https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88922
Bug ID: 88922
Summary: Merge identical constants with different modes
Product: gcc
Version: 9.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: normal
Priority: P3
Component: rtl-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: glisse at gcc dot gnu.org
Target Milestone: ---
#include <stdint.h>
typedef int64_t v64 __attribute__((vector_size(16)));
typedef int32_t v32 __attribute__((vector_size(16)));
typedef int16_t v16 __attribute__((vector_size(16)));
int main(){
volatile v64 x = {1,2};
volatile v32 y = {1,0,2,0};
volatile v16 z = {1,0,0,0,2,0,0,0};
}
movdqa .LC0(%rip), %xmm0
xorl %eax, %eax
movaps %xmm0, -56(%rsp)
movdqa .LC1(%rip), %xmm0
movaps %xmm0, -40(%rsp)
movdqa .LC2(%rip), %xmm0
movaps %xmm0, -24(%rsp)
gcc fails to notice that the 3 constants are the same. I would have expected
the constant pool to be handled as an untyped collection of bits at the end.
