[PATCH] D145866: [DAG] visitAND - fold (and (any_ext V), c) -> (zero_ext (and (trunc V), c)) if profitable.

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon created this revision.
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Try to more aggressively narrow masks of extended values.

This is mainly for cases where the mask is trying to zero out any_extended upper bits, assuming we can zext/trunc the values for free.

This catches a few actual missed folds, as well as helps canonicalize a number of other cases which were being caught in isel etc.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D145866

Files:
  llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
  llvm/test/CodeGen/AMDGPU/amdgpu-codegenprepare-idiv.ll
  llvm/test/CodeGen/AMDGPU/load-constant-i16.ll
  llvm/test/CodeGen/AMDGPU/load-global-i16.ll
  llvm/test/CodeGen/AMDGPU/promote-constOffset-to-imm.ll
  llvm/test/CodeGen/X86/3addr-or.ll
  llvm/test/CodeGen/X86/abdu.ll
  llvm/test/CodeGen/X86/addcarry.ll
  llvm/test/CodeGen/X86/avx512cd-intrinsics-upgrade.ll
  llvm/test/CodeGen/X86/avx512cdvl-intrinsics-upgrade.ll
  llvm/test/CodeGen/X86/avx512fp16-mov.ll
  llvm/test/CodeGen/X86/cmp-concat.ll
  llvm/test/CodeGen/X86/dag-update-nodetomatch.ll
  llvm/test/CodeGen/X86/is_fpclass-fp80.ll
  llvm/test/CodeGen/X86/memset-inline.ll
  llvm/test/CodeGen/X86/memset-nonzero.ll
  llvm/test/CodeGen/X86/memset-vs-memset-inline.ll
  llvm/test/CodeGen/X86/narrow-shl-cst.ll
  llvm/test/CodeGen/X86/pr30562.ll
  llvm/test/CodeGen/X86/pr35763.ll
  llvm/test/CodeGen/X86/subcarry.ll
  llvm/test/CodeGen/X86/switch-phi-const.ll
  llvm/test/CodeGen/X86/switch.ll

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