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eliminate PreprocessForRMW now that isel handles it.

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We still preprocess calls and fp return stuff.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97598 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2010-03-02 22:33:56 +00:00
parent 6b7f39c895
commit 98d45790ae
1 changed files with 27 additions and 136 deletions
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163
lib/Target/X86/X86ISelDAGToDAG.cpp
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@ -207,7 +207,7 @@ namespace {
SDValue &Index, SDValue &Disp,
SDValue &Segment);
void PreprocessForRMW();
void PreprocessForCallLoads();
void PreprocessForFPConvert();
/// SelectInlineAsmMemoryOperand - Implement addressing mode selection for
@ -352,57 +352,6 @@ X86DAGToDAGISel::IsProfitableToFold(SDValue N, SDNode *U, SDNode *Root) const {
return true;
}
/// MoveBelowTokenFactor - Replace TokenFactor operand with load's chain operand
/// and move load below the TokenFactor. Replace store's chain operand with
/// load's chain result.
static void MoveBelowTokenFactor(SelectionDAG *CurDAG, SDValue Load,
SDValue Store, SDValue TF) {
SmallVector<SDValue, 4> Ops;
for (unsigned i = 0, e = TF.getNode()->getNumOperands(); i != e; ++i)
if (Load.getNode() == TF.getOperand(i).getNode())
Ops.push_back(Load.getOperand(0));
else
Ops.push_back(TF.getOperand(i));
SDValue NewTF = CurDAG->UpdateNodeOperands(TF, &Ops[0], Ops.size());
SDValue NewLoad = CurDAG->UpdateNodeOperands(Load, NewTF,
Load.getOperand(1),
Load.getOperand(2));
CurDAG->UpdateNodeOperands(Store, NewLoad.getValue(1), Store.getOperand(1),
Store.getOperand(2), Store.getOperand(3));
}
/// isRMWLoad - Return true if N is a load that's part of RMW sub-DAG. The
/// chain produced by the load must only be used by the store's chain operand,
/// otherwise this may produce a cycle in the DAG.
///
static bool isRMWLoad(SDValue N, SDValue Chain, SDValue Address,
SDValue &Load) {
if (N.getOpcode() == ISD::BIT_CONVERT) {
if (!N.hasOneUse())
return false;
N = N.getOperand(0);
}
LoadSDNode *LD = dyn_cast<LoadSDNode>(N);
if (!LD || LD->isVolatile())
return false;
if (LD->getAddressingMode() != ISD::UNINDEXED)
return false;
ISD::LoadExtType ExtType = LD->getExtensionType();
if (ExtType != ISD::NON_EXTLOAD && ExtType != ISD::EXTLOAD)
return false;
if (N.hasOneUse() &&
LD->hasNUsesOfValue(1, 1) &&
N.getOperand(1) == Address &&
LD->isOperandOf(Chain.getNode())) {
Load = N;
return true;
}
return false;
}
/// MoveBelowCallSeqStart - Replace CALLSEQ_START operand with load's chain
/// operand and move load below the call's chain operand.
static void MoveBelowCallSeqStart(SelectionDAG *CurDAG, SDValue Load,
@ -467,95 +416,37 @@ static bool isCalleeLoad(SDValue Callee, SDValue &Chain) {
}
void X86DAGToDAGISel::PreprocessForRMW() {
void X86DAGToDAGISel::PreprocessForCallLoads() {
for (SelectionDAG::allnodes_iterator I = CurDAG->allnodes_begin(),
E = CurDAG->allnodes_end(); I != E; ++I) {
if (I->getOpcode() == X86ISD::CALL) {
/// Also try moving call address load from outside callseq_start to just
/// before the call to allow it to be folded.
///
/// [Load chain]
/// ^
/// |
/// [Load]
/// ^ ^
/// | |
/// / \--
/// / |
///[CALLSEQ_START] |
/// ^ |
/// | |
/// [LOAD/C2Reg] |
/// | |
/// \ /
/// \ /
/// [CALL]
SDValue Chain = I->getOperand(0);
SDValue Load = I->getOperand(1);
if (!isCalleeLoad(Load, Chain))
continue;
MoveBelowCallSeqStart(CurDAG, Load, SDValue(I, 0), Chain);
++NumLoadMoved;
if (I->getOpcode() != X86ISD::CALL)
continue;
}
continue;
if (!ISD::isNON_TRUNCStore(I))
continue;
/// Also try moving call address load from outside callseq_start to just
/// before the call to allow it to be folded.
///
/// [Load chain]
/// ^
/// |
/// [Load]
/// ^ ^
/// | |
/// / \--
/// / |
///[CALLSEQ_START] |
/// ^ |
/// | |
/// [LOAD/C2Reg] |
/// | |
/// \ /
/// \ /
/// [CALL]
SDValue Chain = I->getOperand(0);
if (Chain.getNode()->getOpcode() != ISD::TokenFactor)
SDValue Load = I->getOperand(1);
if (!isCalleeLoad(Load, Chain))
continue;
SDValue N1 = I->getOperand(1);
SDValue N2 = I->getOperand(2);
if ((N1.getValueType().isFloatingPoint() &&
!N1.getValueType().isVector()) ||
!N1.hasOneUse())
continue;
bool RModW = false;
SDValue Load;
unsigned Opcode = N1.getNode()->getOpcode();
switch (Opcode) {
case ISD::ADD:
case ISD::MUL:
case ISD::AND:
case ISD::OR:
case ISD::XOR:
case ISD::ADDC:
case ISD::ADDE:
case ISD::VECTOR_SHUFFLE: {
SDValue N10 = N1.getOperand(0);
SDValue N11 = N1.getOperand(1);
RModW = isRMWLoad(N10, Chain, N2, Load);
if (!RModW)
RModW = isRMWLoad(N11, Chain, N2, Load);
break;
}
case ISD::SUB:
case ISD::SHL:
case ISD::SRA:
case ISD::SRL:
case ISD::ROTL:
case ISD::ROTR:
case ISD::SUBC:
case ISD::SUBE:
case X86ISD::SHLD:
case X86ISD::SHRD: {
SDValue N10 = N1.getOperand(0);
RModW = isRMWLoad(N10, Chain, N2, Load);
break;
}
}
if (RModW) {
MoveBelowTokenFactor(CurDAG, Load, SDValue(I, 0), Chain);
++NumLoadMoved;
checkForCycles(I);
}
MoveBelowCallSeqStart(CurDAG, Load, SDValue(I, 0), Chain);
++NumLoadMoved;
}
}
@ -631,7 +522,7 @@ void X86DAGToDAGISel::PreprocessISelDAG() {
OptForSize = MF->getFunction()->hasFnAttr(Attribute::OptimizeForSize);
if (OptLevel != CodeGenOpt::None)
PreprocessForRMW();
PreprocessForCallLoads();
// FIXME: This should only happen when not compiled with -O0.
PreprocessForFPConvert();