[PATCH] D111555: [LoopVectorize] Add strict reduction support for fmuladd intrinsic

[Paul Walker via Phabricator via llvm-commits]

paulwalker-arm added inline comments.


================
Comment at: llvm/lib/Analysis/IVDescriptors.cpp:205-210
+  // Recognise a call to the llvm.fmuladd intrinsic.
+  bool IsFMulAdd = RecurrenceDescriptor::isFMulAddIntrinsic(Exit);
+
+  if ((Exit->getOpcode() != Instruction::FAdd && !IsFMulAdd) ||
+      Exit != ExactFPMathInst)
     return false;
----------------
paulwalker-arm wrote:
> Just a suggestion but given this function no longer has a single instruction to care about perhaps it's worth being more explicit.  For example:
> ```
> if (Kind == RecurKind::FAdd && Exit->getOpcode() != Instruction::FAdd)
>   return false;
> if (Kind == RecurKind::FMulAdd && RecurrenceDescriptor::isFMulAddIntrinsic(Exit))
>   return false
> if (Exit != ExactFPMathInst)
>   return false;
> ```
Or rather:
```
if (Kind == RecurKind::FAdd && Exit->getOpcode() != Instruction::FAdd)
  return false;
if (Kind == RecurKind::FMulAdd && !RecurrenceDescriptor::isFMulAddIntrinsic(Exit))
  return false
if (Exit != ExactFPMathInst)
  return false;
```
:)


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  https://reviews.llvm.org/D111555/new/

https://reviews.llvm.org/D111555