phiopt now has dominator queries but fails to compute dominance
info.
Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.
2021-05-04 Richard Biener <rguent...@suse.de>
PR tree-optimization/100414
* tree-ssa-phiopt.c (get_non_trapping): Do not compute dominance
info here.
(tree_ssa_phiopt_worker): But unconditionally here.
* gcc.dg/pr100414.c: New testcase.
---
gcc/testsuite/gcc.dg/pr100414.c | 9 +++++++++
gcc/tree-ssa-phiopt.c | 5 ++---
2 files changed, 11 insertions(+), 3 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/pr100414.c
diff --git a/gcc/testsuite/gcc.dg/pr100414.c b/gcc/testsuite/gcc.dg/pr100414.c
new file mode 100644
index 00000000000..7876f6b56e9
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr100414.c
@@ -0,0 +1,9 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fno-tree-dce -fno-tree-dse -fchecking" } */
+
+int i;
+void
+foo (void)
+{
+ i &= i && __builtin_bswap16 (i);
+}
diff --git a/gcc/tree-ssa-phiopt.c b/gcc/tree-ssa-phiopt.c
index 35ce51e5977..5c18ea16600 100644
--- a/gcc/tree-ssa-phiopt.c
+++ b/gcc/tree-ssa-phiopt.c
@@ -174,6 +174,8 @@ tree_ssa_phiopt_worker (bool do_store_elim, bool
do_hoist_loads, bool early_p)
bool cfgchanged = false;
hash_set<tree> *nontrap = 0;
+ calculate_dominance_info (CDI_DOMINATORS);
+
if (do_store_elim)
/* Calculate the set of non-trapping memory accesses. */
nontrap = get_non_trapping ();
@@ -2438,9 +2440,6 @@ get_non_trapping (void)
{
nt_call_phase = 0;
hash_set<tree> *nontrap = new hash_set<tree>;
- /* We're going to do a dominator walk, so ensure that we have
- dominance information. */
- calculate_dominance_info (CDI_DOMINATORS);
nontrapping_dom_walker (CDI_DOMINATORS, nontrap)
.walk (cfun->cfg->x_entry_block_ptr);
--
2.26.2
