https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106022
Bug ID: 106022
Summary: [12/13 Regression] Enable vectorizer generates extra
load
Product: gcc
Version: 12.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: hjl.tools at gmail dot com
CC: crazylht at gmail dot com
Target Milestone: ---
[hjl@gnu-clx-1 gcc-bisect]$ cat x.c
void foo(char * c) {
c[0] = 0;
c[1] = 1;
c[2] = 2;
c[3] = 3;
}
[hjl@gnu-clx-1 gcc-bisect]$ gcc -O3 x.c -S
[hjl@gnu-clx-1 gcc-bisect]$ cat x.s
.file "x.c"
.text
.p2align 4
.globl foo
.type foo, @function
foo:
.LFB0:
.cfi_startproc
movl .LC0(%rip), %eax
movl %eax, (%rdi)
ret
.cfi_endproc
.LFE0:
.size foo, .-foo
.section .rodata.cst4,"aM",@progbits,4
.align 4
.LC0:
.byte 0
.byte 1
.byte 2
.byte 3
.ident "GCC: (GNU) 12.1.1 20220507 (Red Hat 12.1.1-1)"
.section .note.GNU-stack,"",@progbits
[hjl@gnu-clx-1 gcc-bisect]$ gcc -O3 x.c -S -fno-tree-vectorize
[hjl@gnu-clx-1 gcc-bisect]$ cat x.s
.file "x.c"
.text
.p2align 4
.globl foo
.type foo, @function
foo:
.LFB0:
.cfi_startproc
movl $50462976, (%rdi)
ret
.cfi_endproc
.LFE0:
.size foo, .-foo
.ident "GCC: (GNU) 12.1.1 20220507 (Red Hat 12.1.1-1)"
.section .note.GNU-stack,"",@progbits
[hjl@gnu-clx-1 gcc-bisect]$ /usr/gcc-11.2.1-x32/bin/gcc -S -O3 x.c
[hjl@gnu-clx-1 gcc-bisect]$ cat x.s
.file "x.c"
.text
.p2align 4
.globl foo
.type foo, @function
foo:
.LFB0:
.cfi_startproc
movl $50462976, (%rdi)
ret
.cfi_endproc
.LFE0:
.size foo, .-foo
.ident "GCC: (GNU) 11.2.1 20220118"
.section .note.GNU-stack,"",@progbits
[hjl@gnu-clx-1 gcc-bisect]$
