Revert "[SDAG] Fix fmaximum legalization errors (#142170)"

This reverts commit 58cc1675ec7b4aa5bc2dab56180cb7af1b23ade5.

I also made the incorrect assumption that we know both values are
+/-0.0 here as well. Revert for now.

1 files changed, 8 insertions, 10 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index c8fe897..e8e820a 100644
--- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -8610,18 +8610,16 @@ SDValue TargetLowering::expandFMINIMUM_FMAXIMUM(SDNode *N,
   // fminimum/fmaximum requires -0.0 less than +0.0
   if (!MinMaxMustRespectOrderedZero && !N->getFlags().hasNoSignedZeros() &&
       !DAG.isKnownNeverZeroFloat(RHS) && !DAG.isKnownNeverZeroFloat(LHS)) {
-    auto IsSpecificZero = [&](SDValue F) {
-      FloatSignAsInt State;
-      DAG.getSignAsIntValue(State, DL, F);
-      return DAG.getSetCC(DL, CCVT, State.IntValue,
-                          DAG.getConstant(0, DL, State.IntValue.getValueType()),
-                          IsMax ? ISD::SETEQ : ISD::SETNE);
-    };
     SDValue IsZero = DAG.getSetCC(DL, CCVT, MinMax,
                                   DAG.getConstantFP(0.0, DL, VT), ISD::SETOEQ);
-    SDValue LCmp =
-        DAG.getSelect(DL, VT, IsSpecificZero(LHS), LHS, MinMax, Flags);
-    SDValue RCmp = DAG.getSelect(DL, VT, IsSpecificZero(RHS), RHS, LCmp, Flags);
+    SDValue TestZero =
+        DAG.getTargetConstant(IsMax ? fcPosZero : fcNegZero, DL, MVT::i32);
+    SDValue LCmp = DAG.getSelect(
+        DL, VT, DAG.getNode(ISD::IS_FPCLASS, DL, CCVT, LHS, TestZero), LHS,
+        MinMax, Flags);
+    SDValue RCmp = DAG.getSelect(
+        DL, VT, DAG.getNode(ISD::IS_FPCLASS, DL, CCVT, RHS, TestZero), RHS,
+        LCmp, Flags);
     MinMax = DAG.getSelect(DL, VT, IsZero, RCmp, MinMax, Flags);
   }