[llvm-commits] CVS: llvm/lib/Transforms/Utils/CodeExtractor.cpp
Chris Lattner
lattner at cs.uiuc.edu
Wed Mar 17 23:29:02 PST 2004
Changes in directory llvm/lib/Transforms/Utils:
CodeExtractor.cpp updated: 1.13 -> 1.14
---
Log message:
Seriously simplify and correct the PHI node handling code.
---
Diffs of the changes: (+28 -162)
Index: llvm/lib/Transforms/Utils/CodeExtractor.cpp
diff -u llvm/lib/Transforms/Utils/CodeExtractor.cpp:1.13 llvm/lib/Transforms/Utils/CodeExtractor.cpp:1.14
--- llvm/lib/Transforms/Utils/CodeExtractor.cpp:1.13 Wed Mar 17 22:12:05 2004
+++ llvm/lib/Transforms/Utils/CodeExtractor.cpp Wed Mar 17 23:28:49 2004
@@ -30,20 +30,8 @@
using namespace llvm;
namespace {
-
- /// getFunctionArg - Return a pointer to F's ARGNOth argument.
- ///
- Argument *getFunctionArg(Function *F, unsigned argno) {
- Function::aiterator I = F->abegin();
- std::advance(I, argno);
- return I;
- }
-
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:
@@ -56,15 +44,9 @@
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);
@@ -78,95 +60,6 @@
};
}
-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 (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 {
- // Globals/Constants are internal, but considered `external' if they are
- // coming from an external block.
- if (!BlocksToExtract.count(Phi->getIncomingBlock(i)))
- EValEBB.push_back(i);
- }
- }
-
- // 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 (!isa<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,
BasicBlock *newHeader,
BasicBlock *newRootNode) {
@@ -176,8 +69,13 @@
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 *Phi = dyn_cast<PHINode>(I)) {
- processPhiNodeInputs(Phi, inputs, newHeader, newRootNode);
+ 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);
+ }
} else {
// All other instructions go through the generic input finder
// Loop over the operands of each instruction (inputs)
@@ -203,53 +101,18 @@
} // 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();
-}
-
-
/// 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;
@@ -308,17 +171,13 @@
// 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;
}
@@ -495,15 +354,22 @@
// Step 2: Construct new function based on inputs/outputs,
// Add allocas for all defs
- Function *newFunction = constructFunction(inputs, outputs, newFuncRoot,
+ Function *newFunction = constructFunction(inputs, outputs, code[0],
+ newFuncRoot,
codeReplacer, oldFunction,
oldFunction->getParent());
- rewritePhiNodes(newFunction, newFuncRoot);
-
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);
DEBUG(if (verifyFunction(*newFunction)) abort());
return newFunction;
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