Don't do the X * 0.0 -> 0.0 transformation in instcombine, because

instcombine doesn't know when it's safe. To partially compensate
for this, introduce new code to do this transformation in
dagcombine, which can use UnsafeFPMath.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72872 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 8 insertions, 5 deletions

diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 2c645e4208..c2c884e8d1 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -2807,16 +2807,19 @@ SDValue SelectionDAG::getNode(unsigned Opcode, DebugLoc DL, MVT VT,
     case ISD::ADDC:
     case ISD::ADDE:
     case ISD::SUB:
-    case ISD::FADD:
-    case ISD::FSUB:
-    case ISD::FMUL:
-    case ISD::FDIV:
-    case ISD::FREM:
     case ISD::UDIV:
     case ISD::SDIV:
     case ISD::UREM:
     case ISD::SREM:
       return N2;       // fold op(arg1, undef) -> undef
+    case ISD::FADD:
+    case ISD::FSUB:
+    case ISD::FMUL:
+    case ISD::FDIV:
+    case ISD::FREM:
+      if (UnsafeFPMath)
+        return N2;
+      break;
     case ISD::MUL:
     case ISD::AND:
     case ISD::SRL: