Migrate some more fadd and fsub cases away from UnsafeFPMath control to utilize NoSignedZerosFPMath options control

Summary: Honoring no signed zeroes is also available as a user control through clang separately regardless of fastmath or UnsafeFPMath context, DAG guards should reflect this context.

Reviewers: spatel, arsenm, hfinkel, wristow, craig.topper

Reviewed By: spatel

Subscribers: rampitec, foad, nhaehnle, wuzish, nemanjai, jvesely, wdng, javed.absar, MaskRay, jsji

Differential Revision: https://reviews.llvm.org/D65170

llvm-svn: 367486

2 files changed, 7 insertions, 7 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 2e5ba82af22..185a9a72fa3 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -839,7 +839,7 @@ static char isNegatibleForFree(SDValue Op, bool LegalOperations,
     });
   }
   case ISD::FADD:
-    if (!Options->UnsafeFPMath && !Flags.hasNoSignedZeros())
+    if (!Options->NoSignedZerosFPMath && !Flags.hasNoSignedZeros())
       return 0;
 
     // After operation legalization, it might not be legal to create new FSUBs.
@@ -912,7 +912,7 @@ static SDValue GetNegatedExpression(SDValue Op, SelectionDAG &DAG,
     return DAG.getBuildVector(Op.getValueType(), SDLoc(Op), Ops);
   }
   case ISD::FADD:
-    assert(Options.UnsafeFPMath || Flags.hasNoSignedZeros());
+    assert(Options.NoSignedZerosFPMath || Flags.hasNoSignedZeros());
 
     // fold (fneg (fadd A, B)) -> (fsub (fneg A), B)
     if (isNegatibleForFree(Op.getOperand(0), LegalOperations,
@@ -12017,7 +12017,7 @@ SDValue DAGCombiner::visitFADD(SDNode *N) {
   // N0 + -0.0 --> N0 (also allowed with +0.0 and fast-math)
   ConstantFPSDNode *N1C = isConstOrConstSplatFP(N1, true);
   if (N1C && N1C->isZero())
-    if (N1C->isNegative() || Options.UnsafeFPMath || Flags.hasNoSignedZeros())
+    if (N1C->isNegative() || Options.NoSignedZerosFPMath || Flags.hasNoSignedZeros())
       return N0;
 
   if (SDValue NewSel = foldBinOpIntoSelect(N))
@@ -12075,7 +12075,7 @@ SDValue DAGCombiner::visitFADD(SDNode *N) {
   // If 'unsafe math' or reassoc and nsz, fold lots of things.
   // TODO: break out portions of the transformations below for which Unsafe is
   //       considered and which do not require both nsz and reassoc
-  if ((Options.UnsafeFPMath ||
+  if (((Options.UnsafeFPMath && Options.NoSignedZerosFPMath) ||
        (Flags.hasAllowReassociation() && Flags.hasNoSignedZeros())) &&
       AllowNewConst) {
     // fadd (fadd x, c1), c2 -> fadd x, c1 + c2
@@ -12194,7 +12194,7 @@ SDValue DAGCombiner::visitFSUB(SDNode *N) {
 
   // (fsub A, 0) -> A
   if (N1CFP && N1CFP->isZero()) {
-    if (!N1CFP->isNegative() || Options.UnsafeFPMath ||
+    if (!N1CFP->isNegative() || Options.NoSignedZerosFPMath ||
         Flags.hasNoSignedZeros()) {
       return N0;
     }
@@ -12221,7 +12221,7 @@ SDValue DAGCombiner::visitFSUB(SDNode *N) {
     }
   }
 
-  if ((Options.UnsafeFPMath ||
+  if (((Options.UnsafeFPMath && Options.NoSignedZerosFPMath) ||
       (Flags.hasAllowReassociation() && Flags.hasNoSignedZeros()))
       && N1.getOpcode() == ISD::FADD) {
     // X - (X + Y) -> -Y
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index c1d98a29d63..2520de49efb 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -4630,7 +4630,7 @@ SDValue SelectionDAG::getNode(unsigned Opcode, const SDLoc &DL, EVT VT,
       return getUNDEF(VT);
 
     // -(X-Y) -> (Y-X) is unsafe because when X==Y, -0.0 != +0.0
-    if ((getTarget().Options.UnsafeFPMath || Flags.hasNoSignedZeros()) &&
+    if ((getTarget().Options.NoSignedZerosFPMath || Flags.hasNoSignedZeros()) &&
         OpOpcode == ISD::FSUB)
       return getNode(ISD::FSUB, DL, VT, Operand.getOperand(1),
                      Operand.getOperand(0), Flags);