From ab71fd7ac7a2307723117c796e7ae4d7e9711058 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Tue, 13 Feb 2024 11:58:00 -0800
Subject: [PATCH] x86-64: Use push2/pop2 only if the incoming stack is 16-byte
aligned
Since push2/pop2 requires 16-byte stack alignment, don't use them if the
incoming stack isn't 16-byte aligned.
gcc/
PR target/113876
* config/i386/i386.cc (ix86_pro_and_epilogue_can_use_push2pop2):
Return false if the incoming stack isn't 16-byte aligned.
gcc/testsuite/
PR target/113876
* gcc.target/i386/pr113876.c: New test.
---
gcc/config/i386/i386.cc | 6 ++++++
gcc/testsuite/gcc.target/i386/pr113876.c | 10 ++++++++++
2 files changed, 16 insertions(+)
create mode 100644 gcc/testsuite/gcc.target/i386/pr113876.c
diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
index dbb26e8f76ab..a4e12602f704 100644
--- a/gcc/config/i386/i386.cc
+++ b/gcc/config/i386/i386.cc
@@ -6807,6 +6807,12 @@ get_probe_interval (void)
static bool
ix86_pro_and_epilogue_can_use_push2pop2 (int nregs)
{
+ /* Use push2/pop2 only if the incoming stack is 16-byte aligned. */
+ unsigned int incoming_stack_boundary
+ = (crtl->parm_stack_boundary > ix86_incoming_stack_boundary
+ ? crtl->parm_stack_boundary : ix86_incoming_stack_boundary);
+ if (incoming_stack_boundary % 128 != 0)
+ return false;
int aligned = cfun->machine->fs.sp_offset % 16 == 0;
return TARGET_APX_PUSH2POP2
&& !cfun->machine->frame.save_regs_using_mov
diff --git a/gcc/testsuite/gcc.target/i386/pr113876.c b/gcc/testsuite/gcc.target/i386/pr113876.c
new file mode 100644
index 000000000000..fbf26f6ab8f2
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr113876.c
@@ -0,0 +1,10 @@
+/* { dg-do compile { target { lp64 } } } */
+/* { dg-options "-O -mapxf -mpreferred-stack-boundary=3 -finstrument-functions -mcmodel=large" } */
+
+void
+bar (unsigned long *p)
+{
+ p[0] = 0;
+ p[1] = 0;
+ p[2] = 0;
+}
--
GitLab