Intrinsics which do a vector compare (results are all zero or all ones) are modeled as icmp / fcmp + sext. This is turned into a vsetcc by dag combine (yes, not a good long term solution). The targets can then isel the vsetcc to the appropriate instruction.

The trouble arises when the result of a vector cmp + sext is then and'ed with all ones. Instcombine will turn it into a vector cmp + zext, dag combiner will miss turning it into a vsetcc and hell breaks loose after that.

Teach dag combine to turn a vector cpm + zest into a vsetcc + and 1. This fixes rdar://7923010.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104094 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng 2010-05-19 01:08:17 +00:00
parent 7c2e03916c
commit 0a942dbb1e
2 changed files with 88 additions and 6 deletions

View File

@ -3570,7 +3570,7 @@ SDValue DAGCombiner::visitSIGN_EXTEND(SDNode *N) {
DAG.getVSetCC(N->getDebugLoc(), MatchingVectorType, N0.getOperand(0),
N0.getOperand(1),
cast<CondCodeSDNode>(N0.getOperand(2))->get());
return DAG.getSExtOrTrunc(VsetCC, N->getDebugLoc(), VT);
return DAG.getSExtOrTrunc(VsetCC, N->getDebugLoc(), VT);
}
}
@ -3591,9 +3591,7 @@ SDValue DAGCombiner::visitSIGN_EXTEND(SDNode *N) {
N0.getOperand(0), N0.getOperand(1),
cast<CondCodeSDNode>(N0.getOperand(2))->get()),
NegOne, DAG.getConstant(0, VT));
}
}
// fold (sext x) -> (zext x) if the sign bit is known zero.
if ((!LegalOperations || TLI.isOperationLegal(ISD::ZERO_EXTEND, VT)) &&
@ -3732,8 +3730,48 @@ SDValue DAGCombiner::visitZERO_EXTEND(SDNode *N) {
}
}
// zext(setcc x,y,cc) -> select_cc x, y, 1, 0, cc
if (N0.getOpcode() == ISD::SETCC) {
if (!LegalOperations && VT.isVector()) {
// zext(setcc) -> (and (vsetcc), (1, 1, ...) for vectors.
// Only do this before legalize for now.
EVT N0VT = N0.getOperand(0).getValueType();
EVT EltVT = VT.getVectorElementType();
SmallVector<SDValue,8> OneOps(VT.getVectorNumElements(),
DAG.getConstant(1, EltVT));
if (VT.getSizeInBits() == N0VT.getSizeInBits()) {
// 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.
return DAG.getNode(ISD::AND, N->getDebugLoc(), VT,
DAG.getVSetCC(N->getDebugLoc(), VT, N0.getOperand(0),
N0.getOperand(1),
cast<CondCodeSDNode>(N0.getOperand(2))->get()),
DAG.getNode(ISD::BUILD_VECTOR, N->getDebugLoc(), VT,
&OneOps[0], OneOps.size()));
} else {
// If the desired elements are smaller or larger than the source
// elements we can use a matching integer vector type and then
// truncate/sign extend
EVT MatchingElementType =
EVT::getIntegerVT(*DAG.getContext(),
N0VT.getScalarType().getSizeInBits());
EVT MatchingVectorType =
EVT::getVectorVT(*DAG.getContext(), MatchingElementType,
N0VT.getVectorNumElements());
SDValue VsetCC =
DAG.getVSetCC(N->getDebugLoc(), MatchingVectorType, N0.getOperand(0),
N0.getOperand(1),
cast<CondCodeSDNode>(N0.getOperand(2))->get());
return DAG.getNode(ISD::AND, N->getDebugLoc(), VT,
DAG.getSExtOrTrunc(VsetCC, N->getDebugLoc(), VT),
DAG.getNode(ISD::BUILD_VECTOR, N->getDebugLoc(), VT,
&OneOps[0], OneOps.size()));
}
}
// zext(setcc x,y,cc) -> select_cc x, y, 1, 0, cc
SDValue SCC =
SimplifySelectCC(N->getDebugLoc(), N0.getOperand(0), N0.getOperand(1),
DAG.getConstant(1, VT), DAG.getConstant(0, VT),
@ -3889,8 +3927,39 @@ SDValue DAGCombiner::visitANY_EXTEND(SDNode *N) {
return SDValue(N, 0); // Return N so it doesn't get rechecked!
}
// aext(setcc x,y,cc) -> select_cc x, y, 1, 0, cc
if (N0.getOpcode() == ISD::SETCC) {
// aext(setcc) -> sext_in_reg(vsetcc) for vectors.
// Only do this before legalize for now.
if (VT.isVector() && !LegalOperations) {
EVT N0VT = N0.getOperand(0).getValueType();
// 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())
return DAG.getVSetCC(N->getDebugLoc(), VT, N0.getOperand(0),
N0.getOperand(1),
cast<CondCodeSDNode>(N0.getOperand(2))->get());
// If the desired elements are smaller or larger than the source
// elements we can use a matching integer vector type and then
// truncate/sign extend
else {
EVT MatchingElementType =
EVT::getIntegerVT(*DAG.getContext(),
N0VT.getScalarType().getSizeInBits());
EVT MatchingVectorType =
EVT::getVectorVT(*DAG.getContext(), MatchingElementType,
N0VT.getVectorNumElements());
SDValue VsetCC =
DAG.getVSetCC(N->getDebugLoc(), MatchingVectorType, N0.getOperand(0),
N0.getOperand(1),
cast<CondCodeSDNode>(N0.getOperand(2))->get());
return DAG.getSExtOrTrunc(VsetCC, N->getDebugLoc(), VT);
}
}
// aext(setcc x,y,cc) -> select_cc x, y, 1, 0, cc
SDValue SCC =
SimplifySelectCC(N->getDebugLoc(), N0.getOperand(0), N0.getOperand(1),
DAG.getConstant(1, VT), DAG.getConstant(0, VT),

View File

@ -158,5 +158,18 @@ define <4 x i32> @vacgtQf32(<4 x float>* %A, <4 x float>* %B) nounwind {
ret <4 x i32> %tmp3
}
; rdar://7923010
define <4 x i32> @vcgt_zext(<4 x float>* %A, <4 x float>* %B) nounwind {
;CHECK: vcgt_zext:
;CHECK: vcgt.f32 q0
;CHECK: vmov.i32 q1, #0x1
;CHECK: vand q0, q0, q1
%tmp1 = load <4 x float>* %A
%tmp2 = load <4 x float>* %B
%tmp3 = fcmp ogt <4 x float> %tmp1, %tmp2
%tmp4 = zext <4 x i1> %tmp3 to <4 x i32>
ret <4 x i32> %tmp4
}
declare <2 x i32> @llvm.arm.neon.vacgtd(<2 x float>, <2 x float>) nounwind readnone
declare <4 x i32> @llvm.arm.neon.vacgtq(<4 x float>, <4 x float>) nounwind readnone