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-rw-r--r--lib/Target/MSP430/MSP430ISelDAGToDAG.cpp327
1 files changed, 4 insertions, 323 deletions
diff --git a/lib/Target/MSP430/MSP430ISelDAGToDAG.cpp b/lib/Target/MSP430/MSP430ISelDAGToDAG.cpp
index a8c5e0a..911cfcb 100644
--- a/lib/Target/MSP430/MSP430ISelDAGToDAG.cpp
+++ b/lib/Target/MSP430/MSP430ISelDAGToDAG.cpp
@@ -26,26 +26,12 @@
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/CodeGen/SelectionDAGISel.h"
#include "llvm/Target/TargetLowering.h"
-#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
-#include "llvm/ADT/Statistic.h"
-
using namespace llvm;
-#ifndef NDEBUG
-static cl::opt<bool>
-ViewRMWDAGs("view-msp430-rmw-dags", cl::Hidden,
- cl::desc("Pop up a window to show isel dags after RMW preprocess"));
-#else
-static const bool ViewRMWDAGs = false;
-#endif
-
-STATISTIC(NumLoadMoved, "Number of loads moved below TokenFactor");
-
-
namespace {
struct MSP430ISelAddressMode {
enum {
@@ -123,8 +109,6 @@ namespace {
Lowering(*TM.getTargetLowering()),
Subtarget(*TM.getSubtargetImpl()) { }
- virtual void InstructionSelect();
-
virtual const char *getPassName() const {
return "MSP430 DAG->DAG Pattern Instruction Selection";
}
@@ -133,8 +117,6 @@ namespace {
bool MatchWrapper(SDValue N, MSP430ISelAddressMode &AM);
bool MatchAddressBase(SDValue N, MSP430ISelAddressMode &AM);
- bool IsLegalToFold(SDValue N, SDNode *U, SDNode *Root) const;
-
virtual bool
SelectInlineAsmMemoryOperand(const SDValue &Op, char ConstraintCode,
std::vector<SDValue> &OutOps);
@@ -143,18 +125,12 @@ namespace {
#include "MSP430GenDAGISel.inc"
private:
- DenseMap<SDNode*, SDNode*> RMWStores;
- void PreprocessForRMW();
SDNode *Select(SDNode *N);
SDNode *SelectIndexedLoad(SDNode *Op);
SDNode *SelectIndexedBinOp(SDNode *Op, SDValue N1, SDValue N2,
unsigned Opc8, unsigned Opc16);
bool SelectAddr(SDNode *Op, SDValue Addr, SDValue &Base, SDValue &Disp);
-
- #ifndef NDEBUG
- unsigned Indent;
- #endif
};
} // end anonymous namespace
@@ -216,10 +192,7 @@ bool MSP430DAGToDAGISel::MatchAddressBase(SDValue N, MSP430ISelAddressMode &AM)
}
bool MSP430DAGToDAGISel::MatchAddress(SDValue N, MSP430ISelAddressMode &AM) {
- DEBUG({
- errs() << "MatchAddress: ";
- AM.dump();
- });
+ DEBUG(errs() << "MatchAddress: "; AM.dump());
switch (N.getOpcode()) {
default: break;
@@ -335,270 +308,6 @@ SelectInlineAsmMemoryOperand(const SDValue &Op, char ConstraintCode,
return false;
}
-bool MSP430DAGToDAGISel::IsLegalToFold(SDValue N, SDNode *U,
- SDNode *Root) const {
- if (OptLevel == CodeGenOpt::None) return false;
-
- /// RMW preprocessing creates the following code:
- /// [Load1]
- /// ^ ^
- /// / |
- /// / |
- /// [Load2] |
- /// ^ ^ |
- /// | | |
- /// | \-|
- /// | |
- /// | [Op]
- /// | ^
- /// | |
- /// \ /
- /// \ /
- /// [Store]
- ///
- /// The path Store => Load2 => Load1 is via chain. Note that in general it is
- /// not allowed to fold Load1 into Op (and Store) since it will creates a
- /// cycle. However, this is perfectly legal for the loads moved below the
- /// TokenFactor by PreprocessForRMW. Query the map Store => Load1 (created
- /// during preprocessing) to determine whether it's legal to introduce such
- /// "cycle" for a moment.
- DenseMap<SDNode*, SDNode*>::const_iterator I = RMWStores.find(Root);
- if (I != RMWStores.end() && I->second == N.getNode())
- return true;
-
- // Proceed to 'generic' cycle finder code
- return SelectionDAGISel::IsLegalToFold(N, U, Root);
-}
-
-
-/// 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));
-}
-
-/// MoveBelowTokenFactor2 - Replace TokenFactor operand with load's chain operand
-/// and move load below the TokenFactor. Replace store's chain operand with
-/// load's chain result. This a version which sinks two loads below token factor.
-/// Look into PreprocessForRMW comments for explanation of transform.
-static void MoveBelowTokenFactor2(SelectionDAG *CurDAG,
- SDValue Load1, SDValue Load2,
- SDValue Store, SDValue TF) {
- SmallVector<SDValue, 4> Ops;
- for (unsigned i = 0, e = TF.getNode()->getNumOperands(); i != e; ++i) {
- SDNode* N = TF.getOperand(i).getNode();
- if (Load2.getNode() == N)
- Ops.push_back(Load2.getOperand(0));
- else if (Load1.getNode() != N)
- Ops.push_back(TF.getOperand(i));
- }
-
- SDValue NewTF = SDValue(CurDAG->MorphNodeTo(TF.getNode(),
- TF.getOpcode(),
- TF.getNode()->getVTList(),
- &Ops[0], Ops.size()), TF.getResNo());
- SDValue NewLoad2 = CurDAG->UpdateNodeOperands(Load2, NewTF,
- Load2.getOperand(1),
- Load2.getOperand(2));
-
- SDValue NewLoad1 = CurDAG->UpdateNodeOperands(Load1, NewLoad2.getValue(1),
- Load1.getOperand(1),
- Load1.getOperand(2));
-
- CurDAG->UpdateNodeOperands(Store,
- NewLoad1.getValue(1),
- Store.getOperand(1),
- Store.getOperand(2), Store.getOperand(3));
-}
-
-/// isAllowedToSink - return true if N a load which can be moved below token
-/// factor. Basically, the load should be non-volatile and has single use.
-static bool isLoadAllowedToSink(SDValue N, SDValue Chain) {
- if (N.getOpcode() == ISD::BIT_CONVERT)
- 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;
-
- return (N.hasOneUse() &&
- LD->hasNUsesOfValue(1, 1) &&
- LD->isOperandOf(Chain.getNode()));
-}
-
-
-/// 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 (isLoadAllowedToSink(N, Chain) &&
- N.getOperand(1) == Address) {
- Load = N;
- return true;
- }
- return false;
-}
-
-/// PreprocessForRMW - Preprocess the DAG to make instruction selection better.
-/// This is only run if not in -O0 mode.
-/// This allows the instruction selector to pick more read-modify-write
-/// instructions. This is a common case:
-///
-/// [Load chain]
-/// ^
-/// |
-/// [Load]
-/// ^ ^
-/// | |
-/// / \-
-/// / |
-/// [TokenFactor] [Op]
-/// ^ ^
-/// | |
-/// \ /
-/// \ /
-/// [Store]
-///
-/// The fact the store's chain operand != load's chain will prevent the
-/// (store (op (load))) instruction from being selected. We can transform it to:
-///
-/// [Load chain]
-/// ^
-/// |
-/// [TokenFactor]
-/// ^
-/// |
-/// [Load]
-/// ^ ^
-/// | |
-/// | \-
-/// | |
-/// | [Op]
-/// | ^
-/// | |
-/// \ /
-/// \ /
-/// [Store]
-///
-/// We also recognize the case where second operand of Op is load as well and
-/// move it below token factor as well creating DAG as follows:
-///
-/// [Load chain]
-/// ^
-/// |
-/// [TokenFactor]
-/// ^
-/// |
-/// [Load1]
-/// ^ ^
-/// / |
-/// / |
-/// [Load2] |
-/// ^ ^ |
-/// | | |
-/// | \-|
-/// | |
-/// | [Op]
-/// | ^
-/// | |
-/// \ /
-/// \ /
-/// [Store]
-///
-/// This allows selection of mem-mem instructions. Yay!
-
-void MSP430DAGToDAGISel::PreprocessForRMW() {
- for (SelectionDAG::allnodes_iterator I = CurDAG->allnodes_begin(),
- E = CurDAG->allnodes_end(); I != E; ++I) {
- if (!ISD::isNON_TRUNCStore(I))
- continue;
- SDValue Chain = I->getOperand(0);
-
- if (Chain.getNode()->getOpcode() != ISD::TokenFactor)
- continue;
-
- SDValue N1 = I->getOperand(1);
- SDValue N2 = I->getOperand(2);
- if ((N1.getValueType().isFloatingPoint() &&
- !N1.getValueType().isVector()) ||
- !N1.hasOneUse())
- continue;
-
- unsigned RModW = 0;
- SDValue Load1, Load2;
- unsigned Opcode = N1.getNode()->getOpcode();
- switch (Opcode) {
- case ISD::ADD:
- case ISD::AND:
- case ISD::OR:
- case ISD::XOR:
- case ISD::ADDC:
- case ISD::ADDE: {
- SDValue N10 = N1.getOperand(0);
- SDValue N11 = N1.getOperand(1);
- if (isRMWLoad(N10, Chain, N2, Load1)) {
- if (isLoadAllowedToSink(N11, Chain)) {
- Load2 = N11;
- RModW = 2;
- } else
- RModW = 1;
- } else if (isRMWLoad(N11, Chain, N2, Load1)) {
- if (isLoadAllowedToSink(N10, Chain)) {
- Load2 = N10;
- RModW = 2;
- } else
- RModW = 1;
- }
- break;
- }
- case ISD::SUB:
- case ISD::SUBC:
- case ISD::SUBE: {
- SDValue N10 = N1.getOperand(0);
- SDValue N11 = N1.getOperand(1);
- if (isRMWLoad(N10, Chain, N2, Load1)) {
- if (isLoadAllowedToSink(N11, Chain)) {
- Load2 = N11;
- RModW = 2;
- } else
- RModW = 1;
- }
- break;
- }
- }
-
- NumLoadMoved += RModW;
- if (RModW == 1)
- MoveBelowTokenFactor(CurDAG, Load1, SDValue(I, 0), Chain);
- else if (RModW == 2) {
- MoveBelowTokenFactor2(CurDAG, Load1, Load2, SDValue(I, 0), Chain);
- SDNode* Store = I;
- RMWStores[Store] = Load2.getNode();
- }
- }
-}
-
-
static bool isValidIndexedLoad(const LoadSDNode *LD) {
ISD::MemIndexedMode AM = LD->getAddressingMode();
if (AM != ISD::POST_INC || LD->getExtensionType() != ISD::NON_EXTLOAD)
@@ -681,46 +390,19 @@ SDNode *MSP430DAGToDAGISel::SelectIndexedBinOp(SDNode *Op,
}
-/// InstructionSelect - This callback is invoked by
-/// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
-void MSP430DAGToDAGISel::InstructionSelect() {
- std::string BlockName;
- if (ViewRMWDAGs)
- BlockName = MF->getFunction()->getNameStr() + ":" +
- BB->getBasicBlock()->getNameStr();
-
- PreprocessForRMW();
-
- if (ViewRMWDAGs) CurDAG->viewGraph("RMW preprocessed:" + BlockName);
-
- DEBUG(errs() << "Selection DAG after RMW preprocessing:\n");
- DEBUG(CurDAG->dump());
-
- // Codegen the basic block.
- DEBUG(errs() << "===== Instruction selection begins:\n");
- DEBUG(Indent = 0);
- SelectRoot(*CurDAG);
- DEBUG(errs() << "===== Instruction selection ends:\n");
-
- CurDAG->RemoveDeadNodes();
- RMWStores.clear();
-}
-
SDNode *MSP430DAGToDAGISel::Select(SDNode *Node) {
DebugLoc dl = Node->getDebugLoc();
// Dump information about the Node being selected
- DEBUG(errs().indent(Indent) << "Selecting: ");
+ DEBUG(errs() << "Selecting: ");
DEBUG(Node->dump(CurDAG));
DEBUG(errs() << "\n");
- DEBUG(Indent += 2);
// If we have a custom node, we already have selected!
if (Node->isMachineOpcode()) {
- DEBUG(errs().indent(Indent-2) << "== ";
+ DEBUG(errs() << "== ";
Node->dump(CurDAG);
errs() << "\n");
- DEBUG(Indent -= 2);
return NULL;
}
@@ -808,13 +490,12 @@ SDNode *MSP430DAGToDAGISel::Select(SDNode *Node) {
// Select the default instruction
SDNode *ResNode = SelectCode(Node);
- DEBUG(errs() << std::string(Indent-2, ' ') << "=> ");
+ DEBUG(errs() << "=> ");
if (ResNode == NULL || ResNode == Node)
DEBUG(Node->dump(CurDAG));
else
DEBUG(ResNode->dump(CurDAG));
DEBUG(errs() << "\n");
- DEBUG(Indent -= 2);
return ResNode;
}
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