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remove now redundant code, r86264 handles this case.

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86266 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2009-11-06 18:20:58 +00:00
parent 785672534d
commit 90926ab827
1 changed files with 0 additions and 66 deletions
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66
lib/Transforms/Scalar/JumpThreading.cpp
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@ -89,7 +89,6 @@ namespace {
bool ProcessSwitchOnDuplicateCond(BasicBlock *PredBB, BasicBlock *DestBB);
bool ProcessJumpOnPHI(PHINode *PN);
bool ProcessBranchOnLogical(Value *V, BasicBlock *BB, bool isAnd);
bool ProcessBranchOnCompare(CmpInst *Cmp, BasicBlock *BB);
bool SimplifyPartiallyRedundantLoad(LoadInst *LI);
@ -480,15 +479,6 @@ bool JumpThreading::ProcessBlock(BasicBlock *BB) {
if (PN->getParent() == BB)
return ProcessJumpOnPHI(PN);
// If this is a conditional branch whose condition is and/or of a phi, try to
// simplify it.
if ((CondInst->getOpcode() == Instruction::And ||
CondInst->getOpcode() == Instruction::Or) &&
isa<BranchInst>(BB->getTerminator()) &&
ProcessBranchOnLogical(CondInst, BB,
CondInst->getOpcode() == Instruction::And))
return true;
if (CmpInst *CondCmp = dyn_cast<CmpInst>(CondInst)) {
if (isa<PHINode>(CondCmp->getOperand(0))) {
// If we have "br (phi != 42)" and the phi node has any constant values
@ -1075,62 +1065,6 @@ bool JumpThreading::ProcessJumpOnPHI(PHINode *PN) {
return false;
}
/// ProcessJumpOnLogicalPHI - PN's basic block contains a conditional branch
/// whose condition is an AND/OR where one side is PN. If PN has constant
/// operands that permit us to evaluate the condition for some operand, thread
/// through the block. For example with:
/// br (and X, phi(Y, Z, false))
/// the predecessor corresponding to the 'false' will always jump to the false
/// destination of the branch.
///
bool JumpThreading::ProcessBranchOnLogical(Value *V, BasicBlock *BB,
bool isAnd) {
// If this is a binary operator tree of the same AND/OR opcode, check the
// LHS/RHS.
if (BinaryOperator *BO = dyn_cast<BinaryOperator>(V))
if ((isAnd && BO->getOpcode() == Instruction::And) ||
(!isAnd && BO->getOpcode() == Instruction::Or)) {
if (ProcessBranchOnLogical(BO->getOperand(0), BB, isAnd))
return true;
if (ProcessBranchOnLogical(BO->getOperand(1), BB, isAnd))
return true;
}
// If this isn't a PHI node, we can't handle it.
PHINode *PN = dyn_cast<PHINode>(V);
if (!PN || PN->getParent() != BB) return false;
// We can only do the simplification for phi nodes of 'false' with AND or
// 'true' with OR. See if we have any entries in the phi for this.
unsigned PredNo = ~0U;
ConstantInt *PredCst = ConstantInt::get(Type::getInt1Ty(BB->getContext()),
!isAnd);
for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
if (PN->getIncomingValue(i) == PredCst) {
PredNo = i;
break;
}
}
// If no match, bail out.
if (PredNo == ~0U)
return false;
// If so, we can actually do this threading. Merge any common predecessors
// that will act the same.
BasicBlock *PredBB = FactorCommonPHIPreds(PN, PredCst);
// Next, figure out which successor we are threading to. If this was an AND,
// the constant must be FALSE, and we must be targeting the 'false' block.
// If this is an OR, the constant must be TRUE, and we must be targeting the
// 'true' block.
BasicBlock *SuccBB = BB->getTerminator()->getSuccessor(isAnd);
// Ok, try to thread it!
return ThreadEdge(BB, PredBB, SuccBB);
}
/// ProcessBranchOnCompare - We found a branch on a comparison between a phi
/// node and a value. If we can identify when the comparison is true between
/// the phi inputs and the value, we can fold the compare for that edge and