//
//===----------------------------------------------------------------------===//
-#include "llvm/BasicBlock.h"
+#include "llvm/Transforms/Utils/FunctionUtils.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Instructions.h"
#include "llvm/Module.h"
#include "llvm/Pass.h"
+#include "llvm/Analysis/Dominators.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/Verifier.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
-#include "llvm/Transforms/Utils/FunctionUtils.h"
#include "Support/Debug.h"
#include "Support/StringExtras.h"
#include <algorithm>
using namespace llvm;
namespace {
-
- /// getFunctionArg - Return a pointer to F's ARGNOth argument.
- ///
- Argument *getFunctionArg(Function *F, unsigned argno) {
- Function::aiterator ai = F->abegin();
- while (argno) { ++ai; --argno; }
- return &*ai;
- }
-
- struct CodeExtractor {
+ class CodeExtractor {
typedef std::vector<Value*> Values;
- typedef std::vector<std::pair<unsigned, unsigned> > PhiValChangesTy;
- typedef std::map<PHINode*, PhiValChangesTy> PhiVal2ArgTy;
- PhiVal2ArgTy PhiVal2Arg;
std::set<BasicBlock*> BlocksToExtract;
+ DominatorSet *DS;
public:
+ CodeExtractor(DominatorSet *ds = 0) : DS(ds) {}
+
Function *ExtractCodeRegion(const std::vector<BasicBlock*> &code);
private:
BasicBlock *newHeader,
BasicBlock *newRootNode);
- void processPhiNodeInputs(PHINode *Phi,
- Values &inputs,
- BasicBlock *newHeader,
- BasicBlock *newRootNode);
-
- void rewritePhiNodes(Function *F, BasicBlock *newFuncRoot);
-
Function *constructFunction(const Values &inputs,
const Values &outputs,
+ BasicBlock *header,
BasicBlock *newRootNode, BasicBlock *newHeader,
Function *oldFunction, Module *M);
};
}
-void CodeExtractor::processPhiNodeInputs(PHINode *Phi,
- Values &inputs,
- BasicBlock *codeReplacer,
- BasicBlock *newFuncRoot)
-{
- // Separate incoming values and BasicBlocks as internal/external. We ignore
- // the case where both the value and BasicBlock are internal, because we don't
- // need to do a thing.
- std::vector<unsigned> EValEBB;
- std::vector<unsigned> EValIBB;
- std::vector<unsigned> IValEBB;
-
- for (unsigned i = 0, e = Phi->getNumIncomingValues(); i != e; ++i) {
- Value *phiVal = Phi->getIncomingValue(i);
- if (Instruction *Inst = dyn_cast<Instruction>(phiVal)) {
- if (BlocksToExtract.count(Inst->getParent())) {
- if (!BlocksToExtract.count(Phi->getIncomingBlock(i)))
- IValEBB.push_back(i);
- } else {
- if (BlocksToExtract.count(Phi->getIncomingBlock(i)))
- EValIBB.push_back(i);
- else
- EValEBB.push_back(i);
- }
- } else if (Constant *Const = dyn_cast<Constant>(phiVal)) {
- // Constants are internal, but considered `external' if they are coming
- // from an external block.
- if (!BlocksToExtract.count(Phi->getIncomingBlock(i)))
- EValEBB.push_back(i);
- } else if (Argument *Arg = dyn_cast<Argument>(phiVal)) {
- // arguments are external
- if (BlocksToExtract.count(Phi->getIncomingBlock(i)))
- EValIBB.push_back(i);
- else
- EValEBB.push_back(i);
- } else {
- phiVal->dump();
- assert(0 && "Unhandled input in a Phi node");
- }
- }
-
- // Both value and block are external. Need to group all of
- // these, have an external phi, pass the result as an
- // argument, and have THIS phi use that result.
- if (EValEBB.size() > 0) {
- if (EValEBB.size() == 1) {
- // Now if it's coming from the newFuncRoot, it's that funky input
- unsigned phiIdx = EValEBB[0];
- if (!dyn_cast<Constant>(Phi->getIncomingValue(phiIdx)))
- {
- PhiVal2Arg[Phi].push_back(std::make_pair(phiIdx, inputs.size()));
- // We can just pass this value in as argument
- inputs.push_back(Phi->getIncomingValue(phiIdx));
- }
- Phi->setIncomingBlock(phiIdx, newFuncRoot);
- } else {
- PHINode *externalPhi = new PHINode(Phi->getType(), "extPhi");
- codeReplacer->getInstList().insert(codeReplacer->begin(), externalPhi);
- for (std::vector<unsigned>::iterator i = EValEBB.begin(),
- e = EValEBB.end(); i != e; ++i)
- {
- externalPhi->addIncoming(Phi->getIncomingValue(*i),
- Phi->getIncomingBlock(*i));
-
- // We make these values invalid instead of deleting them because that
- // would shift the indices of other values... The fixPhiNodes should
- // clean these phi nodes up later.
- Phi->setIncomingValue(*i, 0);
- Phi->setIncomingBlock(*i, 0);
- }
- PhiVal2Arg[Phi].push_back(std::make_pair(Phi->getNumIncomingValues(),
- inputs.size()));
- // We can just pass this value in as argument
- inputs.push_back(externalPhi);
- }
- }
-
- // When the value is external, but block internal...
- // just pass it in as argument, no change to phi node
- for (std::vector<unsigned>::iterator i = EValIBB.begin(),
- e = EValIBB.end(); i != e; ++i)
- {
- // rewrite the phi input node to be an argument
- PhiVal2Arg[Phi].push_back(std::make_pair(*i, inputs.size()));
- inputs.push_back(Phi->getIncomingValue(*i));
- }
-
- // Value internal, block external
- // this can happen if we are extracting a part of a loop
- for (std::vector<unsigned>::iterator i = IValEBB.begin(),
- e = IValEBB.end(); i != e; ++i)
- {
- assert(0 && "Cannot (YET) handle internal values via external blocks");
- }
-}
-
-
-void CodeExtractor::findInputsOutputs(Values &inputs,
- Values &outputs,
+void CodeExtractor::findInputsOutputs(Values &inputs, Values &outputs,
BasicBlock *newHeader,
- BasicBlock *newRootNode)
-{
+ BasicBlock *newRootNode) {
for (std::set<BasicBlock*>::const_iterator ci = BlocksToExtract.begin(),
ce = BlocksToExtract.end(); ci != ce; ++ci) {
BasicBlock *BB = *ci;
- for (BasicBlock::iterator BBi = BB->begin(), BBe = BB->end();
- BBi != BBe; ++BBi) {
- // If a use is defined outside the region, it's an input.
- // If a def is used outside the region, it's an output.
- if (Instruction *I = dyn_cast<Instruction>(&*BBi)) {
- // If it's a phi node
- if (PHINode *Phi = dyn_cast<PHINode>(I)) {
- processPhiNodeInputs(Phi, inputs, newHeader, newRootNode);
- } else {
- // All other instructions go through the generic input finder
- // Loop over the operands of each instruction (inputs)
- for (User::op_iterator op = I->op_begin(), opE = I->op_end();
- op != opE; ++op) {
- if (Instruction *opI = dyn_cast<Instruction>(op->get())) {
- // Check if definition of this operand is within the loop
- if (!BlocksToExtract.count(opI->getParent())) {
- // add this operand to the inputs
- inputs.push_back(opI);
- }
- }
- }
+ for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) {
+ // If a used value is defined outside the region, it's an input. If an
+ // instruction is used outside the region, it's an output.
+ if (PHINode *PN = dyn_cast<PHINode>(I)) {
+ for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
+ Value *V = PN->getIncomingValue(i);
+ if (!BlocksToExtract.count(PN->getIncomingBlock(i)) &&
+ (isa<Instruction>(V) || isa<Argument>(V)))
+ inputs.push_back(V);
}
-
- // Consider uses of this instruction (outputs)
- for (Value::use_iterator use = I->use_begin(), useE = I->use_end();
- use != useE; ++use) {
- if (Instruction* inst = dyn_cast<Instruction>(*use)) {
- if (!BlocksToExtract.count(inst->getParent())) {
- // add this op to the outputs
- outputs.push_back(I);
- }
+ } else {
+ // All other instructions go through the generic input finder
+ // Loop over the operands of each instruction (inputs)
+ for (User::op_iterator op = I->op_begin(), opE = I->op_end();
+ op != opE; ++op)
+ if (Instruction *opI = dyn_cast<Instruction>(*op)) {
+ // Check if definition of this operand is within the loop
+ if (!BlocksToExtract.count(opI->getParent()))
+ inputs.push_back(opI);
+ } else if (isa<Argument>(*op)) {
+ inputs.push_back(*op);
}
- }
- } /* if */
- } /* for: insts */
- } /* for: basic blocks */
-}
-
-void CodeExtractor::rewritePhiNodes(Function *F,
- BasicBlock *newFuncRoot) {
- // Write any changes that were saved before: use function arguments as inputs
- for (PhiVal2ArgTy::iterator i = PhiVal2Arg.begin(), e = PhiVal2Arg.end();
- i != e; ++i)
- {
- PHINode *phi = (*i).first;
- PhiValChangesTy &values = (*i).second;
- for (unsigned cIdx = 0, ce = values.size(); cIdx != ce; ++cIdx)
- {
- unsigned phiValueIdx = values[cIdx].first, argNum = values[cIdx].second;
- if (phiValueIdx < phi->getNumIncomingValues())
- phi->setIncomingValue(phiValueIdx, getFunctionArg(F, argNum));
- else
- phi->addIncoming(getFunctionArg(F, argNum), newFuncRoot);
- }
- }
-
- // Delete any invalid Phi node inputs that were marked as NULL previously
- for (PhiVal2ArgTy::iterator i = PhiVal2Arg.begin(), e = PhiVal2Arg.end();
- i != e; ++i)
- {
- PHINode *phi = (*i).first;
- for (unsigned idx = 0, end = phi->getNumIncomingValues(); idx != end; ++idx)
- {
- if (phi->getIncomingValue(idx) == 0 && phi->getIncomingBlock(idx) == 0) {
- phi->removeIncomingValue(idx);
- --idx;
- --end;
}
- }
- }
-
- // We are done with the saved values
- PhiVal2Arg.clear();
+
+ // Consider uses of this instruction (outputs)
+ for (Value::use_iterator UI = I->use_begin(), E = I->use_end();
+ UI != E; ++UI)
+ if (!BlocksToExtract.count(cast<Instruction>(*UI)->getParent())) {
+ outputs.push_back(I);
+ break;
+ }
+ } // for: insts
+ } // for: basic blocks
}
-
/// constructFunction - make a function based on inputs and outputs, as follows:
/// f(in0, ..., inN, out0, ..., outN)
///
Function *CodeExtractor::constructFunction(const Values &inputs,
const Values &outputs,
+ BasicBlock *header,
BasicBlock *newRootNode,
BasicBlock *newHeader,
- Function *oldFunction, Module *M) {
+ Function *oldFunction,
+ Module *M) {
DEBUG(std::cerr << "inputs: " << inputs.size() << "\n");
DEBUG(std::cerr << "outputs: " << outputs.size() << "\n");
- BasicBlock *header = *BlocksToExtract.begin();
// This function returns unsigned, outputs will go back by reference.
Type *retTy = Type::UShortTy;
paramTy.push_back(value->getType());
}
- // Add the types of the output values to the function's argument list, but
- // make them pointer types for scalars
- for (Values::const_iterator i = outputs.begin(),
- e = outputs.end(); i != e; ++i) {
- const Value *value = *i;
- DEBUG(std::cerr << "instr used in func: " << value << "\n");
- const Type *valueType = value->getType();
- // Convert scalar types into a pointer of that type
- if (valueType->isPrimitiveType()) {
- valueType = PointerType::get(valueType);
- }
- paramTy.push_back(valueType);
+ // Add the types of the output values to the function's argument list.
+ for (Values::const_iterator I = outputs.begin(), E = outputs.end();
+ I != E; ++I) {
+ DEBUG(std::cerr << "instr used in func: " << *I << "\n");
+ paramTy.push_back(PointerType::get((*I)->getType()));
}
DEBUG(std::cerr << "Function type: " << retTy << " f(");
for (std::vector<const Type*>::iterator i = paramTy.begin(),
e = paramTy.end(); i != e; ++i)
- DEBUG(std::cerr << (*i) << ", ");
+ DEBUG(std::cerr << *i << ", ");
DEBUG(std::cerr << ")\n");
const FunctionType *funcType = FunctionType::get(retTy, paramTy, false);
oldFunction->getName() + "_code", M);
newFunction->getBasicBlockList().push_back(newRootNode);
- for (unsigned i = 0, e = inputs.size(); i != e; ++i) {
+ // Create an iterator to name all of the arguments we inserted.
+ Function::aiterator AI = newFunction->abegin();
+
+ // Rewrite all users of the inputs in the extracted region to use the
+ // arguments instead.
+ for (unsigned i = 0, e = inputs.size(); i != e; ++i, ++AI) {
+ AI->setName(inputs[i]->getName());
std::vector<User*> Users(inputs[i]->use_begin(), inputs[i]->use_end());
for (std::vector<User*>::iterator use = Users.begin(), useE = Users.end();
use != useE; ++use)
if (Instruction* inst = dyn_cast<Instruction>(*use))
if (BlocksToExtract.count(inst->getParent()))
- inst->replaceUsesOfWith(inputs[i], getFunctionArg(newFunction, i));
+ inst->replaceUsesOfWith(inputs[i], AI);
}
+ // Set names for all of the output arguments.
+ for (unsigned i = 0, e = outputs.size(); i != e; ++i, ++AI)
+ AI->setName(outputs[i]->getName()+".out");
+
+
// Rewrite branches to basic blocks outside of the loop to new dummy blocks
// within the new function. This must be done before we lose track of which
// blocks were originally in the code region.
std::vector<User*> Users(header->use_begin(), header->use_end());
- for (std::vector<User*>::iterator i = Users.begin(), e = Users.end();
- i != e; ++i) {
- if (BranchInst *inst = dyn_cast<BranchInst>(*i)) {
- BasicBlock *BB = inst->getParent();
- if (!BlocksToExtract.count(BB) && BB->getParent() == oldFunction) {
- // The BasicBlock which contains the branch is not in the region
- // modify the branch target to a new block
- inst->replaceUsesOfWith(header, newHeader);
- }
- }
- }
+ for (unsigned i = 0, e = Users.size(); i != e; ++i)
+ // The BasicBlock which contains the branch is not in the region
+ // modify the branch target to a new block
+ if (TerminatorInst *TI = dyn_cast<TerminatorInst>(Users[i]))
+ if (!BlocksToExtract.count(TI->getParent()) &&
+ TI->getParent()->getParent() == oldFunction)
+ TI->replaceUsesOfWith(header, newHeader);
return newFunction;
}
CodeExtractor::emitCallAndSwitchStatement(Function *newFunction,
BasicBlock *codeReplacer,
Values &inputs,
- Values &outputs)
-{
+ Values &outputs) {
// Emit a call to the new function, passing allocated memory for outputs and
// just plain inputs for non-scalars
- std::vector<Value*> params;
- BasicBlock *codeReplacerTail = new BasicBlock("codeReplTail",
- codeReplacer->getParent());
- for (Values::const_iterator i = inputs.begin(),
- e = inputs.end(); i != e; ++i)
- params.push_back(*i);
- for (Values::const_iterator i = outputs.begin(),
- e = outputs.end(); i != e; ++i) {
+ std::vector<Value*> params(inputs);
+
+ // Get an iterator to the first output argument.
+ Function::aiterator OutputArgBegin = newFunction->abegin();
+ std::advance(OutputArgBegin, inputs.size());
+
+ for (unsigned i = 0, e = outputs.size(); i != e; ++i) {
+ Value *Output = outputs[i];
// Create allocas for scalar outputs
- if ((*i)->getType()->isPrimitiveType()) {
- Constant *one = ConstantUInt::get(Type::UIntTy, 1);
- AllocaInst *alloca = new AllocaInst((*i)->getType(), one);
- codeReplacer->getInstList().push_back(alloca);
- params.push_back(alloca);
-
- LoadInst *load = new LoadInst(alloca, "alloca");
- codeReplacerTail->getInstList().push_back(load);
- std::vector<User*> Users((*i)->use_begin(), (*i)->use_end());
- for (std::vector<User*>::iterator use = Users.begin(), useE =Users.end();
- use != useE; ++use) {
- if (Instruction* inst = dyn_cast<Instruction>(*use)) {
- if (!BlocksToExtract.count(inst->getParent())) {
- inst->replaceUsesOfWith(*i, load);
- }
- }
- }
- } else {
- params.push_back(*i);
+ AllocaInst *alloca =
+ new AllocaInst(outputs[i]->getType(), 0, Output->getName()+".loc",
+ codeReplacer->getParent()->begin()->begin());
+ params.push_back(alloca);
+
+ LoadInst *load = new LoadInst(alloca, Output->getName()+".reload");
+ codeReplacer->getInstList().push_back(load);
+ std::vector<User*> Users(outputs[i]->use_begin(), outputs[i]->use_end());
+ for (unsigned u = 0, e = Users.size(); u != e; ++u) {
+ Instruction *inst = cast<Instruction>(Users[u]);
+ if (!BlocksToExtract.count(inst->getParent()))
+ inst->replaceUsesOfWith(outputs[i], load);
}
}
CallInst *call = new CallInst(newFunction, params, "targetBlock");
- codeReplacer->getInstList().push_back(call);
- codeReplacer->getInstList().push_back(new BranchInst(codeReplacerTail));
+ codeReplacer->getInstList().push_front(call);
// Now we can emit a switch statement using the call as a value.
- // FIXME: perhaps instead of default being self BB, it should be a second
- // dummy block which asserts that the value is not within the range...?
- //BasicBlock *defaultBlock = new BasicBlock("defaultBlock", oldF);
- //insert abort() ?
- //defaultBlock->getInstList().push_back(new BranchInst(codeReplacer));
-
- SwitchInst *switchInst = new SwitchInst(call, codeReplacerTail,
- codeReplacerTail);
+ SwitchInst *TheSwitch = new SwitchInst(call, codeReplacer, codeReplacer);
// Since there may be multiple exits from the original region, make the new
// function return an unsigned, switch on that number. This loop iterates
ReturnInst *NTRet = new ReturnInst(brVal, NewTarget);
// Update the switch instruction.
- switchInst->addCase(brVal, OldTarget);
+ TheSwitch->addCase(brVal, OldTarget);
// Restore values just before we exit
// FIXME: Use a GetElementPtr to bunch the outputs in a struct
- for (unsigned out = 0, e = outputs.size(); out != e; ++out)
- new StoreInst(outputs[out], getFunctionArg(newFunction, out),NTRet);
+ Function::aiterator OAI = OutputArgBegin;
+ for (unsigned out = 0, e = outputs.size(); out != e; ++out, ++OAI)
+ if (!DS ||
+ DS->dominates(cast<Instruction>(outputs[out])->getParent(),
+ TI->getParent()))
+ new StoreInst(outputs[out], OAI, NTRet);
}
// rewrite the original branch instruction with this new target
TI->setSuccessor(i, NewTarget);
}
}
+
+ // Now that we've done the deed, make the default destination of the switch
+ // instruction be one of the exit blocks of the region.
+ if (TheSwitch->getNumSuccessors() > 1) {
+ // FIXME: this is broken w.r.t. PHI nodes, but the old code was more broken.
+ // This edge is not traversable.
+ TheSwitch->setSuccessor(0, TheSwitch->getSuccessor(1));
+ }
}
Values inputs, outputs;
// Assumption: this is a single-entry code region, and the header is the first
- // block in the region. FIXME: is this true for a list of blocks from a
- // natural function?
+ // block in the region.
BasicBlock *header = code[0];
+ for (unsigned i = 1, e = code.size(); i != e; ++i)
+ for (pred_iterator PI = pred_begin(code[i]), E = pred_end(code[i]);
+ PI != E; ++PI)
+ assert(BlocksToExtract.count(*PI) &&
+ "No blocks in this region may have entries from outside the region"
+ " except for the first block!");
+
Function *oldFunction = header->getParent();
- Module *module = oldFunction->getParent();
// This takes place of the original loop
BasicBlock *codeReplacer = new BasicBlock("codeRepl", oldFunction);
// Step 2: Construct new function based on inputs/outputs,
// Add allocas for all defs
- Function *newFunction = constructFunction(inputs, outputs, newFuncRoot,
- codeReplacer, oldFunction, module);
-
- rewritePhiNodes(newFunction, newFuncRoot);
+ Function *newFunction = constructFunction(inputs, outputs, code[0],
+ newFuncRoot,
+ codeReplacer, oldFunction,
+ oldFunction->getParent());
emitCallAndSwitchStatement(newFunction, codeReplacer, inputs, outputs);
moveCodeToFunction(newFunction);
+ // Loop over all of the PHI nodes in the entry block (code[0]), and change any
+ // references to the old incoming edge to be the new incoming edge.
+ for (BasicBlock::iterator I = code[0]->begin();
+ PHINode *PN = dyn_cast<PHINode>(I); ++I)
+ for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
+ if (!BlocksToExtract.count(PN->getIncomingBlock(i)))
+ PN->setIncomingBlock(i, newFuncRoot);
+
+ // Look at all successors of the codeReplacer block. If any of these blocks
+ // had PHI nodes in them, we need to update the "from" block to be the code
+ // replacer, not the original block in the extracted region.
+ std::vector<BasicBlock*> Succs(succ_begin(codeReplacer),
+ succ_end(codeReplacer));
+ for (unsigned i = 0, e = Succs.size(); i != e; ++i)
+ for (BasicBlock::iterator I = Succs[i]->begin();
+ PHINode *PN = dyn_cast<PHINode>(I); ++I)
+ for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
+ if (BlocksToExtract.count(PN->getIncomingBlock(i)))
+ PN->setIncomingBlock(i, codeReplacer);
+
+
DEBUG(if (verifyFunction(*newFunction)) abort());
return newFunction;
}
/// ExtractCodeRegion - slurp a sequence of basic blocks into a brand new
/// function
///
-Function* llvm::ExtractCodeRegion(const std::vector<BasicBlock*> &code) {
- return CodeExtractor().ExtractCodeRegion(code);
+Function* llvm::ExtractCodeRegion(DominatorSet &DS,
+ const std::vector<BasicBlock*> &code) {
+ return CodeExtractor(&DS).ExtractCodeRegion(code);
}
/// ExtractBasicBlock - slurp a natural loop into a brand new function
///
-Function* llvm::ExtractLoop(Loop *L) {
- return CodeExtractor().ExtractCodeRegion(L->getBlocks());
+Function* llvm::ExtractLoop(DominatorSet &DS, Loop *L) {
+ return CodeExtractor(&DS).ExtractCodeRegion(L->getBlocks());
}
/// ExtractBasicBlock - slurp a basic block into a brand new function
projects / oota-llvm.git / blobdiff