Reapply 154397. Original message:

Fix a dagcombine optimization which assumes that the vsetcc result type is always
of the same size as the compared values. This is ture for SSE/AVX/NEON but not
for all targets.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154490 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Nadav Rotem 2012-04-11 08:26:11 +00:00
parent 21293ac192
commit 2e506198c8

View File

@ -4354,12 +4354,17 @@ SDValue DAGCombiner::visitSIGN_EXTEND(SDNode *N) {
// Only do this before legalize for now.
if (VT.isVector() && !LegalOperations) {
EVT N0VT = N0.getOperand(0).getValueType();
// On some architectures (such as SSE/NEON/etc) the SETCC result type is
// of the same size as the compared operands. Only optimize sext(setcc())
// if this is the case.
EVT SVT = TLI.getSetCCResultType(N0VT);
// We know that the # elements of the results is the same as the
// # elements of the compare (and the # elements of the compare result
// for that matter). Check to see that they are the same size. If so,
// we know that the element size of the sext'd result matches the
// element size of the compare operands.
if (VT.getSizeInBits() == N0VT.getSizeInBits())
if (VT.getSizeInBits() == SVT.getSizeInBits())
return DAG.getSetCC(N->getDebugLoc(), VT, N0.getOperand(0),
N0.getOperand(1),
cast<CondCodeSDNode>(N0.getOperand(2))->get());
@ -4373,13 +4378,15 @@ SDValue DAGCombiner::visitSIGN_EXTEND(SDNode *N) {
EVT MatchingVectorType =
EVT::getVectorVT(*DAG.getContext(), MatchingElementType,
N0VT.getVectorNumElements());
SDValue VsetCC =
DAG.getSetCC(N->getDebugLoc(), MatchingVectorType, N0.getOperand(0),
N0.getOperand(1),
if (SVT == MatchingVectorType) {
SDValue VsetCC = DAG.getSetCC(N->getDebugLoc(), MatchingVectorType,
N0.getOperand(0), N0.getOperand(1),
cast<CondCodeSDNode>(N0.getOperand(2))->get());
return DAG.getSExtOrTrunc(VsetCC, N->getDebugLoc(), VT);
}
}
}
// sext(setcc x, y, cc) -> (select_cc x, y, -1, 0, cc)
unsigned ElementWidth = VT.getScalarType().getSizeInBits();