[llvm] r361547 - [DAGCombiner] make folds of binops safe for opcodes that produce >1 value

[Sanjay Patel via llvm-commits]

Author: spatel
Date: Thu May 23 13:17:25 2019
New Revision: 361547

URL: http://llvm.org/viewvc/llvm-project?rev=361547&view=rev
Log:
[DAGCombiner] make folds of binops safe for opcodes that produce >1 value

This is no-functional-change-intended currently because the definition
of isBinOp() only includes opcodes that produce 1 value. But if we
share that implementation with isCommutativeBinOp() as proposed in
D62191, then we need to make sure that the callers bail out for
opcodes that they are not prepared to handle correctly.

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=361547&r1=361546&r2=361547&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Thu May 23 13:17:25 2019
@@ -1968,7 +1968,8 @@ static ConstantSDNode *getAsNonOpaqueCon
 }
 
 SDValue DAGCombiner::foldBinOpIntoSelect(SDNode *BO) {
-  assert(TLI.isBinOp(BO->getOpcode()) && "Unexpected binary operator");
+  assert(TLI.isBinOp(BO->getOpcode()) && BO->getNumValues() == 1 &&
+         "Unexpected binary operator");
 
   // Don't do this unless the old select is going away. We want to eliminate the
   // binary operator, not replace a binop with a select.
@@ -16172,7 +16173,8 @@ static SDValue scalarizeExtractedBinop(S
   SDValue Vec = ExtElt->getOperand(0);
   SDValue Index = ExtElt->getOperand(1);
   auto *IndexC = dyn_cast<ConstantSDNode>(Index);
-  if (!IndexC || !TLI.isBinOp(Vec.getOpcode()) || !Vec.hasOneUse())
+  if (!IndexC || !TLI.isBinOp(Vec.getOpcode()) || !Vec.hasOneUse() ||
+      Vec.getNode()->getNumValues() != 1)
     return SDValue();
 
   // Targets may want to avoid this to prevent an expensive register transfer.
@@ -17412,7 +17414,7 @@ static SDValue narrowInsertExtractVector
                                               SelectionDAG &DAG) {
   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
   SDValue BinOp = Extract->getOperand(0);
-  if (!TLI.isBinOp(BinOp.getOpcode()))
+  if (!TLI.isBinOp(BinOp.getOpcode()) || BinOp.getNode()->getNumValues() != 1)
     return SDValue();
 
   SDValue Bop0 = BinOp.getOperand(0), Bop1 = BinOp.getOperand(1);
@@ -17456,7 +17458,7 @@ static SDValue narrowExtractedVectorBinO
   // feeding an extract subvector.
   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
   SDValue BinOp = peekThroughBitcasts(Extract->getOperand(0));
-  if (!TLI.isBinOp(BinOp.getOpcode()))
+  if (!TLI.isBinOp(BinOp.getOpcode()) || BinOp.getNode()->getNumValues() != 1)
     return SDValue();
 
   // The binop must be a vector type, so we can extract some fraction of it.
@@ -18268,7 +18270,7 @@ SDValue DAGCombiner::visitVECTOR_SHUFFLE
   if (SVN->isSplat() && SVN->getSplatIndex() < (int)NumElts) {
     int SplatIndex = SVN->getSplatIndex();
     if (TLI.isExtractVecEltCheap(VT, SplatIndex) &&
-        TLI.isBinOp(N0.getOpcode())) {
+        TLI.isBinOp(N0.getOpcode()) && N0.getNode()->getNumValues() == 1) {
       // splat (vector_bo L, R), Index -->
       // splat (scalar_bo (extelt L, Index), (extelt R, Index))
       SDValue L = N0.getOperand(0), R = N0.getOperand(1);