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Re: [4.2]: Rewrite reassociation
- From: Daniel Berlin <dberlin at dberlin dot org>
- To: GCC Patches <gcc-patches at gcc dot gnu dot org>
- Date: Thu, 08 Sep 2005 10:27:01 -0400
- Subject: Re: [4.2]: Rewrite reassociation
- References: <1126189595.7395.38.camel@dyn9002218190>
Crap, i forgot to attach the patch.
Attached.
On Thu, 2005-09-08 at 10:26 -0400, Daniel Berlin wrote:
> This rewrites the reassociation pass, so that it catches a lot more
> cases, and properly handles recursive expressions. In the process, it
> turns off auto-canonicalization of expressions in get_expr_operands, and
> moves it to DOM, which is the only thing that cared (SPEC/other tests
> show absolutely no difference in performance with or without the
> canonicalization)
>
>
> It fixes a few missed optimization bugs, like PR 15878, 16157, and
> reassoc-2.c.
>
> It's faster than the old reassociation pass, but still could be made
> faster.
>
> It's also got quite a bit of dumping code in it (In fact, it probably
> has more code related to dumping expressions that code that does stuff.
> In part because we have no easy way to print out expressions, etc, in
> the middle of messages like we do with warnings and errors)
>
> I'm posting this patch mainly so i don't lose it before 4.2.
>
> Some of the dumping info is useless, and will be removed before "really"
> submitting it. You could also go down the path of making even better
> decisions about how to rewrite the expressions, as described at the top
> of the file (I've #if 0'd the beginnings of this), but i don't plan on
> doing that.
>
> If someone thinks we want this for 4.1, i'll clean it up.
>
> I've included a bunch of new testcases to make sure we optimize them
> right, and modified ssa-pre-2.c to note that we get an additional
> elimination.
>
> Overall, this causes PRE to be a bit more effective. Over a bootstrap
> of GCC, it eliminates roughly 5% more things than it used to.
>
> (This was also a prelude to fixing PR 23619).
>
>
> Compile time is neutral.
>
> Bootstrapped and regtested on i686-pc-linux-gnu.
>
>
> --Dan
>
2005-09-08 Daniel Berlin <dberlin@dberlin.org>
* Makefile.in (tree-ssa-reassoc.o): Update dependencies.
* passes.c (init_optimization_passes): Move reassoc, add DCE pass
after.
* tree-flow.h (swap_tree_operands): Declare.
* tree-ssa-dom.c (thread_across_edge): Canonicalize condition if
necessary.
(optimize_stmt): Ditto.
(canonicalize_comparison): New function.
* tree-ssa-operands.c (swap_tree_operands): Make external.
(get_expr_operands): Stop auto-canonicalization.
* tree-ssa-reassoc: Rewrite.
Index: Makefile.in
===================================================================
RCS file: /cvs/gcc/gcc/gcc/Makefile.in,v
retrieving revision 1.1537
diff -u -p -r1.1537 Makefile.in
--- Makefile.in 29 Aug 2005 13:52:32 -0000 1.1537
+++ Makefile.in 8 Sep 2005 14:05:19 -0000
@@ -1918,7 +1918,8 @@ tree-ssa-alias.o : tree-ssa-alias.c $(TR
tree-ssa-reassoc.o : tree-ssa-reassoc.c $(TREE_FLOW_H) $(CONFIG_H) \
$(SYSTEM_H) $(TREE_H) $(GGC_H) $(DIAGNOSTIC_H) errors.h $(TIMEVAR_H) \
$(TM_H) coretypes.h $(TREE_DUMP_H) tree-pass.h $(FLAGS_H) tree-iterator.h\
- $(BASIC_BLOCK_H) $(HASHTAB_H) $(TREE_GIMPLE_H) tree-inline.h
+ $(BASIC_BLOCK_H) $(TREE_GIMPLE_H) tree-inline.h vec.h \
+ alloc-pool.h
tree-optimize.o : tree-optimize.c $(TREE_FLOW_H) $(CONFIG_H) $(SYSTEM_H) \
$(RTL_H) $(TREE_H) $(TM_P_H) $(EXPR_H) $(GGC_H) output.h $(DIAGNOSTIC_H) \
$(FLAGS_H) $(TIMEVAR_H) $(TM_H) coretypes.h $(TREE_DUMP_H) toplev.h \
Index: passes.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/passes.c,v
retrieving revision 2.110
diff -u -p -r2.110 passes.c
--- passes.c 20 Aug 2005 16:03:45 -0000 2.110
+++ passes.c 8 Sep 2005 14:05:19 -0000
@@ -524,8 +524,9 @@ init_optimization_passes (void)
which can create arbitrary GIMPLE. */
NEXT_PASS (pass_may_alias);
NEXT_PASS (pass_cse_reciprocals);
- NEXT_PASS (pass_split_crit_edges);
NEXT_PASS (pass_reassoc);
+ NEXT_PASS (pass_dce);
+ NEXT_PASS (pass_split_crit_edges);
NEXT_PASS (pass_pre);
NEXT_PASS (pass_sink_code);
NEXT_PASS (pass_tree_loop);
Index: tree-flow.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/tree-flow.h,v
retrieving revision 2.132
diff -u -p -r2.132 tree-flow.h
--- tree-flow.h 13 Aug 2005 17:28:40 -0000 2.132
+++ tree-flow.h 8 Sep 2005 14:05:19 -0000
@@ -890,4 +890,6 @@ void sort_fieldstack (VEC(fieldoff_s,hea
#include "tree-flow-inline.h"
+void swap_tree_operands (tree, tree *, tree *);
+
#endif /* _TREE_FLOW_H */
Index: tree-ssa-dom.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/tree-ssa-dom.c,v
retrieving revision 2.127
diff -u -p -r2.127 tree-ssa-dom.c
--- tree-ssa-dom.c 2 Aug 2005 00:12:39 -0000 2.127
+++ tree-ssa-dom.c 8 Sep 2005 14:05:19 -0000
@@ -583,6 +583,45 @@ struct tree_opt_pass pass_dominator =
};
+/* Given a stmt CONDSTMT containing a COND_EXPR, canonicalize the
+ COND_EXPR into a canonical form. */
+
+static void
+canonicalize_comparison (tree condstmt)
+{
+ tree cond = COND_EXPR_COND (condstmt);
+ tree op0;
+ tree op1;
+ enum tree_code code = TREE_CODE (cond);
+
+ if (!COMPARISON_CLASS_P (cond))
+ return;
+
+ op0 = TREE_OPERAND (cond, 0);
+ op1 = TREE_OPERAND (cond, 1);
+
+ /* If it would be profitable to swap the operands, then do so to
+ canonicalize the statement, enabling better optimization.
+
+ By placing canonicalization of such expressions here we
+ transparently keep statements in canonical form, even
+ when the statement is modified. */
+ if (tree_swap_operands_p (op0, op1, false))
+ {
+ /* For relationals we need to swap the operands
+ and change the code. */
+ if (code == LT_EXPR
+ || code == GT_EXPR
+ || code == LE_EXPR
+ || code == GE_EXPR)
+ {
+ TREE_SET_CODE (cond, swap_tree_comparison (code));
+ swap_tree_operands (condstmt,
+ &TREE_OPERAND (cond, 0),
+ &TREE_OPERAND (cond, 1));
+ }
+ }
+}
/* We are exiting E->src, see if E->dest ends with a conditional
jump which has a known value when reached via E.
@@ -760,7 +799,10 @@ thread_across_edge (struct dom_walk_data
/* Now temporarily cprop the operands and try to find the resulting
expression in the hash tables. */
if (TREE_CODE (stmt) == COND_EXPR)
- cond = COND_EXPR_COND (stmt);
+ {
+ canonicalize_comparison (stmt);
+ cond = COND_EXPR_COND (stmt);
+ }
else if (TREE_CODE (stmt) == GOTO_EXPR)
cond = GOTO_DESTINATION (stmt);
else
@@ -2880,7 +2922,10 @@ optimize_stmt (struct dom_walk_data *wal
bool may_have_exposed_new_symbols = false;
old_stmt = stmt = bsi_stmt (si);
-
+
+ if (TREE_CODE (stmt) == COND_EXPR)
+ canonicalize_comparison (stmt);
+
update_stmt_if_modified (stmt);
ann = stmt_ann (stmt);
opt_stats.num_stmts++;
Index: tree-ssa-operands.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/tree-ssa-operands.c,v
retrieving revision 2.100
diff -u -p -r2.100 tree-ssa-operands.c
--- tree-ssa-operands.c 2 Aug 2005 11:46:44 -0000 2.100
+++ tree-ssa-operands.c 8 Sep 2005 14:05:19 -0000
@@ -1165,7 +1165,7 @@ create_ssa_artficial_load_stmt (tree new
delink_imm_use (use_p);
}
-static void
+void
swap_tree_operands (tree stmt, tree *exp0, tree *exp1)
{
tree op0, op1;
@@ -1206,7 +1206,6 @@ swap_tree_operands (tree stmt, tree *exp
*exp1 = op0;
}
-
/* Recursively scan the expression pointed to by EXPR_P in statement referred
to by INFO. FLAGS is one of the OPF_* constants modifying how to interpret
the operands found. */
@@ -1416,39 +1415,6 @@ get_expr_operands (tree stmt, tree *expr
case ASSERT_EXPR:
do_binary:
{
- tree op0 = TREE_OPERAND (expr, 0);
- tree op1 = TREE_OPERAND (expr, 1);
-
- /* If it would be profitable to swap the operands, then do so to
- canonicalize the statement, enabling better optimization.
-
- By placing canonicalization of such expressions here we
- transparently keep statements in canonical form, even
- when the statement is modified. */
- if (tree_swap_operands_p (op0, op1, false))
- {
- /* For relationals we need to swap the operands
- and change the code. */
- if (code == LT_EXPR
- || code == GT_EXPR
- || code == LE_EXPR
- || code == GE_EXPR)
- {
- TREE_SET_CODE (expr, swap_tree_comparison (code));
- swap_tree_operands (stmt,
- &TREE_OPERAND (expr, 0),
- &TREE_OPERAND (expr, 1));
- }
-
- /* For a commutative operator we can just swap the operands. */
- else if (commutative_tree_code (code))
- {
- swap_tree_operands (stmt,
- &TREE_OPERAND (expr, 0),
- &TREE_OPERAND (expr, 1));
- }
- }
-
get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags);
get_expr_operands (stmt, &TREE_OPERAND (expr, 1), flags);
return;
Index: tree-ssa-reassoc.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/tree-ssa-reassoc.c,v
retrieving revision 2.6
diff -u -p -r2.6 tree-ssa-reassoc.c
--- tree-ssa-reassoc.c 26 Jul 2005 13:53:51 -0000 2.6
+++ tree-ssa-reassoc.c 8 Sep 2005 14:05:19 -0000
@@ -33,249 +33,220 @@ Boston, MA 02110-1301, USA. */
#include "tree-gimple.h"
#include "tree-dump.h"
#include "timevar.h"
-#include "hashtab.h"
#include "tree-iterator.h"
#include "tree-pass.h"
+#include "alloc-pool.h"
+#include "vec.h"
+#include "langhooks.h"
-/* This is a simple global reassociation pass that uses a combination
- of heuristics and a hashtable to try to expose more operations to
- CSE.
-
- The basic idea behind the heuristic is to rank expressions by
- depth of the computation tree and loop depth, and try to produce
- expressions consisting of small rank operations, as they are more
- likely to reoccur. In addition, we use a hashtable to try to see
- if we can transpose an operation into something we have seen
- before.
-
- Note that the way the hashtable is structured will sometimes find
- matches that will not expose additional redundancies, since it is
- not unwound as we traverse back up one branch of the dominator
- tree and down another. However, the cost of improving this is
- probably not worth the additional benefits it will bring. */
+/* This is a simple global reassociation pass. It is, in part, based
+ on the LLVM pass of the same name (They do some things more/less
+ than we do, in different orders, etc).
-/* Statistics */
-static struct
-{
- int reassociated_by_rank;
- int reassociated_by_match;
-} reassociate_stats;
+ It consists of five steps:
+ 1. Breaking up subtract operations into addition + negate, where
+ it would promote the reassociation of adds.
+ 2. Left linearization of the expression trees, so that (A+B)+(C+D)
+ becomes (((A+B)+C)+D), which is easier for us to rewrite later.
+ During linearization, we place the operands of the binary
+ expressions into the a vector of operand_entry_t
-/* Seen binary operator hashtable. */
-static htab_t seen_binops;
+ 3. Optimization of the operand lists, eliminating things like a +
+ -a, a & a, etc.
-/* Binary operator struct. */
+ 4. Rewrite the expression trees we linearized and optimized so
+ they are in proper rank order.
-typedef struct seen_binop_d
-{
- tree op1;
- tree op2;
-} *seen_binop_t;
+ 5. Repropagate negates, as nothing else will clean it up ATM.
-/* Return a SEEN_BINOP_T if we have seen an associative binary
- operator with OP1 and OP2 in it. */
+ A bit of theory on #4, since nobody seems to write anything down
+ about why it makes sense to do it the way they do it:
-static seen_binop_t
-find_seen_binop (tree op1, tree op2)
-{
- void **slot;
- struct seen_binop_d sbd;
- sbd.op1 = op1;
- sbd.op2 = op2;
- slot = htab_find_slot (seen_binops, &sbd, NO_INSERT);
- if (!slot)
- return NULL;
- return ((seen_binop_t) *slot);
-}
+ We could do this much nicer theoretically, but don't (for reasons
+ explained after how to do it theoretically nice :P).
-/* Insert a binary operator consisting of OP1 and OP2 into the
- SEEN_BINOP table. */
+ In order to promote the most redundancy elimination, you want
+ binary expressions whose operands are the same rank (or
+ preferrably, the same value) exposed to the redundancy eliminator,
+ for possible elimination.
-static void
-insert_seen_binop (tree op1, tree op2)
-{
- void **slot;
- seen_binop_t new_pair = xmalloc (sizeof (*new_pair));
- new_pair->op1 = op1;
- new_pair->op2 = op2;
- slot = htab_find_slot (seen_binops, new_pair, INSERT);
- if (*slot != NULL)
- free (*slot);
- *slot = new_pair;
-}
+ So the way to do this if we really cared, is to build the new op
+ tree from the leaves to the roots, merging as you go, and putting the
+ new op on the end of the worklist, until you are left with one
+ thing on the worklist.
-/* Return the hash value for a seen binop structure pointed to by P.
- Because all the binops we consider are associative, we just add the
- hash value for op1 and op2. */
+ IE if you have to rewrite the following set of operands (listed with
+ rank in parentheses), with opcode PLUS_EXPR:
-static hashval_t
-seen_binop_hash (const void *p)
-{
- const seen_binop_t sb = (seen_binop_t) p;
- return iterative_hash_expr (sb->op1, 0) + iterative_hash_expr (sb->op2, 0);
-}
+ a (1), b (1), c (1), d (2), e (2)
-/* Return true if two seen binop structures pointed to by P1 and P2 are equal.
- We have to check the operators both ways because we don't know what
- order they appear in the table. */
-static int
-seen_binop_eq (const void *p1, const void *p2)
-{
- const seen_binop_t sb1 = (seen_binop_t) p1;
- const seen_binop_t sb2 = (seen_binop_t) p2;
- return (sb1->op1 == sb2->op1 && sb1->op2 == sb2->op2)
- || (sb1->op2 == sb2->op1 && sb1->op1 == sb2->op2);
-}
+We start with our merge worklist empty, and the ops list with all of
+those on it.
+
+You want to first merge all leaves of the same rank, as much as
+possible.
+
+So first build a binary op of
+
+mergetmp = a + b, and put "mergetmp" on the merge worklist.
+
+Because there is no three operand form of PLUS_EXPR, c is not going to
+be exposed to redundancy elimination as a rank 1 operand.
+
+So you might as well throw it on the merge worklist (you could also
+consider it to now be a rank two operand, and merge it with d and e,
+but in this case, you then have evicted e from a binary op. So at
+least in this situation, you can't win.)
+
+Then build a binary op of d + e
+mergetmp2 = d + e
+
+and put mergetmp2 on the merge worklist.
+
+so merge worklist = {mergetmp, c, mergetmp2}
+
+Continue building binary ops of these operations until you have only
+one operation left on the worklist.
+
+So we have
+
+build binary op
+mergetmp3 = mergetmp + c
-/* Value rank structure. */
+worklist = {mergetmp2, mergetmp3}
-typedef struct valrank_d
+mergetmp4 = mergetmp2 + mergetmp3
+
+worklist = {mergetmp4}
+
+because we have one operation left, we can now just set the original
+statement equal to the result of that operation.
+
+This will at least expose a + b and d + e to redundancy elimination
+as binary operations.
+
+For extra points, you can reuse the old statements to build the
+mergetmps, since you shouldn't run out.
+
+
+So why don't we do this?
+
+Because it's expensive, and rarely will help. Most trees we are
+reassociating have 3 or less ops. If they have 2 ops, they already
+will be written into a nice single binary op. If you have 3 ops, a
+single simple check suffices to tell you whether the first two are of the
+same rank. If so, you know to order it
+
+mergetmp = op1 + op2
+newstmt = mergetmp + op3
+
+instead of
+mergetmp = op2 + op3
+newstmt = mergetmp + op1
+
+If all three are of the same rank, you can't expose them all in a
+single binary operator anyway, so the above is *still* the best you
+can do.
+
+Thus, this is what we do. When we have three ops left, we check to see
+what order to put them in, and call it a day. As a nod to vector sum
+reduction, we check if any of ops are a really a phi node that is a
+destructive update for the associating op, and keep the destructive
+update together for vector sum reduction recognition. */
+
+
+/* Statistics */
+static struct
+{
+ int linearized;
+ int constants_eliminated;
+ int ops_eliminated;
+ int rewritten;
+} reassociate_stats;
+
+/* Operator, rank pair. */
+typedef struct operand_entry
{
- tree e;
- unsigned int rank;
-} *valrank_t;
+ unsigned int rank;
+ tree op;
+} *operand_entry_t;
+
+static alloc_pool operand_entry_pool;
+
/* Starting rank number for a given basic block, so that we can rank
operations using unmovable instructions in that BB based on the bb
depth. */
static unsigned int *bb_rank;
-/* Value rank hashtable. */
-static htab_t value_rank;
+/* Operand->rank hashtable. */
+static htab_t operand_rank;
-/* Look up the value rank structure for expression E. */
+/* Look up the operand rank structure for expression E. */
-static valrank_t
-find_value_rank (tree e)
+static operand_entry_t
+find_operand_rank (tree e)
{
void **slot;
- struct valrank_d vrd;
- vrd.e = e;
- slot = htab_find_slot (value_rank, &vrd, NO_INSERT);
+ struct operand_entry vrd;
+
+ vrd.op = e;
+ slot = htab_find_slot (operand_rank, &vrd, NO_INSERT);
if (!slot)
return NULL;
- return ((valrank_t) *slot);
+ return ((operand_entry_t) *slot);
}
-/* Insert {E,RANK} into the value rank hashtable. */
+/* Insert {E,RANK} into the operand rank hashtable. */
static void
-insert_value_rank (tree e, unsigned int rank)
+insert_operand_rank (tree e, unsigned int rank)
{
void **slot;
- valrank_t new_pair = xmalloc (sizeof (*new_pair));
- new_pair->e = e;
+ operand_entry_t new_pair = pool_alloc (operand_entry_pool);
+
+ new_pair->op = e;
new_pair->rank = rank;
- slot = htab_find_slot (value_rank, new_pair, INSERT);
+ slot = htab_find_slot (operand_rank, new_pair, INSERT);
gcc_assert (*slot == NULL);
*slot = new_pair;
-
}
-
-/* Return the hash value for a value rank structure */
+/* Return the hash value for a operand rank structure */
static hashval_t
-valrank_hash (const void *p)
+operand_entry_hash (const void *p)
{
- const valrank_t vr = (valrank_t) p;
- return iterative_hash_expr (vr->e, 0);
+ const operand_entry_t vr = (operand_entry_t) p;
+ return iterative_hash_expr (vr->op, 0);
}
-/* Return true if two value rank structures are equal. */
+/* Return true if two operand rank structures are equal. */
static int
-valrank_eq (const void *p1, const void *p2)
-{
- const valrank_t vr1 = (valrank_t) p1;
- const valrank_t vr2 = (valrank_t) p2;
- return vr1->e == vr2->e;
-}
-
-
-/* Initialize the reassociation pass. */
-
-static void
-init_reassoc (void)
+operand_entry_eq (const void *p1, const void *p2)
{
- int i;
- unsigned int rank = 2;
-
- tree param;
- int *bbs = xmalloc ((last_basic_block + 1) * sizeof (int));
-
- memset (&reassociate_stats, 0, sizeof (reassociate_stats));
-
- /* Reverse RPO (Reverse Post Order) will give us something where
- deeper loops come later. */
- flow_reverse_top_sort_order_compute (bbs);
- bb_rank = xcalloc (last_basic_block + 1, sizeof (unsigned int));
- value_rank = htab_create (511, valrank_hash,
- valrank_eq, free);
- seen_binops = htab_create (511, seen_binop_hash,
- seen_binop_eq, free);
-
- /* Give each argument a distinct rank. */
- for (param = DECL_ARGUMENTS (current_function_decl);
- param;
- param = TREE_CHAIN (param))
- {
- if (default_def (param) != NULL)
- {
- tree def = default_def (param);
- insert_value_rank (def, ++rank);
- }
- }
- /* Give the chain decl a distinct rank. */
- if (cfun->static_chain_decl != NULL)
- {
- tree def = default_def (cfun->static_chain_decl);
- if (def != NULL)
- insert_value_rank (def, ++rank);
- }
-
- /* Set up rank for each BB */
- for (i = 0; i < n_basic_blocks; i++)
- bb_rank[bbs[i]] = ++rank << 16;
-
- free (bbs);
- calculate_dominance_info (CDI_DOMINATORS);
-
+ const operand_entry_t vr1 = (operand_entry_t) p1;
+ const operand_entry_t vr2 = (operand_entry_t) p2;
+ return vr1->op == vr2->op;
}
-/* Cleanup after the reassociation pass, and print stats if
- requested. */
-
-static void
-fini_reassoc (void)
-{
-
- if (dump_file && (dump_flags & TDF_STATS))
- {
- fprintf (dump_file, "Reassociation stats:\n");
- fprintf (dump_file, "Reassociated by rank: %d\n", reassociate_stats.reassociated_by_rank);
- fprintf (dump_file, "Reassociated by match: %d\n", reassociate_stats.reassociated_by_match);
- }
- htab_delete (value_rank);
- htab_delete (seen_binops);
- free (bb_rank);
-}
/* Given an expression E, return the rank of the expression. */
static unsigned int
get_rank (tree e)
{
- valrank_t vr;
+ operand_entry_t vr;
- /* Constants have rank 0. */
+ /* Constants have rank 0. */
if (is_gimple_min_invariant (e))
return 0;
-
+
/* SSA_NAME's have the rank of the expression they are the result
of.
For globals and uninitialized values, the rank is 0.
@@ -290,24 +261,24 @@ get_rank (tree e)
if (TREE_CODE (e) == SSA_NAME)
{
tree stmt;
- tree rhs;
+ tree rhs;
unsigned int rank, maxrank;
int i;
-
+
if (TREE_CODE (SSA_NAME_VAR (e)) == PARM_DECL
&& e == default_def (SSA_NAME_VAR (e)))
- return find_value_rank (e)->rank;
-
+ return find_operand_rank (e)->rank;
+
stmt = SSA_NAME_DEF_STMT (e);
if (bb_for_stmt (stmt) == NULL)
return 0;
-
+
if (TREE_CODE (stmt) != MODIFY_EXPR
|| !ZERO_SSA_OPERANDS (stmt, SSA_OP_VIRTUAL_DEFS))
return bb_rank[bb_for_stmt (stmt)->index];
/* If we already have a rank for this expression, use that. */
- vr = find_value_rank (e);
+ vr = find_operand_rank (e);
if (vr)
return vr->rank;
@@ -318,24 +289,25 @@ get_rank (tree e)
rhs = TREE_OPERAND (stmt, 1);
if (TREE_CODE_LENGTH (TREE_CODE (rhs)) == 0)
rank = MAX (rank, get_rank (rhs));
- else
+ else
{
- for (i = 0;
- i < TREE_CODE_LENGTH (TREE_CODE (rhs))
+ for (i = 0;
+ i < TREE_CODE_LENGTH (TREE_CODE (rhs))
&& TREE_OPERAND (rhs, i)
- && rank != maxrank; i++)
+ && rank != maxrank;
+ i++)
rank = MAX(rank, get_rank (TREE_OPERAND (rhs, i)));
}
-
+
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, "Rank for ");
print_generic_expr (dump_file, e, 0);
fprintf (dump_file, " is %d\n", (rank + 1));
}
-
+
/* Note the rank in the hashtable so we don't recompute it. */
- insert_value_rank (e, (rank + 1));
+ insert_operand_rank (e, (rank + 1));
return (rank + 1);
}
@@ -343,282 +315,1249 @@ get_rank (tree e)
return 0;
}
+DEF_VEC_P(operand_entry_t);
+DEF_VEC_ALLOC_P(operand_entry_t, heap);
+
+/* We want integer ones to end up last no matter what, since they are
+ the ones we can do the most with. */
+#define INTEGER_CONST_TYPE 1 << 3
+#define FLOAT_CONST_TYPE 1 << 2
+#define OTHER_CONST_TYPE 1 << 1
+
+/* Classify an invariant tree into integer, float, or other, so that
+ we can sort them to be near other constants of the same type. */
+static inline int
+constant_type (tree t)
+{
+ if (INTEGRAL_TYPE_P (TREE_TYPE (t)))
+ return INTEGER_CONST_TYPE;
+ else if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (t)))
+ return FLOAT_CONST_TYPE;
+ else
+ return OTHER_CONST_TYPE;
+}
+
+/* qsort comparison function to sort operand entries PA and PB by rank
+ so that the sorted array is ordered by rank in decreasing order. */
+static int
+sort_by_operand_rank (const void *pa, const void *pb)
+{
+ const operand_entry_t oea = *(const operand_entry_t *)pa;
+ const operand_entry_t oeb = *(const operand_entry_t *)pb;
+
+ /* It's nicer for optimize_expression if constants that are likely
+ to fold when added/multiplied//whatever are put next to each
+ other. Since all constants have rank 0, order them by type. */
+ if (oeb->rank == 0 && oea->rank == 0)
+ return constant_type (oeb->op) - constant_type (oea->op);
+
+ /* Lastly, make sure the versions that are the same go next to each
+ other. We use SSA_NAME_VERSION because it's stable. */
+ if ((oeb->rank - oea->rank == 0)
+ && TREE_CODE (oea->op) == SSA_NAME
+ && TREE_CODE (oeb->op) == SSA_NAME)
+ return SSA_NAME_VERSION (oeb->op) - SSA_NAME_VERSION (oea->op);
+
+ return oeb->rank - oea->rank;
+}
+
+/* Add an operand entry to *OPS for the tree operand OP. */
+
+static void
+add_to_ops_vec (VEC(operand_entry_t, heap) **ops, tree op)
+{
+ operand_entry_t oe = pool_alloc (operand_entry_pool);
+
+ oe->op = op;
+ oe->rank = get_rank (op);
+ VEC_safe_push (operand_entry_t, heap, *ops, oe);
+}
-/* Decide whether we should transpose RHS and some operand of
- LHSDEFOP.
- If yes, then return true and set TAKEOP to the operand number of LHSDEFOP to
- switch RHS for.
- Otherwise, return false. */
+/* Return true if STMT is reassociable operation containing a binary
+ operation with tree code CODE. */
static bool
-should_transpose (tree rhs ATTRIBUTE_UNUSED,
- unsigned int rhsrank,
- tree lhsdefop, unsigned int *takeop)
-{
- /* Attempt to expose the low ranked
- arguments to CSE if we have something like:
- a = <rank 2> + c (rank 1)
- b = a (rank 3) + d (rank 1)
- We want to transform this into:
- a = c + d
- b = <rank 2> + <rank 3>
-
- The op finding part wouldn't be necessary if
- we could swap the operands above and not have
- update_stmt change them back on us.
- */
- unsigned int lowrankop;
- unsigned int lowrank;
- unsigned int highrank;
- unsigned int highrankop;
- unsigned int temp;
-
- lowrankop = 0;
- *takeop = 1;
- lowrank = get_rank (TREE_OPERAND (lhsdefop, 0));
- temp = get_rank (TREE_OPERAND (lhsdefop, 1));
- highrank = temp;
- highrankop = 1;
- if (temp < lowrank)
- {
- lowrankop = 1;
- highrankop = 0;
- *takeop = 0;
- highrank = lowrank;
- lowrank = temp;
- }
-
- /* If highrank == lowrank, then we had something
- like:
- a = <rank 1> + <rank 1>
- already, so there is no guarantee that
- swapping our argument in is going to be
- better.
- If we run reassoc twice, we could probably
- have a flag that switches this behavior on,
- so that we try once without it, and once with
- it, so that redundancy elimination sees it
- both ways.
- */
-
- if (lowrank == rhsrank && highrank != lowrank)
+is_reassociable_op (tree stmt, enum tree_code code)
+{
+ if (!IS_EMPTY_STMT (stmt)
+ && TREE_CODE (stmt) == MODIFY_EXPR
+ && TREE_CODE (TREE_OPERAND (stmt, 1)) == code
+ && has_single_use (TREE_OPERAND (stmt, 0)))
return true;
-
- /* Also, see if the LHS's high ranked op should be switched with our
- RHS simply because it is greater in rank than our current RHS. */
- if (TREE_CODE (TREE_OPERAND (lhsdefop, highrankop)) == SSA_NAME)
- {
- tree iop = SSA_NAME_DEF_STMT (TREE_OPERAND (lhsdefop, highrankop));
- if (TREE_CODE (iop) == MODIFY_EXPR)
- iop = TREE_OPERAND (iop, 1);
- if (TREE_CODE (iop) == TREE_CODE (lhsdefop))
- *takeop = 1;
- if (rhsrank < get_rank (TREE_OPERAND (lhsdefop, *takeop)))
- return true;
- }
-
return false;
}
-/* Attempt to reassociate the associative binary operator BEXPR, which
- is in the statement pointed to by CURRBSI. Return true if we
- changed the statement. */
+
+/* Given NAME, if NAME is defined by a unary operation OPCODE, return the
+ operand of the negate operation. Otherwise, return NULL. */
+
+static tree
+get_unary_op (tree name, enum tree_code opcode)
+{
+ tree stmt = SSA_NAME_DEF_STMT (name);
+ tree rhs;
+
+ if (TREE_CODE (stmt) != MODIFY_EXPR)
+ return NULL_TREE;
+
+ rhs = TREE_OPERAND (stmt, 1);
+ if (TREE_CODE (rhs) == opcode)
+ return TREE_OPERAND (rhs, 0);
+ return NULL_TREE;
+}
+
+/* If CURR and LAST are a pair of ops that OPCODE allows us to
+ eliminate through equivalences, do so, remove them from OPS, and
+ return true. Otherwise, return false. */
static bool
-reassociate_expr (tree bexpr, block_stmt_iterator *currbsi)
+eliminate_duplicate_pair (enum tree_code opcode,
+ VEC (operand_entry_t, heap) **ops,
+ bool *all_done,
+ unsigned int i,
+ operand_entry_t curr,
+ operand_entry_t last)
{
- tree lhs = TREE_OPERAND (bexpr, 0);
- tree rhs = TREE_OPERAND (bexpr, 1);
- tree lhsdef;
- tree lhsi;
- bool changed = false;
- unsigned int lhsrank = get_rank (lhs);
- unsigned int rhsrank = get_rank (rhs);
-
- /* If unsafe math optimizations we can do reassociation for non-integral
- types. */
- if ((!INTEGRAL_TYPE_P (TREE_TYPE (lhs))
- || !INTEGRAL_TYPE_P (TREE_TYPE (rhs)))
- && (!SCALAR_FLOAT_TYPE_P (TREE_TYPE (rhs))
- || !SCALAR_FLOAT_TYPE_P (TREE_TYPE(lhs))
- || !flag_unsafe_math_optimizations))
- return false;
-
- /* We want the greater ranked operand to be our "LHS" for simplicity
- sake. There is no point in actually modifying the expression, as
- update_stmt will simply resort the operands anyway. */
- if (lhsrank < rhsrank)
+
+ /* If we have two of the same op, and the opcode is & or |, we can
+ eliminate one of them.
+ If we have two of the same op, and the opcode is ^, we can
+ eliminate both of them. */
+
+ if (last && last->op == curr->op)
{
- tree temp;
- unsigned int temp1;
- temp = lhs;
- lhs = rhs;
- rhs = temp;
- temp1 = lhsrank;
- lhsrank = rhsrank;
- rhsrank = temp1;
- }
-
- /* If the high ranked operand is an SSA_NAME, and the binary
- operator is not something we've already seen somewhere else
- (i.e., it may be redundant), attempt to reassociate it.
-
- We can't reassociate expressions unless the expression we are
- going to reassociate with is only used in our current expression,
- or else we may screw up other computations, like so:
-
- a = b + c
- e = a + d
-
- g = a + f
-
- We cannot reassociate and rewrite the "a = ..." ,
- because that would change the value of the computation of
- "g = a + f". */
- if (TREE_CODE (lhs) == SSA_NAME && !find_seen_binop (lhs, rhs))
- {
- lhsdef = SSA_NAME_DEF_STMT (lhs);
- if (TREE_CODE (lhsdef) == MODIFY_EXPR)
- {
- lhsi = TREE_OPERAND (lhsdef, 1);
- if (TREE_CODE (lhsi) == TREE_CODE (bexpr))
- {
- use_operand_p use;
- tree usestmt;
- if (single_imm_use (lhs, &use, &usestmt))
- {
- unsigned int takeop = 0;
- unsigned int otherop = 1;
- bool foundmatch = false;
- bool foundrank = false;
-
- /* If we can easily transpose this into an operation
- we've already seen, let's do that.
- otherwise, let's try to expose low ranked ops to
- CSE. */
- if (find_seen_binop (TREE_OPERAND (lhsi, 1), rhs))
- {
- takeop = 0;
- otherop = 1;
- foundmatch = true;
- }
- else if (find_seen_binop (TREE_OPERAND (lhsi, 0),
- rhs))
- {
- takeop = 1;
- otherop = 0;
- foundmatch = true;
- }
- else if (should_transpose (rhs, rhsrank, lhsi,
- &takeop))
- {
- foundrank = true;
- }
- if (foundmatch || foundrank)
- {
- block_stmt_iterator lhsbsi = bsi_for_stmt (lhsdef);
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "Reassociating by %s\n",
- foundmatch ? "match" : "rank");
- fprintf (dump_file, "Before LHS:");
- print_generic_stmt (dump_file, lhsi, 0);
- fprintf (dump_file, "Before curr expr:");
- print_generic_stmt (dump_file, bexpr, 0);
- }
- TREE_OPERAND (bexpr, 0) = TREE_OPERAND (lhsi, takeop);
- TREE_OPERAND (lhsi, takeop) = rhs;
- TREE_OPERAND (bexpr, 1) = TREE_OPERAND (lhsdef, 0);
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "After LHS:");
- print_generic_stmt (dump_file, lhsi, 0);
- fprintf (dump_file, "After curr expr:");
- print_generic_stmt (dump_file, bexpr, 0);
- }
- bsi_move_before (&lhsbsi, currbsi);
- update_stmt (lhsdef);
- update_stmt (bsi_stmt (*currbsi));
- lhsbsi = bsi_for_stmt (lhsdef);
- update_stmt (bsi_stmt (lhsbsi));
-
- /* If update_stmt didn't reorder our operands,
- we'd like to recurse on the expression we
- just reassociated and reassociate it
- top-down, exposing further opportunities.
- Unfortunately, update_stmt does reorder them,
- so we can't do this cheaply. */
- if (!foundmatch)
- reassociate_stats.reassociated_by_rank++;
- else
- reassociate_stats.reassociated_by_match++;
- return true;
- }
- }
+ switch (opcode)
+ {
+ case BIT_IOR_EXPR:
+ case BIT_AND_EXPR:
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Equivalence: ");
+ print_generic_expr (dump_file, curr->op, 0);
+ fprintf (dump_file, " [&|] ");
+ print_generic_expr (dump_file, last->op, 0);
+ fprintf (dump_file, " -> ");
+ print_generic_stmt (dump_file, last->op, 0);
+ }
+
+ VEC_ordered_remove (operand_entry_t, *ops, i);
+ reassociate_stats.ops_eliminated ++;
+
+ return true;
+
+ case BIT_XOR_EXPR:
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Equivalence: ");
+ print_generic_expr (dump_file, curr->op, 0);
+ fprintf (dump_file, " ^ ");
+ print_generic_expr (dump_file, last->op, 0);
+ fprintf (dump_file, " -> nothing\n");
+ }
+
+ reassociate_stats.ops_eliminated += 2;
+
+ if (VEC_length (operand_entry_t, *ops) == 2)
+ {
+ VEC_free (operand_entry_t, heap, *ops);
+ *ops = NULL;
+ add_to_ops_vec (ops, build_int_cst (TREE_TYPE (last->op), 0));
+ *all_done = true;
+ }
+ else
+ {
+ VEC_ordered_remove (operand_entry_t, *ops, i-1);
+ VEC_ordered_remove (operand_entry_t, *ops, i-1);
}
+
+ return true;
+
+ default:
+ break;
}
}
- return changed;
+ return false;
}
-/* Reassociate expressions in basic block BB and its dominator as
- children , return true if any
- expressions changed. */
+/* If OPCODE is PLUS_EXPR, CURR->OP is really a negate expression,
+ look in OPS for a corresponding positive operation to cancel it
+ out. If we find one, remove the other from OPS, replace
+ OPS[CURRINDEX] with 0, and return true. Otherwise, return
+ false. */
static bool
-reassociate_bb (basic_block bb)
+eliminate_plus_minus_pair (enum tree_code opcode,
+ VEC (operand_entry_t, heap) **ops,
+ unsigned int currindex,
+ operand_entry_t curr)
{
- bool changed = false;
- block_stmt_iterator bsi;
- basic_block son;
+ tree negateop;
+ unsigned int i;
+ operand_entry_t oe;
- for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
+ if (opcode != PLUS_EXPR || TREE_CODE (curr->op) != SSA_NAME)
+ return false;
+
+ negateop = get_unary_op (curr->op, NEGATE_EXPR);
+ if (negateop == NULL_TREE)
+ return false;
+
+ /* Any non-negated version will have a rank that is one less than
+ the current rank. So once we hit those ranks, if we don't find
+ one, we can stop. */
+
+ for (i = currindex;
+ VEC_iterate (operand_entry_t, *ops, i, oe) && oe->rank >= curr->rank - 1 ;
+ i++)
{
- tree stmt = bsi_stmt (bsi);
-
- if (TREE_CODE (stmt) == MODIFY_EXPR)
+ if (oe->op == negateop && i != currindex)
{
- tree rhs = TREE_OPERAND (stmt, 1);
- if (associative_tree_code (TREE_CODE (rhs)))
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
{
- if (reassociate_expr (rhs, &bsi))
- {
- changed = true;
- update_stmt (stmt);
- }
- insert_seen_binop (TREE_OPERAND (rhs, 0),
- TREE_OPERAND (rhs, 1));
+ fprintf (dump_file, "Equivalence: ");
+ print_generic_expr (dump_file, negateop, 0);
+ fprintf (dump_file, " + -");
+ print_generic_expr (dump_file, oe->op, 0);
+ fprintf (dump_file, " -> 0\n");
}
+
+ VEC_ordered_remove (operand_entry_t, *ops, i);
+ add_to_ops_vec (ops, build_int_cst (TREE_TYPE (oe->op), 0));
+ VEC_ordered_remove (operand_entry_t, *ops, currindex);
+ reassociate_stats.ops_eliminated ++;
+
+ return true;
}
}
- for (son = first_dom_son (CDI_DOMINATORS, bb);
- son;
- son = next_dom_son (CDI_DOMINATORS, son))
- {
- changed |= reassociate_bb (son);
- }
- return changed;
+
+ return false;
}
-
+/* If OPCODE is BIT_IOR_EXPR, BIT_AND_EXPR, and, CURR->OP is really a
+ bitwise not expression, look in OPS for a corresponding operand to
+ cancel it out. If we find one, remove the other from OPS, replace
+ OPS[CURRINDEX] with 0, and return true. Otherwise, return
+ false. */
+
static bool
-do_reassoc (void)
-{
- bool changed = false;
-
- changed = reassociate_bb (ENTRY_BLOCK_PTR);
+eliminate_not_pairs (enum tree_code opcode,
+ VEC (operand_entry_t, heap) **ops,
+ unsigned int currindex,
+ operand_entry_t curr)
+{
+ tree notop;
+ unsigned int i;
+ operand_entry_t oe;
+
+ if ((opcode != BIT_IOR_EXPR && opcode != BIT_AND_EXPR)
+ || TREE_CODE (curr->op) != SSA_NAME)
+ return false;
+
+ notop = get_unary_op (curr->op, BIT_NOT_EXPR);
+ if (notop == NULL_TREE)
+ return false;
+
+ /* Any non-not version will have a rank that is one less than
+ the current rank. So once we hit those ranks, if we don't find
+ one, we can stop. */
+
+ for (i = currindex;
+ VEC_iterate (operand_entry_t, *ops, i, oe) && oe->rank >= curr->rank - 1 ;
+ i++)
+ {
+ if (oe->op == notop && i != currindex)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Equivalence: ");
+ print_generic_expr (dump_file, notop, 0);
+ if (opcode == BIT_AND_EXPR)
+ fprintf (dump_file, " & ~");
+ else if (opcode == BIT_IOR_EXPR)
+ fprintf (dump_file, " | ~");
+ print_generic_expr (dump_file, oe->op, 0);
+ if (opcode == BIT_AND_EXPR)
+ fprintf (dump_file, " -> 0\n");
+ else if (opcode == BIT_IOR_EXPR)
+ fprintf (dump_file, " -> -1\n");
+ }
- return changed;
+ if (opcode == BIT_AND_EXPR)
+ oe->op = build_int_cst (TREE_TYPE (oe->op), 0);
+ else if (opcode == BIT_IOR_EXPR)
+ oe->op = build_low_bits_mask (TREE_TYPE (oe->op),
+ TYPE_PRECISION (TREE_TYPE (oe->op)));
+
+ reassociate_stats.ops_eliminated += VEC_length (operand_entry_t, *ops) - 1;
+ VEC_free (operand_entry_t, heap, *ops);
+ *ops = NULL;
+ VEC_safe_push (operand_entry_t, heap, *ops, oe);
+ return true;
+ }
+ }
+
+ return false;
}
+/* Use constant value that may be present in OPS to try to eliminate
+ operands. Note that this function is only really used when we've
+ eliminated ops for other reasons, or merged constants. Across
+ single statements, fold already does all of this, plus more. There
+ is little point in duplicating logic, so I've only included the
+ identities that I could ever construct testcases to trigger. */
-/* Gate and execute functions for Reassociation. */
+static void
+eliminate_using_constants (enum tree_code opcode,
+ VEC(operand_entry_t, heap) **ops)
+{
+ operand_entry_t oelast = VEC_last (operand_entry_t, *ops);
+
+ if (oelast->rank == 0 && INTEGRAL_TYPE_P (TREE_TYPE (oelast->op)))
+ {
+ switch (opcode)
+ {
+ case BIT_AND_EXPR:
+ if (integer_zerop (oelast->op))
+ {
+ if (VEC_length (operand_entry_t, *ops) != 1)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Found & 0, removing all other ops\n");
+ reassociate_stats.ops_eliminated += VEC_length (operand_entry_t, *ops) - 1;
+ VEC_free (operand_entry_t, heap, *ops);
+ *ops = NULL;
+ VEC_safe_push (operand_entry_t, heap, *ops, oelast);
+ return;
+ }
+ }
+ /* FALLTHRU */
+ case BIT_IOR_EXPR:
+ if (integer_all_onesp (oelast->op))
+ {
+ if (VEC_length (operand_entry_t, *ops) != 1)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Found [&|] -1, removing\n");
+ VEC_pop (operand_entry_t, *ops);
+ reassociate_stats.ops_eliminated++;
+ }
+ }
+ break;
+ case MULT_EXPR:
+ if (integer_zerop (oelast->op))
+ {
+ if (VEC_length (operand_entry_t, *ops) != 1)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Found * 0, removing all other ops\n");
+ reassociate_stats.ops_eliminated += VEC_length (operand_entry_t, *ops) - 1;
+ VEC_free (operand_entry_t, heap, *ops);
+ *ops = NULL;
+ VEC_safe_push (operand_entry_t, heap, *ops, oelast);
+ return;
+ }
+ }
+ else if (integer_onep (oelast->op))
+ {
+ if (VEC_length (operand_entry_t, *ops) != 1)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Found * 1, removing\n");
+ VEC_pop (operand_entry_t, *ops);
+ reassociate_stats.ops_eliminated++;
+ return;
+ }
+ }
+ break;
+ case BIT_XOR_EXPR:
+ case PLUS_EXPR:
+ case MINUS_EXPR:
+ if (integer_zerop (oelast->op))
+ {
+ if (VEC_length (operand_entry_t, *ops) != 1)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Found [|^+] 0, removing\n");
+ VEC_pop (operand_entry_t, *ops);
+ reassociate_stats.ops_eliminated++;
+ return;
+ }
+ }
+ break;
+ default:
+ break;
+ }
+ }
+}
+
+/* Perform various identities and other optimizations on the list of
+ operand entries, stored in OPS. The tree code for the binary
+ operation between all the operands is OPCODE. */
static void
-execute_reassoc (void)
+optimize_ops_list (enum tree_code opcode,
+ VEC (operand_entry_t, heap) **ops)
{
- init_reassoc ();
- do_reassoc ();
+ unsigned int length = VEC_length (operand_entry_t, *ops);
+ unsigned int i;
+ operand_entry_t oe;
+ int fconstcount = 0;
+ int iconstcount = 0;
+ int oconstcount = 0;
+ operand_entry_t oelast = NULL;
+ bool iterate = false;
+
+ if (length == 1)
+ return;
+
+ oelast = VEC_last (operand_entry_t, *ops);
+
+ /* If the last two are constants, pop the constants off, merge them
+ and try the next two. */
+ if (oelast->rank == 0 && is_gimple_min_invariant (oelast->op))
+ {
+ operand_entry_t oelm1 = VEC_index (operand_entry_t, *ops, length - 2);
+
+ if (oelm1->rank == 0
+ && is_gimple_min_invariant (oelm1->op)
+ && lang_hooks.types_compatible_p (TREE_TYPE (oelm1->op),
+ TREE_TYPE (oelast->op)))
+ {
+ tree folded = fold_build2 (opcode, TREE_TYPE (oelm1->op),
+ oelm1->op, oelast->op);
+
+ if (is_gimple_min_invariant (folded))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Merging constants\n");
+
+ VEC_pop (operand_entry_t, *ops);
+ VEC_pop (operand_entry_t, *ops);
+
+ add_to_ops_vec (ops, folded);
+ reassociate_stats.constants_eliminated++;
+
+ optimize_ops_list (opcode, ops);
+ return;
+ }
+ }
+ }
+
+ eliminate_using_constants (opcode, ops);
+ oelast = NULL;
+
+ for (i = 0; VEC_iterate (operand_entry_t, *ops, i, oe);)
+ {
+ bool done = false;
+
+ if (eliminate_not_pairs (opcode, ops, i, oe))
+ return;
+ if (eliminate_duplicate_pair (opcode, ops, &done, i, oe, oelast)
+ || (!done && eliminate_plus_minus_pair (opcode, ops, i, oe)))
+ {
+ if (done)
+ return;
+ iterate = true;
+ oelast = NULL;
+ continue;
+ }
+ if (oe->rank == 0 && is_gimple_min_invariant (oe->op))
+ {
+ switch (constant_type (oe->op))
+ {
+ case INTEGER_CONST_TYPE:
+ iconstcount++;
+ break;
+
+ case FLOAT_CONST_TYPE:
+ fconstcount++;
+ break;
+ case OTHER_CONST_TYPE:
+ oconstcount++;
+ break;
+
+ default:
+ break;
+ }
+ }
+ oelast = oe;
+ i++;
+ }
+ if (iconstcount > 0 && dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "iconstcount is %d\n", iconstcount);
+ if (fconstcount > 0 && dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "fconstcount is %d\n", fconstcount);
+ if (oconstcount> 0 && dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "oconstcount is %d\n", oconstcount);
+
+ length = VEC_length (operand_entry_t, *ops);
+ oelast = VEC_last (operand_entry_t, *ops);
+
+ if (iterate)
+ optimize_ops_list (opcode, ops);
+}
+
+#if 0
+static tree
+merge_two_ops (enum tree_code code, tree op1, tree op2)
+{
+ tree temp;
+ tree name;
+ tree newexpr;
+
+ temp = create_tmp_var (TREE_TYPE (op1), "mergetmp");
+ add_referenced_tmp_var (temp);
+ newexpr = fold_build2 (code, TREE_TYPE (op1), op1, op2);
+ newexpr = build (MODIFY_EXPR, TREE_TYPE (op1), temp, newexpr);
+ name = make_ssa_name (temp, newexpr);
+ TREE_OPERAND (newexpr, 0) = name;
+ return name;
+}
+
+static void
+merge_leaves_of_rank (enum tree_code opcode, VEC (tree, heap) *worklist,
+ VEC (tree, heap) **results)
+{
+ unsigned int length = VEC_length (tree, worklist);
+ if (length % 2 == 1)
+ {
+ VEC_safe_push (tree, heap, *results, VEC_pop (tree, worklist));
+ length--;
+ }
+ while (length != 0)
+ {
+ tree oe1 = VEC_pop (tree, worklist);
+ tree oe2 = VEC_pop (tree, worklist);
+ length -= 2;
+ VEC_safe_push (tree, heap, *results, merge_two_ops (opcode, oe1, oe2));
+ }
+ VEC_free (tree, heap, worklist);
+
+}
+
+static void
+rewrite_expr_tree_new (tree stmt, enum tree_code opcode,
+ VEC (operand_entry_t, heap) **ops)
+{
+ VEC(tree, heap) *initial_merge_worklist = NULL;
+ VEC(tree, heap) *merge_worklist = NULL;
+ VEC(tree, heap) *stmtsforsale = NULL;
+ operand_entry_t oe;
+ unsigned int opslength = VEC_length (operand_entry_t, *ops);
+
+ if (opslength < 4)
+ return;
+
+ /* Initialize the worklist */
+ while (VEC_length (operand_entry_t, *ops) != 0)
+ {
+ initial_merge_worklist = NULL;
+ oe = VEC_pop (operand_entry_t, *ops);
+ while (!VEC_empty (operand_entry_t, *ops)
+ && VEC_last (operand_entry_t, *ops)->rank == oe->rank)
+ {
+ VEC_safe_push (tree, heap, initial_merge_worklist, oe->op);
+ oe = VEC_pop (operand_entry_t, *ops);
+ }
+ VEC_safe_push (tree, heap, initial_merge_worklist, oe->op);
+ merge_leaves_of_rank (opcode, initial_merge_worklist, &merge_worklist);
+ }
+
+ gcc_assert (VEC_length (tree, merge_worklist) <= opslength);
+
+ while (VEC_length (tree, merge_worklist) != 0)
+ add_to_ops_vec (ops, VEC_pop (tree, merge_worklist));
+}
+#endif
+
+static bool
+is_phi_for_stmt (tree stmt, tree operand)
+{
+ tree def_stmt;
+ tree lhs = TREE_OPERAND (stmt, 0);
+ use_operand_p arg_p;
+ ssa_op_iter i;
+
+ if (TREE_CODE (operand) != SSA_NAME)
+ return false;
+
+ def_stmt = SSA_NAME_DEF_STMT (operand);
+ if (TREE_CODE (def_stmt) != PHI_NODE)
+ return false;
+
+ FOR_EACH_PHI_ARG (arg_p, def_stmt, i, SSA_OP_USE)
+ if (lhs == USE_FROM_PTR (arg_p))
+ return true;
+ return false;
+}
+
+/* Recursively rewrite our linearized statements so that the operators
+ match those in OPS[OPINDEX], putting the computation in rank
+ order. */
+
+static void
+rewrite_expr_tree (tree stmt, unsigned int opindex,
+ VEC(operand_entry_t, heap) * ops)
+{
+ tree rhs = TREE_OPERAND (stmt, 1);
+ operand_entry_t oe;
+
+ /* If we have three operands left, then we want to make sure the one
+ that gets the double binary op are the ones with the same rank.
+
+ The alternative we try is to see if this is a destructive
+ update style statement, which is like:
+ b = phi (a, ...)
+ a = c + b;
+ In that case, we want to use the destructive update form to
+ expose the possible vectorizer sum reduction opportunity.
+ In that case, the third operand will be the phi node.
+
+ We could, of course, try to be better as noted above, and do a
+ lot of work to try to find these opportunities in >3 operand
+ cases, but it is unlikely to be worth it. */
+ if (opindex + 3 == VEC_length (operand_entry_t, ops))
+ {
+ operand_entry_t oe1, oe2, oe3;
+
+ oe1 = VEC_index (operand_entry_t, ops, opindex);
+ oe2 = VEC_index (operand_entry_t, ops, opindex + 1);
+ oe3 = VEC_index (operand_entry_t, ops, opindex + 2);
+
+ if ((oe1->rank == oe2->rank
+ && oe2->rank != oe3->rank)
+ || (is_phi_for_stmt (stmt, oe3->op)
+ && !is_phi_for_stmt (stmt, oe1->op)
+ && !is_phi_for_stmt (stmt, oe2->op)))
+ {
+ struct operand_entry temp = *oe3;
+ oe3->op = oe1->op;
+ oe3->rank = oe1->rank;
+ oe1->op = temp.op;
+ oe1->rank= temp.rank;
+ }
+ }
+
+ /* The final recursion case for this function is that you have
+ exactly two operations left.
+ If we had one exactly one op in the entire list to start with, we
+ would have never called this function, and the tail recursion
+ rewrites them one at a time. */
+ if (opindex + 2 == VEC_length (operand_entry_t, ops))
+ {
+ operand_entry_t oe1, oe2;
+
+ oe1 = VEC_index (operand_entry_t, ops, opindex);
+ oe2 = VEC_index (operand_entry_t, ops, opindex + 1);
+
+ if (TREE_OPERAND (rhs, 0) != oe1->op
+ || TREE_OPERAND (rhs, 1) != oe2->op)
+ {
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Transforming ");
+ print_generic_expr (dump_file, rhs, 0);
+ }
+
+ TREE_OPERAND (rhs, 0) = oe1->op;
+ TREE_OPERAND (rhs, 1) = oe2->op;
+ update_stmt (stmt);
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, " into ");
+ print_generic_stmt (dump_file, rhs, 0);
+ }
+
+ }
+ return;
+ }
+
+ /* If we hit here, we should have 3 or more ops left. */
+ gcc_assert (opindex + 2 < VEC_length (operand_entry_t, ops));
+
+ /* Rewrite the next operator. */
+ oe = VEC_index (operand_entry_t, ops, opindex);
+
+ if (oe->op != TREE_OPERAND (rhs, 1))
+ {
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Transforming ");
+ print_generic_expr (dump_file, rhs, 0);
+ }
+
+ TREE_OPERAND (rhs, 1) = oe->op;
+ update_stmt (stmt);
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, " into ");
+ print_generic_stmt (dump_file, rhs, 0);
+ }
+ }
+ /* Recurse on the LHS of the binary operator, which is guaranteed to
+ be the non-leaf side. */
+ rewrite_expr_tree (SSA_NAME_DEF_STMT (TREE_OPERAND (rhs, 0)),
+ opindex + 1, ops);
+}
+
+/* Return true if STMT is a subtract operation. */
+static bool
+is_subtract_stmt (tree stmt)
+{
+ return (TREE_CODE (stmt) == MODIFY_EXPR
+ && TREE_CODE (TREE_OPERAND (stmt, 1)) == MINUS_EXPR);
+}
+
+
+/* Transform STMT, which is really (A +B) + (C + D) into the left
+ linear form, ((A+B)+C)+D.
+ Recurse on D if necessary. */
+
+static void
+linearize_expr (tree stmt)
+{
+ block_stmt_iterator bsinow, bsirhs;
+ tree rhs = TREE_OPERAND (stmt, 1);
+ enum tree_code rhscode = TREE_CODE (rhs);
+ tree binrhs = SSA_NAME_DEF_STMT (TREE_OPERAND (rhs, 1));
+ tree binlhs = SSA_NAME_DEF_STMT (TREE_OPERAND (rhs, 0));
+ tree newbinrhs = NULL_TREE;
+
+ gcc_assert (is_reassociable_op (binlhs, TREE_CODE (rhs))
+ && is_reassociable_op (binrhs, TREE_CODE (rhs)));
+
+ bsinow = bsi_for_stmt (stmt);
+ bsirhs = bsi_for_stmt (binrhs);
+ bsi_move_before (&bsirhs, &bsinow);
+
+ TREE_OPERAND (rhs, 1) = TREE_OPERAND (TREE_OPERAND (binrhs, 1), 0);
+ if (TREE_CODE (TREE_OPERAND (rhs, 1)) == SSA_NAME)
+ newbinrhs = SSA_NAME_DEF_STMT (TREE_OPERAND (rhs, 1));
+ TREE_OPERAND (TREE_OPERAND (binrhs, 1), 0) = TREE_OPERAND (binlhs, 0);
+ TREE_OPERAND (rhs, 0) = TREE_OPERAND (binrhs, 0);
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Linearized: ");
+ print_generic_stmt (dump_file, rhs, 0);
+ }
+
+ reassociate_stats.linearized++;
+ update_stmt (binrhs);
+ update_stmt (binlhs);
+ update_stmt (stmt);
+ TREE_VISITED (binrhs) = 1;
+ TREE_VISITED (binlhs) = 1;
+ TREE_VISITED (stmt) = 1;
+
+ gcc_assert (!is_subtract_stmt (newbinrhs));
+
+ /* Tail recurse on the new rhs if it still needs reassociation. */
+ if (newbinrhs && is_reassociable_op (newbinrhs, rhscode))
+ linearize_expr (stmt);
+
+}
+
+/* If LHS has a single immediate use that is a MODIFY_EXPR, return
+ it. Otherwise, return NULL. */
+
+static tree
+get_single_immediate_use (tree lhs)
+{
+ use_operand_p immuse;
+ tree immusestmt;
+
+ if (TREE_CODE (lhs) == SSA_NAME
+ && single_imm_use (lhs, &immuse, &immusestmt))
+ {
+ if (TREE_CODE (immusestmt) == RETURN_EXPR)
+ immusestmt = TREE_OPERAND (immusestmt, 0);
+ if (TREE_CODE (immusestmt) == MODIFY_EXPR)
+ return immusestmt;
+ }
+ return NULL_TREE;
+}
+static VEC(tree, heap) *broken_up_subtracts;
+
+
+/* Recursively negate the value of TONEGATE, and return the SSA_NAME
+ representing the negated value. Insertions of any necessary
+ instructions go before BSI.
+ This function is recursive in that, if you hand it "a_5" as the
+ value to negate, and a_5 is defined by "a_5 = b_3 + b_4", it will
+ transform b_3 + b_4 into a_5 = -b_3 + -b_4. */
+
+static tree
+negate_value (tree tonegate, block_stmt_iterator *bsi)
+{
+ tree negatedef = tonegate;
+ tree resultofnegate;
+
+ if (TREE_CODE (tonegate) == SSA_NAME)
+ negatedef = SSA_NAME_DEF_STMT (tonegate);
+
+ /* If we are trying to negate a name, defined by an add, negate the
+ add operands instead. */
+ if (TREE_CODE (tonegate) == SSA_NAME
+ && TREE_CODE (negatedef) == MODIFY_EXPR
+ && TREE_CODE (TREE_OPERAND (negatedef, 0)) == SSA_NAME
+ && num_imm_uses (TREE_OPERAND (negatedef, 0)) == 1
+ && TREE_CODE (TREE_OPERAND (negatedef, 1)) == PLUS_EXPR)
+ {
+ block_stmt_iterator bsi;
+ tree binop = TREE_OPERAND (negatedef, 1);
+
+ bsi = bsi_for_stmt (negatedef);
+ TREE_OPERAND (binop, 0) = negate_value (TREE_OPERAND (binop, 0),
+ &bsi);
+ bsi = bsi_for_stmt (negatedef);
+ TREE_OPERAND (binop, 1) = negate_value (TREE_OPERAND (binop, 1),
+ &bsi);
+ update_stmt (negatedef);
+ return TREE_OPERAND (negatedef, 0);
+ }
+
+ tonegate = fold_build1 (NEGATE_EXPR, TREE_TYPE (tonegate), tonegate);
+ resultofnegate = force_gimple_operand_bsi (bsi, tonegate, true,
+ NULL_TREE);
+ VEC_safe_push (tree, heap, broken_up_subtracts, resultofnegate);
+ return resultofnegate;
+
+}
+
+/* Return true if we should break up the subtract in STMT into an add
+ with negate. This is true when we the subtract operands are really
+ adds, or the subtract itself is used in an add expression. In
+ either case, breaking up the subtract into an add with negate
+ exposes the adds to reassociation. */
+
+static bool
+should_break_up_subtract (tree stmt)
+{
+
+ tree lhs = TREE_OPERAND (stmt, 0);
+ tree rhs = TREE_OPERAND (stmt, 1);
+ tree binlhs = TREE_OPERAND (rhs, 0);
+ tree binrhs = TREE_OPERAND (rhs, 1);
+ tree immusestmt;
+
+ if (TREE_CODE (binlhs) == SSA_NAME
+ && is_reassociable_op (SSA_NAME_DEF_STMT (binlhs), PLUS_EXPR))
+ return true;
+
+ if (TREE_CODE (binrhs) == SSA_NAME
+ && is_reassociable_op (SSA_NAME_DEF_STMT (binrhs), PLUS_EXPR))
+ return true;
+
+ if (TREE_CODE (lhs) == SSA_NAME
+ && (immusestmt = get_single_immediate_use (lhs))
+ && TREE_CODE (TREE_OPERAND (immusestmt, 1)) == PLUS_EXPR)
+ return true;
+ return false;
+
+}
+
+/* Transform STMT from A - B into A + -B. */
+
+static void
+break_up_subtract (tree stmt, block_stmt_iterator *bsi)
+{
+ tree rhs = TREE_OPERAND (stmt, 1);
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Breaking up subtract ");
+ print_generic_stmt (dump_file, stmt, 0);
+ }
+
+ TREE_SET_CODE (TREE_OPERAND (stmt, 1), PLUS_EXPR);
+ TREE_OPERAND (rhs, 1) = negate_value (TREE_OPERAND (rhs, 1), bsi);
+
+ update_stmt (stmt);
+}
+
+/* Recursively linearize a binary expression that is the RHS of STMT.
+ Place the operands of the expression tree in the vector named OPS. */
+
+static void
+linearize_expr_tree (VEC(operand_entry_t, heap) **ops, tree stmt)
+{
+ block_stmt_iterator bsinow, bsilhs;
+ tree rhs = TREE_OPERAND (stmt, 1);
+ tree binrhs = TREE_OPERAND (rhs, 1);
+ tree binlhs = TREE_OPERAND (rhs, 0);
+ tree binlhsdef, binrhsdef;
+ bool binlhsisreassoc = false;
+ bool binrhsisreassoc = false;
+ enum tree_code rhscode = TREE_CODE (rhs);
+
+ TREE_VISITED (stmt) = 1;
+
+ if (TREE_CODE (binlhs) == SSA_NAME)
+ {
+ binlhsdef = SSA_NAME_DEF_STMT (binlhs);
+ binlhsisreassoc = is_reassociable_op (binlhsdef, rhscode);
+ }
+
+ if (TREE_CODE (binrhs) == SSA_NAME)
+ {
+ binrhsdef = SSA_NAME_DEF_STMT (binrhs);
+ binrhsisreassoc = is_reassociable_op (binrhsdef, rhscode);
+ }
+
+ /* If the LHS is not reassociable, but the RHS is, we need to swap
+ them. If neither is reassociable, there is nothing we can do, so
+ just put them in the ops vector. If the LHS is reassociable,
+ linearize it. If both are reassociable, then linearize the RHS
+ and the LHS. */
+
+ if (!binlhsisreassoc)
+ {
+ tree temp;
+
+ if (!binrhsisreassoc)
+ {
+ add_to_ops_vec (ops, binrhs);
+ add_to_ops_vec (ops, binlhs);
+ return;
+ }
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "swapping operands of ");
+ print_generic_expr (dump_file, stmt, 0);
+ }
+
+ swap_tree_operands (stmt, &TREE_OPERAND (rhs, 0),
+ &TREE_OPERAND (rhs, 1));
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, " is now ");
+ print_generic_stmt (dump_file, stmt, 0);
+ }
+
+ /* We want to make it so the lhs is always the reassociative op,
+ so swap. */
+ temp = binlhs;
+ binlhs = binrhs;
+ binrhs = temp;
+ }
+ else if (binrhsisreassoc)
+ {
+ linearize_expr (stmt);
+ gcc_assert (rhs == TREE_OPERAND (stmt, 1));
+ binlhs = TREE_OPERAND (rhs, 0);
+ binrhs = TREE_OPERAND (rhs, 1);
+ }
+
+ gcc_assert (TREE_CODE (binrhs) != SSA_NAME
+ || !is_reassociable_op (SSA_NAME_DEF_STMT (binrhs), rhscode));
+ bsinow = bsi_for_stmt (stmt);
+ bsilhs = bsi_for_stmt (SSA_NAME_DEF_STMT (binlhs));
+ bsi_move_before (&bsilhs, &bsinow);
+ linearize_expr_tree (ops, SSA_NAME_DEF_STMT (binlhs));
+ add_to_ops_vec (ops, binrhs);
+}
+
+/* Repropagate the negates back into subtracts, since no other pass
+ currently does it. */
+
+static void
+repropagate_negates (void)
+{
+ unsigned int i = 0;
+ tree negate;
+
+ for (i = 0; VEC_iterate (tree, broken_up_subtracts, i, negate); i++)
+ {
+ tree user = get_single_immediate_use (negate);
+
+ /* Due to linearization, the negate operand should now be an RHS
+ leaf of some PLUS expression. I.E.
+
+ d = -c
+ e = a + d
+
+ So just repropagate it, transforming the PLUS_EXPR back into
+ a MINUS_EXPR. */
+
+ if (user
+ && TREE_CODE (user) == MODIFY_EXPR
+ && TREE_CODE (TREE_OPERAND (user, 1)) == PLUS_EXPR
+ && TREE_OPERAND (TREE_OPERAND (user, 1), 1) == negate)
+ {
+ tree rhs = TREE_OPERAND (user, 1);
+ TREE_SET_CODE (rhs, MINUS_EXPR);
+ TREE_OPERAND (rhs, 1) = get_unary_op (negate, NEGATE_EXPR);
+ update_stmt (user);
+ }
+ }
+}
+
+/* Break up subtract operations in block BB.
+
+ We do this top down because we don't know whether the subtract is
+ part of a possible chain of reassociation except at the top.
+
+ IE given
+ d = f + g
+ c = a + e
+ b = c - d
+ q = b - r
+ k = t - q
+
+ we want to break up k = t - q, but we won't until we've transformed q
+ = b - r, which won't be broken up until we transform b = c - d. */
+
+static void
+break_up_subtract_bb (basic_block bb)
+{
+ block_stmt_iterator bsi;
+ basic_block son;
+
+ for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
+ {
+ tree stmt = bsi_stmt (bsi);
+
+ if (TREE_CODE (stmt) == MODIFY_EXPR)
+ {
+ tree lhs = TREE_OPERAND (stmt, 0);
+ tree rhs = TREE_OPERAND (stmt, 1);
+
+ TREE_VISITED (stmt) = 0;
+ /* If unsafe math optimizations we can do reassociation for
+ non-integral types. */
+ if ((!INTEGRAL_TYPE_P (TREE_TYPE (lhs))
+ || !INTEGRAL_TYPE_P (TREE_TYPE (rhs)))
+ && (!SCALAR_FLOAT_TYPE_P (TREE_TYPE (rhs))
+ || !SCALAR_FLOAT_TYPE_P (TREE_TYPE(lhs))
+ || !flag_unsafe_math_optimizations))
+ continue;
+
+ /* Check for a subtract used only in an addition. If this
+ is the case, transform it into add of a negate for better
+ reassociation. IE transform C = A-B into C = A + -B if C
+ is only used in an addition. */
+ if (TREE_CODE (rhs) == MINUS_EXPR)
+ if (should_break_up_subtract (stmt))
+ break_up_subtract (stmt, &bsi);
+ }
+ }
+ for (son = first_dom_son (CDI_DOMINATORS, bb);
+ son;
+ son = next_dom_son (CDI_DOMINATORS, son))
+ break_up_subtract_bb (son);
+}
+
+/* Reassociate expressions in basic block BB and its post-dominator as
+ children. */
+
+static void
+reassociate_bb (basic_block bb)
+{
+ block_stmt_iterator bsi;
+ basic_block son;
+
+ for (bsi = bsi_last (bb); !bsi_end_p (bsi); bsi_prev (&bsi))
+ {
+ tree stmt = bsi_stmt (bsi);
+
+ if (TREE_CODE (stmt) == MODIFY_EXPR)
+ {
+ tree lhs = TREE_OPERAND (stmt, 0);
+ tree rhs = TREE_OPERAND (stmt, 1);
+
+ /* If this was part of an already processed tree, we don't
+ need to touch it again. */
+ if (TREE_VISITED (stmt))
+ continue;
+
+ /* If unsafe math optimizations we can do reassociation for
+ non-integral types. */
+ if ((!INTEGRAL_TYPE_P (TREE_TYPE (lhs))
+ || !INTEGRAL_TYPE_P (TREE_TYPE (rhs)))
+ && (!SCALAR_FLOAT_TYPE_P (TREE_TYPE (rhs))
+ || !SCALAR_FLOAT_TYPE_P (TREE_TYPE(lhs))
+ || !flag_unsafe_math_optimizations))
+ continue;
+
+ if (associative_tree_code (TREE_CODE (rhs)))
+ {
+ VEC(operand_entry_t, heap) *ops = NULL;
+
+ /* There may be no immediate uses left by the time we
+ get here because we may have eliminated them all. */
+ if (TREE_CODE (lhs) == SSA_NAME && num_imm_uses (lhs) == 0)
+ continue;
+
+ TREE_VISITED (stmt) = 1;
+ linearize_expr_tree (&ops, stmt);
+ qsort (VEC_address (operand_entry_t, ops),
+ VEC_length (operand_entry_t, ops),
+ sizeof (operand_entry_t),
+ sort_by_operand_rank);
+ optimize_ops_list (TREE_CODE (rhs), &ops);
+
+ if (VEC_length (operand_entry_t, ops) == 1)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Transforming ");
+ print_generic_expr (dump_file, rhs, 0);
+ }
+ TREE_OPERAND (stmt, 1) = VEC_last (operand_entry_t, ops)->op;
+ update_stmt (stmt);
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, " into ");
+ print_generic_stmt (dump_file,
+ TREE_OPERAND (stmt, 1), 0);
+ }
+ }
+ else
+ {
+ /*rewrite_expr_tree_new (stmt, TREE_CODE (rhs), &ops);*/
+ rewrite_expr_tree (stmt, 0, ops);
+ }
+
+ VEC_free (operand_entry_t, heap, ops);
+ }
+ }
+ }
+ for (son = first_dom_son (CDI_POST_DOMINATORS, bb);
+ son;
+ son = next_dom_son (CDI_POST_DOMINATORS, son))
+ reassociate_bb (son);
+}
+
+void dump_ops_vector (FILE *file, VEC (operand_entry_t, heap) *ops);
+void debug_ops_vector (VEC (operand_entry_t, heap) *ops);
+
+/* Dump the operand entry vector OPS to FILE. */
+
+void
+dump_ops_vector (FILE *file, VEC (operand_entry_t, heap) *ops)
+{
+ operand_entry_t oe;
+ unsigned int i;
+
+ for (i = 0; VEC_iterate (operand_entry_t, ops, i, oe); i++)
+ {
+ fprintf (file, "Op %d -> rank: %d, tree: ", i, oe->rank);
+ print_generic_stmt (file, oe->op, 0);
+ }
+}
+
+/* Dump the operand entry vector OPS to STDERR. */
+
+void
+debug_ops_vector (VEC (operand_entry_t, heap) *ops)
+{
+ dump_ops_vector (stderr, ops);
+}
+
+static void
+do_reassoc (void)
+{
+ break_up_subtract_bb (ENTRY_BLOCK_PTR);
+ reassociate_bb (EXIT_BLOCK_PTR);
+}
+
+/* Initialize the reassociation pass. */
+
+static void
+init_reassoc (void)
+{
+ int i;
+ unsigned int rank = 2;
+ tree param;
+ int *bbs = xmalloc ((last_basic_block + 1) * sizeof (int));
+
+
+ memset (&reassociate_stats, 0, sizeof (reassociate_stats));
+
+ operand_entry_pool = create_alloc_pool ("operand entry pool",
+ sizeof (struct operand_entry), 30);
+
+ /* Reverse RPO (Reverse Post Order) will give us something where
+ deeper loops come later. */
+ flow_reverse_top_sort_order_compute (bbs);
+ bb_rank = xcalloc (last_basic_block + 1, sizeof (unsigned int));
+ operand_rank = htab_create (511, operand_entry_hash,
+ operand_entry_eq, 0);
+
+ /* Give each argument a distinct rank. */
+ for (param = DECL_ARGUMENTS (current_function_decl);
+ param;
+ param = TREE_CHAIN (param))
+ {
+ if (default_def (param) != NULL)
+ {
+ tree def = default_def (param);
+ insert_operand_rank (def, ++rank);
+ }
+ }
+
+ /* Give the chain decl a distinct rank. */
+ if (cfun->static_chain_decl != NULL)
+ {
+ tree def = default_def (cfun->static_chain_decl);
+ if (def != NULL)
+ insert_operand_rank (def, ++rank);
+ }
+
+ /* Set up rank for each BB */
+ for (i = 0; i < n_basic_blocks; i++)
+ bb_rank[bbs[i]] = ++rank << 16;
+
+ free (bbs);
+ calculate_dominance_info (CDI_DOMINATORS);
+ calculate_dominance_info (CDI_POST_DOMINATORS);
+ broken_up_subtracts = NULL;
+}
+
+/* Cleanup after the reassociation pass, and print stats if
+ requested. */
+
+static void
+fini_reassoc (void)
+{
+
+ if (dump_file && (dump_flags & TDF_STATS))
+ {
+ fprintf (dump_file, "Reassociation stats:\n");
+ fprintf (dump_file, "Linearized: %d\n", reassociate_stats.linearized);
+ fprintf (dump_file, "Constants eliminated: %d\n",
+ reassociate_stats.constants_eliminated);
+ fprintf (dump_file, "Ops eliminated: %d\n",
+ reassociate_stats.ops_eliminated);
+ fprintf (dump_file, "Statements rewritten: %d\n",
+ reassociate_stats.rewritten);
+ }
+ htab_delete (operand_rank);
+
+ free_alloc_pool (operand_entry_pool);
+ free (bb_rank);
+ VEC_free (tree, heap, broken_up_subtracts);
+}
+
+/* Gate and execute functions for Reassociation. */
+
+static void
+execute_reassoc (void)
+{
+ init_reassoc ();
+
+ do_reassoc ();
+ repropagate_negates ();
+
fini_reassoc ();
}
@@ -635,7 +1574,6 @@ struct tree_opt_pass pass_reassoc =
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
- TODO_update_ssa | TODO_dump_func
- | TODO_ggc_collect | TODO_verify_ssa, /* todo_flags_finish */
+ TODO_dump_func | TODO_ggc_collect | TODO_verify_ssa, /* todo_flags_finish */
0 /* letter */
};
Index: testsuite/gcc.dg/tree-ssa/reassoc-1.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/testsuite/gcc.dg/tree-ssa/reassoc-1.c,v
retrieving revision 1.1
diff -u -p -r1.1 reassoc-1.c
--- testsuite/gcc.dg/tree-ssa/reassoc-1.c 6 Jun 2005 18:55:59 -0000 1.1
+++ testsuite/gcc.dg/tree-ssa/reassoc-1.c 8 Sep 2005 14:05:20 -0000
@@ -14,5 +14,5 @@ int main(void)
printf ("%d %d\n", e, f);
}
-/* { dg-final { scan-tree-dump-times "a \\\+ b" 1 "optimized"} } */
+/* { dg-final { scan-tree-dump-times "b \\\+ a" 1 "optimized"} } */
/* { dg-final { cleanup-tree-dump "optimized" } } */
Index: testsuite/gcc.dg/tree-ssa/reassoc-10.c
===================================================================
RCS file: testsuite/gcc.dg/tree-ssa/reassoc-10.c
diff -N testsuite/gcc.dg/tree-ssa/reassoc-10.c
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ testsuite/gcc.dg/tree-ssa/reassoc-10.c 8 Sep 2005 14:05:20 -0000
@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+int main(int a, int b, int c, int d)
+{
+ /* Should become just a & b & c & d */
+ int e = (a & b) & (c & d);
+ int f = (c & a) & (b & d);
+ return e & f;
+}
+/* { dg-final { scan-tree-dump-times "\\\& " 3 "optimized"} } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */
Index: testsuite/gcc.dg/tree-ssa/reassoc-11.c
===================================================================
RCS file: testsuite/gcc.dg/tree-ssa/reassoc-11.c
diff -N testsuite/gcc.dg/tree-ssa/reassoc-11.c
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ testsuite/gcc.dg/tree-ssa/reassoc-11.c 8 Sep 2005 14:05:20 -0000
@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-reassoc" } */
+int main(int a, int b, int c, int d)
+{
+ /* All the xor's cancel each other out, leaving 0 */
+ int e = (a ^ b) ^ (c ^ d);
+ int f = (c ^ a) ^ (b ^ d);
+ return e ^ f;
+}
+/* { dg-final { scan-tree-dump-times "= 0" 1 "reassoc"} } */
+/* { dg-final { cleanup-tree-dump "reassoc" } } */
Index: testsuite/gcc.dg/tree-ssa/reassoc-2.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/testsuite/gcc.dg/tree-ssa/reassoc-2.c,v
retrieving revision 1.1
diff -u -p -r1.1 reassoc-2.c
--- testsuite/gcc.dg/tree-ssa/reassoc-2.c 6 Jun 2005 18:55:59 -0000 1.1
+++ testsuite/gcc.dg/tree-ssa/reassoc-2.c 8 Sep 2005 14:05:20 -0000
@@ -1,18 +1,17 @@
/* { dg-do compile } */
-/* { dg-options "-O2 -fdump-tree-optimized -fdump-tree-reassoc-details" } */
-extern int a0, a1, a2, a3, a4;
-int f ()
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+int f (int a0,int a1,int a2,int a3,int a4)
{
-int b0, b1, b2, b3, b4;
+int b0, b1, b2, b3, b4,e;
/* this can be optimized to four additions... */
b4 = a4 + a3 + a2 + a1 + a0;
b3 = a3 + a2 + a1 + a0;
b2 = a2 + a1 + a0;
b1 = a1 + a0;
/* This is actually 0 */
- return b4 - b3 + b2 - b1 - a4 - a2;
-}
-/* { dg-final { scan-tree-dump-times "Reassociating by rank" 3 "reassoc" } } */
-/* { dg-final { scan-tree-dump-times "return 0" 1 "optimized" { xfail *-*-* } } } */
+ e = b4 - b3 + b2 - b1 - a4 - a2;
+ return e;
+}
+
+/* { dg-final { scan-tree-dump-times "return 0" 1 "optimized" } } */
/* { dg-final { cleanup-tree-dump "optimized" } } */
-/* { dg-final { cleanup-tree-dump "reassoc" } } */
Index: testsuite/gcc.dg/tree-ssa/reassoc-3.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/testsuite/gcc.dg/tree-ssa/reassoc-3.c,v
retrieving revision 1.1
diff -u -p -r1.1 reassoc-3.c
--- testsuite/gcc.dg/tree-ssa/reassoc-3.c 25 Jul 2005 20:23:50 -0000 1.1
+++ testsuite/gcc.dg/tree-ssa/reassoc-3.c 8 Sep 2005 14:05:20 -0000
@@ -1,18 +1,6 @@
-/* { dg-do compile } */
-/* { dg-options "-O2 -fdump-tree-optimized -ffast-math" } */
-float a, b, c, d;
-extern int printf (const char *, ...);
-int main(void)
+int main(int a, int b, int c, int d)
{
- float e;
- float f;
- /* We should be able to transform these into the same expression, and only have two additions. */
- e = a + b;
- e = e + c;
- f = c + a;
- f = f + b;
- printf ("%f %f\n", e, f);
+ int e = (a & ~b) & (~c & d);
+ int f = (~c & a) & (b & ~d);
+ return (e & f);
}
-
-/* { dg-final { scan-tree-dump-times "\\\+" 2 "optimized"} } */
-/* { dg-final { cleanup-tree-dump "optimized" } } */
Index: testsuite/gcc.dg/tree-ssa/reassoc-4.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/testsuite/gcc.dg/tree-ssa/reassoc-4.c,v
retrieving revision 1.1
diff -u -p -r1.1 reassoc-4.c
--- testsuite/gcc.dg/tree-ssa/reassoc-4.c 25 Jul 2005 20:23:50 -0000 1.1
+++ testsuite/gcc.dg/tree-ssa/reassoc-4.c 8 Sep 2005 14:05:20 -0000
@@ -1,5 +1,5 @@
/* { dg-do compile } */
-/* { dg-options "-O2 -fdump-tree-optimized" } */
+/* { dg-options "-O2 -fdump-tree-optimized -ffast-math" } */
float a, b, c, d;
extern int printf (const char *, ...);
int main(void)
@@ -14,5 +14,5 @@ int main(void)
printf ("%f %f\n", e, f);
}
-/* { dg-final { scan-tree-dump-times "\\\+" 4 "optimized"} } */
+/* { dg-final { scan-tree-dump-times "\\\+" 2 "optimized"} } */
/* { dg-final { cleanup-tree-dump "optimized" } } */
Index: testsuite/gcc.dg/tree-ssa/reassoc-5.c
===================================================================
RCS file: testsuite/gcc.dg/tree-ssa/reassoc-5.c
diff -N testsuite/gcc.dg/tree-ssa/reassoc-5.c
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ testsuite/gcc.dg/tree-ssa/reassoc-5.c 8 Sep 2005 14:05:20 -0000
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+extern int printf (const char *, ...);
+int main(int argc, int b)
+{
+ /* We should be able to get rid of the a - i. */
+ int i;
+ for (i = 0; i < 50; i++)
+ {
+ int a = b + i;
+ int c = a - i;
+ int d = argc + b;
+ printf ("%d %d\n", c,d);
+ }
+}
+/* { dg-final { scan-tree-dump-times "a - i" 0 "optimized"} } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */
Index: testsuite/gcc.dg/tree-ssa/reassoc-6.c
===================================================================
RCS file: testsuite/gcc.dg/tree-ssa/reassoc-6.c
diff -N testsuite/gcc.dg/tree-ssa/reassoc-6.c
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ testsuite/gcc.dg/tree-ssa/reassoc-6.c 8 Sep 2005 14:05:20 -0000
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-reassoc" } */
+int main(int a, int b, int c, int d)
+{
+ /* Should be transformed into a + c + 8 */
+ int e = a + 3;
+ int f = c + 5;
+ int g = e + f;
+ return g;
+}
+
+/* { dg-final { scan-tree-dump-times "\\\+ 8" 1 "reassoc"} } */
+/* { dg-final { cleanup-tree-dump "reassoc" } } */
Index: testsuite/gcc.dg/tree-ssa/reassoc-7.c
===================================================================
RCS file: testsuite/gcc.dg/tree-ssa/reassoc-7.c
diff -N testsuite/gcc.dg/tree-ssa/reassoc-7.c
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ testsuite/gcc.dg/tree-ssa/reassoc-7.c 8 Sep 2005 14:05:20 -0000
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-reassoc" } */
+int main(int a, int b, int c, int d, int e, int f, int g, int h)
+{
+ /* Should be transformed into a + c + d + e + g + 15 */
+ int i = (a + 9) + (c + d);
+ int j = (e + 4) + (2 + g);
+ e = i + j;
+ return e;
+}
+/* { dg-final { scan-tree-dump-times "\\\+ 15" 1 "reassoc"} } */
+/* { dg-final { cleanup-tree-dump "reassoc" } } */
Index: testsuite/gcc.dg/tree-ssa/reassoc-8.c
===================================================================
RCS file: testsuite/gcc.dg/tree-ssa/reassoc-8.c
diff -N testsuite/gcc.dg/tree-ssa/reassoc-8.c
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ testsuite/gcc.dg/tree-ssa/reassoc-8.c 8 Sep 2005 14:05:20 -0000
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-reassoc" } */
+
+int main(int a, int b, int c, int d, int e, int f, int g, int h)
+{
+ /* e & ~e -> 0 */
+ int i = (a & 9) & (c & d);
+ int j = (~e & d) & (~c & e);
+ e = i & j;
+ return e;
+}
+/* { dg-final { scan-tree-dump-times "= 0" 1 "reassoc"} } */
+/* { dg-final { cleanup-tree-dump "reassoc" } } */
Index: testsuite/gcc.dg/tree-ssa/reassoc-9.c
===================================================================
RCS file: testsuite/gcc.dg/tree-ssa/reassoc-9.c
diff -N testsuite/gcc.dg/tree-ssa/reassoc-9.c
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ testsuite/gcc.dg/tree-ssa/reassoc-9.c 8 Sep 2005 14:05:20 -0000
@@ -0,0 +1,14 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-reassoc" } */
+
+int main(int a, int b, int c, int d, int e, int f, int g, int h)
+{
+ /* Should be transformed into e = 20 */
+ int i = (a + 9) + (c + 8);
+ int j = (-c + 1) + (-a + 2);
+
+ e = i + j;
+ return e;
+}
+/* { dg-final { scan-tree-dump-times "= 20" 1 "reassoc"} } */
+/* { dg-final { cleanup-tree-dump "reassoc" } } */
Index: testsuite/gcc.dg/tree-ssa/ssa-pre-2.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-2.c,v
retrieving revision 1.5
diff -u -p -r1.5 ssa-pre-2.c
--- testsuite/gcc.dg/tree-ssa/ssa-pre-2.c 4 Apr 2005 19:02:15 -0000 1.5
+++ testsuite/gcc.dg/tree-ssa/ssa-pre-2.c 8 Sep 2005 14:05:20 -0000
@@ -16,6 +16,7 @@ int motion_test1(int data, int data_0, i
return v * t * u;
}
/* We should eliminate one computation of data_0 + data_3 along the
- main path, causing one reload. */
-/* { dg-final { scan-tree-dump-times "Eliminated: 1" 1 "pre"} } */
+ main path, and one computation of v * i along the main path, causing
+ two eliminations. */
+/* { dg-final { scan-tree-dump-times "Eliminated: 2" 1 "pre"} } */
/* { dg-final { cleanup-tree-dump "pre" } } */