RPCSX/llvm
1
0
Fork 0
mirror of https://github.com/RPCSX/llvm.git synced 2025-02-27 00:15:58 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

NewGVN: Add basic support for symbolic comparison evaluation

Browse Source 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@293706 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Daniel Berlin 2017-01-31 22:31:58 +00:00
parent 740306c544
commit 05b6b111d2
1 changed files with 20 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
lib/Transforms/Scalar/NewGVN.cpp
View File

@ -347,6 +347,8 @@ private:
const BasicBlock *);
const Expression *performSymbolicAggrValueEvaluation(Instruction *,
const BasicBlock *);
const Expression *performSymbolicCmpEvaluation(Instruction *,
const BasicBlock *);
// Congruence finding.
Value *lookupOperandLeader(Value *) const;
@ -1002,6 +1004,20 @@ NewGVN::performSymbolicAggrValueEvaluation(Instruction *I,
return createAggregateValueExpression(I, B);
}
const Expression *NewGVN::performSymbolicCmpEvaluation(Instruction *I,
const BasicBlock *B) {
CmpInst *CI = dyn_cast<CmpInst>(I);
// See if our operands are equal and that implies something.
auto Op0 = lookupOperandLeader(CI->getOperand(0));
auto Op1 = lookupOperandLeader(CI->getOperand(1));
if (Op0 == Op1) {
if (CI->isTrueWhenEqual())
return createConstantExpression(ConstantInt::getTrue(CI->getType()));
else if (CI->isFalseWhenEqual())
return createConstantExpression(ConstantInt::getFalse(CI->getType()));
}
return createExpression(I, B);
}
// Substitute and symbolize the value before value numbering.
const Expression *NewGVN::performSymbolicEvaluation(Value *V,
@ -1036,7 +1052,10 @@ const Expression *NewGVN::performSymbolicEvaluation(Value *V,
case Instruction::BitCast: {
E = createExpression(I, B);
} break;
case Instruction::ICmp:
case Instruction::FCmp: {
E = performSymbolicCmpEvaluation(I, B);
} break;
case Instruction::Add:
case Instruction::FAdd:
case Instruction::Sub:
@ -1055,8 +1074,6 @@ const Expression *NewGVN::performSymbolicEvaluation(Value *V,
case Instruction::And:
case Instruction::Or:
case Instruction::Xor:
case Instruction::ICmp:
case Instruction::FCmp:
case Instruction::Trunc:
case Instruction::ZExt:
case Instruction::SExt: