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From: "crazylht at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/104723] New: [12 regression] Redundant usage of stack
Date: Tue, 01 Mar 2022 08:35:42 +0000 [thread overview]
Message-ID: <bug-104723-4@http.gcc.gnu.org/bugzilla/> (raw)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104723
Bug ID: 104723
Summary: [12 regression] Redundant usage of stack
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: crazylht at gmail dot com
Target Milestone: ---
Host: x86_64-pc-linux-gnu
Target: x86_64-*-* i?86-*-*
bool f256(char *a)
{
char t[] = "012345678901234567890123456789012345678901234567";
return __builtin_memcpy(a, &t[0], sizeof(t)) == 0;
}
https://godbolt.org/z/jcjbT4d8e
gcc12 generates
vmovdqa64 ymm31, YMMWORD PTR .LC0[rip]
xor eax, eax
vmovdqu64 YMMWORD PTR [rsp-72], ymm31
vmovdqa64 ymm31, YMMWORD PTR .LC1[rip]
vmovdqu64 YMMWORD PTR [rsp-55], ymm31
vmovdqu64 ymm31, YMMWORD PTR [rsp-72]
vmovdqu64 YMMWORD PTR [rdi], ymm31
vmovdqu64 ymm31, YMMWORD PTR [rsp-55]
vmovdqu64 YMMWORD PTR [rdi+17], ymm31
Why build “unaligned string" by stack instead of putting it directly into the
constant pool.
gcc 11 seems fine.
f256(char*):
vmovdqa xmm0, XMMWORD PTR .LC0[rip]
mov BYTE PTR [rdi+48], 0
vmovdqu XMMWORD PTR [rdi], xmm0
vmovdqa xmm0, XMMWORD PTR .LC1[rip]
xor eax, eax
vmovdqu XMMWORD PTR [rdi+16], xmm0
vmovdqa xmm0, XMMWORD PTR .LC2[rip]
vmovdqu XMMWORD PT
next reply other threads:[~2022-03-01 8:35 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-01 8:35 crazylht at gmail dot com [this message]
2022-03-01 8:44 ` [Bug target/104723] " crazylht at gmail dot com
2022-03-01 8:47 ` crazylht at gmail dot com
2022-03-01 12:38 ` lili.cui at intel dot com
2022-03-01 13:41 ` rguenth at gcc dot gnu.org
2022-03-01 16:00 ` jakub at gcc dot gnu.org
2022-03-01 16:07 ` jakub at gcc dot gnu.org
2022-03-01 18:45 ` hjl.tools at gmail dot com
2022-03-01 18:50 ` hjl.tools at gmail dot com
2022-03-02 8:11 ` lili.cui at intel dot com
2022-04-22 16:28 ` jakub at gcc dot gnu.org
2022-04-24 7:37 ` lili.cui at intel dot com
2022-04-26 9:41 ` jakub at gcc dot gnu.org
2022-05-06 8:32 ` [Bug target/104723] [12/13 " jakub at gcc dot gnu.org
2022-07-26 12:58 ` rguenth at gcc dot gnu.org
2023-05-08 12:23 ` [Bug target/104723] [12/13/14 " rguenth at gcc dot gnu.org
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