#include "llvm/IntrinsicInst.h"
#include "llvm/Analysis/CallGraph.h"
#include "llvm/Analysis/InlineCost.h"
-#include "llvm/Analysis/InstructionSimplify.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Transforms/IPO/InlinerPass.h"
#include "llvm/Transforms/Utils/Cloning.h"
return false;
}
-/// \brief Simplify arguments going into a particular callsite.
-///
-/// This is important to do each time we add a callsite due to inlining so that
-/// constants and other entities which feed into inline cost estimation are
-/// properly recognized when analyzing the new callsite. Consider:
-/// void outer(int x) {
-/// if (x < 42)
-/// return inner(42 - x);
-/// ...
-/// }
-/// void inner(int x) {
-/// ...
-/// }
-///
-/// The inliner gives calls to 'outer' with a constant argument a bonus because
-/// it will delete one side of a branch. But the resulting call to 'inner'
-/// will, after inlining, also have a constant operand. We need to do just
-/// enough constant folding to expose this for callsite arguments. The rest
-/// will be taken care of after the inliner finishes running.
-static void simplifyCallSiteArguments(const TargetData *TD, CallSite CS) {
- // FIXME: It would be nice to avoid this smallvector if RAUW doesn't
- // invalidate operand iterators in any cases.
- SmallVector<std::pair<Value *, Value*>, 4> SimplifiedArgs;
- for (CallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end();
- I != E; ++I)
- if (Instruction *Inst = dyn_cast<Instruction>(*I))
- if (Value *SimpleArg = SimplifyInstruction(Inst, TD))
- SimplifiedArgs.push_back(std::make_pair(Inst, SimpleArg));
- for (unsigned Idx = 0, Size = SimplifiedArgs.size(); Idx != Size; ++Idx)
- SimplifiedArgs[Idx].first->replaceAllUsesWith(SimplifiedArgs[Idx].second);
-}
-
bool Inliner::runOnSCC(CallGraphSCC &SCC) {
CallGraph &CG = getAnalysis<CallGraph>();
const TargetData *TD = getAnalysisIfAvailable<TargetData>();
for (unsigned i = 0, e = InlineInfo.InlinedCalls.size();
i != e; ++i) {
Value *Ptr = InlineInfo.InlinedCalls[i];
- CallSite NewCS = Ptr;
- simplifyCallSiteArguments(TD, NewCS);
- CallSites.push_back(std::make_pair(NewCS, NewHistoryID));
+ CallSites.push_back(std::make_pair(CallSite(Ptr), NewHistoryID));
}
}
#include "llvm/Support/CFG.h"
#include "llvm/Transforms/Utils/ValueMapper.h"
#include "llvm/Analysis/ConstantFolding.h"
+#include "llvm/Analysis/InstructionSimplify.h"
#include "llvm/Analysis/DebugInfo.h"
#include "llvm/ADT/SmallVector.h"
#include <map>
/// anything that it can reach.
void CloneBlock(const BasicBlock *BB,
std::vector<const BasicBlock*> &ToClone);
-
- public:
- /// ConstantFoldMappedInstruction - Constant fold the specified instruction,
- /// mapping its operands through VMap if they are available.
- Constant *ConstantFoldMappedInstruction(const Instruction *I);
};
}
// loop doesn't include the terminator.
for (BasicBlock::const_iterator II = BB->begin(), IE = --BB->end();
II != IE; ++II) {
- // If this instruction constant folds, don't bother cloning the instruction,
- // instead, just add the constant to the value map.
- if (Constant *C = ConstantFoldMappedInstruction(II)) {
- VMap[II] = C;
- continue;
+ Instruction *NewInst = II->clone();
+
+ // Eagerly remap operands to the newly cloned instruction, except for PHI
+ // nodes for which we defer processing until we update the CFG.
+ if (!isa<PHINode>(NewInst)) {
+ RemapInstruction(NewInst, VMap,
+ ModuleLevelChanges ? RF_None : RF_NoModuleLevelChanges);
+
+ // If we can simplify this instruction to some other value, simply add
+ // a mapping to that value rather than inserting a new instruction into
+ // the basic block.
+ if (Value *V = SimplifyInstruction(NewInst, TD)) {
+ // On the off-chance that this simplifies to an instruction in the old
+ // function, map it back into the new function.
+ if (Value *MappedV = VMap.lookup(V))
+ V = MappedV;
+
+ VMap[II] = V;
+ delete NewInst;
+ continue;
+ }
}
- Instruction *NewInst = II->clone();
if (II->hasName())
NewInst->setName(II->getName()+NameSuffix);
- NewBB->getInstList().push_back(NewInst);
VMap[II] = NewInst; // Add instruction map to value.
-
+ NewBB->getInstList().push_back(NewInst);
hasCalls |= (isa<CallInst>(II) && !isa<DbgInfoIntrinsic>(II));
if (const AllocaInst *AI = dyn_cast<AllocaInst>(II)) {
if (isa<ConstantInt>(AI->getArraySize()))
Returns.push_back(RI);
}
-/// ConstantFoldMappedInstruction - Constant fold the specified instruction,
-/// mapping its operands through VMap if they are available.
-Constant *PruningFunctionCloner::
-ConstantFoldMappedInstruction(const Instruction *I) {
- SmallVector<Constant*, 8> Ops;
- for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i)
- if (Constant *Op = dyn_cast_or_null<Constant>(MapValue(I->getOperand(i),
- VMap,
- ModuleLevelChanges ? RF_None : RF_NoModuleLevelChanges)))
- Ops.push_back(Op);
- else
- return 0; // All operands not constant!
-
- if (const CmpInst *CI = dyn_cast<CmpInst>(I))
- return ConstantFoldCompareInstOperands(CI->getPredicate(), Ops[0], Ops[1],
- TD);
-
- if (const LoadInst *LI = dyn_cast<LoadInst>(I))
- if (!LI->isVolatile())
- return ConstantFoldLoadFromConstPtr(Ops[0], TD);
-
- return ConstantFoldInstOperands(I->getOpcode(), I->getType(), Ops, TD);
-}
-
/// CloneAndPruneFunctionInto - This works exactly like CloneFunctionInto,
/// except that it does some simple constant prop and DCE on the fly. The
/// effect of this is to copy significantly less code in cases where (for
// Add the new block to the new function.
NewFunc->getBasicBlockList().push_back(NewBB);
-
- // Loop over all of the instructions in the block, fixing up operand
- // references as we go. This uses VMap to do all the hard work.
- //
- BasicBlock::iterator I = NewBB->begin();
// Handle PHI nodes specially, as we have to remove references to dead
// blocks.
- if (PHINode *PN = dyn_cast<PHINode>(I)) {
- // Skip over all PHI nodes, remembering them for later.
- BasicBlock::const_iterator OldI = BI->begin();
- for (; (PN = dyn_cast<PHINode>(I)); ++I, ++OldI)
- PHIToResolve.push_back(cast<PHINode>(OldI));
- }
-
- // Otherwise, remap the rest of the instructions normally.
- for (; I != NewBB->end(); ++I)
- RemapInstruction(I, VMap,
- ModuleLevelChanges ? RF_None : RF_NoModuleLevelChanges);
+ for (BasicBlock::const_iterator I = BI->begin(), E = BI->end(); I != E; ++I)
+ if (const PHINode *PN = dyn_cast<PHINode>(I))
+ PHIToResolve.push_back(PN);
+ else
+ break;
+
+ // Finally, remap the terminator instructions, as those can't be remapped
+ // until all BBs are mapped.
+ RemapInstruction(NewBB->getTerminator(), VMap,
+ ModuleLevelChanges ? RF_None : RF_NoModuleLevelChanges);
}
// Defer PHI resolution until rest of function is resolved, PHI resolution
projects / oota-llvm.git / commitdiff