[llvm] relaxed simd fma (PR #147487)

[via llvm-commits]

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@@ -3412,6 +3418,37 @@ static SDValue performSETCCCombine(SDNode *N,
   return SDValue();
 }
 
+static SDValue performFAddCombine(SDNode *N, SelectionDAG &DAG) {
+  assert(N->getOpcode() == ISD::FADD);
+  using namespace llvm::SDPatternMatch;
+  if (!N->getFlags().hasFastMath())
+    return SDValue();
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badumbatish wrote:

I'm not sure when I see sth such as `fadd fast ....` in the selection dag input, which flag should i check for?

https://github.com/llvm/llvm-project/pull/147487