[PATCH] D132837: [ISel] Enable generating more fma instructions.

[Jay Foad via Phabricator via llvm-commits]

foad added a comment.

I think the patch looks good now, but I am a little confused by the test changes: one of them now uses fmac instead of mac, and the other uses mad instead of fma.

Also could you add another version of fmac_sequence_innermost_fmul to show that it still works if you swap the operands of the outermost fadd?



================
Comment at: llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp:14175
+    SDValue TmpFMA = FMA;
+    while (E && TmpFMA && isFusedOp(TmpFMA)) {
+      SDValue FMul = TmpFMA->getOperand(2);
----------------
You don't need to test TmpFMA here. Optionally, this loop could be rewritten as:
```
  if (E) {
    do {
      ...
    } while (isFusedOp(TmpFMA));
  }
```


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D132837/new/

https://reviews.llvm.org/D132837