https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83171
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
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Last reconfirmed|2017-11-26 00:00:00 |2021-8-19
--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
>Clang (-O2, using libstdc++) and MSVC(/O2, Visual 2017) seem to handle this
>correctly.
clang is definitely able to handle it.
We should inline the popcount too if the target does not support popcount but
that is a different bug report I had saw before.
anyways here is a reduced testcase:
#include <stdint.h>
#include <stddef.h>
size_t foo1(uint32_t value)
{
unsigned char t = value;
return __builtin_popcount(t);
}
size_t foo2(uint32_t value)
{
unsigned char t = value;
unsigned int t1 = t;
return __builtin_popcountl(t1);
}
----- CUT ----
Note for aarch64, it does not matter as we always zero_extend to 64bit, though
I suspect there might be a way to remove the addv if we are just doing one byte
popcount.
