http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50633
--- Comment #4 from H.J. Lu <hjl.tools at gmail dot com> 2011-10-06 17:55:48
UTC ---
Here is a small testcase. shrink-wrap screwed up stack adjustment
for local variables:
[hjl@gnu-mic-2 pr50633]$ cat x.i
struct s { int val[16]; };
extern double f (struct s pb, double pc);
int main ()
{
struct s x;
int i;
for (i = 0; i < 16; i++)
x.val[i] = i + 1;
if (f (x, 10000.0L) != 10136.0L)
__builtin_abort ();
return 0;
}
[hjl@gnu-mic-2 pr50633]$ /export/build/gnu/gcc-x32/build-x86_64-linux/gcc/xgcc
-B/export/build/gnu/gcc-x32/build-x86_64-linux/gcc/ -mx32 -O -S x.i
-fno-shrink-wrap -o good.s
[hjl@gnu-mic-2 pr50633]$ /export/build/gnu/gcc-x32/build-x86_64-linux/gcc/xgcc
-B/export/build/gnu/gcc-x32/build-x86_64-linux/gcc/ -mx32 -O -S x.i -o bad.s
[hjl@gnu-mic-2 pr50633]$ cat good.s
.file "x.i"
.text
.globl main
.type main, @function
main:
.LFB0:
.cfi_startproc
subq $136, %rsp
.cfi_def_cfa_offset 144
movl $0, %eax
movl %esp, %ecx
addl $60, %ecx
.L2:
addl $1, %eax
leal (%rcx,%rax,4), %edx
movl %eax, (%edx)
cmpl $16, %eax
jne .L2
movq 64(%rsp), %rax
movq %rax, (%rsp)
movq 72(%rsp), %rax
movq %rax, 8(%rsp)
movq 80(%rsp), %rax
movq %rax, 16(%rsp)
movq 88(%rsp), %rax
movq %rax, 24(%rsp)
movq 96(%rsp), %rax
movq %rax, 32(%rsp)
movq 104(%rsp), %rax
movq %rax, 40(%rsp)
movq 112(%rsp), %rax
movq %rax, 48(%rsp)
movq 120(%rsp), %rax
movq %rax, 56(%rsp)
movsd .LC0(%rip), %xmm0
call f
ucomisd .LC1(%rip), %xmm0
jp .L5
je .L7
.L5:
call abort
.L7:
movl $0, %eax
addq $136, %rsp
.cfi_def_cfa_offset 8
ret
.cfi_endproc
.LFE0:
.size main, .-main
.section .rodata.cst8,"aM",@progbits,8
.align 8
.LC0:
.long 0
.long 1086556160
.align 8
.LC1:
.long 0
.long 1086573568
.ident "GCC: (GNU) 4.7.0 20111005 (experimental)"
.section .note.GNU-stack,"",@progbits
[hjl@gnu-mic-2 pr50633]$ cat bad.s
.file "x.i"
.text
.globl main
.type main, @function
main:
.LFB0:
.cfi_startproc
movl $0, %eax
movl %esp, %ecx
addl $60, %ecx
.L2:
addl $1, %eax
leal (%rcx,%rax,4), %edx
movl %eax, (%edx)
cmpl $16, %eax
jne .L2
subq $136, %rsp
.cfi_def_cfa_offset 144
movq 64(%rsp), %rax
movq %rax, (%rsp)
movq 72(%rsp), %rax
movq %rax, 8(%rsp)
movq 80(%rsp), %rax
movq %rax, 16(%rsp)
movq 88(%rsp), %rax
movq %rax, 24(%rsp)
movq 96(%rsp), %rax
movq %rax, 32(%rsp)
movq 104(%rsp), %rax
movq %rax, 40(%rsp)
movq 112(%rsp), %rax
movq %rax, 48(%rsp)
movq 120(%rsp), %rax
movq %rax, 56(%rsp)
movsd .LC0(%rip), %xmm0
call f
ucomisd .LC1(%rip), %xmm0
jp .L5
je .L7
.L5:
call abort
.L7:
movl $0, %eax
addq $136, %rsp
.cfi_def_cfa_offset 8
ret
.cfi_endproc
.LFE0:
.size main, .-main
.section .rodata.cst8,"aM",@progbits,8
.align 8
.LC0:
.long 0
.long 1086556160
.align 8
.LC1:
.long 0
.long 1086573568
.ident "GCC: (GNU) 4.7.0 20111005 (experimental)"
.section .note.GNU-stack,"",@progbits
[hjl@gnu-mic-2 pr50633]$ diff -up good.s bad.s
--- good.s 2011-10-06 10:52:45.410961190 -0700
+++ bad.s 2011-10-06 10:52:48.938896097 -0700
@@ -5,8 +5,6 @@
main:
.LFB0:
.cfi_startproc
- subq $136, %rsp
- .cfi_def_cfa_offset 144
movl $0, %eax
movl %esp, %ecx
addl $60, %ecx
@@ -16,6 +14,8 @@ main:
movl %eax, (%edx)
cmpl $16, %eax
jne .L2
+ subq $136, %rsp
+ .cfi_def_cfa_offset 144
movq 64(%rsp), %rax
movq %rax, (%rsp)
movq 72(%rsp), %rax
[hjl@gnu-mic-2 pr50633]$
