https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124697
Bug ID: 124697
Summary: Unnecessary stack realignment
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: hjl.tools at gmail dot com
Target Milestone: ---
On x86-64, for
typedef struct {
double a;
double b;
double c;
double d;
} c __attribute__((aligned(32)));
extern double d;
void
e (float a1, float a2, float a3, float a4, float a5, float a6, c f)
{
d = f.a;
}
-O2 generates
pushq %rbp
movq %rsp, %rbp
andq $-32, %rsp
movdqu 16(%rbp), %xmm0
movaps %xmm0, -32(%rsp)
movsd -32(%rsp), %xmm0
movsd %xmm0, d(%rip)
leave
ret
MEM_ALIGN (stack_parm) is properly aligned according to ISA
and ABI as set by target. There is no need to realign stack
if address isn't taken.
