[AMDGPU] Remove NoInfsFPMath uses (llvm#163028)

Only `ninf` should be used.

Author: paperchalice

llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp

@@ -2833,8 +2833,8 @@ SDValue AMDGPUTargetLowering::LowerFLOGCommon(SDValue Op,
     R = getMad(DAG, DL, VT, YH, CH, Mad1);
   }
 
-  const bool IsFiniteOnly = (Flags.hasNoNaNs() || Options.NoNaNsFPMath) &&
-                            (Flags.hasNoInfs() || Options.NoInfsFPMath);
+  const bool IsFiniteOnly =
+      (Flags.hasNoNaNs() || Options.NoNaNsFPMath) && Flags.hasNoInfs();
 
   // TODO: Check if known finite from source value.
   if (!IsFiniteOnly) {
@@ -3161,9 +3161,8 @@ SDValue AMDGPUTargetLowering::lowerFEXP(SDValue Op, SelectionDAG &DAG) const {
       DAG.getSetCC(SL, SetCCVT, X, UnderflowCheckConst, ISD::SETOLT);
 
   R = DAG.getNode(ISD::SELECT, SL, VT, Underflow, Zero, R);
-  const auto &Options = getTargetMachine().Options;
 
-  if (!Flags.hasNoInfs() && !Options.NoInfsFPMath) {
+  if (!Flags.hasNoInfs()) {
     SDValue OverflowCheckConst =
         DAG.getConstantFP(IsExp10 ? 0x1.344136p+5f : 0x1.62e430p+6f, SL, VT);
     SDValue Overflow =

llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp

@@ -3575,7 +3575,7 @@ bool AMDGPULegalizerInfo::legalizeFlogCommon(MachineInstr &MI,
 
   const bool IsFiniteOnly =
       (MI.getFlag(MachineInstr::FmNoNans) || TM.Options.NoNaNsFPMath) &&
-      (MI.getFlag(MachineInstr::FmNoInfs) || TM.Options.NoInfsFPMath);
+      MI.getFlag(MachineInstr::FmNoInfs);
 
   if (!IsFiniteOnly) {
     // Expand isfinite(x) => fabs(x) < inf
@@ -3864,9 +3864,7 @@ bool AMDGPULegalizerInfo::legalizeFExp(MachineInstr &MI,
 
   R = B.buildSelect(Ty, Underflow, Zero, R);
 
-  const auto &Options = MF.getTarget().Options;
-
-  if (!(Flags & MachineInstr::FmNoInfs) && !Options.NoInfsFPMath) {
+  if (!(Flags & MachineInstr::FmNoInfs)) {
     auto OverflowCheckConst =
         B.buildFConstant(Ty, IsExp10 ? 0x1.344136p+5f : 0x1.62e430p+6f);