From: Uros Bizjak <ubizjak@gmail.com>
To: "gcc-patches@gcc.gnu.org" <gcc-patches@gcc.gnu.org>
Cc: "H. J. Lu" <hjl.tools@gmail.com>
Subject: [PATCH, i386]: Allow -mpreferred-stack-boundary=3 for 64-bit targets independently of SSE (PR 53383)
Date: Tue, 28 Mar 2017 17:02:00 -0000 [thread overview]
Message-ID: <CAFULd4YEx4tau0HOZ0pdEr0Gp23eq46tUjadiFSXnY7jZjYqrA@mail.gmail.com> (raw)
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Hello!
As argued in the PR [1], limiting -mpreferred-stack-boundary=3 only
for non-SSE 64bit targets represent artificial limitation, restricting
compiler functionality and user freedom.
Attached patch allows -mpreferred-stack-boundary=3 in all cases. The
compiler will align stack when needed, imposing a small runtime
penalty for functions that require 16-byte alignment.
2017-03-28 Uros Bizjak <ubizjak@gmail.com>
PR target/53383
* config/i386/i386.c (ix86_option_override_internal): Always
allow -mpreferred-stack-boundary=3 for 64-bit targets.
testsuite/ChangeLog:
2017-03-28 Uros Bizjak <ubizjak@gmail.com>
PR target/53383
* gcc.target/i386/pr53383-1.c (dg-options): Remove -mno-sse.
* gcc.target/i386/pr53383-2.c (dg-options): Ditto.
* gcc.target/i386/pr53383-3.c (dg-options): Ditto.
Patch was bootstrapped and regression tested on x86_64-linux-gnu {,-m32}.
Committed to mainline SVN.
[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53383#c25
Uros.
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Index: config/i386/i386.c
===================================================================
--- config/i386/i386.c (revision 246531)
+++ config/i386/i386.c (working copy)
@@ -5927,9 +5927,8 @@ ix86_option_override_internal (bool main_args_p,
ix86_preferred_stack_boundary = PREFERRED_STACK_BOUNDARY_DEFAULT;
if (opts_set->x_ix86_preferred_stack_boundary_arg)
{
- int min = (TARGET_64BIT_P (opts->x_ix86_isa_flags)
- ? (TARGET_SSE_P (opts->x_ix86_isa_flags) ? 4 : 3) : 2);
- int max = (TARGET_SEH ? 4 : 12);
+ int min = TARGET_64BIT_P (opts->x_ix86_isa_flags)? 3 : 2;
+ int max = TARGET_SEH ? 4 : 12;
if (opts->x_ix86_preferred_stack_boundary_arg < min
|| opts->x_ix86_preferred_stack_boundary_arg > max)
Index: testsuite/gcc.target/i386/pr53383-1.c
===================================================================
--- testsuite/gcc.target/i386/pr53383-1.c (revision 246531)
+++ testsuite/gcc.target/i386/pr53383-1.c (working copy)
@@ -1,5 +1,5 @@
/* { dg-do compile } */
-/* { dg-options "-O2 -mno-sse -mpreferred-stack-boundary=3" } */
+/* { dg-options "-O2 -mpreferred-stack-boundary=3" } */
int
bar (int x)
Index: testsuite/gcc.target/i386/pr53383-2.c
===================================================================
--- testsuite/gcc.target/i386/pr53383-2.c (revision 246531)
+++ testsuite/gcc.target/i386/pr53383-2.c (working copy)
@@ -1,5 +1,5 @@
/* { dg-do compile } */
-/* { dg-options "-O2 -mno-sse -mpreferred-stack-boundary=3 -mincoming-stack-boundary=3" } */
+/* { dg-options "-O2 -mpreferred-stack-boundary=3 -mincoming-stack-boundary=3" } */
int
bar (int x)
Index: testsuite/gcc.target/i386/pr53383-3.c
===================================================================
--- testsuite/gcc.target/i386/pr53383-3.c (revision 246531)
+++ testsuite/gcc.target/i386/pr53383-3.c (working copy)
@@ -1,5 +1,5 @@
/* { dg-do compile } */
-/* { dg-options "-O2 -mno-sse -mincoming-stack-boundary=3 -mpreferred-stack-boundary=3" } */
+/* { dg-options "-O2 -mincoming-stack-boundary=3 -mpreferred-stack-boundary=3" } */
int
bar (int x)
reply other threads:[~2017-03-28 17:01 UTC|newest]
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