[llvm] [InstSimplify] Optimize maximumnum and minimumnum (PR #139581)

[Matt Arsenault via llvm-commits]

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@@ -6725,32 +6735,43 @@ Value *llvm::simplifyBinaryIntrinsic(Intrinsic::ID IID, Type *ReturnType,
       return Op0;
 
     bool PropagateNaN = IID == Intrinsic::minimum || IID == Intrinsic::maximum;
-    bool IsMin = IID == Intrinsic::minimum || IID == Intrinsic::minnum;
-
-    // minnum(X, nan) -> X
-    // maxnum(X, nan) -> X
-    // minimum(X, nan) -> nan
-    // maximum(X, nan) -> nan
-    if (match(Op1, m_NaN()))
-      return PropagateNaN ? propagateNaN(cast<Constant>(Op1)) : Op0;
+    bool PropagateSNaN = IID == Intrinsic::minnum || IID == Intrinsic::maxnum;
+    bool IsMin = IID == Intrinsic::minimum || IID == Intrinsic::minnum ||
+                 IID == Intrinsic::minimumnum;
+
+    // minnum(x, qnan) -> x
+    // maxnum(x, qnan) -> x
+    // minnum(x, snan) -> qnan
+    // maxnum(x, snan) -> qnan
+    // minimum(X, nan) -> qnan
+    // maximum(X, nan) -> qnan
+    if (match(Op1, m_NaN())) {
+      if (PropagateNaN || (PropagateSNaN && match(Op1, m_sNaN())))
+        return propagateNaN(cast<Constant>(Op1));
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arsenm wrote:

Applying multiple matchers to the same value is a bit cumbersome; I also don't think this handles vectors with mixed snan and qnan elements correctly 

https://github.com/llvm/llvm-project/pull/139581