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[gomp4] Avoiding predication for certain blocks
- From: Bernd Schmidt <bernds at codesourcery dot com>
- To: <gcc-patches at gnu dot org>
- Cc: Jakub Jelinek <jakub at redhat dot com>
- Date: Fri, 29 May 2015 18:23:21 +0200
- Subject: [gomp4] Avoiding predication for certain blocks
- Authentication-results: sourceware.org; auth=none
When predicating the code for OpenACC, we should avoid the entry block
in an offloaded region, which contains setup code that should be run in
every thread. The following patch adds a new marker statement that is
used to identify this block. Currently, predication doesn't happen
anyway due to an oversight in the algorithm, but I'll be fixing that in
a followup patch.
Committed on gomp-4_0-branch.
Bernd
Index: gcc/ChangeLog.gomp
===================================================================
--- gcc/ChangeLog.gomp (revision 223867)
+++ gcc/ChangeLog.gomp (working copy)
@@ -1,3 +1,18 @@
+2015-05-29 Bernd Schmidt <bernds@codesourcery.com>
+
+ * gimple.def (GIMPLE_OMP_ENTRY_END): New code.
+ * gimple.h (gimple_build_omp_entry_end): Declare.
+ (CASE_GIMPLE_OMP): Add GIMPLE_OMP_ENTRY_END.
+ * gimple.c (gimple_build_omp_entry_end): New function.
+ * gimple-low.c (lower_stmt): Handle GIMPLE_OMP_ENTRY_END.
+ * omp-low.c (expand_omp_target): Remove the entry end statement.
+ (predicate_bb): Don't predicate a block ending with
+ GIMPLE_OMP_ENTRY_END.
+ (lower_omp_target): Append a GIMPLE_OMP_ENTRY_END after the
+ ganglocal data allocation.
+ (make_gimple_omp_edges): Handle GIMPLE_OMP_ENTRY_END.
+ * gimple-pretty-print.c (pp_gimple_stmt_1): Likewise.
+
2015-05-28 Tom de Vries <tom@codesourcery.com>
* passes.def: Replace pass_copy_prop with pass_fre. Surround with
Index: gcc/gimple-low.c
===================================================================
--- gcc/gimple-low.c (revision 223867)
+++ gcc/gimple-low.c (working copy)
@@ -337,6 +337,7 @@ lower_stmt (gimple_stmt_iterator *gsi, s
case GIMPLE_OMP_ATOMIC_LOAD:
case GIMPLE_OMP_ATOMIC_STORE:
case GIMPLE_OMP_CONTINUE:
+ case GIMPLE_OMP_ENTRY_END:
break;
case GIMPLE_CALL:
Index: gcc/gimple-pretty-print.c
===================================================================
--- gcc/gimple-pretty-print.c (revision 223867)
+++ gcc/gimple-pretty-print.c (working copy)
@@ -2253,6 +2253,10 @@ pp_gimple_stmt_1 (pretty_printer *buffer
pp_string (buffer, "GIMPLE_SECTIONS_SWITCH");
break;
+ case GIMPLE_OMP_ENTRY_END:
+ pp_string (buffer, "GIMPLE_OMP_ENTRY_END");
+ break;
+
case GIMPLE_OMP_MASTER:
case GIMPLE_OMP_TASKGROUP:
case GIMPLE_OMP_ORDERED:
Index: gcc/gimple.c
===================================================================
--- gcc/gimple.c (revision 223867)
+++ gcc/gimple.c (working copy)
@@ -852,6 +852,15 @@ gimple_build_debug_source_bind_stat (tre
}
+/* Build a GIMPLE_OMP_ENTRY_END statement. */
+
+gimple
+gimple_build_omp_entry_end (void)
+{
+ return gimple_alloc (GIMPLE_OMP_ENTRY_END, 0);
+}
+
+
/* Build a GIMPLE_OMP_CRITICAL statement.
BODY is the sequence of statements for which only one thread can execute.
Index: gcc/gimple.def
===================================================================
--- gcc/gimple.def (revision 223867)
+++ gcc/gimple.def (working copy)
@@ -227,6 +227,10 @@ DEFGSCODE(GIMPLE_OMP_ATOMIC_STORE, "gimp
iteration in partially lowered OpenMP code. */
DEFGSCODE(GIMPLE_OMP_CONTINUE, "gimple_omp_continue", GSS_OMP_CONTINUE)
+/* GIMPLE_OMP_ENTRY_END marks the end of the unpredicated entry block
+ into an offloaded region. */
+DEFGSCODE(GIMPLE_OMP_ENTRY_END, "gimple_omp_entry_end", GSS_BASE)
+
/* GIMPLE_OMP_CRITICAL <NAME, BODY> represents
#pragma omp critical [name]
Index: gcc/gimple.h
===================================================================
--- gcc/gimple.h (revision 223867)
+++ gcc/gimple.h (working copy)
@@ -1351,6 +1351,7 @@ gimple gimple_build_omp_taskgroup (gimpl
gomp_continue *gimple_build_omp_continue (tree, tree);
gimple gimple_build_omp_ordered (gimple_seq);
gimple gimple_build_omp_return (bool);
+gimple gimple_build_omp_entry_end ();
gomp_sections *gimple_build_omp_sections (gimple_seq, tree);
gimple gimple_build_omp_sections_switch (void);
gomp_single *gimple_build_omp_single (gimple_seq, tree);
@@ -5597,6 +5598,7 @@ gimple_return_set_retbnd (gimple gs, tre
case GIMPLE_OMP_ORDERED: \
case GIMPLE_OMP_CRITICAL: \
case GIMPLE_OMP_RETURN: \
+ case GIMPLE_OMP_ENTRY_END: \
case GIMPLE_OMP_ATOMIC_LOAD: \
case GIMPLE_OMP_ATOMIC_STORE: \
case GIMPLE_OMP_CONTINUE
Index: gcc/omp-low.c
===================================================================
--- gcc/omp-low.c (revision 223867)
+++ gcc/omp-low.c (working copy)
@@ -9480,6 +9480,11 @@ expand_omp_target (struct omp_region *re
}
}
+ basic_block entry_succ_bb = single_succ (entry_bb);
+ gsi = gsi_last_bb (entry_succ_bb);
+ if (gimple_code (gsi_stmt (gsi)) == GIMPLE_OMP_ENTRY_END)
+ gsi_remove (&gsi, true);
+
if (offloaded
&& do_splitoff)
{
@@ -9501,7 +9506,6 @@ expand_omp_target (struct omp_region *re
tree data_arg = gimple_omp_target_data_arg (entry_stmt);
if (data_arg)
{
- basic_block entry_succ_bb = single_succ (entry_bb);
gimple_stmt_iterator gsi;
tree arg, narg;
gimple tgtcopy_stmt = NULL;
@@ -10131,6 +10135,8 @@ build_omp_regions_1 (basic_block bb, str
gcc_assert (parent);
parent->cont = bb;
}
+ else if (code == GIMPLE_OMP_ENTRY_END)
+ gcc_assert (parent);
else if (code == GIMPLE_OMP_SECTIONS_SWITCH)
{
/* GIMPLE_OMP_SECTIONS_SWITCH is part of
@@ -10308,6 +10314,9 @@ predicate_bb (basic_block bb, struct omp
basic_block skip_dest_bb = NULL;
basic_block *adjust_bb_ptr = NULL;
+ if (gimple_code (stmt) == GIMPLE_OMP_ENTRY_END)
+ return;
+
if (gimple_code (stmt) == GIMPLE_COND)
{
tree cond_var = create_tmp_var (boolean_type_node);
@@ -12705,6 +12714,7 @@ lower_omp_target (gimple_stmt_iterator *
if (offloaded)
{
+ gimple_seq_add_stmt (&new_body, gimple_build_omp_entry_end ());
if (has_reduction)
{
gimple_seq_add_seq (&irlist, tgt_body);
@@ -13442,6 +13452,7 @@ make_gimple_omp_edges (basic_block bb, s
fallthru = false;
break;
+ case GIMPLE_OMP_ENTRY_END:
case GIMPLE_OMP_ATOMIC_LOAD:
case GIMPLE_OMP_ATOMIC_STORE:
fallthru = true;