https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126560
Bug ID: 126560
Summary: [15/16/17 Regression] wrong code at -O3 on aarch64
Product: gcc
Version: 17.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: xxs_chy at outlook dot com
Target Milestone: ---
Reproducer: https://godbolt.org/z/MWrb9TYeq
Testcase:
#include <stdint.h>
#include <stdio.h>
#define BITCAST(DST_TYPE, SRC_TYPE, VALUE)
\
(union {
\
SRC_TYPE src;
\
DST_TYPE dst
\
}){ VALUE }
\
.dst
typedef uint8_t v2u8 __attribute__((vector_size(2)));
uint16_t g1;
uint32_t g6;
uint16_t g7 = 7252;
uint8_t g10;
uint8_t g14;
void launch()
{
_Bool c4 = g14;
v2u8 bc6;
if (g6 != 4) goto lbl_sw_def3;
lbl_sw2:
bc6 = BITCAST(v2u8, uint16_t, g7);
if ((int8_t)g10 == -8) goto lbl_br7;
while (c4);
g10 = (178 & g14) / 22;
return;
lbl_sw_def3:
if (4 != g1)
{
g14 = g7;
goto lbl_sw2;
}
lbl_br7:
g1 = BITCAST(uint16_t, v2u8, bc6);
goto lbl_sw_def3;
}
int main()
{
launch();
uint64_t __chk = g10;
printf("checksum=0x%016llx\n", (unsigned long long)__chk);
}
This case outputs checksum=0x0000000000000000 at -O0, and outputs
checksum=0x0000000000000046 at -O3.
