https://gcc.gnu.org/g:5a9a70a5837aba373e3f36a89943c52e37a19809
commit 5a9a70a5837aba373e3f36a89943c52e37a19809
Author: Michael Matz <m...@suse.de>
Date: Tue Jul 9 02:20:10 2024 +0200
x86-ssw: don't clobber flags
Diff:
---
gcc/config/i386/i386.cc | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
index 33e69e96008d..734802dbed4f 100644
--- a/gcc/config/i386/i386.cc
+++ b/gcc/config/i386/i386.cc
@@ -10878,8 +10878,12 @@ ix86_components_for_bb (basic_block bb)
}
static void
-ix86_disqualify_components (sbitmap, edge, sbitmap, bool)
+ix86_disqualify_components (sbitmap components, edge e, sbitmap, bool)
{
+ /* If the flags are needed at the start of e->dest then we can't insert
+ our stack adjustment insns (they default to flag-clobbering add/sub). */
+ if (bitmap_bit_p (DF_LIVE_IN (e->dest), FLAGS_REG))
+ bitmap_clear_bit (components, SW_FRAME);
}
static void
