt);
+ if (lhs && TREE_CODE (lhs) == SSA_NAME
+ && !gimple_has_volatile_ops (stmt)
+ /* See PR43491. Do not replace a global register variable when
+ it is a the RHS of an assignment. Do replace local register
+ variables since gcc does not guarantee a local variable will
+ be allocated in register.
+ ??? The fix isn't effective here. This should instead
+ be ensured by not value-numbering them the same but treating
+ them like volatiles? */
+ && !(gimple_assign_single_p (stmt)
+ && (TREE_CODE (gimple_assign_rhs1 (stmt)) == VAR_DECL
+ && DECL_HARD_REGISTER (gimple_assign_rhs1 (stmt))
+ && is_global_var (gimple_assign_rhs1 (stmt)))))
{
- gphi *phi = gsi.phi ();
- tree res = PHI_RESULT (phi);
-
- if (virtual_operand_p (res))
+ sprime = eliminate_avail (b, lhs);
+ if (!sprime)
{
- gsi_next (&gsi);
- continue;
+ /* If there is no existing usable leader but SCCVN thinks
+ it has an expression it wants to use as replacement,
+ insert that. */
+ tree val = VN_INFO (lhs)->valnum;
+ if (val != VN_TOP
+ && TREE_CODE (val) == SSA_NAME
+ && VN_INFO (val)->needs_insertion
+ && VN_INFO (val)->expr != NULL
+ && (sprime = eliminate_insert (b, gsi, val)) != NULL_TREE)
+ eliminate_push_avail (b, sprime);
}
- tree sprime = eliminate_avail (res);
+ /* If this now constitutes a copy duplicate points-to
+ and range info appropriately. This is especially
+ important for inserted code. See tree-ssa-copy.c
+ for similar code. */
if (sprime
- && sprime != res)
+ && TREE_CODE (sprime) == SSA_NAME)
{
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "Replaced redundant PHI node defining ");
- print_generic_expr (dump_file, res);
- fprintf (dump_file, " with ");
- print_generic_expr (dump_file, sprime);
- fprintf (dump_file, "\n");
- }
-
- /* If we inserted this PHI node ourself, it's not an elimination. */
- if (! inserted_exprs
- || ! bitmap_bit_p (inserted_exprs, SSA_NAME_VERSION (res)))
- eliminations++;
-
- /* If we will propagate into all uses don't bother to do
- anything. */
- if (may_propagate_copy (res, sprime))
+ basic_block sprime_b = gimple_bb (SSA_NAME_DEF_STMT (sprime));
+ if (POINTER_TYPE_P (TREE_TYPE (lhs))
+ && SSA_NAME_PTR_INFO (lhs)
+ && ! SSA_NAME_PTR_INFO (sprime))
{
- /* Mark the PHI for removal. */
- to_remove.safe_push (phi);
- gsi_next (&gsi);
- continue;
+ duplicate_ssa_name_ptr_info (sprime,
+ SSA_NAME_PTR_INFO (lhs));
+ if (b != sprime_b)
+ mark_ptr_info_alignment_unknown
+ (SSA_NAME_PTR_INFO (sprime));
}
-
- remove_phi_node (&gsi, false);
-
- if (!useless_type_conversion_p (TREE_TYPE (res), TREE_TYPE (sprime)))
- sprime = fold_convert (TREE_TYPE (res), sprime);
- gimple *stmt = gimple_build_assign (res, sprime);
- gimple_stmt_iterator gsi2 = gsi_after_labels (b);
- gsi_insert_before (&gsi2, stmt, GSI_NEW_STMT);
- continue;
+ else if (INTEGRAL_TYPE_P (TREE_TYPE (lhs))
+ && SSA_NAME_RANGE_INFO (lhs)
+ && ! SSA_NAME_RANGE_INFO (sprime)
+ && b == sprime_b)
+ duplicate_ssa_name_range_info (sprime,
+ SSA_NAME_RANGE_TYPE (lhs),
+ SSA_NAME_RANGE_INFO (lhs));
}
- eliminate_push_avail (res);
- gsi_next (&gsi);
- }
-
- for (gimple_stmt_iterator gsi = gsi_start_bb (b);
- !gsi_end_p (gsi);
- gsi_next (&gsi))
- {
- tree sprime = NULL_TREE;
- gimple *stmt = gsi_stmt (gsi);
- tree lhs = gimple_get_lhs (stmt);
- if (lhs && TREE_CODE (lhs) == SSA_NAME
- && !gimple_has_volatile_ops (stmt)
- /* See PR43491. Do not replace a global register variable when
- it is a the RHS of an assignment. Do replace local register
- variables since gcc does not guarantee a local variable will
- be allocated in register.
- ??? The fix isn't effective here. This should instead
- be ensured by not value-numbering them the same but treating
- them like volatiles? */
- && !(gimple_assign_single_p (stmt)
- && (TREE_CODE (gimple_assign_rhs1 (stmt)) == VAR_DECL
- && DECL_HARD_REGISTER (gimple_assign_rhs1 (stmt))
- && is_global_var (gimple_assign_rhs1 (stmt)))))
+ /* Inhibit the use of an inserted PHI on a loop header when
+ the address of the memory reference is a simple induction
+ variable. In other cases the vectorizer won't do anything
+ anyway (either it's loop invariant or a complicated
+ expression). */
+ if (sprime
+ && TREE_CODE (sprime) == SSA_NAME
+ && do_pre
+ && (flag_tree_loop_vectorize || flag_tree_parallelize_loops > 1)
+ && loop_outer (b->loop_father)
+ && has_zero_uses (sprime)
+ && bitmap_bit_p (inserted_exprs, SSA_NAME_VERSION (sprime))
+ && gimple_assign_load_p (stmt))
{
- sprime = eliminate_avail (lhs);
- if (!sprime)
- {
- /* If there is no existing usable leader but SCCVN thinks
- it has an expression it wants to use as replacement,
- insert that. */
- tree val = VN_INFO (lhs)->valnum;
- if (val != VN_TOP
- && TREE_CODE (val) == SSA_NAME
- && VN_INFO (val)->needs_insertion
- && VN_INFO (val)->expr != NULL
- && (sprime = eliminate_insert (&gsi, val)) != NULL_TREE)
- eliminate_push_avail (sprime);
- }
-
- /* If this now constitutes a copy duplicate points-to
- and range info appropriately. This is especially
- important for inserted code. See tree-ssa-copy.c
- for similar code. */
- if (sprime
- && TREE_CODE (sprime) == SSA_NAME)
- {
- basic_block sprime_b = gimple_bb (SSA_NAME_DEF_STMT (sprime));
- if (POINTER_TYPE_P (TREE_TYPE (lhs))
- && VN_INFO_PTR_INFO (lhs)
- && ! VN_INFO_PTR_INFO (sprime))
- {
- duplicate_ssa_name_ptr_info (sprime,
- VN_INFO_PTR_INFO (lhs));
- if (b != sprime_b)
- mark_ptr_info_alignment_unknown
- (SSA_NAME_PTR_INFO (sprime));
- }
- else if (INTEGRAL_TYPE_P (TREE_TYPE (lhs))
- && VN_INFO_RANGE_INFO (lhs)
- && ! VN_INFO_RANGE_INFO (sprime)
- && b == sprime_b)
- duplicate_ssa_name_range_info (sprime,
- VN_INFO_RANGE_TYPE (lhs),
- VN_INFO_RANGE_INFO (lhs));
- }
-
- /* Inhibit the use of an inserted PHI on a loop header when
- the address of the memory reference is a simple induction
- variable. In other cases the vectorizer won't do anything
- anyway (either it's loop invariant or a complicated
- expression). */
- if (sprime
- && TREE_CODE (sprime) == SSA_NAME
- && do_pre
- && (flag_tree_loop_vectorize || flag_tree_parallelize_loops > 1)
- && loop_outer (b->loop_father)
- && has_zero_uses (sprime)
- && bitmap_bit_p (inserted_exprs, SSA_NAME_VERSION (sprime))
- && gimple_assign_load_p (stmt))
+ gimple *def_stmt = SSA_NAME_DEF_STMT (sprime);
+ basic_block def_bb = gimple_bb (def_stmt);
+ if (gimple_code (def_stmt) == GIMPLE_PHI
+ && def_bb->loop_father->header == def_bb)
{
- gimple *def_stmt = SSA_NAME_DEF_STMT (sprime);
- basic_block def_bb = gimple_bb (def_stmt);
- if (gimple_code (def_stmt) == GIMPLE_PHI
- && def_bb->loop_father->header == def_bb)
+ loop_p loop = def_bb->loop_father;
+ ssa_op_iter iter;
+ tree op;
+ bool found = false;
+ FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_USE)
{
- loop_p loop = def_bb->loop_father;
- ssa_op_iter iter;
- tree op;
- bool found = false;
- FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_USE)
+ affine_iv iv;
+ def_bb = gimple_bb (SSA_NAME_DEF_STMT (op));
+ if (def_bb
+ && flow_bb_inside_loop_p (loop, def_bb)
+ && simple_iv (loop, loop, op, &iv, true))
{
- affine_iv iv;
- def_bb = gimple_bb (SSA_NAME_DEF_STMT (op));
- if (def_bb
- && flow_bb_inside_loop_p (loop, def_bb)
- && simple_iv (loop, loop, op, &iv, true))
- {
- found = true;
- break;
- }
+ found = true;
+ break;
}
- if (found)
+ }
+ if (found)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
{
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "Not replacing ");
- print_gimple_expr (dump_file, stmt, 0);
- fprintf (dump_file, " with ");
- print_generic_expr (dump_file, sprime);
- fprintf (dump_file, " which would add a loop"
- " carried dependence to loop %d\n",
- loop->num);
- }
- /* Don't keep sprime available. */
- sprime = NULL_TREE;
+ fprintf (dump_file, "Not replacing ");
+ print_gimple_expr (dump_file, stmt, 0);
+ fprintf (dump_file, " with ");
+ print_generic_expr (dump_file, sprime);
+ fprintf (dump_file, " which would add a loop"
+ " carried dependence to loop %d\n",
+ loop->num);
}
+ /* Don't keep sprime available. */
+ sprime = NULL_TREE;
}
}
+ }
- if (sprime)
+ if (sprime)
+ {
+ /* If we can propagate the value computed for LHS into
+ all uses don't bother doing anything with this stmt. */
+ if (may_propagate_copy (lhs, sprime))
{
- /* If we can propagate the value computed for LHS into
- all uses don't bother doing anything with this stmt. */
- if (may_propagate_copy (lhs, sprime))
+ /* Mark it for removal. */
+ to_remove.safe_push (stmt);
+
+ /* ??? Don't count copy/constant propagations. */
+ if (gimple_assign_single_p (stmt)
+ && (TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME
+ || gimple_assign_rhs1 (stmt) == sprime))
+ return;
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
{
- /* Mark it for removal. */
- to_remove.safe_push (stmt);
+ fprintf (dump_file, "Replaced ");
+ print_gimple_expr (dump_file, stmt, 0);
+ fprintf (dump_file, " with ");
+ print_generic_expr (dump_file, sprime);
+ fprintf (dump_file, " in all uses of ");
+ print_gimple_stmt (dump_file, stmt, 0);
+ }
- /* ??? Don't count copy/constant propagations. */
- if (gimple_assign_single_p (stmt)
- && (TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME
- || gimple_assign_rhs1 (stmt) == sprime))
- continue;
+ eliminations++;
+ return;
+ }
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "Replaced ");
- print_gimple_expr (dump_file, stmt, 0);
- fprintf (dump_file, " with ");
- print_generic_expr (dump_file, sprime);
- fprintf (dump_file, " in all uses of ");
- print_gimple_stmt (dump_file, stmt, 0);
+ /* If this is an assignment from our leader (which
+ happens in the case the value-number is a constant)
+ then there is nothing to do. */
+ if (gimple_assign_single_p (stmt)
+ && sprime == gimple_assign_rhs1 (stmt))
+ return;
+
+ /* Else replace its RHS. */
+ bool can_make_abnormal_goto
+ = is_gimple_call (stmt)
+ && stmt_can_make_abnormal_goto (stmt);
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Replaced ");
+ print_gimple_expr (dump_file, stmt, 0);
+ fprintf (dump_file, " with ");
+ print_generic_expr (dump_file, sprime);
+ fprintf (dump_file, " in ");
+ print_gimple_stmt (dump_file, stmt, 0);
+ }
+
+ eliminations++;
+ gimple *orig_stmt = stmt;
+ if (!useless_type_conversion_p (TREE_TYPE (lhs),
+ TREE_TYPE (sprime)))
+ sprime = fold_convert (TREE_TYPE (lhs), sprime);
+ tree vdef = gimple_vdef (stmt);
+ tree vuse = gimple_vuse (stmt);
+ propagate_tree_value_into_stmt (gsi, sprime);
+ stmt = gsi_stmt (*gsi);
+ update_stmt (stmt);
+ if (vdef != gimple_vdef (stmt))
+ VN_INFO (vdef)->valnum = vuse;
+
+ /* If we removed EH side-effects from the statement, clean
+ its EH information. */
+ if (maybe_clean_or_replace_eh_stmt (orig_stmt, stmt))
+ {
+ bitmap_set_bit (need_eh_cleanup,
+ gimple_bb (stmt)->index);
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, " Removed EH side-effects.\n");
+ }
+
+ /* Likewise for AB side-effects. */
+ if (can_make_abnormal_goto
+ && !stmt_can_make_abnormal_goto (stmt))
+ {
+ bitmap_set_bit (need_ab_cleanup,
+ gimple_bb (stmt)->index);
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, " Removed AB side-effects.\n");
+ }
+
+ return;
+ }
+ }
+
+ /* If the statement is a scalar store, see if the expression
+ has the same value number as its rhs. If so, the store is
+ dead. */
+ if (gimple_assign_single_p (stmt)
+ && !gimple_has_volatile_ops (stmt)
+ && !is_gimple_reg (gimple_assign_lhs (stmt))
+ && (TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME
+ || is_gimple_min_invariant (gimple_assign_rhs1 (stmt))))
+ {
+ tree val;
+ tree rhs = gimple_assign_rhs1 (stmt);
+ vn_reference_t vnresult;
+ val = vn_reference_lookup (lhs, gimple_vuse (stmt), VN_WALKREWRITE,
+ &vnresult, false);
+ if (TREE_CODE (rhs) == SSA_NAME)
+ rhs = VN_INFO (rhs)->valnum;
+ if (val
+ && operand_equal_p (val, rhs, 0))
+ {
+ /* We can only remove the later store if the former aliases
+ at least all accesses the later one does or if the store
+ was to readonly memory storing the same value. */
+ alias_set_type set = get_alias_set (lhs);
+ if (! vnresult
+ || vnresult->set == set
+ || alias_set_subset_of (set, vnresult->set))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Deleted redundant store ");
+ print_gimple_stmt (dump_file, stmt, 0);
+ }
+
+ /* Queue stmt for removal. */
+ to_remove.safe_push (stmt);
+ return;
+ }
+ }
+ }
+
+ /* If this is a control statement value numbering left edges
+ unexecuted on force the condition in a way consistent with
+ that. */
+ if (gcond *cond = dyn_cast <gcond *> (stmt))
+ {
+ if ((EDGE_SUCC (b, 0)->flags & EDGE_EXECUTABLE)
+ ^ (EDGE_SUCC (b, 1)->flags & EDGE_EXECUTABLE))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Removing unexecutable edge from ");
+ print_gimple_stmt (dump_file, stmt, 0);
+ }
+ if (((EDGE_SUCC (b, 0)->flags & EDGE_TRUE_VALUE) != 0)
+ == ((EDGE_SUCC (b, 0)->flags & EDGE_EXECUTABLE) != 0))
+ gimple_cond_make_true (cond);
+ else
+ gimple_cond_make_false (cond);
+ update_stmt (cond);
+ el_todo |= TODO_cleanup_cfg;
+ return;
+ }
+ }
+
+ bool can_make_abnormal_goto = stmt_can_make_abnormal_goto (stmt);
+ bool was_noreturn = (is_gimple_call (stmt)
+ && gimple_call_noreturn_p (stmt));
+ tree vdef = gimple_vdef (stmt);
+ tree vuse = gimple_vuse (stmt);
+
+ /* If we didn't replace the whole stmt (or propagate the result
+ into all uses), replace all uses on this stmt with their
+ leaders. */
+ bool modified = false;
+ use_operand_p use_p;
+ ssa_op_iter iter;
+ FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_USE)
+ {
+ tree use = USE_FROM_PTR (use_p);
+ /* ??? The call code above leaves stmt operands un-updated. */
+ if (TREE_CODE (use) != SSA_NAME)
+ continue;
+ tree sprime;
+ if (SSA_NAME_IS_DEFAULT_DEF (use))
+ /* ??? For default defs BB shouldn't matter, but we have to
+ solve the inconsistency between rpo eliminate and
+ dom eliminate avail valueization first. */
+ sprime = eliminate_avail (b, use);
+ else
+ /* Look for sth available at the definition block of the argument.
+ This avoids inconsistencies between availability there which
+ decides if the stmt can be removed and availability at the
+ use site. The SSA property ensures that things available
+ at the definition are also available at uses. */
+ sprime = eliminate_avail (gimple_bb (SSA_NAME_DEF_STMT (use)), use);
+ if (sprime && sprime != use
+ && may_propagate_copy (use, sprime)
+ /* We substitute into debug stmts to avoid excessive
+ debug temporaries created by removed stmts, but we need
+ to avoid doing so for inserted sprimes as we never want
+ to create debug temporaries for them. */
+ && (!inserted_exprs
+ || TREE_CODE (sprime) != SSA_NAME
+ || !is_gimple_debug (stmt)
+ || !bitmap_bit_p (inserted_exprs, SSA_NAME_VERSION (sprime))))
+ {
+ propagate_value (use_p, sprime);
+ modified = true;
+ }
+ }
+
+ /* Fold the stmt if modified, this canonicalizes MEM_REFs we propagated
+ into which is a requirement for the IPA devirt machinery. */
+ gimple *old_stmt = stmt;
+ if (modified)
+ {
+ /* If a formerly non-invariant ADDR_EXPR is turned into an
+ invariant one it was on a separate stmt. */
+ if (gimple_assign_single_p (stmt)
+ && TREE_CODE (gimple_assign_rhs1 (stmt)) == ADDR_EXPR)
+ recompute_tree_invariant_for_addr_expr (gimple_assign_rhs1 (stmt));
+ gimple_stmt_iterator prev = *gsi;
+ gsi_prev (&prev);
+ if (fold_stmt (gsi))
+ {
+ /* fold_stmt may have created new stmts inbetween
+ the previous stmt and the folded stmt. Mark
+ all defs created there as varying to not confuse
+ the SCCVN machinery as we're using that even during
+ elimination. */
+ if (gsi_end_p (prev))
+ prev = gsi_start_bb (b);
+ else
+ gsi_next (&prev);
+ if (gsi_stmt (prev) != gsi_stmt (*gsi))
+ do
+ {
+ tree def;
+ ssa_op_iter dit;
+ FOR_EACH_SSA_TREE_OPERAND (def, gsi_stmt (prev),
+ dit, SSA_OP_ALL_DEFS)
+ /* As existing DEFs may move between stmts
+ only process new ones. */
+ if (! has_VN_INFO (def))
+ {
+ VN_INFO (def)->valnum = def;
+ VN_INFO (def)->visited = true;
+ }
+ if (gsi_stmt (prev) == gsi_stmt (*gsi))
+ break;
+ gsi_next (&prev);
+ }
+ while (1);
+ }
+ stmt = gsi_stmt (*gsi);
+ /* In case we folded the stmt away schedule the NOP for removal. */
+ if (gimple_nop_p (stmt))
+ to_remove.safe_push (stmt);
+ }
+
+ /* Visit indirect calls and turn them into direct calls if
+ possible using the devirtualization machinery. Do this before
+ checking for required EH/abnormal/noreturn cleanup as devird
+ may expose more of those. */
+ if (gcall *call_stmt = dyn_cast <gcall *> (stmt))
+ {
+ tree fn = gimple_call_fn (call_stmt);
+ if (fn
+ && flag_devirtualize
+ && virtual_method_call_p (fn))
+ {
+ tree otr_type = obj_type_ref_class (fn);
+ unsigned HOST_WIDE_INT otr_tok
+ = tree_to_uhwi (OBJ_TYPE_REF_TOKEN (fn));
+ tree instance;
+ ipa_polymorphic_call_context context (current_function_decl,
+ fn, stmt, &instance);
+ context.get_dynamic_type (instance, OBJ_TYPE_REF_OBJECT (fn),
+ otr_type, stmt);
+ bool final;
+ vec <cgraph_node *> targets
+ = possible_polymorphic_call_targets (obj_type_ref_class (fn),
+ otr_tok, context, &final);
+ if (dump_file)
+ dump_possible_polymorphic_call_targets (dump_file,
+ obj_type_ref_class (fn),
+ otr_tok, context);
+ if (final && targets.length () <= 1 && dbg_cnt (devirt))
+ {
+ tree fn;
+ if (targets.length () == 1)
+ fn = targets[0]->decl;
+ else
+ fn = builtin_decl_implicit (BUILT_IN_UNREACHABLE);
+ if (dump_enabled_p ())
+ {
+ dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, stmt,
+ "converting indirect call to "
+ "function %s\n",
+ lang_hooks.decl_printable_name (fn, 2));
+ }
+ gimple_call_set_fndecl (call_stmt, fn);
+ /* If changing the call to __builtin_unreachable
+ or similar noreturn function, adjust gimple_call_fntype
+ too. */
+ if (gimple_call_noreturn_p (call_stmt)
+ && VOID_TYPE_P (TREE_TYPE (TREE_TYPE (fn)))
+ && TYPE_ARG_TYPES (TREE_TYPE (fn))
+ && (TREE_VALUE (TYPE_ARG_TYPES (TREE_TYPE (fn)))
+ == void_type_node))
+ gimple_call_set_fntype (call_stmt, TREE_TYPE (fn));
+ maybe_remove_unused_call_args (cfun, call_stmt);
+ modified = true;
+ }
+ }
+ }
+
+ if (modified)
+ {
+ /* When changing a call into a noreturn call, cfg cleanup
+ is needed to fix up the noreturn call. */
+ if (!was_noreturn
+ && is_gimple_call (stmt) && gimple_call_noreturn_p (stmt))
+ to_fixup.safe_push (stmt);
+ /* When changing a condition or switch into one we know what
+ edge will be executed, schedule a cfg cleanup. */
+ if ((gimple_code (stmt) == GIMPLE_COND
+ && (gimple_cond_true_p (as_a <gcond *> (stmt))
+ || gimple_cond_false_p (as_a <gcond *> (stmt))))
+ || (gimple_code (stmt) == GIMPLE_SWITCH
+ && TREE_CODE (gimple_switch_index
+ (as_a <gswitch *> (stmt))) == INTEGER_CST))
+ el_todo |= TODO_cleanup_cfg;
+ /* If we removed EH side-effects from the statement, clean
+ its EH information. */
+ if (maybe_clean_or_replace_eh_stmt (old_stmt, stmt))
+ {
+ bitmap_set_bit (need_eh_cleanup,
+ gimple_bb (stmt)->index);
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, " Removed EH side-effects.\n");
+ }
+ /* Likewise for AB side-effects. */
+ if (can_make_abnormal_goto
+ && !stmt_can_make_abnormal_goto (stmt))
+ {
+ bitmap_set_bit (need_ab_cleanup,
+ gimple_bb (stmt)->index);
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, " Removed AB side-effects.\n");
+ }
+ update_stmt (stmt);
+ if (vdef != gimple_vdef (stmt))
+ VN_INFO (vdef)->valnum = vuse;
+ }
+
+ /* Make new values available - for fully redundant LHS we
+ continue with the next stmt above and skip this. */
+ def_operand_p defp;
+ FOR_EACH_SSA_DEF_OPERAND (defp, stmt, iter, SSA_OP_DEF)
+ eliminate_push_avail (b, DEF_FROM_PTR (defp));
+}
+
+/* Perform elimination for the basic-block B during the domwalk. */
+
+edge
+eliminate_dom_walker::before_dom_children (basic_block b)
+{
+ /* Mark new bb. */
+ avail_stack.safe_push (NULL_TREE);
+
+ /* Skip unreachable blocks marked unreachable during the SCCVN domwalk. */
+ if (!(b->flags & BB_EXECUTABLE))
+ return NULL;
+
+ vn_context_bb = b;
+
+ for (gphi_iterator gsi = gsi_start_phis (b); !gsi_end_p (gsi);)
+ {
+ gphi *phi = gsi.phi ();
+ tree res = PHI_RESULT (phi);
+
+ if (virtual_operand_p (res))
+ {
+ gsi_next (&gsi);
+ continue;
+ }
+
+ tree sprime = eliminate_avail (b, res);
+ if (sprime
+ && sprime != res)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Replaced redundant PHI node defining ");
+ print_generic_expr (dump_file, res);
+ fprintf (dump_file, " with ");
+ print_generic_expr (dump_file, sprime);
+ fprintf (dump_file, "\n");
+ }
+
+ /* If we inserted this PHI node ourself, it's not an elimination. */
+ if (! inserted_exprs
+ || ! bitmap_bit_p (inserted_exprs, SSA_NAME_VERSION (res)))
+ eliminations++;
+
+ /* If we will propagate into all uses don't bother to do
+ anything. */
+ if (may_propagate_copy (res, sprime))
+ {
+ /* Mark the PHI for removal. */
+ to_remove.safe_push (phi);
+ gsi_next (&gsi);
+ continue;
+ }
+
+ remove_phi_node (&gsi, false);
+
+ if (!useless_type_conversion_p (TREE_TYPE (res), TREE_TYPE (sprime)))
+ sprime = fold_convert (TREE_TYPE (res), sprime);
+ gimple *stmt = gimple_build_assign (res, sprime);
+ gimple_stmt_iterator gsi2 = gsi_after_labels (b);
+ gsi_insert_before (&gsi2, stmt, GSI_NEW_STMT);
+ continue;
+ }
+
+ eliminate_push_avail (b, res);
+ gsi_next (&gsi);
+ }
+
+ for (gimple_stmt_iterator gsi = gsi_start_bb (b);
+ !gsi_end_p (gsi);
+ gsi_next (&gsi))
+ eliminate_stmt (b, &gsi);
+
+ /* Replace destination PHI arguments. */
+ edge_iterator ei;
+ edge e;
+ FOR_EACH_EDGE (e, ei, b->succs)
+ if (e->flags & EDGE_EXECUTABLE)
+ for (gphi_iterator gsi = gsi_start_phis (e->dest);
+ !gsi_end_p (gsi);
+ gsi_next (&gsi))
+ {
+ gphi *phi = gsi.phi ();
+ use_operand_p use_p = PHI_ARG_DEF_PTR_FROM_EDGE (phi, e);
+ tree arg = USE_FROM_PTR (use_p);
+ if (TREE_CODE (arg) != SSA_NAME
+ || virtual_operand_p (arg))
+ continue;
+ tree sprime = eliminate_avail (b, arg);
+ if (sprime && may_propagate_copy (arg, sprime))
+ propagate_value (use_p, sprime);
+ }
+
+ vn_context_bb = NULL;
+
+ return NULL;
+}
+
+/* Make no longer available leaders no longer available. */
+
+void
+eliminate_dom_walker::after_dom_children (basic_block)
+{
+ tree entry;
+ while ((entry = avail_stack.pop ()) != NULL_TREE)
+ {
+ tree valnum = VN_INFO (entry)->valnum;
+ tree old = avail[SSA_NAME_VERSION (valnum)];
+ if (old == entry)
+ avail[SSA_NAME_VERSION (valnum)] = NULL_TREE;
+ else
+ avail[SSA_NAME_VERSION (valnum)] = entry;
+ }
+}
+
+/* Remove queued stmts and perform delayed cleanups. */
+
+unsigned
+eliminate_dom_walker::eliminate_cleanup (bool region_p)
+{
+ statistics_counter_event (cfun, "Eliminated", eliminations);
+ statistics_counter_event (cfun, "Insertions", insertions);
+
+ /* We cannot remove stmts during BB walk, especially not release SSA
+ names there as this confuses the VN machinery. The stmts ending
+ up in to_remove are either stores or simple copies.
+ Remove stmts in reverse order to make debug stmt creation possible. */
+ while (!to_remove.is_empty ())
+ {
+ bool do_release_defs = true;
+ gimple *stmt = to_remove.pop ();
+
+ /* When we are value-numbering a region we do not require exit PHIs to
+ be present so we have to make sure to deal with uses outside of the
+ region of stmts that we thought are eliminated.
+ ??? Note we may be confused by uses in dead regions we didn't run
+ elimination on. Rather than checking individual uses we accept
+ dead copies to be generated here (gcc.c-torture/execute/20060905-1.c
+ contains such example). */
+ if (region_p)
+ {
+ if (gphi *phi = dyn_cast <gphi *> (stmt))
+ {
+ tree lhs = gimple_phi_result (phi);
+ if (!has_zero_uses (lhs))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Keeping eliminated stmt live "
+ "as copy because of out-of-region uses\n");
+ tree sprime = eliminate_avail (gimple_bb (stmt), lhs);
+ gimple *copy = gimple_build_assign (lhs, sprime);
+ gimple_stmt_iterator gsi
+ = gsi_after_labels (gimple_bb (stmt));
+ gsi_insert_before (&gsi, copy, GSI_SAME_STMT);
+ do_release_defs = false;
+ }
+ }
+ else
+ {
+ tree lhs = gimple_get_lhs (stmt);
+ if (TREE_CODE (lhs) == SSA_NAME
+ && !has_zero_uses (lhs))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Keeping eliminated stmt live "
+ "as copy because of out-of-region uses\n");
+ tree sprime = eliminate_avail (gimple_bb (stmt), lhs);
+ gimple_stmt_iterator gsi = gsi_for_stmt (stmt);
+ if (is_gimple_assign (stmt))
+ {
+ gimple_assign_set_rhs_from_tree (&gsi, sprime);
+ update_stmt (gsi_stmt (gsi));
+ continue;
}
+ else
+ {
+ gimple *copy = gimple_build_assign (lhs, sprime);
+ gsi_insert_before (&gsi, copy, GSI_SAME_STMT);
+ do_release_defs = false;
+ }
+ }
+ }
+ }
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Removing dead stmt ");
+ print_gimple_stmt (dump_file, stmt, 0, TDF_NONE);
+ }
+
+ gimple_stmt_iterator gsi = gsi_for_stmt (stmt);
+ if (gimple_code (stmt) == GIMPLE_PHI)
+ remove_phi_node (&gsi, do_release_defs);
+ else
+ {
+ basic_block bb = gimple_bb (stmt);
+ unlink_stmt_vdef (stmt);
+ if (gsi_remove (&gsi, true))
+ bitmap_set_bit (need_eh_cleanup, bb->index);
+ if (is_gimple_call (stmt) && stmt_can_make_abnormal_goto (stmt))
+ bitmap_set_bit (need_ab_cleanup, bb->index);
+ if (do_release_defs)
+ release_defs (stmt);
+ }
+
+ /* Removing a stmt may expose a forwarder block. */
+ el_todo |= TODO_cleanup_cfg;
+ }
+
+ /* Fixup stmts that became noreturn calls. This may require splitting
+ blocks and thus isn't possible during the dominator walk. Do this
+ in reverse order so we don't inadvertedly remove a stmt we want to
+ fixup by visiting a dominating now noreturn call first. */
+ while (!to_fixup.is_empty ())
+ {
+ gimple *stmt = to_fixup.pop ();
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Fixing up noreturn call ");
+ print_gimple_stmt (dump_file, stmt, 0);
+ }
+
+ if (fixup_noreturn_call (stmt))
+ el_todo |= TODO_cleanup_cfg;
+ }
+
+ bool do_eh_cleanup = !bitmap_empty_p (need_eh_cleanup);
+ bool do_ab_cleanup = !bitmap_empty_p (need_ab_cleanup);
+
+ if (do_eh_cleanup)
+ gimple_purge_all_dead_eh_edges (need_eh_cleanup);
+
+ if (do_ab_cleanup)
+ gimple_purge_all_dead_abnormal_call_edges (need_ab_cleanup);
+
+ if (do_eh_cleanup || do_ab_cleanup)
+ el_todo |= TODO_cleanup_cfg;
+
+ return el_todo;
+}
+
+/* Eliminate fully redundant computations. */
+
+unsigned
+eliminate_with_rpo_vn (bitmap inserted_exprs)
+{
+ eliminate_dom_walker walker (CDI_DOMINATORS, inserted_exprs);
+
+ walker.walk (cfun->cfg->x_entry_block_ptr);
+ return walker.eliminate_cleanup ();
+}
+
+static unsigned
+do_rpo_vn (function *fn, edge entry, bitmap exit_bbs,
+ bool iterate, bool eliminate);
+
+void
+run_rpo_vn (vn_lookup_kind kind)
+{
+ default_vn_walk_kind = kind;
+ do_rpo_vn (cfun, NULL, NULL, true, false);
+
+ /* ??? Prune requirement of these. */
+ constant_to_value_id = new hash_table<vn_constant_hasher> (23);
+ constant_value_ids = BITMAP_ALLOC (NULL);
+
+ /* Initialize the value ids and prune out remaining VN_TOPs
+ from dead code. */
+ tree name;
+ unsigned i;
+ FOR_EACH_SSA_NAME (i, name, cfun)
+ {
+ vn_ssa_aux_t info = VN_INFO (name);
+ if (!info->visited
+ || info->valnum == VN_TOP)
+ info->valnum = name;
+ if (info->valnum == name)
+ info->value_id = get_next_value_id ();
+ else if (is_gimple_min_invariant (info->valnum))
+ info->value_id = get_or_alloc_constant_value_id (info->valnum);
+ }
+
+ /* Propagate. */
+ FOR_EACH_SSA_NAME (i, name, cfun)
+ {
+ vn_ssa_aux_t info = VN_INFO (name);
+ if (TREE_CODE (info->valnum) == SSA_NAME
+ && info->valnum != name
+ && info->value_id != VN_INFO (info->valnum)->value_id)
+ info->value_id = VN_INFO (info->valnum)->value_id;
+ }
+
+ set_hashtable_value_ids ();
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Value numbers:\n");
+ FOR_EACH_SSA_NAME (i, name, cfun)
+ {
+ if (VN_INFO (name)->visited
+ && SSA_VAL (name) != name)
+ {
+ print_generic_expr (dump_file, name);
+ fprintf (dump_file, " = ");
+ print_generic_expr (dump_file, SSA_VAL (name));
+ fprintf (dump_file, " (%04d)\n", VN_INFO (name)->value_id);
+ }
+ }
+ }
+}
+
+/* Free VN associated data structures. */
+
+void
+free_rpo_vn (void)
+{
+ free_vn_table (valid_info);
+ XDELETE (valid_info);
+ obstack_free (&vn_tables_obstack, NULL);
+ obstack_free (&vn_tables_insert_obstack, NULL);
+
+ BITMAP_FREE (const_parms);
+
+ vn_ssa_aux_iterator_type it;
+ vn_ssa_aux_t info;
+ FOR_EACH_HASH_TABLE_ELEMENT (*vn_ssa_aux_hash, info, vn_ssa_aux_t, it)
+ if (info->needs_insertion)
+ release_ssa_name (info->name);
+ obstack_free (&vn_ssa_aux_obstack, NULL);
+ delete vn_ssa_aux_hash;
+
+ delete constant_to_value_id;
+ constant_to_value_id = NULL;
+ BITMAP_FREE (constant_value_ids);
+}
+
+/* Adaptor to the elimination engine using RPO availability. */
+
+class rpo_elim : public eliminate_dom_walker
+{
+public:
+ rpo_elim(basic_block entry_)
+ : eliminate_dom_walker (CDI_DOMINATORS, NULL), entry (entry_) {}
+ ~rpo_elim();
+
+ virtual tree eliminate_avail (basic_block, tree op);
+
+ virtual void eliminate_push_avail (basic_block, tree);
+
+ basic_block entry;
+ /* Instead of having a local availability lattice for each
+ basic-block and availability at X defined as union of
+ the local availabilities at X and its dominators we're
+ turning this upside down and track availability per
+ value given values are usually made available at very
+ few points (at least one).
+ So we have a value -> vec<location, leader> map where
+ LOCATION is specifying the basic-block LEADER is made
+ available for VALUE. We push to this vector in RPO
+ order thus for iteration we can simply pop the last
+ entries.
+ LOCATION is the basic-block index and LEADER is its
+ SSA name version. */
+ /* ??? We'd like to use auto_vec here with embedded storage
+ but that doesn't play well until we can provide move
+ constructors and use std::move on hash-table expansion.
+ So for now this is a bit more expensive than necessary.
+ We eventually want to switch to a chaining scheme like
+ for hashtable entries for unwinding which would make
+ making the vector part of the vn_ssa_aux structure possible. */
+ typedef hash_map<tree, vec<std::pair<int, int> > > rpo_avail_t;
+ rpo_avail_t m_rpo_avail;
+};
+
+/* Global RPO state for access from hooks. */
+static rpo_elim *rpo_avail;
+
+/* Hook for maybe_push_res_to_seq, lookup the expression in the VN tables. */
+
+static tree
+vn_lookup_simplify_result (gimple_match_op *res_op)
+{
+ if (!res_op->code.is_tree_code ())
+ return NULL_TREE;
+ tree *ops = res_op->ops;
+ unsigned int length = res_op->num_ops;
+ if (res_op->code == CONSTRUCTOR
+ /* ??? We're arriving here with SCCVNs view, decomposed CONSTRUCTOR
+ and GIMPLEs / match-and-simplifies, CONSTRUCTOR as GENERIC tree. */
+ && TREE_CODE (res_op->ops[0]) == CONSTRUCTOR)
+ {
+ length = CONSTRUCTOR_NELTS (res_op->ops[0]);
+ ops = XALLOCAVEC (tree, length);
+ for (unsigned i = 0; i < length; ++i)
+ ops[i] = CONSTRUCTOR_ELT (res_op->ops[0], i)->value;
+ }
+ vn_nary_op_t vnresult = NULL;
+ tree res = vn_nary_op_lookup_pieces (length, (tree_code) res_op->code,
+ res_op->type, ops, &vnresult);
+ /* If this is used from expression simplification make sure to
+ return an available expression. */
+ if (res && mprts_hook && rpo_avail)
+ res = rpo_avail->eliminate_avail (vn_context_bb, res);
+ return res;
+}
+
+rpo_elim::~rpo_elim ()
+{
+ /* Release the avail vectors. */
+ for (rpo_avail_t::iterator i = m_rpo_avail.begin ();
+ i != m_rpo_avail.end (); ++i)
+ (*i).second.release ();
+}
+
+/* Return a leader for OPs value that is valid at BB. */
+
+tree
+rpo_elim::eliminate_avail (basic_block bb, tree op)
+{
+ tree valnum = SSA_VAL (op);
+ if (TREE_CODE (valnum) == SSA_NAME)
+ {
+ if (SSA_NAME_IS_DEFAULT_DEF (valnum))
+ return valnum;
+ vec<std::pair<int, int> > *av = m_rpo_avail.get (valnum);
+ if (!av || av->is_empty ())
+ return NULL_TREE;
+ int i = av->length () - 1;
+ if ((*av)[i].first == bb->index)
+ /* On tramp3d 90% of the cases are here. */
+ return ssa_name ((*av)[i].second);
+ do
+ {
+ basic_block abb = BASIC_BLOCK_FOR_FN (cfun, (*av)[i].first);
+ /* ??? During elimination we have to use availability at the
+ definition site of a use we try to replace. This
+ is required to not run into inconsistencies because
+ of dominated_by_p_w_unex behavior and removing a definition
+ while not replacing all uses.
+ ??? We could try to consistently walk dominators
+ ignoring non-executable regions. The nearest common
+ dominator of bb and abb is where we can stop walking. We
+ may also be able to "pre-compute" (bits of) the next immediate
+ (non-)dominator during the RPO walk when marking edges as
+ executable. */
+ if (dominated_by_p_w_unex (bb, abb))
+ {
+ tree leader = ssa_name ((*av)[i].second);
+ /* Prevent eliminations that break loop-closed SSA. */
+ if (loops_state_satisfies_p (LOOP_CLOSED_SSA)
+ && ! SSA_NAME_IS_DEFAULT_DEF (leader)
+ && ! flow_bb_inside_loop_p (gimple_bb (SSA_NAME_DEF_STMT
+ (leader))->loop_father,
+ bb))
+ return NULL_TREE;
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ print_generic_expr (dump_file, leader);
+ fprintf (dump_file, " is available for ");
+ print_generic_expr (dump_file, valnum);
+ fprintf (dump_file, "\n");
+ }
+ /* On tramp3d 99% of the _remaining_ cases succeed at
+ the first enty. */
+ return leader;
+ }
+ /* ??? Can we somehow skip to the immediate dominator
+ RPO index (bb_to_rpo)? Again, maybe not worth, on
+ tramp3d the worst number of elements in the vector is 9. */
+ }
+ while (--i >= 0);
+ }
+ else if (valnum != VN_TOP)
+ /* valnum is is_gimple_min_invariant. */
+ return valnum;
+ return NULL_TREE;
+}
+
+/* Make LEADER a leader for its value at BB. */
+
+void
+rpo_elim::eliminate_push_avail (basic_block bb, tree leader)
+{
+ tree valnum = VN_INFO (leader)->valnum;
+ if (valnum == VN_TOP)
+ return;
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Making available beyond BB%d ", bb->index);
+ print_generic_expr (dump_file, leader);
+ fprintf (dump_file, " for value ");
+ print_generic_expr (dump_file, valnum);
+ fprintf (dump_file, "\n");
+ }
+ bool existed;
+ vec<std::pair<int, int> > &av = m_rpo_avail.get_or_insert (valnum, &existed);
+ if (!existed)
+ {
+ new (&av) vec<std::pair<int, int> >;
+ av.reserve_exact (2);
+ }
+ av.safe_push (std::make_pair (bb->index, SSA_NAME_VERSION (leader)));
+}
+
+/* Valueization hook for RPO VN plus required state. */
+
+tree
+rpo_vn_valueize (tree name)
+{
+ if (TREE_CODE (name) == SSA_NAME)
+ {
+ vn_ssa_aux_t val = VN_INFO (name);
+ /* For region-based VN this makes walk_non_aliased_vuses stop walking
+ when we are about to look at a def outside of the region. */
+ if (SSA_NAME_IS_VIRTUAL_OPERAND (name)
+ && !val->visited)
+ return NULL_TREE;
+ if (val)
+ {
+ tree tem = val->valnum;
+ if (tem != VN_TOP && tem != name)
+ {
+ if (TREE_CODE (tem) != SSA_NAME)
+ return tem;
+ /* For all values we only valueize to an available leader
+ which means we can use SSA name info without restriction. */
+ tem = rpo_avail->eliminate_avail (vn_context_bb, tem);
+ if (tem)
+ return tem;
+ }
+ }
+ }
+ return name;
+}
- eliminations++;
- continue;
- }
+/* Insert on PRED_E predicates derived from CODE OPS being true besides the
+ inverted condition. */
- /* If this is an assignment from our leader (which
- happens in the case the value-number is a constant)
- then there is nothing to do. */
- if (gimple_assign_single_p (stmt)
- && sprime == gimple_assign_rhs1 (stmt))
- continue;
+static void
+insert_related_predicates_on_edge (enum tree_code code, tree *ops, edge pred_e)
+{
+ switch (code)
+ {
+ case LT_EXPR:
+ /* a < b -> a {!,<}= b */
+ vn_nary_op_insert_pieces_predicated (2, NE_EXPR, boolean_type_node,
+ ops, boolean_true_node, 0, pred_e);
+ vn_nary_op_insert_pieces_predicated (2, LE_EXPR, boolean_type_node,
+ ops, boolean_true_node, 0, pred_e);
+ /* a < b -> ! a {>,=} b */
+ vn_nary_op_insert_pieces_predicated (2, GT_EXPR, boolean_type_node,
+ ops, boolean_false_node, 0, pred_e);
+ vn_nary_op_insert_pieces_predicated (2, EQ_EXPR, boolean_type_node,
+ ops, boolean_false_node, 0, pred_e);
+ break;
+ case GT_EXPR:
+ /* a > b -> a {!,>}= b */
+ vn_nary_op_insert_pieces_predicated (2, NE_EXPR, boolean_type_node,
+ ops, boolean_true_node, 0, pred_e);
+ vn_nary_op_insert_pieces_predicated (2, GE_EXPR, boolean_type_node,
+ ops, boolean_true_node, 0, pred_e);
+ /* a > b -> ! a {<,=} b */
+ vn_nary_op_insert_pieces_predicated (2, LT_EXPR, boolean_type_node,
+ ops, boolean_false_node, 0, pred_e);
+ vn_nary_op_insert_pieces_predicated (2, EQ_EXPR, boolean_type_node,
+ ops, boolean_false_node, 0, pred_e);
+ break;
+ case EQ_EXPR:
+ /* a == b -> ! a {<,>} b */
+ vn_nary_op_insert_pieces_predicated (2, LT_EXPR, boolean_type_node,
+ ops, boolean_false_node, 0, pred_e);
+ vn_nary_op_insert_pieces_predicated (2, GT_EXPR, boolean_type_node,
+ ops, boolean_false_node, 0, pred_e);
+ break;
+ case LE_EXPR:
+ case GE_EXPR:
+ case NE_EXPR:
+ /* Nothing besides inverted condition. */
+ break;
+ default:;
+ }
+}
- /* Else replace its RHS. */
- bool can_make_abnormal_goto
- = is_gimple_call (stmt)
- && stmt_can_make_abnormal_goto (stmt);
+/* Main stmt worker for RPO VN, process BB. */
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "Replaced ");
- print_gimple_expr (dump_file, stmt, 0);
- fprintf (dump_file, " with ");
- print_generic_expr (dump_file, sprime);
- fprintf (dump_file, " in ");
- print_gimple_stmt (dump_file, stmt, 0);
- }
+static unsigned
+process_bb (rpo_elim &avail, basic_block bb,
+ bool bb_visited, bool iterate_phis, bool iterate, bool eliminate,
+ bool do_region, bitmap exit_bbs)
+{
+ unsigned todo = 0;
+ edge_iterator ei;
+ edge e;
- eliminations++;
- gimple *orig_stmt = stmt;
- if (!useless_type_conversion_p (TREE_TYPE (lhs),
- TREE_TYPE (sprime)))
- sprime = fold_convert (TREE_TYPE (lhs), sprime);
- tree vdef = gimple_vdef (stmt);
- tree vuse = gimple_vuse (stmt);
- propagate_tree_value_into_stmt (&gsi, sprime);
- stmt = gsi_stmt (gsi);
- update_stmt (stmt);
- if (vdef != gimple_vdef (stmt))
- VN_INFO (vdef)->valnum = vuse;
-
- /* If we removed EH side-effects from the statement, clean
- its EH information. */
- if (maybe_clean_or_replace_eh_stmt (orig_stmt, stmt))
- {
- bitmap_set_bit (need_eh_cleanup,
- gimple_bb (stmt)->index);
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, " Removed EH side-effects.\n");
- }
+ vn_context_bb = bb;
- /* Likewise for AB side-effects. */
- if (can_make_abnormal_goto
- && !stmt_can_make_abnormal_goto (stmt))
- {
- bitmap_set_bit (need_ab_cleanup,
- gimple_bb (stmt)->index);
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, " Removed AB side-effects.\n");
- }
+ /* If we are in loop-closed SSA preserve this state. This is
+ relevant when called on regions from outside of FRE/PRE. */
+ bool lc_phi_nodes = false;
+ if (loops_state_satisfies_p (LOOP_CLOSED_SSA))
+ FOR_EACH_EDGE (e, ei, bb->preds)
+ if (e->src->loop_father != e->dest->loop_father
+ && flow_loop_nested_p (e->dest->loop_father,
+ e->src->loop_father))
+ {
+ lc_phi_nodes = true;
+ break;
+ }
- continue;
- }
+ /* Value-number all defs in the basic-block. */
+ for (gphi_iterator gsi = gsi_start_phis (bb); !gsi_end_p (gsi);
+ gsi_next (&gsi))
+ {
+ gphi *phi = gsi.phi ();
+ tree res = PHI_RESULT (phi);
+ vn_ssa_aux_t res_info = VN_INFO (res);
+ if (!bb_visited)
+ {
+ gcc_assert (!res_info->visited);
+ res_info->valnum = VN_TOP;
+ res_info->visited = true;
}
- /* If the statement is a scalar store, see if the expression
- has the same value number as its rhs. If so, the store is
- dead. */
- if (gimple_assign_single_p (stmt)
- && !gimple_has_volatile_ops (stmt)
- && !is_gimple_reg (gimple_assign_lhs (stmt))
- && (TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME
- || is_gimple_min_invariant (gimple_assign_rhs1 (stmt))))
+ /* When not iterating force backedge values to varying. */
+ visit_stmt (phi, !iterate_phis);
+ if (virtual_operand_p (res))
+ continue;
+
+ /* Eliminate */
+ /* The interesting case is gcc.dg/tree-ssa/pr22230.c for correctness
+ how we handle backedges and availability.
+ And gcc.dg/tree-ssa/ssa-sccvn-2.c for optimization. */
+ tree val = res_info->valnum;
+ if (res != val && !iterate && eliminate)
{
- tree val;
- tree rhs = gimple_assign_rhs1 (stmt);
- vn_reference_t vnresult;
- val = vn_reference_lookup (lhs, gimple_vuse (stmt), VN_WALKREWRITE,
- &vnresult, false);
- if (TREE_CODE (rhs) == SSA_NAME)
- rhs = VN_INFO (rhs)->valnum;
- if (val
- && operand_equal_p (val, rhs, 0))
+ if (tree leader = avail.eliminate_avail (bb, res))
{
- /* We can only remove the later store if the former aliases
- at least all accesses the later one does or if the store
- was to readonly memory storing the same value. */
- alias_set_type set = get_alias_set (lhs);
- if (! vnresult
- || vnresult->set == set
- || alias_set_subset_of (set, vnresult->set))
+ if (leader != res
+ /* Preserve loop-closed SSA form. */
+ && (! lc_phi_nodes
+ || is_gimple_min_invariant (leader)))
{
if (dump_file && (dump_flags & TDF_DETAILS))
{
- fprintf (dump_file, "Deleted redundant store ");
- print_gimple_stmt (dump_file, stmt, 0);
+ fprintf (dump_file, "Replaced redundant PHI node "
+ "defining ");
+ print_generic_expr (dump_file, res);
+ fprintf (dump_file, " with ");
+ print_generic_expr (dump_file, leader);
+ fprintf (dump_file, "\n");
}
+ avail.eliminations++;
- /* Queue stmt for removal. */
- to_remove.safe_push (stmt);
- continue;
+ if (may_propagate_copy (res, leader))
+ {
+ /* Schedule for removal. */
+ avail.to_remove.safe_push (phi);
+ continue;
+ }
+ /* ??? Else generate a copy stmt. */
}
}
}
+ /* Only make defs available that not already are. But make
+ sure loop-closed SSA PHI node defs are picked up for
+ downstream uses. */
+ if (lc_phi_nodes
+ || res == val
+ || ! avail.eliminate_avail (bb, res))
+ avail.eliminate_push_avail (bb, res);
+ }
- /* If this is a control statement value numbering left edges
- unexecuted on force the condition in a way consistent with
- that. */
- if (gcond *cond = dyn_cast <gcond *> (stmt))
+ /* For empty BBs mark outgoing edges executable. For non-empty BBs
+ we do this when processing the last stmt as we have to do this
+ before elimination which otherwise forces GIMPLE_CONDs to
+ if (1 != 0) style when seeing non-executable edges. */
+ if (gsi_end_p (gsi_start_bb (bb)))
+ {
+ FOR_EACH_EDGE (e, ei, bb->succs)
{
- if ((EDGE_SUCC (b, 0)->flags & EDGE_EXECUTABLE)
- ^ (EDGE_SUCC (b, 1)->flags & EDGE_EXECUTABLE))
- {
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "Removing unexecutable edge from ");
- print_gimple_stmt (dump_file, stmt, 0);
- }
- if (((EDGE_SUCC (b, 0)->flags & EDGE_TRUE_VALUE) != 0)
- == ((EDGE_SUCC (b, 0)->flags & EDGE_EXECUTABLE) != 0))
- gimple_cond_make_true (cond);
- else
- gimple_cond_make_false (cond);
- update_stmt (cond);
- el_todo |= TODO_cleanup_cfg;
- continue;
- }
+ if (e->flags & EDGE_EXECUTABLE)
+ continue;
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file,
+ "marking outgoing edge %d -> %d executable\n",
+ e->src->index, e->dest->index);
+ gcc_checking_assert (iterate || !(e->flags & EDGE_DFS_BACK));
+ e->flags |= EDGE_EXECUTABLE;
+ e->dest->flags |= BB_EXECUTABLE;
}
-
- bool can_make_abnormal_goto = stmt_can_make_abnormal_goto (stmt);
- bool was_noreturn = (is_gimple_call (stmt)
- && gimple_call_noreturn_p (stmt));
- tree vdef = gimple_vdef (stmt);
- tree vuse = gimple_vuse (stmt);
-
- /* If we didn't replace the whole stmt (or propagate the result
- into all uses), replace all uses on this stmt with their
- leaders. */
- bool modified = false;
- use_operand_p use_p;
- ssa_op_iter iter;
- FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_USE)
+ }
+ for (gimple_stmt_iterator gsi = gsi_start_bb (bb);
+ !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ ssa_op_iter i;
+ tree op;
+ if (!bb_visited)
{
- tree use = USE_FROM_PTR (use_p);
- /* ??? The call code above leaves stmt operands un-updated. */
- if (TREE_CODE (use) != SSA_NAME)
- continue;
- tree sprime = eliminate_avail (use);
- if (sprime && sprime != use
- && may_propagate_copy (use, sprime)
- /* We substitute into debug stmts to avoid excessive
- debug temporaries created by removed stmts, but we need
- to avoid doing so for inserted sprimes as we never want
- to create debug temporaries for them. */
- && (!inserted_exprs
- || TREE_CODE (sprime) != SSA_NAME
- || !is_gimple_debug (stmt)
- || !bitmap_bit_p (inserted_exprs, SSA_NAME_VERSION (sprime))))
+ FOR_EACH_SSA_TREE_OPERAND (op, gsi_stmt (gsi), i, SSA_OP_ALL_DEFS)
{
- propagate_value (use_p, sprime);
- modified = true;
+ vn_ssa_aux_t op_info = VN_INFO (op);
+ gcc_assert (!op_info->visited);
+ op_info->valnum = VN_TOP;
+ op_info->visited = true;
}
+
+ /* We somehow have to deal with uses that are not defined
+ in the processed region. Forcing unvisited uses to
+ varying here doesn't play well with def-use following during
+ expression simplification, so we deal with this by checking
+ the visited flag in SSA_VAL. */
}
- /* Fold the stmt if modified, this canonicalizes MEM_REFs we propagated
- into which is a requirement for the IPA devirt machinery. */
- gimple *old_stmt = stmt;
- if (modified)
+ visit_stmt (gsi_stmt (gsi));
+
+ gimple *last = gsi_stmt (gsi);
+ e = NULL;
+ switch (gimple_code (last))
{
- /* If a formerly non-invariant ADDR_EXPR is turned into an
- invariant one it was on a separate stmt. */
- if (gimple_assign_single_p (stmt)
- && TREE_CODE (gimple_assign_rhs1 (stmt)) == ADDR_EXPR)
- recompute_tree_invariant_for_addr_expr (gimple_assign_rhs1 (stmt));
- gimple_stmt_iterator prev = gsi;
- gsi_prev (&prev);
- if (fold_stmt (&gsi))
- {
- /* fold_stmt may have created new stmts inbetween
- the previous stmt and the folded stmt. Mark
- all defs created there as varying to not confuse
- the SCCVN machinery as we're using that even during
- elimination. */
- if (gsi_end_p (prev))
- prev = gsi_start_bb (b);
- else
- gsi_next (&prev);
- if (gsi_stmt (prev) != gsi_stmt (gsi))
- do
+ case GIMPLE_SWITCH:
+ e = find_taken_edge (bb, vn_valueize (gimple_switch_index
+ (as_a <gswitch *> (last))));
+ break;
+ case GIMPLE_COND:
+ {
+ tree lhs = vn_valueize (gimple_cond_lhs (last));
+ tree rhs = vn_valueize (gimple_cond_rhs (last));
+ tree val = gimple_simplify (gimple_cond_code (last),
+ boolean_type_node, lhs, rhs,
+ NULL, vn_valueize);
+ /* If the condition didn't simplfy see if we have recorded
+ an expression from sofar taken edges. */
+ if (! val || TREE_CODE (val) != INTEGER_CST)
+ {
+ vn_nary_op_t vnresult;
+ tree ops[2];
+ ops[0] = lhs;
+ ops[1] = rhs;
+ val = vn_nary_op_lookup_pieces (2, gimple_cond_code (last),
+ boolean_type_node, ops,
+ &vnresult);
+ /* Did we get a predicated value? */
+ if (! val && vnresult && vnresult->predicated_values)
{
- tree def;
- ssa_op_iter dit;
- FOR_EACH_SSA_TREE_OPERAND (def, gsi_stmt (prev),
- dit, SSA_OP_ALL_DEFS)
- /* As existing DEFs may move between stmts
- we have to guard VN_INFO_GET. */
- if (! has_VN_INFO (def))
- VN_INFO_GET (def)->valnum = def;
- if (gsi_stmt (prev) == gsi_stmt (gsi))
- break;
- gsi_next (&prev);
+ val = vn_nary_op_get_predicated_value (vnresult, bb);
+ if (val && dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Got predicated value ");
+ print_generic_expr (dump_file, val, TDF_NONE);
+ fprintf (dump_file, " for ");
+ print_gimple_stmt (dump_file, last, TDF_SLIM);
+ }
}
- while (1);
- }
- stmt = gsi_stmt (gsi);
- /* In case we folded the stmt away schedule the NOP for removal. */
- if (gimple_nop_p (stmt))
- to_remove.safe_push (stmt);
+ }
+ if (val)
+ e = find_taken_edge (bb, val);
+ if (! e)
+ {
+ /* If we didn't manage to compute the taken edge then
+ push predicated expressions for the condition itself
+ and related conditions to the hashtables. This allows
+ simplification of redundant conditions which is
+ important as early cleanup. */
+ edge true_e, false_e;
+ extract_true_false_edges_from_block (bb, &true_e, &false_e);
+ enum tree_code code = gimple_cond_code (last);
+ enum tree_code icode
+ = invert_tree_comparison (code, HONOR_NANS (lhs));
+ tree ops[2];
+ ops[0] = lhs;
+ ops[1] = rhs;
+ if (do_region
+ && bitmap_bit_p (exit_bbs, true_e->dest->index))
+ true_e = NULL;
+ if (do_region
+ && bitmap_bit_p (exit_bbs, false_e->dest->index))
+ false_e = NULL;
+ if (true_e)
+ vn_nary_op_insert_pieces_predicated
+ (2, code, boolean_type_node, ops,
+ boolean_true_node, 0, true_e);
+ if (false_e)
+ vn_nary_op_insert_pieces_predicated
+ (2, code, boolean_type_node, ops,
+ boolean_false_node, 0, false_e);
+ if (icode != ERROR_MARK)
+ {
+ if (true_e)
+ vn_nary_op_insert_pieces_predicated
+ (2, icode, boolean_type_node, ops,
+ boolean_false_node, 0, true_e);
+ if (false_e)
+ vn_nary_op_insert_pieces_predicated
+ (2, icode, boolean_type_node, ops,
+ boolean_true_node, 0, false_e);
+ }
+ /* Relax for non-integers, inverted condition handled
+ above. */
+ if (INTEGRAL_TYPE_P (TREE_TYPE (lhs)))
+ {
+ if (true_e)
+ insert_related_predicates_on_edge (code, ops, true_e);
+ if (false_e)
+ insert_related_predicates_on_edge (icode, ops, false_e);
+ }
+ }
+ break;
+ }
+ case GIMPLE_GOTO:
+ e = find_taken_edge (bb, vn_valueize (gimple_goto_dest (last)));
+ break;
+ default:
+ e = NULL;
}
-
- /* Visit indirect calls and turn them into direct calls if
- possible using the devirtualization machinery. Do this before
- checking for required EH/abnormal/noreturn cleanup as devird
- may expose more of those. */
- if (gcall *call_stmt = dyn_cast <gcall *> (stmt))
+ if (e)
{
- tree fn = gimple_call_fn (call_stmt);
- if (fn
- && flag_devirtualize
- && virtual_method_call_p (fn))
+ todo = TODO_cleanup_cfg;
+ if (!(e->flags & EDGE_EXECUTABLE))
{
- tree otr_type = obj_type_ref_class (fn);
- unsigned HOST_WIDE_INT otr_tok
- = tree_to_uhwi (OBJ_TYPE_REF_TOKEN (fn));
- tree instance;
- ipa_polymorphic_call_context context (current_function_decl,
- fn, stmt, &instance);
- context.get_dynamic_type (instance, OBJ_TYPE_REF_OBJECT (fn),
- otr_type, stmt);
- bool final;
- vec <cgraph_node *> targets
- = possible_polymorphic_call_targets (obj_type_ref_class (fn),
- otr_tok, context, &final);
- if (dump_file)
- dump_possible_polymorphic_call_targets (dump_file,
- obj_type_ref_class (fn),
- otr_tok, context);
- if (final && targets.length () <= 1 && dbg_cnt (devirt))
- {
- tree fn;
- if (targets.length () == 1)
- fn = targets[0]->decl;
- else
- fn = builtin_decl_implicit (BUILT_IN_UNREACHABLE);
- if (dump_enabled_p ())
- {
- dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, stmt,
- "converting indirect call to "
- "function %s\n",
- lang_hooks.decl_printable_name (fn, 2));
- }
- gimple_call_set_fndecl (call_stmt, fn);
- /* If changing the call to __builtin_unreachable
- or similar noreturn function, adjust gimple_call_fntype
- too. */
- if (gimple_call_noreturn_p (call_stmt)
- && VOID_TYPE_P (TREE_TYPE (TREE_TYPE (fn)))
- && TYPE_ARG_TYPES (TREE_TYPE (fn))
- && (TREE_VALUE (TYPE_ARG_TYPES (TREE_TYPE (fn)))
- == void_type_node))
- gimple_call_set_fntype (call_stmt, TREE_TYPE (fn));
- maybe_remove_unused_call_args (cfun, call_stmt);
- modified = true;
- }
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file,
+ "marking known outgoing %sedge %d -> %d executable\n",
+ e->flags & EDGE_DFS_BACK ? "back-" : "",
+ e->src->index, e->dest->index);
+ gcc_checking_assert (iterate || !(e->flags & EDGE_DFS_BACK));
+ e->flags |= EDGE_EXECUTABLE;
+ e->dest->flags |= BB_EXECUTABLE;
}
}
-
- if (modified)
+ else if (gsi_one_before_end_p (gsi))
{
- /* When changing a call into a noreturn call, cfg cleanup
- is needed to fix up the noreturn call. */
- if (!was_noreturn
- && is_gimple_call (stmt) && gimple_call_noreturn_p (stmt))
- to_fixup.safe_push (stmt);
- /* When changing a condition or switch into one we know what
- edge will be executed, schedule a cfg cleanup. */
- if ((gimple_code (stmt) == GIMPLE_COND
- && (gimple_cond_true_p (as_a <gcond *> (stmt))
- || gimple_cond_false_p (as_a <gcond *> (stmt))))
- || (gimple_code (stmt) == GIMPLE_SWITCH
- && TREE_CODE (gimple_switch_index
- (as_a <gswitch *> (stmt))) == INTEGER_CST))
- el_todo |= TODO_cleanup_cfg;
- /* If we removed EH side-effects from the statement, clean
- its EH information. */
- if (maybe_clean_or_replace_eh_stmt (old_stmt, stmt))
- {
- bitmap_set_bit (need_eh_cleanup,
- gimple_bb (stmt)->index);
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, " Removed EH side-effects.\n");
- }
- /* Likewise for AB side-effects. */
- if (can_make_abnormal_goto
- && !stmt_can_make_abnormal_goto (stmt))
+ FOR_EACH_EDGE (e, ei, bb->succs)
{
- bitmap_set_bit (need_ab_cleanup,
- gimple_bb (stmt)->index);
+ if (e->flags & EDGE_EXECUTABLE)
+ continue;
if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, " Removed AB side-effects.\n");
+ fprintf (dump_file,
+ "marking outgoing edge %d -> %d executable\n",
+ e->src->index, e->dest->index);
+ gcc_checking_assert (iterate || !(e->flags & EDGE_DFS_BACK));
+ e->flags |= EDGE_EXECUTABLE;
+ e->dest->flags |= BB_EXECUTABLE;
}
- update_stmt (stmt);
- if (vdef != gimple_vdef (stmt))
- VN_INFO (vdef)->valnum = vuse;
}
- /* Make new values available - for fully redundant LHS we
- continue with the next stmt above and skip this. */
- def_operand_p defp;
- FOR_EACH_SSA_DEF_OPERAND (defp, stmt, iter, SSA_OP_DEF)
- eliminate_push_avail (DEF_FROM_PTR (defp));
+ /* Eliminate. That also pushes to avail. */
+ if (eliminate && ! iterate)
+ avail.eliminate_stmt (bb, &gsi);
+ else
+ /* If not eliminating, make all not already available defs
+ available. */
+ FOR_EACH_SSA_TREE_OPERAND (op, gsi_stmt (gsi), i, SSA_OP_DEF)
+ if (! avail.eliminate_avail (bb, op))
+ avail.eliminate_push_avail (bb, op);
}
- /* Replace destination PHI arguments. */
- FOR_EACH_EDGE (e, ei, b->succs)
- if (e->flags & EDGE_EXECUTABLE)
+ /* Eliminate in destination PHI arguments. Always substitute in dest
+ PHIs, even for non-executable edges. This handles region
+ exits PHIs. */
+ if (!iterate && eliminate)
+ FOR_EACH_EDGE (e, ei, bb->succs)
for (gphi_iterator gsi = gsi_start_phis (e->dest);
- !gsi_end_p (gsi);
- gsi_next (&gsi))
+ !gsi_end_p (gsi); gsi_next (&gsi))
{
gphi *phi = gsi.phi ();
use_operand_p use_p = PHI_ARG_DEF_PTR_FROM_EDGE (phi, e);
@@ -5904,106 +6138,419 @@ eliminate_dom_walker::before_dom_children (basic_block b)
if (TREE_CODE (arg) != SSA_NAME
|| virtual_operand_p (arg))
continue;
- tree sprime = eliminate_avail (arg);
- if (sprime && may_propagate_copy (arg, sprime))
+ tree sprime;
+ if (SSA_NAME_IS_DEFAULT_DEF (arg))
+ {
+ sprime = SSA_VAL (arg);
+ gcc_assert (TREE_CODE (sprime) != SSA_NAME
+ || SSA_NAME_IS_DEFAULT_DEF (sprime));
+ }
+ else
+ /* Look for sth available at the definition block of the argument.
+ This avoids inconsistencies between availability there which
+ decides if the stmt can be removed and availability at the
+ use site. The SSA property ensures that things available
+ at the definition are also available at uses. */
+ sprime = avail.eliminate_avail (gimple_bb (SSA_NAME_DEF_STMT (arg)),
+ arg);
+ if (sprime
+ && sprime != arg
+ && may_propagate_copy (arg, sprime))
propagate_value (use_p, sprime);
}
- return NULL;
+
+ vn_context_bb = NULL;
+ return todo;
}
-/* Make no longer available leaders no longer available. */
+/* Unwind state per basic-block. */
-void
-eliminate_dom_walker::after_dom_children (basic_block)
+struct unwind_state
{
- tree entry;
- while ((entry = avail_stack.pop ()) != NULL_TREE)
+ /* Times this block has been visited. */
+ unsigned visited;
+ /* Whether to handle this as iteration point or whether to treat
+ incoming backedge PHI values as varying. */
+ bool iterate;
+ void *ob_top;
+ vn_reference_t ref_top;
+ vn_phi_t phi_top;
+ vn_nary_op_t nary_top;
+};
+
+/* Unwind the RPO VN state for iteration. */
+
+static void
+do_unwind (unwind_state *to, int rpo_idx, rpo_elim &avail, int *bb_to_rpo)
+{
+ gcc_assert (to->iterate);
+ for (; last_inserted_nary != to->nary_top;
+ last_inserted_nary = last_inserted_nary->next)
{
- tree valnum = VN_INFO (entry)->valnum;
- tree old = avail[SSA_NAME_VERSION (valnum)];
- if (old == entry)
- avail[SSA_NAME_VERSION (valnum)] = NULL_TREE;
+ vn_nary_op_t *slot;
+ slot = valid_info->nary->find_slot_with_hash
+ (last_inserted_nary, last_inserted_nary->hashcode, NO_INSERT);
+ /* Predication causes the need to restore previous state. */
+ if ((*slot)->unwind_to)
+ *slot = (*slot)->unwind_to;
else
- avail[SSA_NAME_VERSION (valnum)] = entry;
+ valid_info->nary->clear_slot (slot);
+ }
+ for (; last_inserted_phi != to->phi_top;
+ last_inserted_phi = last_inserted_phi->next)
+ {
+ vn_phi_t *slot;
+ slot = valid_info->phis->find_slot_with_hash
+ (last_inserted_phi, last_inserted_phi->hashcode, NO_INSERT);
+ valid_info->phis->clear_slot (slot);
+ }
+ for (; last_inserted_ref != to->ref_top;
+ last_inserted_ref = last_inserted_ref->next)
+ {
+ vn_reference_t *slot;
+ slot = valid_info->references->find_slot_with_hash
+ (last_inserted_ref, last_inserted_ref->hashcode, NO_INSERT);
+ (*slot)->operands.release ();
+ valid_info->references->clear_slot (slot);
+ }
+ obstack_free (&vn_tables_obstack, to->ob_top);
+
+ /* Prune [rpo_idx, ] from avail. */
+ /* ??? This is O(number-of-values-in-region) which is
+ O(region-size) rather than O(iteration-piece). */
+ for (rpo_elim::rpo_avail_t::iterator i
+ = avail.m_rpo_avail.begin ();
+ i != avail.m_rpo_avail.end (); ++i)
+ {
+ while (! (*i).second.is_empty ())
+ {
+ if (bb_to_rpo[(*i).second.last ().first] < rpo_idx)
+ break;
+ (*i).second.pop ();
+ }
}
}
-/* Eliminate fully redundant computations. */
+/* Do VN on a SEME region specified by ENTRY and EXIT_BBS in FN.
+ If ITERATE is true then treat backedges optimistically as not
+ executed and iterate. If ELIMINATE is true then perform
+ elimination, otherwise leave that to the caller. */
-unsigned int
-vn_eliminate (bitmap inserted_exprs)
+static unsigned
+do_rpo_vn (function *fn, edge entry, bitmap exit_bbs,
+ bool iterate, bool eliminate)
{
- eliminate_dom_walker el (CDI_DOMINATORS, inserted_exprs);
- el.avail.reserve (num_ssa_names);
+ unsigned todo = 0;
- el.walk (cfun->cfg->x_entry_block_ptr);
+ /* We currently do not support region-based iteration when
+ elimination is requested. */
+ gcc_assert (!entry || !iterate || !eliminate);
+ /* When iterating we need loop info up-to-date. */
+ gcc_assert (!iterate || !loops_state_satisfies_p (LOOPS_NEED_FIXUP));
- /* We cannot remove stmts during BB walk, especially not release SSA
- names there as this confuses the VN machinery. The stmts ending
- up in to_remove are either stores or simple copies.
- Remove stmts in reverse order to make debug stmt creation possible. */
- while (!el.to_remove.is_empty ())
+ bool do_region = entry != NULL;
+ if (!do_region)
{
- gimple *stmt = el.to_remove.pop ();
+ entry = single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (fn));
+ exit_bbs = BITMAP_ALLOC (NULL);
+ bitmap_set_bit (exit_bbs, EXIT_BLOCK);
+ }
- if (dump_file && (dump_flags & TDF_DETAILS))
+ int *rpo = XNEWVEC (int, n_basic_blocks_for_fn (fn) - NUM_FIXED_BLOCKS);
+ int n = rev_post_order_and_mark_dfs_back_seme (fn, entry, exit_bbs,
+ iterate, rpo);
+ /* rev_post_order_and_mark_dfs_back_seme fills RPO in reverse order. */
+ for (int i = 0; i < n / 2; ++i)
+ std::swap (rpo[i], rpo[n-i-1]);
+
+ if (!do_region)
+ BITMAP_FREE (exit_bbs);
+
+ int *bb_to_rpo = XNEWVEC (int, last_basic_block_for_fn (fn));
+ for (int i = 0; i < n; ++i)
+ bb_to_rpo[rpo[i]] = i;
+
+ unwind_state *rpo_state = XNEWVEC (unwind_state, n);
+
+ rpo_elim avail (entry->dest);
+ rpo_avail = &avail;
+
+ /* Verify we have no extra entries into the region. */
+ if (flag_checking && do_region)
+ {
+ auto_bb_flag bb_in_region (fn);
+ for (int i = 0; i < n; ++i)
{
- fprintf (dump_file, "Removing dead stmt ");
- print_gimple_stmt (dump_file, stmt, 0, TDF_NONE);
+ basic_block bb = BASIC_BLOCK_FOR_FN (fn, rpo[i]);
+ bb->flags |= bb_in_region;
+ }
+ /* We can't merge the first two loops because we cannot rely
+ on EDGE_DFS_BACK for edges not within the region. But if
+ we decide to always have the bb_in_region flag we can
+ do the checking during the RPO walk itself (but then it's
+ also easy to handle MEME conservatively). */
+ for (int i = 0; i < n; ++i)
+ {
+ basic_block bb = BASIC_BLOCK_FOR_FN (fn, rpo[i]);
+ edge e;
+ edge_iterator ei;
+ FOR_EACH_EDGE (e, ei, bb->preds)
+ gcc_assert (e == entry || (e->src->flags & bb_in_region));
+ }
+ for (int i = 0; i < n; ++i)
+ {
+ basic_block bb = BASIC_BLOCK_FOR_FN (fn, rpo[i]);
+ bb->flags &= ~bb_in_region;
}
+ }
- gimple_stmt_iterator gsi = gsi_for_stmt (stmt);
- if (gimple_code (stmt) == GIMPLE_PHI)
- remove_phi_node (&gsi, true);
- else
+ /* Create the VN state. For the initial size of the various hashtables
+ use a heuristic based on region size and number of SSA names. */
+ unsigned region_size = (((unsigned HOST_WIDE_INT)n * num_ssa_names)
+ / (n_basic_blocks_for_fn (fn) - NUM_FIXED_BLOCKS));
+ VN_TOP = create_tmp_var_raw (void_type_node, "vn_top");
+ init_const_parms ();
+
+ vn_ssa_aux_hash = new hash_table <vn_ssa_aux_hasher> (region_size * 2);
+ gcc_obstack_init (&vn_ssa_aux_obstack);
+
+ gcc_obstack_init (&vn_tables_obstack);
+ gcc_obstack_init (&vn_tables_insert_obstack);
+ valid_info = XCNEW (struct vn_tables_s);
+ allocate_vn_table (valid_info, region_size);
+ last_inserted_ref = NULL;
+ last_inserted_phi = NULL;
+ last_inserted_nary = NULL;
+
+ vn_valueize = rpo_vn_valueize;
+
+ /* Initialize the unwind state and edge/BB executable state. */
+ for (int i = 0; i < n; ++i)
+ {
+ basic_block bb = BASIC_BLOCK_FOR_FN (fn, rpo[i]);
+ rpo_state[i].visited = 0;
+ bool has_backedges = false;
+ edge e;
+ edge_iterator ei;
+ FOR_EACH_EDGE (e, ei, bb->preds)
{
- basic_block bb = gimple_bb (stmt);
- unlink_stmt_vdef (stmt);
- if (gsi_remove (&gsi, true))
- bitmap_set_bit (el.need_eh_cleanup, bb->index);
- if (is_gimple_call (stmt) && stmt_can_make_abnormal_goto (stmt))
- bitmap_set_bit (el.need_ab_cleanup, bb->index);
- release_defs (stmt);
+ if (e->flags & EDGE_DFS_BACK)
+ has_backedges = true;
+ if (! iterate && (e->flags & EDGE_DFS_BACK))
+ e->flags |= EDGE_EXECUTABLE;
+ else
+ e->flags &= ~EDGE_EXECUTABLE;
}
+ rpo_state[i].iterate = iterate && has_backedges;
+ bb->flags &= ~BB_EXECUTABLE;
+ }
+ entry->flags |= EDGE_EXECUTABLE;
+ entry->dest->flags |= BB_EXECUTABLE;
- /* Removing a stmt may expose a forwarder block. */
- el.el_todo |= TODO_cleanup_cfg;
+ /* As heuristic to improve compile-time we handle only the N innermost
+ loops and the outermost one optimistically. */
+ if (iterate)
+ {
+ loop_p loop;
+ unsigned max_depth = PARAM_VALUE (PARAM_RPO_VN_MAX_LOOP_DEPTH);
+ FOR_EACH_LOOP (loop, LI_ONLY_INNERMOST)
+ if (loop_depth (loop) > max_depth)
+ for (unsigned i = 2;
+ i < loop_depth (loop) - max_depth; ++i)
+ {
+ basic_block header = superloop_at_depth (loop, i)->header;
+ rpo_state[bb_to_rpo[header->index]].iterate = false;
+ edge e;
+ edge_iterator ei;
+ FOR_EACH_EDGE (e, ei, header->preds)
+ if (e->flags & EDGE_DFS_BACK)
+ e->flags |= EDGE_EXECUTABLE;
+ }
}
- /* Fixup stmts that became noreturn calls. This may require splitting
- blocks and thus isn't possible during the dominator walk. Do this
- in reverse order so we don't inadvertedly remove a stmt we want to
- fixup by visiting a dominating now noreturn call first. */
- while (!el.to_fixup.is_empty ())
+ /* Go and process all blocks, iterating as necessary. */
+ int idx = 0;
+ uint64_t nblk = 0;
+ do
{
- gimple *stmt = el.to_fixup.pop ();
+ basic_block bb = BASIC_BLOCK_FOR_FN (fn, rpo[idx]);
+
+ /* If the block has incoming backedges remember unwind state. This
+ is required even for non-executable blocks since in irreducible
+ regions we might reach them via the backedge and re-start iterating
+ from there.
+ Note we can individually mark blocks with incoming backedges to
+ not iterate where we then handle PHIs conservatively. We do that
+ heuristically to reduce compile-time for degenerate cases. */
+ if (rpo_state[idx].iterate)
+ {
+ rpo_state[idx].ob_top = obstack_alloc (&vn_tables_obstack, 0);
+ rpo_state[idx].ref_top = last_inserted_ref;
+ rpo_state[idx].phi_top = last_inserted_phi;
+ rpo_state[idx].nary_top = last_inserted_nary;
+ }
+
+ if (!(bb->flags & BB_EXECUTABLE))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Block %d: BB%d found not executable\n",
+ idx, bb->index);
+ idx++;
+ continue;
+ }
if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Processing block %d: BB%d\n", idx, bb->index);
+ nblk++;
+ todo |= process_bb (avail, bb,
+ rpo_state[idx].visited != 0,
+ rpo_state[idx].iterate,
+ iterate, eliminate, do_region, exit_bbs);
+ rpo_state[idx].visited++;
+
+ if (iterate)
{
- fprintf (dump_file, "Fixing up noreturn call ");
- print_gimple_stmt (dump_file, stmt, 0);
+ /* Verify if changed values flow over executable outgoing backedges
+ and those change destination PHI values (that's the thing we
+ can easily verify). Reduce over all such edges to the farthest
+ away PHI. */
+ int iterate_to = -1;
+ edge_iterator ei;
+ edge e;
+ FOR_EACH_EDGE (e, ei, bb->succs)
+ if ((e->flags & (EDGE_DFS_BACK|EDGE_EXECUTABLE))
+ == (EDGE_DFS_BACK|EDGE_EXECUTABLE)
+ && rpo_state[bb_to_rpo[e->dest->index]].iterate)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Looking for changed values of backedge "
+ "%d->%d destination PHIs\n",
+ e->src->index, e->dest->index);
+ vn_context_bb = e->dest;
+ gphi_iterator gsi;
+ for (gsi = gsi_start_phis (e->dest);
+ !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ bool inserted = false;
+ /* While we'd ideally just iterate on value changes
+ we CSE PHIs and do that even across basic-block
+ boundaries. So even hashtable state changes can
+ be important (which is roughly equivalent to
+ PHI argument value changes). To not excessively
+ iterate because of that we track whether a PHI
+ was CSEd to with GF_PLF_1. */
+ bool phival_changed;
+ if ((phival_changed = visit_phi (gsi.phi (),
+ &inserted, false))
+ || (inserted && gimple_plf (gsi.phi (), GF_PLF_1)))
+ {
+ if (!phival_changed
+ && dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "PHI was CSEd and hashtable "
+ "state (changed)\n");
+ int destidx = bb_to_rpo[e->dest->index];
+ if (iterate_to == -1
+ || destidx < iterate_to)
+ iterate_to = destidx;
+ break;
+ }
+ }
+ vn_context_bb = NULL;
+ }
+ if (iterate_to != -1)
+ {
+ do_unwind (&rpo_state[iterate_to], iterate_to,
+ avail, bb_to_rpo);
+ idx = iterate_to;
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Iterating to %d BB%d\n",
+ iterate_to, rpo[iterate_to]);
+ continue;
+ }
}
- if (fixup_noreturn_call (stmt))
- el.el_todo |= TODO_cleanup_cfg;
+ idx++;
+ }
+ while (idx < n);
+
+ /* If statistics or dump file active. */
+ int nex = 0;
+ unsigned max_visited = 1;
+ for (int i = 0; i < n; ++i)
+ {
+ basic_block bb = BASIC_BLOCK_FOR_FN (fn, rpo[i]);
+ if (bb->flags & BB_EXECUTABLE)
+ nex++;
+ statistics_histogram_event (cfun, "RPO block visited times",
+ rpo_state[i].visited);
+ if (rpo_state[i].visited > max_visited)
+ max_visited = rpo_state[i].visited;
+ }
+ unsigned nvalues = 0, navail = 0;
+ for (rpo_elim::rpo_avail_t::iterator i = avail.m_rpo_avail.begin ();
+ i != avail.m_rpo_avail.end (); ++i)
+ {
+ nvalues++;
+ navail += (*i).second.length ();
+ }
+ statistics_counter_event (cfun, "RPO blocks", n);
+ statistics_counter_event (cfun, "RPO blocks visited", nblk);
+ statistics_counter_event (cfun, "RPO blocks executable", nex);
+ statistics_histogram_event (cfun, "RPO iterations", 10*nblk / nex);
+ statistics_histogram_event (cfun, "RPO num values", nvalues);
+ statistics_histogram_event (cfun, "RPO num avail", navail);
+ statistics_histogram_event (cfun, "RPO num lattice",
+ vn_ssa_aux_hash->elements ());
+ if (dump_file && (dump_flags & (TDF_DETAILS|TDF_STATS)))
+ {
+ fprintf (dump_file, "RPO iteration over %d blocks visited %" PRIu64
+ " blocks in total discovering %d executable blocks iterating "
+ "%d.%d times, a block was visited max. %u times\n",
+ n, nblk, nex,
+ (int)((10*nblk / nex)/10), (int)((10*nblk / nex)%10),
+ max_visited);
+ fprintf (dump_file, "RPO tracked %d values available at %d locations "
+ "and %" PRIu64 " lattice elements\n",
+ nvalues, navail, (uint64_t) vn_ssa_aux_hash->elements ());
}
- bool do_eh_cleanup = !bitmap_empty_p (el.need_eh_cleanup);
- bool do_ab_cleanup = !bitmap_empty_p (el.need_ab_cleanup);
+ if (eliminate)
+ {
+ /* When !iterate we already performed elimination during the RPO
+ walk. */
+ if (iterate)
+ {
+ /* Elimination for region-based VN needs to be done within the
+ RPO walk. */
+ gcc_assert (! do_region);
+ /* Note we can't use avail.walk here because that gets confused
+ by the existing availability and it will be less efficient
+ as well. */
+ todo |= eliminate_with_rpo_vn (NULL);
+ }
+ else
+ todo |= avail.eliminate_cleanup (do_region);
+ }
- if (do_eh_cleanup)
- gimple_purge_all_dead_eh_edges (el.need_eh_cleanup);
+ vn_valueize = NULL;
+ rpo_avail = NULL;
- if (do_ab_cleanup)
- gimple_purge_all_dead_abnormal_call_edges (el.need_ab_cleanup);
+ XDELETEVEC (bb_to_rpo);
+ XDELETEVEC (rpo);
- if (do_eh_cleanup || do_ab_cleanup)
- el.el_todo |= TODO_cleanup_cfg;
+ return todo;
+}
- statistics_counter_event (cfun, "Eliminated", el.eliminations);
- statistics_counter_event (cfun, "Insertions", el.insertions);
+/* Region-based entry for RPO VN. Performs value-numbering and elimination
+ on the SEME region specified by ENTRY and EXIT_BBS. */
- return el.el_todo;
+unsigned
+do_rpo_vn (function *fn, edge entry, bitmap exit_bbs)
+{
+ default_vn_walk_kind = VN_WALKREWRITE;
+ unsigned todo = do_rpo_vn (fn, entry, exit_bbs, false, true);
+ free_rpo_vn ();
+ return todo;
}
@@ -6037,17 +6584,21 @@ public:
}; // class pass_fre
unsigned int
-pass_fre::execute (function *)
+pass_fre::execute (function *fun)
{
- unsigned int todo = 0;
+ unsigned todo = 0;
- run_scc_vn (VN_WALKREWRITE);
+ /* At -O[1g] use the cheap non-iterating mode. */
+ calculate_dominance_info (CDI_DOMINATORS);
+ if (optimize > 1)
+ loop_optimizer_init (AVOID_CFG_MODIFICATIONS);
- /* Remove all the redundant expressions. */
- todo |= vn_eliminate (NULL);
+ default_vn_walk_kind = VN_WALKREWRITE;
+ todo = do_rpo_vn (fun, NULL, NULL, optimize > 1, true);
+ free_rpo_vn ();
- scc_vn_restore_ssa_info ();
- free_scc_vn ();
+ if (optimize > 1)
+ loop_optimizer_finalize ();
return todo;
}
@@ -6059,3 +6610,5 @@ make_pass_fre (gcc::context *ctxt)
{
return new pass_fre (ctxt);
}
+
+#undef BB_EXECUTABLE
diff --git a/gcc/tree-ssa-sccvn.h b/gcc/tree-ssa-sccvn.h
index 323c85fde55..ea4efd8e23b 100644
--- a/gcc/tree-ssa-sccvn.h
+++ b/gcc/tree-ssa-sccvn.h
@@ -28,6 +28,18 @@ bool expressions_equal_p (tree, tree);
/* TOP of the VN lattice. */
extern tree VN_TOP;
+/* A predicated value. */
+struct vn_pval
+{
+ vn_pval *next;
+ /* The value of the expression this is attached to is RESULT in
+ case the expression is computed dominated by one of the blocks
+ in valid_dominated_by_p. */
+ tree result;
+ unsigned n;
+ int valid_dominated_by_p[1];
+};
+
/* N-ary operations in the hashtable consist of length operands, an
opcode, and a type. Result is the value number of the operation,
and hashcode is stored to avoid having to calculate it
@@ -36,12 +48,19 @@ extern tree VN_TOP;
typedef struct vn_nary_op_s
{
vn_nary_op_s *next;
+ vn_nary_op_s *unwind_to;
/* Unique identify that all expressions with the same value have. */
unsigned int value_id;
ENUM_BITFIELD(tree_code) opcode : 16;
unsigned length : 16;
hashval_t hashcode;
- tree result;
+ unsigned predicated_values : 1;
+ union {
+ /* If ! predicated_values this is the value of the expression. */
+ tree result;
+ /* If predicated_values this is a list of values of the expression. */
+ vn_pval *values;
+ } u;
tree type;
tree op[1];
} *vn_nary_op_t;
@@ -176,36 +195,23 @@ vn_constant_eq_with_type (tree c1, tree c2)
typedef struct vn_ssa_aux
{
+ /* SSA name this vn_ssa_aux is associated with in the lattice. */
+ tree name;
/* Value number. This may be an SSA name or a constant. */
tree valnum;
/* Statements to insert if needs_insertion is true. */
gimple_seq expr;
- /* Saved SSA name info. */
- tree_ssa_name::ssa_name_info_type info;
-
/* Unique identifier that all expressions with the same value have. */
unsigned int value_id;
- /* SCC information. */
- unsigned int dfsnum;
- unsigned int low;
+ /* Whether the SSA_NAME has been processed at least once. */
unsigned visited : 1;
- unsigned on_sccstack : 1;
-
- /* Whether the SSA_NAME has been value numbered already. This is
- only saying whether visit_use has been called on it at least
- once. It cannot be used to avoid visitation for SSA_NAME's
- involved in non-singleton SCC's. */
- unsigned use_processed : 1;
/* Whether the SSA_NAME has no defining statement and thus an
insertion of such with EXPR as definition is required before
a use can be created of it. */
unsigned needs_insertion : 1;
-
- /* Whether range-info is anti-range. */
- unsigned range_info_anti_range_p : 1;
} *vn_ssa_aux_t;
enum vn_lookup_kind { VN_NOWALK, VN_WALK, VN_WALKREWRITE };
@@ -213,11 +219,7 @@ enum vn_lookup_kind { VN_NOWALK, VN_WALK, VN_WALKREWRITE };
/* Return the value numbering info for an SSA_NAME. */
bool has_VN_INFO (tree);
extern vn_ssa_aux_t VN_INFO (tree);
-extern vn_ssa_aux_t VN_INFO_GET (tree);
tree vn_get_expr_for (tree);
-void run_scc_vn (vn_lookup_kind);
-unsigned int vn_eliminate (bitmap);
-void free_scc_vn (void);
void scc_vn_restore_ssa_info (void);
tree vn_nary_op_lookup (tree, vn_nary_op_t *);
tree vn_nary_op_lookup_stmt (gimple *, vn_nary_op_t *);
@@ -250,55 +252,17 @@ bool value_id_constant_p (unsigned int);
tree fully_constant_vn_reference_p (vn_reference_t);
tree vn_nary_simplify (vn_nary_op_t);
-/* Valueize NAME if it is an SSA name, otherwise just return it. */
-
-static inline tree
-vn_valueize (tree name)
-{
- if (TREE_CODE (name) == SSA_NAME)
- {
- tree tem = VN_INFO (name)->valnum;
- return tem == VN_TOP ? name : tem;
- }
- return name;
-}
+unsigned do_rpo_vn (function *, edge, bitmap);
+void run_rpo_vn (vn_lookup_kind);
+unsigned eliminate_with_rpo_vn (bitmap);
+void free_rpo_vn (void);
-/* Get at the original range info for NAME. */
+/* Valueize NAME if it is an SSA name, otherwise just return it. This hook
+ is initialized by run_scc_vn. */
+extern tree (*vn_valueize) (tree);
-inline range_info_def *
-VN_INFO_RANGE_INFO (tree name)
-{
- return (VN_INFO (name)->info.range_info
- ? VN_INFO (name)->info.range_info
- : SSA_NAME_RANGE_INFO (name));
-}
+/* Context that valueization should operate on. */
+extern basic_block vn_context_bb;
-/* Whether the original range info of NAME is an anti-range. */
-
-inline bool
-VN_INFO_ANTI_RANGE_P (tree name)
-{
- return (VN_INFO (name)->info.range_info
- ? VN_INFO (name)->range_info_anti_range_p
- : SSA_NAME_ANTI_RANGE_P (name));
-}
-
-/* Get at the original range info kind for NAME. */
-
-inline value_range_type
-VN_INFO_RANGE_TYPE (tree name)
-{
- return VN_INFO_ANTI_RANGE_P (name) ? VR_ANTI_RANGE : VR_RANGE;
-}
-
-/* Get at the original pointer info for NAME. */
-
-inline ptr_info_def *
-VN_INFO_PTR_INFO (tree name)
-{
- return (VN_INFO (name)->info.ptr_info
- ? VN_INFO (name)->info.ptr_info
- : SSA_NAME_PTR_INFO (name));
-}
#endif /* TREE_SSA_SCCVN_H */