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tidy up

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112643 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2010-08-31 21:21:25 +00:00
parent f2db5b48d0
commit b5d84d13bc
1 changed files with 30 additions and 29 deletions
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59
lib/Transforms/Scalar/TailRecursionElimination.cpp
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@ -278,22 +278,22 @@ static Value *getCommonReturnValue(ReturnInst *IgnoreRI, CallInst *CI) {
Function *F = CI->getParent()->getParent();
Value *ReturnedValue = 0;
for (Function::iterator BBI = F->begin(), E = F->end(); BBI != E; ++BBI)
if (ReturnInst *RI = dyn_cast<ReturnInst>(BBI->getTerminator()))
if (RI != IgnoreRI) {
Value *RetOp = RI->getOperand(0);
for (Function::iterator BBI = F->begin(), E = F->end(); BBI != E; ++BBI) {
ReturnInst *RI = dyn_cast<ReturnInst>(BBI->getTerminator());
if (RI == 0 || RI == IgnoreRI) continue;
// We can only perform this transformation if the value returned is
// evaluatable at the start of the initial invocation of the function,
// instead of at the end of the evaluation.
//
if (!isDynamicConstant(RetOp, CI, RI))
return 0;
// We can only perform this transformation if the value returned is
// evaluatable at the start of the initial invocation of the function,
// instead of at the end of the evaluation.
//
Value *RetOp = RI->getOperand(0);
if (!isDynamicConstant(RetOp, CI, RI))
return 0;
if (ReturnedValue && RetOp != ReturnedValue)
return 0; // Cannot transform if differing values are returned.
ReturnedValue = RetOp;
}
if (ReturnedValue && RetOp != ReturnedValue)
return 0; // Cannot transform if differing values are returned.
ReturnedValue = RetOp;
}
return ReturnedValue;
}
@ -307,7 +307,7 @@ Value *TailCallElim::CanTransformAccumulatorRecursion(Instruction *I,
assert(I->getNumOperands() == 2 &&
"Associative/commutative operations should have 2 args!");
// Exactly one operand should be the result of the call instruction...
// Exactly one operand should be the result of the call instruction.
if ((I->getOperand(0) == CI && I->getOperand(1) == CI) ||
(I->getOperand(0) != CI && I->getOperand(1) != CI))
return 0;
@ -387,21 +387,22 @@ bool TailCallElim::ProcessReturningBlock(ReturnInst *Ret, BasicBlock *&OldEntry,
// tail call if all of the instructions between the call and the return are
// movable to above the call itself, leaving the call next to the return.
// Check that this is the case now.
for (BBI = CI, ++BBI; &*BBI != Ret; ++BBI)
if (!CanMoveAboveCall(BBI, CI)) {
// If we can't move the instruction above the call, it might be because it
// is an associative and commutative operation that could be tranformed
// using accumulator recursion elimination. Check to see if this is the
// case, and if so, remember the initial accumulator value for later.
if ((AccumulatorRecursionEliminationInitVal =
CanTransformAccumulatorRecursion(BBI, CI))) {
// Yes, this is accumulator recursion. Remember which instruction
// accumulates.
AccumulatorRecursionInstr = BBI;
} else {
return false; // Otherwise, we cannot eliminate the tail recursion!
}
for (BBI = CI, ++BBI; &*BBI != Ret; ++BBI) {
if (CanMoveAboveCall(BBI, CI)) continue;
// If we can't move the instruction above the call, it might be because it
// is an associative and commutative operation that could be tranformed
// using accumulator recursion elimination. Check to see if this is the
// case, and if so, remember the initial accumulator value for later.
if ((AccumulatorRecursionEliminationInitVal =
CanTransformAccumulatorRecursion(BBI, CI))) {
// Yes, this is accumulator recursion. Remember which instruction
// accumulates.
AccumulatorRecursionInstr = BBI;
} else {
return false; // Otherwise, we cannot eliminate the tail recursion!
}
}
// We can only transform call/return pairs that either ignore the return value
// of the call and return void, ignore the value of the call and return a