[PATCH] D108619: [DAGCombine] Allow FMA combine with both FMA and FMAD

[Carl Ritson via Phabricator via llvm-commits]

critson marked an inline comment as done.
critson added inline comments.


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Comment at: llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp:13056
+    unsigned Opcode = N.getOpcode();
+    return (HasFMA && Opcode == ISD::FMA) || (HasFMAD && Opcode == ISD::FMAD);
+  };
----------------
foad wrote:
> Why do you need the HasFMA and HasFMAD checks here? I can see that you don't want to create //new// FMA instructions if FMA is not legal, but I can't see why you wouldn't want to combine existing FMAs.
> 
> In other words can this just be `return Opcode == ISD::FMA || Opcode == ISD::FMAD;`?
Sure, this yields some test changes (instruction count reductions).


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  https://reviews.llvm.org/D108619/new/

https://reviews.llvm.org/D108619