maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

expose edge information and switch j-t to use it. 

llvm-svn: 86920
This commit is contained in:
Chris Lattner 2009-11-12 01:29:10 +00:00
parent bff25cb044
commit d5e25436a1
3 changed files with 27 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
llvm/include/llvm/Analysis/LazyValueInfo.h
View File

@ -47,6 +47,10 @@ public:
/// getConstant - Determine whether the specified value is known to be a
/// constant at the end of the specified block. Return null if not.
Constant *getConstant(Value *V, BasicBlock *BB);
/// getConstantOnEdge - Determine whether the specified value is known to be a
/// constant on the specified edge. Return null if not.
Constant *getConstantOnEdge(Value *V, BasicBlock *FromBB, BasicBlock *ToBB);
// Implementation boilerplate.

21
llvm/lib/Analysis/LazyValueInfo.cpp
View File

@ -270,6 +270,27 @@ Constant *LazyValueInfo::getConstant(Value *V, BasicBlock *BB) {
return 0;
}
/// getConstantOnEdge - Determine whether the specified value is known to be a
/// constant on the specified edge. Return null if not.
Constant *LazyValueInfo::getConstantOnEdge(Value *V, BasicBlock *FromBB,
BasicBlock *ToBB) {
// If already a constant, return it.
if (Constant *VC = dyn_cast<Constant>(V))
return VC;
DenseMap<BasicBlock*, LVILatticeVal> BlockValues;
DEBUG(errs() << "Getting value " << *V << " on edge from '"
<< FromBB->getName() << "' to '" << ToBB->getName() << "'\n");
LVILatticeVal Result = GetValueOnEdge(V, FromBB, ToBB, BlockValues);
DEBUG(errs() << " Result = " << Result << "\n");
if (Result.isConstant())
return Result.getConstant();
return 0;
}
/// isEqual - Determine whether the specified value is known to be equal or
/// not-equal to the specified constant at the end of the specified block.
LazyValueInfo::Tristate

4
llvm/lib/Transforms/Scalar/JumpThreading.cpp
View File

@ -278,7 +278,7 @@ ComputeValueKnownInPredecessors(Value *V, BasicBlock *BB,PredValueInfo &Result){
for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI) {
// If the value is known by LazyValueInfo to be a constant in a
// predecessor, use that information to try to thread this block.
Constant *PredCst = LVI->getConstant(V, *PI);
Constant *PredCst = LVI->getConstantOnEdge(V, *PI, BB);
if (PredCst == 0 ||
(!isa<ConstantInt>(PredCst) && !isa<UndefValue>(PredCst)))
continue;
@ -384,7 +384,7 @@ ComputeValueKnownInPredecessors(Value *V, BasicBlock *BB,PredValueInfo &Result){
for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI) {
// If the value is known by LazyValueInfo to be a constant in a
// predecessor, use that information to try to thread this block.
Constant *PredCst = LVI->getConstant(Cmp->getOperand(0), *PI);
Constant *PredCst = LVI->getConstantOnEdge(Cmp->getOperand(0), *PI, BB);
if (PredCst == 0)
continue;