public inbox for gcc-cvs@sourceware.org
help / color / mirror / Atom feed
* [gcc r13-1375] if-to-switch: properly allow side effects only for first condition
@ 2022-07-01 6:48 Martin Liska
0 siblings, 0 replies; only message in thread
From: Martin Liska @ 2022-07-01 6:48 UTC (permalink / raw)
To: gcc-cvs
https://gcc.gnu.org/g:618bac5b486832edd3f8eb3ada74740e389dfcb8
commit r13-1375-g618bac5b486832edd3f8eb3ada74740e389dfcb8
Author: Martin Liska <mliska@suse.cz>
Date: Thu Jun 30 15:00:17 2022 +0200
if-to-switch: properly allow side effects only for first condition
Properly allow side effects only for a first BB in a condition chain.
PR tree-optimization/106126
gcc/ChangeLog:
* gimple-if-to-switch.cc (struct condition_info): Save
has_side_effect.
(find_conditions): Parse all BBs.
(pass_if_to_switch::execute): Allow only side effects for first
BB.
gcc/testsuite/ChangeLog:
* gcc.dg/tree-ssa/pr106126.c: New test.
Diff:
---
gcc/gimple-if-to-switch.cc | 20 +++++++++++---------
gcc/testsuite/gcc.dg/tree-ssa/pr106126.c | 12 ++++++++++++
2 files changed, 23 insertions(+), 9 deletions(-)
diff --git a/gcc/gimple-if-to-switch.cc b/gcc/gimple-if-to-switch.cc
index 70daae2003c..4441206c481 100644
--- a/gcc/gimple-if-to-switch.cc
+++ b/gcc/gimple-if-to-switch.cc
@@ -61,9 +61,11 @@ struct condition_info
{
typedef auto_vec<std::pair<gphi *, tree>> mapping_vec;
- condition_info (gcond *cond): m_cond (cond), m_bb (gimple_bb (cond)),
- m_forwarder_bb (NULL), m_ranges (), m_true_edge (NULL), m_false_edge (NULL),
- m_true_edge_phi_mapping (), m_false_edge_phi_mapping ()
+ condition_info (gcond *cond, bool has_side_effect): m_cond (cond),
+ m_bb (gimple_bb (cond)), m_forwarder_bb (NULL), m_ranges (),
+ m_true_edge (NULL), m_false_edge (NULL),
+ m_true_edge_phi_mapping (), m_false_edge_phi_mapping (),
+ m_has_side_effect (has_side_effect)
{
m_ranges.create (0);
}
@@ -80,6 +82,7 @@ struct condition_info
edge m_false_edge;
mapping_vec m_true_edge_phi_mapping;
mapping_vec m_false_edge_phi_mapping;
+ bool m_has_side_effect;
};
/* Recond PHI mapping for an original edge E and save these into vector VEC. */
@@ -389,16 +392,11 @@ find_conditions (basic_block bb,
if (cond == NULL)
return;
- /* An empty conditions_in_bbs indicates we are processing the first
- basic-block then no need check side effect. */
- if (!conditions_in_bbs->is_empty () && !no_side_effect_bb (bb))
- return;
-
tree lhs = gimple_cond_lhs (cond);
tree rhs = gimple_cond_rhs (cond);
tree_code code = gimple_cond_code (cond);
- condition_info *info = new condition_info (cond);
+ condition_info *info = new condition_info (cond, !no_side_effect_bb (bb));
gassign *def;
if (code == NE_EXPR
@@ -536,6 +534,10 @@ pass_if_to_switch::execute (function *fun)
if ((*info2)->m_false_edge != e)
break;
+ /* Only the first BB in a chain can have a side effect. */
+ if (info->m_has_side_effect)
+ break;
+
chain->m_entries.safe_push (*info2);
bitmap_set_bit (seen_bbs, e->src->index);
info = *info2;
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr106126.c b/gcc/testsuite/gcc.dg/tree-ssa/pr106126.c
new file mode 100644
index 00000000000..2f0fd44164b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr106126.c
@@ -0,0 +1,12 @@
+/* PR tree-optimization/106126 */
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+char *var_1;
+void pool_conda_matchspec() {
+ for (; var_1 && *var_1 &&
+ *var_1 != '<' && *var_1 != '>' &&
+ *var_1 != '!' && *var_1 != '~';)
+ if (*var_1 >= 'A' && *var_1 <= 'Z')
+ *var_1 += 'A';
+}
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2022-07-01 6:48 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-07-01 6:48 [gcc r13-1375] if-to-switch: properly allow side effects only for first condition Martin Liska
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).