Expose isXxxConstant() functions from SelectionDAGNodes.h (NFC)

Summary:
Many target lowerings copy-paste the code to test SDValues for known constants.
This code can instead be shared in SelectionDAG.cpp, and reused in the targets.

Reviewers: MatzeB, andreadb, tstellarAMD

Subscribers: arsenm, jyknight, llvm-commits

Differential Revision: http://reviews.llvm.org/D14945

llvm-svn: 254085

1 files changed, 3 insertions, 10 deletions

diff --git a/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp b/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp
index f32e75a1eef..6f673f4f395 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp
@@ -2611,20 +2611,14 @@ bool AMDGPUTargetLowering::isHWTrueValue(SDValue Op) const {
   if (ConstantFPSDNode * CFP = dyn_cast<ConstantFPSDNode>(Op)) {
     return CFP->isExactlyValue(1.0);
   }
-  if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
-    return C->isAllOnesValue();
-  }
-  return false;
+  return isAllOnesConstant(Op);
 }
 
 bool AMDGPUTargetLowering::isHWFalseValue(SDValue Op) const {
   if (ConstantFPSDNode * CFP = dyn_cast<ConstantFPSDNode>(Op)) {
     return CFP->getValueAPF().isZero();
   }
-  if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
-    return C->isNullValue();
-  }
-  return false;
+  return isNullConstant(Op);
 }
 
 SDValue AMDGPUTargetLowering::CreateLiveInRegister(SelectionDAG &DAG,
@@ -2852,8 +2846,7 @@ unsigned AMDGPUTargetLowering::ComputeNumSignBitsForTargetNode(
       return 1;
 
     unsigned SignBits = 32 - Width->getZExtValue() + 1;
-    ConstantSDNode *Offset = dyn_cast<ConstantSDNode>(Op.getOperand(1));
-    if (!Offset || !Offset->isNullValue())
+    if (!isNullConstant(Op.getOperand(1)))
       return SignBits;
 
     // TODO: Could probably figure something out with non-0 offsets.