public inbox for gcc-cvs@sourceware.org
help / color / mirror / Atom feed
* [gcc(refs/users/aoliva/heads/testme)] hardcmp: split before dispatch edge
@ 2022-03-23 23:41 Alexandre Oliva
0 siblings, 0 replies; only message in thread
From: Alexandre Oliva @ 2022-03-23 23:41 UTC (permalink / raw)
To: gcc-cvs
https://gcc.gnu.org/g:361f4fcac4d9e948d22bb7ad87a0251aef5b03e0
commit 361f4fcac4d9e948d22bb7ad87a0251aef5b03e0
Author: Alexandre Oliva <oliva@adacore.com>
Date: Wed Mar 23 20:16:22 2022 -0300
hardcmp: split before dispatch edge
If we harden a compare at the end of a block with an edge to the
abnormal dispatch block, it won't have a single successor. Arrange to
split the block at its final stmt so as to have a single succ.
for gcc/ChangeLog
PR middle-end/104975
* gimple-harden-conditionals.cc
(pass_harden_compares::execute): Force split in case of
multiple edges.
for gcc/testsuite/ChangeLog
PR middle-end/104975
* gcc.dg/pr104975.c: New.
Diff:
---
gcc/gimple-harden-conditionals.cc | 12 +++++++++---
gcc/testsuite/gcc.dg/pr104975.c | 20 ++++++++++++++++++++
2 files changed, 29 insertions(+), 3 deletions(-)
diff --git a/gcc/gimple-harden-conditionals.cc b/gcc/gimple-harden-conditionals.cc
index 6a5fc3fb9e1..be01f3ea8c4 100644
--- a/gcc/gimple-harden-conditionals.cc
+++ b/gcc/gimple-harden-conditionals.cc
@@ -509,10 +509,16 @@ pass_harden_compares::execute (function *fun)
gsi_insert_before (&gsi_split, asgnck, GSI_SAME_STMT);
/* We wish to insert a cond_expr after the compare, so arrange
- for it to be at the end of a block if it isn't. */
- if (!gsi_end_p (gsi_split))
+ for it to be at the end of a block if it isn't, and for it
+ to have a single successor in case there's more than
+ one, as in PR104975. */
+ if (!gsi_end_p (gsi_split)
+ || !single_succ_p (gsi_bb (gsi_split)))
{
- gsi_prev (&gsi_split);
+ if (!gsi_end_p (gsi_split))
+ gsi_prev (&gsi_split);
+ else
+ gsi_split = gsi_last_bb (gsi_bb (gsi_split));
basic_block obb = gsi_bb (gsi_split);
basic_block nbb = split_block (obb, gsi_stmt (gsi_split))->dest;
gsi_next (&gsi_split);
diff --git a/gcc/testsuite/gcc.dg/pr104975.c b/gcc/testsuite/gcc.dg/pr104975.c
new file mode 100644
index 00000000000..04532fc4443
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr104975.c
@@ -0,0 +1,20 @@
+/* { dg-do compile } */
+/* { dg-options "-O1 -fharden-compares -fno-inline -fno-ipa-pure-const" } */
+
+__attribute__ ((pure, returns_twice)) int
+bar (int);
+
+int
+quux (void)
+{
+ return 0;
+}
+
+int
+foo (short int x)
+{
+ x = !x;
+ bar (quux ());
+
+ return x;
+}
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2022-03-23 23:41 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-03-23 23:41 [gcc(refs/users/aoliva/heads/testme)] hardcmp: split before dispatch edge Alexandre Oliva
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).