[PATCH] D39289: [SelectionDAG] Support 'bit preserving' floating points bitcasts on computeKnownBits/ComputeNumSignBits

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon created this revision.

For cases where we know the floating point representations match the bitcasted integer equivalent, allow bitcasting to these types.

This is especially useful for the X86 floating point compare results which return all/zero bits but as a floating point type.


Repository:
  rL LLVM

https://reviews.llvm.org/D39289

Files:
  lib/CodeGen/SelectionDAG/SelectionDAG.cpp
  test/CodeGen/X86/avx512-vec-cmp.ll
  test/CodeGen/X86/bitcast-and-setcc-256.ll
  test/CodeGen/X86/bitcast-and-setcc-512.ll
  test/CodeGen/X86/cast-vsel.ll
  test/CodeGen/X86/combine-fcopysign.ll
  test/CodeGen/X86/machine-cp.ll
  test/CodeGen/X86/vector-compare-results.ll

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