maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

[SCCP] Generalize tryToReplaceInstWithConstant to work also with arguments. 

llvm-svn: 275357
This commit is contained in:
Davide Italiano 2016-07-14 01:27:29 +00:00
parent 284652beec
commit 6ed6d77950
1 changed files with 18 additions and 22 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

40
llvm/lib/Transforms/Scalar/SCCP.cpp
View File

@ -1510,16 +1510,16 @@ bool SCCPSolver::ResolvedUndefsIn(Function &F) {
return false;
}
static bool tryToReplaceInstWithConstant(SCCPSolver Solver, Instruction *Inst,
bool shouldEraseFromParent) {
template <typename ArgOrInst>
static bool tryToReplaceWithConstant(SCCPSolver Solver, ArgOrInst *AI) {
Constant *Const = nullptr;
if (Inst->getType()->isStructTy()) {
std::vector<LatticeVal> IVs = Solver.getStructLatticeValueFor(Inst);
if (AI->getType()->isStructTy()) {
std::vector<LatticeVal> IVs = Solver.getStructLatticeValueFor(AI);
if (std::any_of(IVs.begin(), IVs.end(),
[](LatticeVal &LV) { return LV.isOverdefined(); }))
return false;
std::vector<Constant *> ConstVals;
StructType *ST = dyn_cast<StructType>(Inst->getType());
StructType *ST = dyn_cast<StructType>(AI->getType());
for (unsigned i = 0, e = ST->getNumElements(); i != e; ++i) {
LatticeVal V = IVs[i];
ConstVals.push_back(V.isConstant()
@ -1528,18 +1528,23 @@ static bool tryToReplaceInstWithConstant(SCCPSolver Solver, Instruction *Inst,
}
Const = ConstantStruct::get(ST, ConstVals);
} else {
LatticeVal IV = Solver.getLatticeValueFor(Inst);
LatticeVal IV = Solver.getLatticeValueFor(AI);
if (IV.isOverdefined())
return false;
Const =
IV.isConstant() ? IV.getConstant() : UndefValue::get(Inst->getType());
Const = IV.isConstant() ? IV.getConstant() : UndefValue::get(AI->getType());
}
assert(Const && "Constant is nullptr here!");
DEBUG(dbgs() << " Constant: " << *Const << " = " << *Inst << '\n');
DEBUG(dbgs() << " Constant: " << *Const << " = " << *AI << '\n');
// Replaces all of the uses of a variable with uses of the constant.
Inst->replaceAllUsesWith(Const);
AI->replaceAllUsesWith(Const);
return true;
}
static bool tryToReplaceInstWithConstant(SCCPSolver Solver, Instruction *Inst,
bool shouldEraseFromParent) {
if (!tryToReplaceWithConstant(Solver, Inst))
return false;
// Delete the instruction.
if (shouldEraseFromParent)
@ -1766,17 +1771,8 @@ static bool runIPSCCP(Module &M, const DataLayout &DL,
// TODO: Could use getStructLatticeValueFor to find out if the entire
// result is a constant and replace it entirely if so.
LatticeVal IV = Solver.getLatticeValueFor(&*AI);
if (IV.isOverdefined()) continue;
Constant *CST = IV.isConstant() ?
IV.getConstant() : UndefValue::get(AI->getType());
DEBUG(dbgs() << "*** Arg " << *AI << " = " << *CST <<"\n");
// Replaces all of the uses of a variable with uses of the
// constant.
AI->replaceAllUsesWith(CST);
++IPNumArgsElimed;
if (tryToReplaceWithConstant(Solver, &*AI))
++IPNumArgsElimed;
}
}