commit 46f8c8ccf19e45b29452001471cabcc2c601e908
author Eric Christopher <echristo@gmail.com> Wed Feb 20 04:42:07 2019 +0000
committer Eric Christopher <echristo@gmail.com> Wed Feb 20 04:42:07 2019 +0000
tree 98c3af9194a0aea6ec29795ab2de71c803ff45a4
parent 796e6423ba13e3a03e52b47d6e1239d88b8d9304

Temporarily Revert "[X86][SLP] Enable SLP vectorization for 128-bit horizontal X86 instructions (add, sub)"

As this has broken the lto bootstrap build for 3 days and is
showing a significant regression on the Dither_benchmark results (from
the LLVM benchmark suite) -- specifically, on the
BENCHMARK_FLOYD_DITHER_128, BENCHMARK_FLOYD_DITHER_256, and
BENCHMARK_FLOYD_DITHER_512; the others are unchanged.  These have
regressed by about 28% on Skylake, 34% on Haswell, and over 40% on
Sandybridge.

This reverts commit r353923.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354434 91177308-0d34-0410-b5e6-96231b3b80d8