[all-commits] [llvm/llvm-project] acac29: [DAGCombiner] Don't fold FCOPYSIGN vector sign ope...

Luís Marques via All-commits all-commits at lists.llvm.org
Wed Feb 10 06:26:35 PST 2021


  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: acac29ca4250281358ccdf6a258597a68999cd2d
      https://github.com/llvm/llvm-project/commit/acac29ca4250281358ccdf6a258597a68999cd2d
  Author: Luís Marques <luismarques at lowrisc.org>
  Date:   2021-02-10 (Wed, 10 Feb 2021)

  Changed paths:
    M llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
    M llvm/test/CodeGen/AArch64/vector-fcopysign.ll
    M llvm/test/CodeGen/X86/combine-fcopysign.ll

  Log Message:
  -----------
  [DAGCombiner] Don't fold FCOPYSIGN vector sign operand casts

Avoid doing the following combine for vector types:

```
copysign(x, fp_extend(y)) -> copysign(x, y)
copysign(x, fp_round(y)) -> copysign(x, y)
```

That combine seemed to impede the selection of vector instruction and cause
a mess in some circumstances.

Differential Revision: https://reviews.llvm.org/D96037




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