http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47812
Summary: [x32] __builtin_strlen is miscompiled at -O2
Product: gcc
Version: 4.6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
AssignedTo: [email protected]
ReportedBy: [email protected]
CC: [email protected]
On x32 branch, I got
[hjl@gnu-6 strcat-1]$ cat tester.c
char one[50] = "ijk";
int
main (void)
{
return __builtin_strlen (one) != 3;
}
[hjl@gnu-6 strcat-1]$ make tester.s
/usr/gcc-4.6.0-x32/bin/gcc -mx32 -g -O2 -S tester.c -o tester.s
[hjl@gnu-6 strcat-1]$ cat tester.s
.file "tester.c"
.text
.Ltext0:
.section .text.startup,"ax",@progbits
.p2align 4,,15
.globl main
.type main, @function
main:
.LFB0:
.file 1 "tester.c"
.loc 1 4 0
.cfi_startproc
.loc 1 5 0
movl $one, %edx
.L2:
movl (%rdx), %eax
addq $4, %rdx
leal -16843009(%eax), %ecx
notl %eax
andl %eax, %ecx
andl $-2139062144, %ecx
je .L2
.loc 1 6 0
movl $1, %eax
ret
.cfi_endproc
This always returns 1 instead of 0.
