https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89993
Bug ID: 89993
Summary: Inconsistent incoming stack boundary
Product: gcc
Version: 8.3.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: hjl.tools at gmail dot com
CC: ubizjak at gmail dot com
Target Milestone: ---
Target: i386,x86-64
It looks like the default incoming stack isn't a constant:
[hjl@gnu-cfl-1 tmp]$ cat a.c
int tst2Foo(int*, int*, int);
int tst1Foo(int* pSrc, int* pDst, int len)
{
return tst2Foo(pSrc, pDst, len);
}
[hjl@gnu-cfl-1 tmp]$ gcc -mstackrealign -S -O2 a.c
[hjl@gnu-cfl-1 tmp]$ cat a.s
.file "a.c"
.text
.p2align 4,,15
.globl tst1Foo
.type tst1Foo, @function
tst1Foo:
.LFB0:
.cfi_startproc
jmp tst2Foo
.cfi_endproc
.LFE0:
.size tst1Foo, .-tst1Foo
.ident "GCC: (GNU) 8.3.1 20190311 (Red Hat 8.3.1-3)"
.section .note.GNU-stack,"",@progbits
[hjl@gnu-cfl-1 tmp]$ gcc -mstackrealign -S -O2 a.c -mincoming-stack-boundary=3
[hjl@gnu-cfl-1 tmp]$ cat a.s
.file "a.c"
.text
.p2align 4,,15
.globl tst1Foo
.type tst1Foo, @function
tst1Foo:
.LFB0:
.cfi_startproc
pushq %rbp
.cfi_def_cfa_offset 16
.cfi_offset 6, -16
movq %rsp, %rbp
.cfi_def_cfa_register 6
andq $-16, %rsp
call tst2Foo
leave
.cfi_def_cfa 7, 8
ret
.cfi_endproc
.LFE0:
.size tst1Foo, .-tst1Foo
.ident "GCC: (GNU) 8.3.1 20190311 (Red Hat 8.3.1-3)"
.section .note.GNU-stack,"",@progbits
[hjl@gnu-cfl-1 tmp]$ cat b.c
#include <xmmintrin.h>
int tst2Foo(int*, int*, int, __m128*);
int tst1Foo(int* pSrc, int* pDst, int len)
{
__m128 x;
return tst2Foo(pSrc, pDst, len, &x);
}
[hjl@gnu-cfl-1 tmp]$ gcc -mstackrealign -S -O2 b.c -mincoming-stack-boundary=4
[hjl@gnu-cfl-1 tmp]$ cat b.s
.file "b.c"
.text
.p2align 4,,15
.globl tst1Foo
.type tst1Foo, @function
tst1Foo:
.LFB526:
.cfi_startproc
subq $24, %rsp
.cfi_def_cfa_offset 32
movq %rsp, %rcx
call tst2Foo
addq $24, %rsp
.cfi_def_cfa_offset 8
ret
.cfi_endproc
.LFE526:
.size tst1Foo, .-tst1Foo
.ident "GCC: (GNU) 8.3.1 20190311 (Red Hat 8.3.1-3)"
.section .note.GNU-stack,"",@progbits
[hjl@gnu-cfl-1 tmp]$
