[llvm-commits] [llvm] r86920 - in /llvm/trunk: include/llvm/Analysis/LazyValueInfo.h lib/Analysis/LazyValueInfo.cpp lib/Transforms/Scalar/JumpThreading.cpp
Chris Lattner
sabre at nondot.org
Wed Nov 11 17:29:10 PST 2009
Author: lattner
Date: Wed Nov 11 19:29:10 2009
New Revision: 86920
URL: http://llvm.org/viewvc/llvm-project?rev=86920&view=rev
Log:
expose edge information and switch j-t to use it.
Modified:
llvm/trunk/include/llvm/Analysis/LazyValueInfo.h
llvm/trunk/lib/Analysis/LazyValueInfo.cpp
llvm/trunk/lib/Transforms/Scalar/JumpThreading.cpp
Modified: llvm/trunk/include/llvm/Analysis/LazyValueInfo.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/LazyValueInfo.h?rev=86920&r1=86919&r2=86920&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Analysis/LazyValueInfo.h (original)
+++ llvm/trunk/include/llvm/Analysis/LazyValueInfo.h Wed Nov 11 19:29:10 2009
@@ -47,6 +47,10 @@
/// 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.
Modified: llvm/trunk/lib/Analysis/LazyValueInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/LazyValueInfo.cpp?rev=86920&r1=86919&r2=86920&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/LazyValueInfo.cpp (original)
+++ llvm/trunk/lib/Analysis/LazyValueInfo.cpp Wed Nov 11 19:29:10 2009
@@ -270,6 +270,27 @@
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
Modified: llvm/trunk/lib/Transforms/Scalar/JumpThreading.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/JumpThreading.cpp?rev=86920&r1=86919&r2=86920&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/JumpThreading.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/JumpThreading.cpp Wed Nov 11 19:29:10 2009
@@ -278,7 +278,7 @@
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 @@
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;
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