https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111384
Bug ID: 111384
Summary: missed optimization: GCC adds extra any extend when
storing subreg#0 multiple times
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: lis8215 at gmail dot com
Target Milestone: ---
Simple example:
void store_hi_twice(uint32_t src, uint16_t *dst1, uint16_t *dst2)
{
*dst1 = src;
*dst2 = src;
}
shows that GCC can't opt out unnecessary zero extend of the src's low half
aimed to store two or more times. Many targets are affected, although x86-64
don't.
