Implement computeKnownBits for min/max nodes
llvm-svn: 239378
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 804c080..cf51e75 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -2432,6 +2432,19 @@
KnownOne = KnownOne.trunc(BitWidth);
break;
}
+ case ISD::SMIN:
+ case ISD::SMAX:
+ case ISD::UMIN:
+ case ISD::UMAX: {
+ APInt Op0Zero, Op0One;
+ APInt Op1Zero, Op1One;
+ computeKnownBits(Op.getOperand(0), Op0Zero, Op0One, Depth);
+ computeKnownBits(Op.getOperand(1), Op1Zero, Op1One, Depth);
+
+ KnownZero = Op0Zero & Op1Zero;
+ KnownOne = Op0One & Op1One;
+ break;
+ }
case ISD::FrameIndex:
case ISD::TargetFrameIndex:
if (unsigned Align = InferPtrAlignment(Op)) {
@@ -2535,7 +2548,15 @@
if (Tmp == 1) return 1; // Early out.
Tmp2 = ComputeNumSignBits(Op.getOperand(2), Depth+1);
return std::min(Tmp, Tmp2);
-
+ case ISD::SMIN:
+ case ISD::SMAX:
+ case ISD::UMIN:
+ case ISD::UMAX:
+ Tmp = ComputeNumSignBits(Op.getOperand(0), Depth + 1);
+ if (Tmp == 1)
+ return 1; // Early out.
+ Tmp2 = ComputeNumSignBits(Op.getOperand(1), Depth + 1);
+ return std::min(Tmp, Tmp2);
case ISD::SADDO:
case ISD::UADDO:
case ISD::SSUBO: