From 314ee04268c2556f987000d76fba6deb0cf73978 Mon Sep 17 00:00:00 2001
From: Artyom Skrobov <Artyom.Skrobov@arm.com>
Date: Wed, 25 Nov 2015 19:41:11 +0000
Subject: 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
---
 llvm/lib/Target/ARM/ARMISelLowering.cpp | 28 ++++++++--------------------
 1 file changed, 8 insertions(+), 20 deletions(-)

(limited to 'llvm/lib/Target/ARM/ARMISelLowering.cpp')

diff --git a/llvm/lib/Target/ARM/ARMISelLowering.cpp b/llvm/lib/Target/ARM/ARMISelLowering.cpp
index b9b37396187..7366697343e 100644
--- a/llvm/lib/Target/ARM/ARMISelLowering.cpp
+++ b/llvm/lib/Target/ARM/ARMISelLowering.cpp
@@ -3287,13 +3287,9 @@ static bool isFloatingPointZero(SDValue Op) {
     // Handle (ISD::BITCAST (ARMISD::VMOVIMM (ISD::TargetConstant 0)) MVT::f64)
     // created by LowerConstantFP().
     SDValue BitcastOp = Op->getOperand(0);
-    if (BitcastOp->getOpcode() == ARMISD::VMOVIMM) {
-      SDValue MoveOp = BitcastOp->getOperand(0);
-      if (MoveOp->getOpcode() == ISD::TargetConstant &&
-          cast<ConstantSDNode>(MoveOp)->getZExtValue() == 0) {
-        return true;
-      }
-    }
+    if (BitcastOp->getOpcode() == ARMISD::VMOVIMM &&
+        isNullConstant(BitcastOp->getOperand(0)))
+      return true;
   }
   return false;
 }
@@ -4538,8 +4534,7 @@ static SDValue Expand64BitShift(SDNode *N, SelectionDAG &DAG,
          "Unknown shift to lower!");
 
   // We only lower SRA, SRL of 1 here, all others use generic lowering.
-  if (!isa<ConstantSDNode>(N->getOperand(1)) ||
-      cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() != 1)
+  if (!isOneConstant(N->getOperand(1)))
     return SDValue();
 
   // If we are in thumb mode, we don't have RRX.
@@ -5421,16 +5416,14 @@ SDValue ARMTargetLowering::LowerBUILD_VECTOR(SDValue Op, SelectionDAG &DAG,
       // just use VDUPLANE. We can only do this if the lane being extracted
       // is at a constant index, as the VDUP from lane instructions only have
       // constant-index forms.
+      ConstantSDNode *constIndex;
       if (Value->getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
-          isa<ConstantSDNode>(Value->getOperand(1))) {
+          (constIndex = dyn_cast<ConstantSDNode>(Value->getOperand(1)))) {
         // We need to create a new undef vector to use for the VDUPLANE if the
         // size of the vector from which we get the value is different than the
         // size of the vector that we need to create. We will insert the element
         // such that the register coalescer will remove unnecessary copies.
         if (VT != Value->getOperand(0).getValueType()) {
-          ConstantSDNode *constIndex;
-          constIndex = dyn_cast<ConstantSDNode>(Value->getOperand(1));
-          assert(constIndex && "The index is not a constant!");
           unsigned index = constIndex->getAPIntValue().getLimitedValue() %
                              VT.getVectorNumElements();
           N =  DAG.getNode(ARMISD::VDUPLANE, dl, VT,
@@ -8198,10 +8191,7 @@ void ARMTargetLowering::AdjustInstrPostInstrSelection(MachineInstr *MI,
 
 // Helper function that checks if N is a null or all ones constant.
 static inline bool isZeroOrAllOnes(SDValue N, bool AllOnes) {
-  ConstantSDNode *C = dyn_cast<ConstantSDNode>(N);
-  if (!C)
-    return false;
-  return AllOnes ? C->isAllOnesValue() : C->isNullValue();
+  return AllOnes ? isAllOnesConstant(N) : isNullConstant(N);
 }
 
 // Return true if N is conditionally 0 or all ones.
@@ -10390,9 +10380,7 @@ SDValue ARMTargetLowering::PerformCMOVToBFICombine(SDNode *CMOV, SelectionDAG &D
   SDValue CmpZ = CMOV->getOperand(4);
 
   // The compare must be against zero.
-  SDValue Zero = CmpZ->getOperand(1);
-  if (!isa<ConstantSDNode>(Zero.getNode()) ||
-      !cast<ConstantSDNode>(Zero.getNode())->isNullValue())
+  if (!isNullConstant(CmpZ->getOperand(1)))
     return SDValue();
 
   assert(CmpZ->getOpcode() == ARMISD::CMPZ);
-- 
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