[SelectionDAG] Make ISD::isConstantSplatVector always return an element sized APInt.

This partially reverts r311429 in favor of making ISD::isConstantSplatVector do something not confusing. Turns out the only other user of it was also having to deal with the weird property of it returning a smaller size.

So rather than continue to deal with this quirk everywhere, just make the interface do something sane.

Differential Revision: https://reviews.llvm.org/D37039

llvm-svn: 311510

1 files changed, 3 insertions, 5 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index d555315c523..b4154210329 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -125,8 +125,7 @@ bool ConstantFPSDNode::isValueValidForType(EVT VT,
 //                              ISD Namespace
 //===----------------------------------------------------------------------===//
 
-bool ISD::isConstantSplatVector(const SDNode *N, APInt &SplatVal,
-                                bool AllowShrink) {
+bool ISD::isConstantSplatVector(const SDNode *N, APInt &SplatVal) {
   auto *BV = dyn_cast<BuildVectorSDNode>(N);
   if (!BV)
     return false;
@@ -135,10 +134,9 @@ bool ISD::isConstantSplatVector(const SDNode *N, APInt &SplatVal,
   unsigned SplatBitSize;
   bool HasUndefs;
   unsigned EltSize = N->getValueType(0).getVectorElementType().getSizeInBits();
-  unsigned MinSplatBits = AllowShrink ? 0 : EltSize;
   return BV->isConstantSplat(SplatVal, SplatUndef, SplatBitSize, HasUndefs,
-                             MinSplatBits) &&
-         EltSize >= SplatBitSize;
+                             EltSize) &&
+         EltSize == SplatBitSize;
 }
 
 // FIXME: AllOnes and AllZeros duplicate a lot of code. Could these be