RPCS3/llvm-mirror
1
0
Fork 0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-24 03:33:20 +01:00
Code Issues Projects Releases Wiki Activity

Refactor some code

Browse Source 
llvm-svn: 21772
This commit is contained in:
Chris Lattner 2005-05-08 00:19:31 +00:00
parent cd7caaa866
commit c2670a0da6
1 changed files with 55 additions and 45 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

100
lib/Transforms/Scalar/Reassociate.cpp
View File

@ -63,6 +63,7 @@ namespace {
unsigned getRank(Value *V);
void RewriteExprTree(BinaryOperator *I, unsigned Idx,
std::vector<ValueEntry> &Ops);
void OptimizeExpression(unsigned Opcode, std::vector<ValueEntry> &Ops);
void LinearizeExprTree(BinaryOperator *I, std::vector<ValueEntry> &Ops);
void LinearizeExpr(BinaryOperator *I);
void ReassociateBB(BasicBlock *BB);
@ -343,6 +344,57 @@ static Instruction *ConvertShiftToMul(Instruction *Shl) {
return Mul;
}
void Reassociate::OptimizeExpression(unsigned Opcode,
std::vector<ValueEntry> &Ops) {
// Now that we have the linearized expression tree, try to optimize it.
// Start by folding any constants that we found.
FoldConstants:
if (Ops.size() == 1) return;
if (Constant *V1 = dyn_cast<Constant>(Ops[Ops.size()-2].Op))
if (Constant *V2 = dyn_cast<Constant>(Ops.back().Op)) {
Ops.pop_back();
Ops.back().Op = ConstantExpr::get(Opcode, V1, V2);
goto FoldConstants;
}
// Check for destructive annihilation due to a constant being used.
if (ConstantIntegral *CstVal = dyn_cast<ConstantIntegral>(Ops.back().Op))
switch (Opcode) {
default: break;
case Instruction::And:
if (CstVal->isNullValue()) { // ... & 0 -> 0
Ops[0].Op = CstVal;
Ops.erase(Ops.begin()+1, Ops.end());
} else if (CstVal->isAllOnesValue()) { // ... & -1 -> ...
Ops.pop_back();
}
break;
case Instruction::Mul:
if (CstVal->isNullValue()) { // ... * 0 -> 0
Ops[0].Op = CstVal;
Ops.erase(Ops.begin()+1, Ops.end());
} else if (cast<ConstantInt>(CstVal)->getRawValue() == 1) {
Ops.pop_back(); // ... * 1 -> ...
}
break;
case Instruction::Or:
if (CstVal->isAllOnesValue()) { // ... | -1 -> -1
Ops[0].Op = CstVal;
Ops.erase(Ops.begin()+1, Ops.end());
}
// FALLTHROUGH!
case Instruction::Add:
case Instruction::Xor:
if (CstVal->isNullValue()) // ... [|^+] 0 -> ...
Ops.pop_back();
break;
}
// Handle destructive annihilation do to identities between elements in the
// argument list here.
}
/// ReassociateBB - Inspect all of the instructions in this basic block,
/// reassociating them as we go.
@ -383,51 +435,9 @@ void Reassociate::ReassociateBB(BasicBlock *BB) {
// the vector.
std::stable_sort(Ops.begin(), Ops.end());
// Now that we have the linearized expression tree, try to optimize it.
// Start by folding any constants that we found.
FoldConstants:
if (Ops.size() > 1)
if (Constant *V1 = dyn_cast<Constant>(Ops[Ops.size()-2].Op))
if (Constant *V2 = dyn_cast<Constant>(Ops.back().Op)) {
Ops.pop_back();
Ops.back().Op = ConstantExpr::get(I->getOpcode(), V1, V2);
goto FoldConstants;
}
// Check for destructive annihilation due to a constant being used.
if (Ops.size() != 1) { // Nothing to annihilate?
if (ConstantIntegral *CstVal = dyn_cast<ConstantIntegral>(Ops.back().Op))
switch (I->getOpcode()) {
default: break;
case Instruction::And:
if (CstVal->isNullValue()) { // ... & 0 -> 0
Ops[0].Op = CstVal;
Ops.erase(Ops.begin()+1, Ops.end());
} else if (CstVal->isAllOnesValue()) { // ... & -1 -> ...
Ops.pop_back();
}
break;
case Instruction::Mul:
if (CstVal->isNullValue()) { // ... * 0 -> 0
Ops[0].Op = CstVal;
Ops.erase(Ops.begin()+1, Ops.end());
} else if (cast<ConstantInt>(CstVal)->getRawValue() == 1) {
Ops.pop_back(); // ... * 1 -> ...
}
break;
case Instruction::Or:
if (CstVal->isAllOnesValue()) { // ... | -1 -> -1
Ops[0].Op = CstVal;
Ops.erase(Ops.begin()+1, Ops.end());
}
// FALLTHROUGH!
case Instruction::Add:
case Instruction::Xor:
if (CstVal->isNullValue()) // ... [|^+] 0 -> ...
Ops.pop_back();
break;
}
}
// OptimizeExpression - Now that we have the expression tree in a convenient
// sorted form, optimize it globally if possible.
OptimizeExpression(I->getOpcode(), Ops);
if (Ops.size() == 1) {
// This expression tree simplified to something that isn't a tree,