[llvm] r310405 - [DAG] Introduce peekThroughBitcast function. NFCI.

[Nirav Dave via llvm-commits]

Author: niravd
Date: Tue Aug  8 13:01:18 2017
New Revision: 310405

URL: http://llvm.org/viewvc/llvm-project?rev=310405&view=rev
Log:
[DAG] Introduce peekThroughBitcast function. NFCI.

Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp?rev=310405&r1=310404&r2=310405&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Tue Aug  8 13:01:18 2017
@@ -12419,6 +12419,12 @@ bool DAGCombiner::isMulAddWithConstProfi
   return false;
 }
 
+static SDValue peekThroughBitcast(SDValue V) {
+  while (V.getOpcode() == ISD::BITCAST)
+    V = V.getOperand(0);
+  return V;
+}
+
 SDValue DAGCombiner::getMergeStoreChains(SmallVectorImpl<MemOpLink> &StoreNodes,
                                          unsigned NumStores) {
   SmallVector<SDValue, 8> Chains;
@@ -14614,8 +14620,7 @@ static SDValue combineConcatVectorOfExtr
 
   for (SDValue Op : N->ops()) {
     // Peek through any bitcast.
-    while (Op.getOpcode() == ISD::BITCAST)
-      Op = Op.getOperand(0);
+    Op = peekThroughBitcast(Op);
 
     // UNDEF nodes convert to UNDEF shuffle mask values.
     if (Op.isUndef()) {
@@ -14634,8 +14639,7 @@ static SDValue combineConcatVectorOfExtr
     EVT ExtVT = ExtVec.getValueType();
 
     // Peek through any bitcast.
-    while (ExtVec.getOpcode() == ISD::BITCAST)
-      ExtVec = ExtVec.getOperand(0);
+    ExtVec = peekThroughBitcast(ExtVec);
 
     // UNDEF nodes convert to UNDEF shuffle mask values.
     if (ExtVec.isUndef()) {
@@ -14860,9 +14864,7 @@ static SDValue narrowExtractedVectorBinO
 
   // We are looking for an optionally bitcasted wide vector binary operator
   // feeding an extract subvector.
-  SDValue BinOp = Extract->getOperand(0);
-  if (BinOp.getOpcode() == ISD::BITCAST)
-    BinOp = BinOp.getOperand(0);
+  SDValue BinOp = peekThroughBitcast(Extract->getOperand(0));
 
   // TODO: The motivating case for this transform is an x86 AVX1 target. That
   // target has temptingly almost legal versions of bitwise logic ops in 256-bit
@@ -14886,13 +14888,8 @@ static SDValue narrowExtractedVectorBinO
     return SDValue();
 
   // Peek through bitcasts of the binary operator operands if needed.
-  SDValue LHS = BinOp.getOperand(0);
-  if (LHS.getOpcode() == ISD::BITCAST)
-    LHS = LHS.getOperand(0);
-
-  SDValue RHS = BinOp.getOperand(1);
-  if (RHS.getOpcode() == ISD::BITCAST)
-    RHS = RHS.getOperand(0);
+  SDValue LHS = peekThroughBitcast(BinOp.getOperand(0));
+  SDValue RHS = peekThroughBitcast(BinOp.getOperand(1));
 
   // We need at least one concatenation operation of a binop operand to make
   // this transform worthwhile. The concat must double the input vector sizes.
@@ -14991,8 +14988,7 @@ SDValue DAGCombiner::visitEXTRACT_SUBVEC
   }
 
   // Skip bitcasting
-  if (V->getOpcode() == ISD::BITCAST)
-    V = V.getOperand(0);
+  V = peekThroughBitcast(V);
 
   if (V->getOpcode() == ISD::INSERT_SUBVECTOR) {
     // Handle only simple case where vector being inserted and vector
@@ -15349,9 +15345,7 @@ static SDValue combineTruncationShuffle(
   if (!VT.isInteger() || IsBigEndian)
     return SDValue();
 
-  SDValue N0 = SVN->getOperand(0);
-  while (N0.getOpcode() == ISD::BITCAST)
-    N0 = N0.getOperand(0);
+  SDValue N0 = peekThroughBitcast(SVN->getOperand(0));
 
   unsigned Opcode = N0.getOpcode();
   if (Opcode != ISD::ANY_EXTEND_VECTOR_INREG &&
@@ -15937,7 +15931,7 @@ SDValue DAGCombiner::visitFP16_TO_FP(SDN
 SDValue DAGCombiner::XformToShuffleWithZero(SDNode *N) {
   EVT VT = N->getValueType(0);
   SDValue LHS = N->getOperand(0);
-  SDValue RHS = N->getOperand(1);
+  SDValue RHS = peekThroughBitcast(N->getOperand(1));
   SDLoc DL(N);
 
   // Make sure we're not running after operation legalization where it
@@ -15948,9 +15942,6 @@ SDValue DAGCombiner::XformToShuffleWithZ
   if (N->getOpcode() != ISD::AND)
     return SDValue();
 
-  if (RHS.getOpcode() == ISD::BITCAST)
-    RHS = RHS.getOperand(0);
-
   if (RHS.getOpcode() != ISD::BUILD_VECTOR)
     return SDValue();