https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104151
Barnabás Pőcze <pobrn at protonmail dot com> changed:
What |Removed |Added
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CC| |pobrn at protonmail dot com
--- Comment #15 from Barnabás Pőcze <pobrn at protonmail dot com> ---
Sorry, I haven't found a better issue. But I think the example below exhibits
the same or a very similar issue.
I would expect the following code
void f(unsigned char *p, std::uint32_t x, std::uint32_t y)
{
p[0] = x >> 24;
p[1] = x >> 16;
p[2] = x >> 8;
p[3] = x >> 0;
p[4] = y >> 24;
p[5] = y >> 16;
p[6] = y >> 8;
p[7] = y >> 0;
}
to be compiled to something along the lines of
f(unsigned char*, unsigned int, unsigned int):
bswap esi
bswap edx
mov DWORD PTR [rdi], esi
mov DWORD PTR [rdi+4], edx
ret
however, I get scores of bitwise operations instead if `-fno-tree-vectorize` is
not specified.
https://gcc.godbolt.org/z/z51K6qorv
