[llvm] r175014 - Actually delete this code, since it's really not clear what it's
Dan Gohman
dan433584 at gmail.com
Tue Feb 12 14:26:41 PST 2013
Author: djg
Date: Tue Feb 12 16:26:41 2013
New Revision: 175014
URL: http://llvm.org/viewvc/llvm-project?rev=175014&view=rev
Log:
Actually delete this code, since it's really not clear what it's
trying to do.
Modified:
llvm/trunk/lib/Transforms/Scalar/GVN.cpp
Modified: llvm/trunk/lib/Transforms/Scalar/GVN.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/GVN.cpp?rev=175014&r1=175013&r2=175014&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/GVN.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/GVN.cpp Tue Feb 12 16:26:41 2013
@@ -1526,10 +1526,8 @@ bool GVN::processNonLocalLoad(LoadInst *
BasicBlock *LoadBB = LI->getParent();
BasicBlock *TmpBB = LoadBB;
- bool isSinglePred = false;
bool allSingleSucc = true;
while (TmpBB->getSinglePredecessor()) {
- isSinglePred = true;
TmpBB = TmpBB->getSinglePredecessor();
if (TmpBB == LoadBB) // Infinite (unreachable) loop.
return false;
@@ -1548,28 +1546,6 @@ bool GVN::processNonLocalLoad(LoadInst *
assert(TmpBB);
LoadBB = TmpBB;
- // FIXME: It is extremely unclear what this loop is doing, other than
- // artificially restricting loadpre.
- if (isSinglePred) {
- bool isHot = false;
- for (unsigned i = 0, e = ValuesPerBlock.size(); i != e; ++i) {
- const AvailableValueInBlock &AV = ValuesPerBlock[i];
- if (AV.isSimpleValue())
- // "Hot" Instruction is in some loop (because it dominates its dep.
- // instruction).
- if (Instruction *I = dyn_cast<Instruction>(AV.getSimpleValue()))
- if (DT->dominates(LI, I)) {
- isHot = true;
- break;
- }
- }
-
- // We are interested only in "hot" instructions. We don't want to do any
- // mis-optimizations here.
- if (!isHot)
- return false;
- }
-
// Check to see how many predecessors have the loaded value fully
// available.
DenseMap<BasicBlock*, Value*> PredLoads;
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