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* [Bug c/98161] New: [11 Regression] Incorrect stack realignment on __force_align_arg_pointer__+-mavx @ 2020-12-06 10:06 slyfox at gcc dot gnu.org 2020-12-06 17:41 ` [Bug c/98161] [11 Regression] Incorrect stack realignment on __force_align_arg_pointer__ with -msse4 by r11-446 hjl.tools at gmail dot com ` (3 more replies) 0 siblings, 4 replies; 5+ messages in thread From: slyfox at gcc dot gnu.org @ 2020-12-06 10:06 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98161 Bug ID: 98161 Summary: [11 Regression] Incorrect stack realignment on __force_align_arg_pointer__+-mavx Product: gcc Version: 11.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c Assignee: unassigned at gcc dot gnu.org Reporter: slyfox at gcc dot gnu.org Target Milestone: --- The bug was initially observed as a miscompilation of wine-5.22 built with gcc-11 -march=sandybridge. gcc-10 seems to generate something that works. Here is the extracted executable reproducer. It should return 12, but returns 56: // $ cat bug.c.c typedef unsigned short u16; typedef unsigned int u32; typedef unsigned char u8; u32 __attribute__((__force_align_arg_pointer__)) unreach( const u16 * pu16, u16 *dst, u32 dstlen, const u8 *src, u32 srclen ) { for (u32 i = dstlen; srclen && i; i--, srclen--, src++, dst++) { u16 off = pu16[*src]; if (off) { src++; srclen--; *dst = pu16[off + *src]; } } return 56; } u32 __attribute__((__force_align_arg_pointer__)) __attribute__((noipa)) bug( const u16 * pu16, u16 *dst, u32 dstlen, const u8 *src, u32 srclen ) { if (pu16) /* Branch should not execute, but stack realignment * reads wrong 'pu16' value from stack. */ return unreach(pu16, dst, dstlen, src, srclen); return (srclen < dstlen) ? srclen : dstlen; } int main() { /* Should return 12 */ return bug(0, 0, 12, 0, 34); } Running the example: $ x86_64-pc-linux-gnu-gcc -m32 -fno-PIC -fno-builtin -pipe -fcf-protection=none -fno-stack-protector -fno-omit-frame-pointer -O1 -mavx -o bug bug.c.c; ./bug ; echo $? 12 $ x86_64-pc-linux-gnu-gcc -m32 -fno-PIC -fno-builtin -pipe -fcf-protection=none -fno-stack-protector -fno-omit-frame-pointer -O2 -mavx -o bug bug.c.c; ./bug ; echo $? 56 Looking at generated code %ebp and %ecx are confused as a pointer to arguments on stack: bug: leal 4(%esp), %ecx ; argument pointer andl $-16, %esp ; %esp is realigned pushl -4(%ecx) pushl %ebp movl %esp, %ebp ; %ebp points to realigned location pushl %ebx vmovd 16(%ebp), %xmm1 ; arg3(pu16) BUG: arguments are read ; related to %ebp, not %ecx vmovd 24(%ebp), %xmm2 ; arg5(dstlen) movl 8(%ebp), %edx ; arg1(srclen) pushl %ecx vpminud %xmm2, %xmm1, %xmm0 movl 12(%ebp), %ecx movl 20(%ebp), %ebx vmovd %xmm0, %eax testl %edx, %edx je .L21 subl $4, %esp vmovd %xmm2, (%esp) pushl %ebx subl $4, %esp vmovd %xmm1, (%esp) pushl %ecx pushl %edx call unreach addl $20, %esp .L21: leal -8(%ebp), %esp popl %ecx popl %ebx popl %ebp leal -4(%ecx), %esp ret ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c/98161] [11 Regression] Incorrect stack realignment on __force_align_arg_pointer__ with -msse4 by r11-446 2020-12-06 10:06 [Bug c/98161] New: [11 Regression] Incorrect stack realignment on __force_align_arg_pointer__+-mavx slyfox at gcc dot gnu.org @ 2020-12-06 17:41 ` hjl.tools at gmail dot com 2020-12-06 18:52 ` [Bug target/98161] " hjl.tools at gmail dot com ` (2 subsequent siblings) 3 siblings, 0 replies; 5+ messages in thread From: hjl.tools at gmail dot com @ 2020-12-06 17:41 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98161 H.J. Lu <hjl.tools at gmail dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- Summary|[11 Regression] Incorrect |[11 Regression] Incorrect |stack realignment on |stack realignment on |__force_align_arg_pointer__ |__force_align_arg_pointer__ |+-mavx |with -msse4 by r11-446 Target Milestone|--- |11.0 CC| |crazylht at gmail dot com, | |hjl.tools at gmail dot com, | |wwwhhhyyy333 at gmail dot com Status|UNCONFIRMED |NEW Last reconfirmed| |2020-12-06 Ever confirmed|0 |1 --- Comment #1 from H.J. Lu <hjl.tools at gmail dot com> --- It is triggered by r11-446. -m32 -msse2 -O2 is OK. But -m32 -msse4 -O2 is not. Hongyu, can you take a look? ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug target/98161] [11 Regression] Incorrect stack realignment on __force_align_arg_pointer__ with -msse4 by r11-446 2020-12-06 10:06 [Bug c/98161] New: [11 Regression] Incorrect stack realignment on __force_align_arg_pointer__+-mavx slyfox at gcc dot gnu.org 2020-12-06 17:41 ` [Bug c/98161] [11 Regression] Incorrect stack realignment on __force_align_arg_pointer__ with -msse4 by r11-446 hjl.tools at gmail dot com @ 2020-12-06 18:52 ` hjl.tools at gmail dot com 2020-12-06 20:57 ` cvs-commit at gcc dot gnu.org 2020-12-06 21:12 ` hjl.tools at gmail dot com 3 siblings, 0 replies; 5+ messages in thread From: hjl.tools at gmail dot com @ 2020-12-06 18:52 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98161 H.J. Lu <hjl.tools at gmail dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- Keywords| |patch Component|c |target URL| |https://gcc.gnu.org/piperma | |il/gcc-patches/2020-Decembe | |r/561224.html --- Comment #2 from H.J. Lu <hjl.tools at gmail dot com> --- A patch is posted at https://gcc.gnu.org/pipermail/gcc-patches/2020-December/561224.html ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug target/98161] [11 Regression] Incorrect stack realignment on __force_align_arg_pointer__ with -msse4 by r11-446 2020-12-06 10:06 [Bug c/98161] New: [11 Regression] Incorrect stack realignment on __force_align_arg_pointer__+-mavx slyfox at gcc dot gnu.org 2020-12-06 17:41 ` [Bug c/98161] [11 Regression] Incorrect stack realignment on __force_align_arg_pointer__ with -msse4 by r11-446 hjl.tools at gmail dot com 2020-12-06 18:52 ` [Bug target/98161] " hjl.tools at gmail dot com @ 2020-12-06 20:57 ` cvs-commit at gcc dot gnu.org 2020-12-06 21:12 ` hjl.tools at gmail dot com 3 siblings, 0 replies; 5+ messages in thread From: cvs-commit at gcc dot gnu.org @ 2020-12-06 20:57 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98161 --- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by H.J. Lu <hjl@gcc.gnu.org>: https://gcc.gnu.org/g:6643ca0be6f34786b686415e457de96d0d9fbd2d commit r11-5806-g6643ca0be6f34786b686415e457de96d0d9fbd2d Author: H.J. Lu <hjl.tools@gmail.com> Date: Sun Dec 6 10:43:16 2020 -0800 x86: Check mode of pseudo register push commit 266f44a91c0c9705d3d18e82d7c5bab32927a18f Author: H.J. Lu <hjl.tools@gmail.com> Date: Sun May 17 10:10:34 2020 -0700 x86: Allow V1TI vector register pushes Add V1TI vector register push and split it after reload to a sequence of: (set (reg:P SP_REG) (plus:P SP_REG) (const_int -8))) (set (match_dup 0) (match_dup 1)) added a pseudo register push check. But (insn 13 12 14 3 (set (mem:SI (pre_dec:SI (reg/f:SI 7 sp)) [0 S4 A32]) (reg/v:SI 87 [ srclen ])) "x.c":37:16 54 {*pushsi2} (expr_list:REG_DEAD (reg/v:SI 87 [ srclen ]) (expr_list:REG_ARGS_SIZE (const_int 4 [0x4]) (nil)))) is not a pseudo register push. In 64-bit mode, mode of pseudo register push is TImode. In 32-bit mode, it is DImode. Add pseudo register push mode check to pseudo_reg_set. gcc/ PR target/98161 * config/i386/i386-features.c (pseudo_reg_set): Check mode of pseudo register push. gcc/testsuite/ * gcc.target/i386/pr98161.c: New test. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug target/98161] [11 Regression] Incorrect stack realignment on __force_align_arg_pointer__ with -msse4 by r11-446 2020-12-06 10:06 [Bug c/98161] New: [11 Regression] Incorrect stack realignment on __force_align_arg_pointer__+-mavx slyfox at gcc dot gnu.org ` (2 preceding siblings ...) 2020-12-06 20:57 ` cvs-commit at gcc dot gnu.org @ 2020-12-06 21:12 ` hjl.tools at gmail dot com 3 siblings, 0 replies; 5+ messages in thread From: hjl.tools at gmail dot com @ 2020-12-06 21:12 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98161 H.J. Lu <hjl.tools at gmail dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- Resolution|--- |FIXED Status|NEW |RESOLVED --- Comment #4 from H.J. Lu <hjl.tools at gmail dot com> --- Fixed for GCC 11. ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2020-12-06 21:12 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2020-12-06 10:06 [Bug c/98161] New: [11 Regression] Incorrect stack realignment on __force_align_arg_pointer__+-mavx slyfox at gcc dot gnu.org 2020-12-06 17:41 ` [Bug c/98161] [11 Regression] Incorrect stack realignment on __force_align_arg_pointer__ with -msse4 by r11-446 hjl.tools at gmail dot com 2020-12-06 18:52 ` [Bug target/98161] " hjl.tools at gmail dot com 2020-12-06 20:57 ` cvs-commit at gcc dot gnu.org 2020-12-06 21:12 ` hjl.tools at gmail dot com
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