[Bug tree-optimization/78821] GCC7: Copying whole 32 bits structure field by field not optimised into copying whole 32 bits at once

[ubizjak at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78821

Uroš Bizjak <ubizjak at gmail dot com> changed:

           What    |Removed                     |Added
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                 CC|                            |jakub at gcc dot gnu.org

--- Comment #7 from Uroš Bizjak <ubizjak at gmail dot com> ---
On a related note, following testcase:

--cut here--
typedef __SIZE_TYPE__ size_t;

void baz (char *buf, unsigned int data)
{
  buf[0] = data;
  buf[1] = data >> 8;

  buf[2] = ~data >> 8;
  buf[3] = ~data;
}
--cut here--

could be optimized with -march=haswell to:

        movw    %si, (%rdi)
        notl    %eax
        movbew  %si, 2(%rdi)