https://gcc.gnu.org/g:8b959ca27ee95ba32e5a587e0490f6cb49ef9760
commit r14-11924-g8b959ca27ee95ba32e5a587e0490f6cb49ef9760
Author: H.J. Lu <hjl.to...@gmail.com>
Date: Tue Jul 29 11:22:35 2025 -0700
x86: Transform to "pushq $-1; popq reg" for -Oz
commit 4c80062d7b8c272e2e193b8074a8440dbb4fe588
Author: H.J. Lu <hjl.to...@gmail.com>
Date: Sun May 25 07:40:29 2025 +0800
x86: Enable *mov<mode>_(and|or) only for -Oz
disabled transformation from "movq $-1,reg" to "pushq $-1; popq reg" for
-Oz. But for legacy integer registers, the former is 4 bytes and the
latter is 3 bytes. Enable such transformation for -Oz.
gcc/
PR target/120427
* config/i386/i386.md (peephole2): Transform "movq $-1,reg" to
"pushq $-1; popq reg" for -Oz if reg is a legacy integer register.
gcc/testsuite/
PR target/120427
* gcc.target/i386/pr120427-5.c: New test.
Signed-off-by: H.J. Lu <hjl.to...@gmail.com>
(cherry picked from commit 71dae74158d05b75e367629ce21da3f0a2945576)
Diff:
---
gcc/config/i386/i386.md | 3 ++-
gcc/testsuite/gcc.target/i386/pr120427-5.c | 10 ++++++++++
2 files changed, 12 insertions(+), 1 deletion(-)
diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index 3ed4b2938b93..b11cab30ee3c 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -2862,7 +2862,8 @@
(match_operand:SWI248 1 "const_int_operand"))]
"optimize_insn_for_size_p () && optimize_size > 1
&& operands[1] != const0_rtx
- && operands[1] != constm1_rtx
+ && (operands[1] != constm1_rtx
+ || (<MODE>mode == DImode && LEGACY_INT_REG_P (operands[0])))
&& IN_RANGE (INTVAL (operands[1]), -128, 127)
&& !ix86_red_zone_used
&& REGNO (operands[0]) != SP_REG"
diff --git a/gcc/testsuite/gcc.target/i386/pr120427-5.c
b/gcc/testsuite/gcc.target/i386/pr120427-5.c
new file mode 100644
index 000000000000..7199aef7924d
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr120427-5.c
@@ -0,0 +1,10 @@
+/* { dg-do compile { target { ! ia32 } } } */
+/* { dg-options "-Oz" } */
+
+long long
+func1 (void)
+{
+ return -1;
+}
+/* { dg-final { scan-assembler-times "pushq\[ \\t\]+\\\$-1" 1 } } */
+/* { dg-final { scan-assembler-times "popq\[ \\t\]+%rax" 1 } } */
