[TargetLowering] Remove NoSignedZerosFPMath uses (llvm#160975)

Remove NoSignedZerosFPMath in TargetLowering part, users should always
use instruction level fast math flags.

Author: paperchalice

llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp

@@ -7492,7 +7492,6 @@ SDValue TargetLowering::getNegatedExpression(SDValue Op, SelectionDAG &DAG,
   // Pre-increment recursion depth for use in recursive calls.
   ++Depth;
   const SDNodeFlags Flags = Op->getFlags();
-  const TargetOptions &Options = DAG.getTarget().Options;
   EVT VT = Op.getValueType();
   unsigned Opcode = Op.getOpcode();
 
@@ -7572,7 +7571,7 @@ SDValue TargetLowering::getNegatedExpression(SDValue Op, SelectionDAG &DAG,
     return DAG.getBuildVector(VT, DL, Ops);
   }
   case ISD::FADD: {
-    if (!Options.NoSignedZerosFPMath && !Flags.hasNoSignedZeros())
+    if (!Flags.hasNoSignedZeros())
       break;
 
     // After operation legalization, it might not be legal to create new FSUBs.
@@ -7617,7 +7616,7 @@ SDValue TargetLowering::getNegatedExpression(SDValue Op, SelectionDAG &DAG,
   }
   case ISD::FSUB: {
     // We can't turn -(A-B) into B-A when we honor signed zeros.
-    if (!Options.NoSignedZerosFPMath && !Flags.hasNoSignedZeros())
+    if (!Flags.hasNoSignedZeros())
       break;
 
     SDValue X = Op.getOperand(0), Y = Op.getOperand(1);
@@ -7678,7 +7677,7 @@ SDValue TargetLowering::getNegatedExpression(SDValue Op, SelectionDAG &DAG,
   }
   case ISD::FMA:
   case ISD::FMAD: {
-    if (!Options.NoSignedZerosFPMath && !Flags.hasNoSignedZeros())
+    if (!Flags.hasNoSignedZeros())
       break;
 
     SDValue X = Op.getOperand(0), Y = Op.getOperand(1), Z = Op.getOperand(2);
@@ -8797,7 +8796,6 @@ SDValue TargetLowering::expandFMINIMUMNUM_FMAXIMUMNUM(SDNode *Node,
   EVT VT = Node->getValueType(0);
   EVT CCVT = getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT);
   bool IsMax = Opc == ISD::FMAXIMUMNUM;
-  const TargetOptions &Options = DAG.getTarget().Options;
   SDNodeFlags Flags = Node->getFlags();
 
   unsigned NewOp =
@@ -8858,8 +8856,8 @@ SDValue TargetLowering::expandFMINIMUMNUM_FMAXIMUMNUM(SDNode *Node,
   // TODO: We need quiet sNaN if strictfp.
 
   // Fixup signed zero behavior.
-  if (Options.NoSignedZerosFPMath || Flags.hasNoSignedZeros() ||
-      DAG.isKnownNeverZeroFloat(LHS) || DAG.isKnownNeverZeroFloat(RHS)) {
+  if (Flags.hasNoSignedZeros() || DAG.isKnownNeverZeroFloat(LHS) ||
+      DAG.isKnownNeverZeroFloat(RHS)) {
     return MinMax;
   }
   SDValue TestZero =