Hi!
After merging from trunk to get #pragma omp for zero iteration handling
fixes, this is a port of that for expand_omp_simd which doesn't exist on the
trunk.
Committed to gomp-4_0-branch.
2013-05-20 Jakub Jelinek <ja...@redhat.com>
* omp-low.c (expand_omp_simd): For collapse > 1 loops,
if some loop condition might be not true initially, add runtime
test and skip the whole loop.
--- gcc/omp-low.c.jj 2013-05-20 13:34:42.000000000 +0200
+++ gcc/omp-low.c 2013-05-20 15:07:59.466798336 +0200
@@ -5120,7 +5120,7 @@ static void
expand_omp_simd (struct omp_region *region, struct omp_for_data *fd)
{
tree type, t;
- basic_block entry_bb, cont_bb, exit_bb, l0_bb, l1_bb, l2_bb;
+ basic_block entry_bb, cont_bb, exit_bb, l0_bb, l1_bb, l2_bb, l2_dom_bb;
gimple_stmt_iterator gsi;
gimple stmt;
bool broken_loop = region->cont == NULL;
@@ -5151,6 +5151,7 @@ expand_omp_simd (struct omp_region *regi
l2_bb = single_succ (l1_bb);
}
exit_bb = region->exit;
+ l2_dom_bb = l1_bb;
gsi = gsi_last_bb (entry_bb);
@@ -5164,6 +5165,41 @@ expand_omp_simd (struct omp_region *regi
{
tree itype = TREE_TYPE (fd->loops[i].v);
+ if (SSA_VAR_P (fd->loop.n2)
+ && ((t = fold_binary (fd->loops[i].cond_code, boolean_type_node,
+ fold_convert (itype, fd->loops[i].n1),
+ fold_convert (itype, fd->loops[i].n2)))
+ == NULL_TREE || !integer_onep (t)))
+ {
+ tree n1, n2;
+ n1 = fold_convert (itype, unshare_expr (fd->loops[i].n1));
+ n1 = force_gimple_operand_gsi (&gsi, n1, true, NULL_TREE,
+ true, GSI_SAME_STMT);
+ n2 = fold_convert (itype, unshare_expr (fd->loops[i].n2));
+ n2 = force_gimple_operand_gsi (&gsi, n2, true, NULL_TREE,
+ true, GSI_SAME_STMT);
+ stmt = gimple_build_cond (fd->loops[i].cond_code, n1, n2,
+ NULL_TREE, NULL_TREE);
+ gsi_insert_before (&gsi, stmt, GSI_SAME_STMT);
+ if (walk_tree (gimple_cond_lhs_ptr (stmt),
+ expand_omp_regimplify_p, NULL, NULL)
+ || walk_tree (gimple_cond_rhs_ptr (stmt),
+ expand_omp_regimplify_p, NULL, NULL))
+ {
+ gsi = gsi_for_stmt (stmt);
+ gimple_regimplify_operands (stmt, &gsi);
+ }
+ e = split_block (entry_bb, stmt);
+ ne = make_edge (entry_bb, l2_bb, EDGE_FALSE_VALUE);
+ ne->probability = REG_BR_PROB_BASE / 2000 - 1;
+ e->flags = EDGE_TRUE_VALUE;
+ e->probability = REG_BR_PROB_BASE - ne->probability;
+ if (l2_dom_bb == l1_bb)
+ l2_dom_bb = entry_bb;
+ entry_bb = e->dest;
+ e = BRANCH_EDGE (entry_bb);
+ gsi = gsi_last_bb (entry_bb);
+ }
if (POINTER_TYPE_P (itype))
itype = signed_type_for (itype);
t = build_int_cst (itype, (fd->loops[i].cond_code == LT_EXPR
@@ -5324,7 +5360,7 @@ expand_omp_simd (struct omp_region *regi
ne->probability = REG_BR_PROB_BASE / 8;
set_immediate_dominator (CDI_DOMINATORS, l1_bb, entry_bb);
- set_immediate_dominator (CDI_DOMINATORS, l2_bb, l1_bb);
+ set_immediate_dominator (CDI_DOMINATORS, l2_bb, l2_dom_bb);
set_immediate_dominator (CDI_DOMINATORS, l0_bb, l1_bb);
if (!broken_loop)
Jakub
