https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93507
--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
The fix for PR94703 at least makes RTL optimze it to
foo:
.LFB0:
.cfi_startproc
movl %edi, %eax
ret
GIMPLE is still
foo (unsigned int x)
{
long unsigned int dst;
long unsigned int _5;
<bb 2> [local count: 1073741824]:
dst = 0;
MEM <unsigned int> [(char * {ref-all})&dst] = x_1(D);
_5 = dst;
dst ={v} {CLOBBER};
return _5;
I have a patch teaching VN partial def handling to turn it into a
BIT_INSERT and a match.pd pattern to simplify some BIT_INSERTs
to conversions. Queued for GCC 11.
