https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113722
Bug ID: 113722
Summary: Folding of __builtin_bswap128 doesn't work anymore
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: regression
Assignee: unassigned at gcc dot gnu.org
Reporter: bouanto at zoho dot com
Target Milestone: ---
With the following code:
#include <stdio.h>
int main(int argc, char* argv[]) {
__uint128_t res = __builtin_bswap128 (2);
printf("Value: %ld\n", res >> 64);
res = __builtin_bswap128 (argc + 1);
printf("Value: %ld\n", res >> 64);
}
it gives the following output in gcc 13.2.1:
Value: 144115188075855872
Value: 144115188075855872
while it gives the following output in the master branch, commit
2c27aa8d75113f404bf9cd39364611af386d9719:
Value: 0
Value: 144115188075855872
So it seems to be a regression in the folding of wide_int::bswap.
