Revert r241790: Fix shift legalization and lowering for big constants.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241792 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Pawel Bylica 2015-07-09 09:50:54 +00:00
parent 71386b0e04
commit b0205f5937
4 changed files with 19 additions and 62 deletions

View File

@ -1358,9 +1358,9 @@ std::pair <SDValue, SDValue> DAGTypeLegalizer::ExpandAtomic(SDNode *Node) {
return ExpandChainLibCall(LC, Node, false);
}
/// N is a shift by a value that needs to be expanded,
/// ExpandShiftByConstant - N is a shift by a value that needs to be expanded,
/// and the shift amount is a constant 'Amt'. Expand the operation.
void DAGTypeLegalizer::ExpandShiftByConstant(SDNode *N, const APInt &Amt,
void DAGTypeLegalizer::ExpandShiftByConstant(SDNode *N, unsigned Amt,
SDValue &Lo, SDValue &Hi) {
SDLoc DL(N);
// Expand the incoming operand to be shifted, so that we have its parts
@ -1381,12 +1381,12 @@ void DAGTypeLegalizer::ExpandShiftByConstant(SDNode *N, const APInt &Amt,
EVT ShTy = N->getOperand(1).getValueType();
if (N->getOpcode() == ISD::SHL) {
if (Amt.ugt(VTBits)) {
if (Amt > VTBits) {
Lo = Hi = DAG.getConstant(0, DL, NVT);
} else if (Amt.ugt(NVTBits)) {
} else if (Amt > NVTBits) {
Lo = DAG.getConstant(0, DL, NVT);
Hi = DAG.getNode(ISD::SHL, DL,
NVT, InL, DAG.getConstant(-Amt + NVTBits, DL, ShTy));
NVT, InL, DAG.getConstant(Amt - NVTBits, DL, ShTy));
} else if (Amt == NVTBits) {
Lo = DAG.getConstant(0, DL, NVT);
Hi = InL;
@ -1405,15 +1405,16 @@ void DAGTypeLegalizer::ExpandShiftByConstant(SDNode *N, const APInt &Amt,
DAG.getNode(ISD::SHL, DL, NVT, InH,
DAG.getConstant(Amt, DL, ShTy)),
DAG.getNode(ISD::SRL, DL, NVT, InL,
DAG.getConstant(-Amt + NVTBits, DL, ShTy)));
DAG.getConstant(NVTBits - Amt, DL, ShTy)));
}
return;
}
if (N->getOpcode() == ISD::SRL) {
if (Amt.ugt(VTBits)) {
Lo = Hi = DAG.getConstant(0, DL, NVT);
} else if (Amt.ugt(NVTBits)) {
if (Amt > VTBits) {
Lo = DAG.getConstant(0, DL, NVT);
Hi = DAG.getConstant(0, DL, NVT);
} else if (Amt > NVTBits) {
Lo = DAG.getNode(ISD::SRL, DL,
NVT, InH, DAG.getConstant(Amt - NVTBits, DL, ShTy));
Hi = DAG.getConstant(0, DL, NVT);
@ -1425,19 +1426,19 @@ void DAGTypeLegalizer::ExpandShiftByConstant(SDNode *N, const APInt &Amt,
DAG.getNode(ISD::SRL, DL, NVT, InL,
DAG.getConstant(Amt, DL, ShTy)),
DAG.getNode(ISD::SHL, DL, NVT, InH,
DAG.getConstant(-Amt + NVTBits, DL, ShTy)));
DAG.getConstant(NVTBits - Amt, DL, ShTy)));
Hi = DAG.getNode(ISD::SRL, DL, NVT, InH, DAG.getConstant(Amt, DL, ShTy));
}
return;
}
assert(N->getOpcode() == ISD::SRA && "Unknown shift!");
if (Amt.ugt(VTBits)) {
if (Amt > VTBits) {
Hi = Lo = DAG.getNode(ISD::SRA, DL, NVT, InH,
DAG.getConstant(NVTBits - 1, DL, ShTy));
} else if (Amt.ugt(NVTBits)) {
} else if (Amt > NVTBits) {
Lo = DAG.getNode(ISD::SRA, DL, NVT, InH,
DAG.getConstant(Amt - NVTBits, DL, ShTy));
DAG.getConstant(Amt-NVTBits, DL, ShTy));
Hi = DAG.getNode(ISD::SRA, DL, NVT, InH,
DAG.getConstant(NVTBits - 1, DL, ShTy));
} else if (Amt == NVTBits) {
@ -1449,7 +1450,7 @@ void DAGTypeLegalizer::ExpandShiftByConstant(SDNode *N, const APInt &Amt,
DAG.getNode(ISD::SRL, DL, NVT, InL,
DAG.getConstant(Amt, DL, ShTy)),
DAG.getNode(ISD::SHL, DL, NVT, InH,
DAG.getConstant(-Amt + NVTBits, DL, ShTy)));
DAG.getConstant(NVTBits - Amt, DL, ShTy)));
Hi = DAG.getNode(ISD::SRA, DL, NVT, InH, DAG.getConstant(Amt, DL, ShTy));
}
}
@ -2177,7 +2178,7 @@ void DAGTypeLegalizer::ExpandIntRes_Shift(SDNode *N,
// If we can emit an efficient shift operation, do so now. Check to see if
// the RHS is a constant.
if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N->getOperand(1)))
return ExpandShiftByConstant(N, CN->getAPIntValue(), Lo, Hi);
return ExpandShiftByConstant(N, CN->getZExtValue(), Lo, Hi);
// If we can determine that the high bit of the shift is zero or one, even if
// the low bits are variable, emit this shift in an optimized form.

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@ -167,7 +167,7 @@ private:
SDValue GetVectorElementPointer(SDValue VecPtr, EVT EltVT, SDValue Index);
SDValue JoinIntegers(SDValue Lo, SDValue Hi);
SDValue LibCallify(RTLIB::Libcall LC, SDNode *N, bool isSigned);
std::pair<SDValue, SDValue> ExpandChainLibCall(RTLIB::Libcall LC,
SDNode *Node, bool isSigned);
std::pair<SDValue, SDValue> ExpandAtomic(SDNode *Node);
@ -347,7 +347,7 @@ private:
void ExpandIntRes_ATOMIC_LOAD (SDNode *N, SDValue &Lo, SDValue &Hi);
void ExpandShiftByConstant(SDNode *N, const APInt &Amt,
void ExpandShiftByConstant(SDNode *N, unsigned Amt,
SDValue &Lo, SDValue &Hi);
bool ExpandShiftWithKnownAmountBit(SDNode *N, SDValue &Lo, SDValue &Hi);
bool ExpandShiftWithUnknownAmountBit(SDNode *N, SDValue &Lo, SDValue &Hi);

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@ -23167,7 +23167,7 @@ static SDValue PerformSHLCombine(SDNode *N, SelectionDAG &DAG) {
// We shift all of the values by one. In many cases we do not have
// hardware support for this operation. This is better expressed as an ADD
// of two values.
if (N1SplatC->getAPIntValue() == 1)
if (N1SplatC->getZExtValue() == 1)
return DAG.getNode(ISD::ADD, SDLoc(N), VT, N0, N0);
}

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@ -1,44 +0,0 @@
; RUN: llc < %s -march=x86-64 | FileCheck %s
define <2 x i256> @test_shl(<2 x i256> %In) {
%Amt = insertelement <2 x i256> undef, i256 -1, i32 0
%Out = shl <2 x i256> %In, %Amt
ret <2 x i256> %Out
; CHECK-LABEL: test_shl
; CHECK: movq $0
; CHECK-NEXT: movq $0
; CHECK-NEXT: movq $0
; CHECK-NEXT: movq $0
; CHECK-NEXT: movq $0
; CHECK-NEXT: movq $0
; CHECK-NEXT: movq $0
; CHECK-NEXT: movq $0
; CHECK: retq
}
define <2 x i256> @test_srl(<2 x i256> %In) {
%Amt = insertelement <2 x i256> undef, i256 -1, i32 0
%Out = lshr <2 x i256> %In, %Amt
ret <2 x i256> %Out
; CHECK-LABEL: test_srl
; CHECK: movq $0
; CHECK-NEXT: movq $0
; CHECK-NEXT: movq $0
; CHECK-NEXT: movq $0
; CHECK-NEXT: movq $0
; CHECK-NEXT: movq $0
; CHECK-NEXT: movq $0
; CHECK-NEXT: movq $0
; CHECK: retq
}
define <2 x i256> @test_sra(<2 x i256> %In) {
%Amt = insertelement <2 x i256> undef, i256 -1, i32 0
%Out = ashr <2 x i256> %In, %Amt
ret <2 x i256> %Out
; CHECK-LABEL: test_sra
; CHECK: sarq $63
}