[llvm] [X86] Lower `minimum`/`maximum`/`minimumnum`/`maximumnum` using bitwise operations (PR #170069)

[Matt Arsenault via llvm-commits]

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@@ -29751,10 +29745,80 @@ static SDValue LowerFMINIMUM_FMAXIMUM(SDValue Op, const X86Subtarget &Subtarget,
 
   SDValue MinMax = DAG.getNode(MinMaxOp, DL, VT, NewX, NewY, Op->getFlags());
 
+  // We handle signed-zero ordering by taking the larger (or smaller) sign bit.
+  if (ShouldHandleZeros) {
+    const fltSemantics &Sem = VT.getFltSemantics();
+    unsigned EltBits = VT.getScalarSizeInBits();
+    bool IsFakeVector = !VT.isVector();
+    MVT LogicVT = VT.getSimpleVT();
+    if (IsFakeVector)
+      LogicVT = (VT == MVT::f64)   ? MVT::v2f64
----------------
arsenm wrote:

```suggestion
      LogicVT = VT == MVT::f64   ? MVT::v2f64
```

https://github.com/llvm/llvm-project/pull/170069