[PATCH] D42679: [DAGCombiner] When combining zero_extend of a truncate, only mask before extending for vectors.

Craig Topper via Phabricator via llvm-commits llvm-commits at lists.llvm.org
Tue Jan 30 01:16:53 PST 2018


craig.topper created this revision.
Herald added subscribers: javed.absar, nemanjai, jholewinski.
craig.topper added a reviewer: RKSimon.

Masking first, prevents the extend from being combine with loads. Its also interfering with some vXi1 extraction code.

Not sure if the other targets here are good or bad. Or if there's some other changes that could be made to recover any loss.


Repository:
  rL LLVM

https://reviews.llvm.org/D42679

Files:
  lib/CodeGen/SelectionDAG/DAGCombiner.cpp
  test/CodeGen/AArch64/arm64-aapcs.ll
  test/CodeGen/AArch64/arm64-arith.ll
  test/CodeGen/AArch64/bitfield.ll
  test/CodeGen/NVPTX/param-load-store.ll
  test/CodeGen/PowerPC/vec_extract_p9_2.ll
  test/CodeGen/SystemZ/insert-05.ll
  test/CodeGen/X86/3addr-or.ll
  test/CodeGen/X86/avx512cd-intrinsics-upgrade.ll
  test/CodeGen/X86/avx512cdvl-intrinsics-upgrade.ll
  test/CodeGen/X86/avx512vl-vec-masked-cmp.ll
  test/CodeGen/X86/memset-nonzero.ll
  test/CodeGen/X86/pr27591.ll
  test/CodeGen/X86/pr35763.ll
  test/CodeGen/X86/sext-i1.ll
  test/CodeGen/X86/swift-return.ll
  test/DebugInfo/X86/sdag-combine.ll

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