6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-07-29 10:25:12 +00:00
Code Issues Projects Releases Wiki Activity

Rewrite ScalarEvolution::hasOperand to use an explicit worklist instead

Browse Source 
of recursion, to avoid excessive stack usage on deep expressions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156554 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Dan Gohman
2012-05-10 17:21:30 +00:00
parent e54874471c
commit ac84461e5a
1 changed files with 50 additions and 35 deletions
Download Patch File Download Diff File Expand all files Collapse all files

29
lib/Analysis/ScalarEvolution.cpp
View File

@@ -6860,15 +6860,23 @@ bool ScalarEvolution::properlyDominates(const SCEV *S, const BasicBlock *BB) {
} }
bool ScalarEvolution::hasOperand(const SCEV *S, const SCEV *Op) const { bool ScalarEvolution::hasOperand(const SCEV *S, const SCEV *Op) const {
SmallVector<const SCEV *, 8> Worklist;
Worklist.push_back(S);
do {
S = Worklist.pop_back_val();
switch (S->getSCEVType()) { switch (S->getSCEVType()) {
case scConstant: case scConstant:
return false; break;
case scTruncate: case scTruncate:
case scZeroExtend: case scZeroExtend:
case scSignExtend: { case scSignExtend: {
const SCEVCastExpr *Cast = cast<SCEVCastExpr>(S); const SCEVCastExpr *Cast = cast<SCEVCastExpr>(S);
const SCEV *CastOp = Cast->getOperand(); const SCEV *CastOp = Cast->getOperand();
return Op == CastOp || hasOperand(CastOp, Op); if (Op == CastOp)
return true;
Worklist.push_back(CastOp);
break;
} }
case scAddRecExpr: case scAddRecExpr:
case scAddExpr: case scAddExpr:
@@ -6879,24 +6887,31 @@ bool ScalarEvolution::hasOperand(const SCEV *S, const SCEV *Op) const {
for (SCEVNAryExpr::op_iterator I = NAry->op_begin(), E = NAry->op_end(); for (SCEVNAryExpr::op_iterator I = NAry->op_begin(), E = NAry->op_end();
I != E; ++I) { I != E; ++I) {
const SCEV *NAryOp = *I; const SCEV *NAryOp = *I;
if (NAryOp == Op || hasOperand(NAryOp, Op)) if (NAryOp == Op)
return true; return true;
Worklist.push_back(NAryOp);
} }
return false; break;
} }
case scUDivExpr: { case scUDivExpr: {
const SCEVUDivExpr *UDiv = cast<SCEVUDivExpr>(S); const SCEVUDivExpr *UDiv = cast<SCEVUDivExpr>(S);
const SCEV *LHS = UDiv->getLHS(), *RHS = UDiv->getRHS(); const SCEV *LHS = UDiv->getLHS(), *RHS = UDiv->getRHS();
return LHS == Op || hasOperand(LHS, Op) || if (LHS == Op || RHS == Op)
RHS == Op || hasOperand(RHS, Op); return true;
Worklist.push_back(LHS);
Worklist.push_back(RHS);
break;
} }
case scUnknown: case scUnknown:
return false; break;
case scCouldNotCompute: case scCouldNotCompute:
llvm_unreachable("Attempt to use a SCEVCouldNotCompute object!"); llvm_unreachable("Attempt to use a SCEVCouldNotCompute object!");
default: default:
llvm_unreachable("Unknown SCEV kind!"); llvm_unreachable("Unknown SCEV kind!");
} }
} while (!Worklist.empty());
return false;
} }
void ScalarEvolution::forgetMemoizedResults(const SCEV *S) { void ScalarEvolution::forgetMemoizedResults(const SCEV *S) {