[X86] stack realignment is incorrect when Spill/restore BP is used

[mahesh-attarde]

Recently PR addressed #81048 as Fix for Issue #17204
We addressed issue regarding "Spill/restore FP/BP around instructions in which they are clobbered"

After merge of PR, We saw runtime fails with general protection fault. It was at vmovdqa64 %zmm19, 0x90(%rsp) where effective address end up unaligned.
Check more details on #114791 discussion.

Repro from @rnk
https://godbolt.org/z/s16MxPME3

#include <immintrin.h>
int f() {
    __m512i aligned{};
    asm volatile ("vmovdqa64 %%zmm0, %0" : "=m"(aligned) : "m"(aligned) : "rbp");
    return aligned[0];
}
---->
f():
        push    rbp
        mov     rbp, rsp
        and     rsp, -64
        sub     rsp, 128
....
        push    rbp
        push    rax
        vmovdqa64       zmmword ptr [rsp], zmm0
        add     rsp, 8
        pop     rbp
        mov     rax, qword ptr [rsp]
        mov     rsp, rbp
        pop     rbp
        ret

This is one of such issues.

[llvmbot]

@llvm/issue-subscribers-backend-x86

Author: Mahesh-Attarde (mahesh-attarde)

Recently PR addressed https://github.com//pull/81048 as Fix for Issue https://github.com//issues/17204 We addressed issue regarding "Spill/restore FP/BP around instructions in which they are clobbered"

After merge of PR, We saw runtime fails with general protection fault. It was at vmovdqa64 %zmm19, 0x90(%rsp) where effective address end up unaligned.
Check more details on #114791 discussion.

Repro from @rnk
https://godbolt.org/z/s16MxPME3

#include <immintrin.h>
int f() {
    __m512i aligned{};
    asm volatile ("vmovdqa64 %%zmm0, %0" : "=m"(aligned) : "m"(aligned) : "rbp");
    return aligned[0];
}
---->
f():
        push    rbp
        mov     rbp, rsp
        and     rsp, -64
        sub     rsp, 128
....
        push    rbp
        push    rax
        vmovdqa64       zmmword ptr [rsp], zmm0
        add     rsp, 8
        pop     rbp
        mov     rax, qword ptr [rsp]
        mov     rsp, rbp
        pop     rbp
        ret

This is one of such issues.