On June 26, 2019 10:17:26 AM GMT+02:00, Uros Bizjak <ubiz...@gmail.com> wrote:
>Now that TARGET_MMX_WITH_SSE is implemented, the compiler should be
>able to auto-vectorize:
>
>void
>foo (char *restrict r, char *restrict a)
>{
> for (int i = 0; i < 8; i++)
> r[i] += a[i];
>}
>
>Attached patch enables the conversion and produces:
>
>foo:
> movq (%rdi), %xmm1
> movq (%rsi), %xmm0
> paddb %xmm1, %xmm0
> movq %xmm0, (%rdi)
> ret
>
>Please note that the patch regresses
>
>FAIL: gcc.target/i386/sse2-vect-simd-11.c scan-tree-dump-times vect
>"vectorized [1-3] loops" 2
>FAIL: gcc.target/i386/sse2-vect-simd-15.c scan-tree-dump-times vect
>"vectorized [1-3] loops" 2
>
>For some reason, the compiler decides to vectorize with 8-byte
>vectors, resulting in:
>
>missed: not vectorized: relevant stmt not supported: _8 = (short
>unsigned int) _4;
>missed: bad operation or unsupported loop bound.
>missed: couldn't vectorize loop
>
>However, the unpatched compiler is able to vectorize loop using
>16-byte vectors. It looks that the compiler should re-run
>vectorization with wider vectors, if vectorization with narrower
>vectors fails. Jakub, Richard, do you have any insight in this issue?
Double check the ordering of the vector size pushes - it should already iterate
but first successful wins.
Richard.
>2019-06-26 Uroš Bizjak <ubiz...@gmail.com>
>
> * config/i386/i386.c (ix86_autovectorize_vector_sizes):
> Autovectorize 8-byte vectors for TARGET_MMX_WITH_SSE.
>
>testsuite/ChangeLog:
>
>2019-06-26 Uroš Bizjak <ubiz...@gmail.com>
>
> * lib/target-supports.exp (available_vector_sizes)
> <[istarget i?86-*-*] || [istarget x86_64-*-*]>: Add
> 64-bit vectors for !ia32.
>
>The patch was bootstrapped and regression tested on x86_64-linux-gnu
>{,-m32}.
>
>Uros.
