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authorBill Wendling <isanbard@gmail.com>2012-02-17 02:09:28 +0000
committerBill Wendling <isanbard@gmail.com>2012-02-17 02:09:28 +0000
commit1bc147b892b4b881a020a3fb706c5415ef244730 (patch)
tree6811aa4519ad0e819c69b48f8b7eb5e02aca91ca /lib/Transforms/Utils/DemoteRegToStack.cpp
parent00195d828b934455da597dbba72f1aade4e53393 (diff)
Fix some grammar-os and formatting.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150779 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms/Utils/DemoteRegToStack.cpp')
-rw-r--r--lib/Transforms/Utils/DemoteRegToStack.cpp38
1 files changed, 17 insertions, 21 deletions
diff --git a/lib/Transforms/Utils/DemoteRegToStack.cpp b/lib/Transforms/Utils/DemoteRegToStack.cpp
index 3ef6b018bf..c2483ab43c 100644
--- a/lib/Transforms/Utils/DemoteRegToStack.cpp
+++ b/lib/Transforms/Utils/DemoteRegToStack.cpp
@@ -28,7 +28,6 @@ using namespace llvm;
/// alloca. This allows the CFG to be changed around without fear of
/// invalidating the SSA information for the value. It returns the pointer to
/// the alloca inserted to create a stack slot for I.
-///
AllocaInst* llvm::DemoteRegToStack(Instruction &I, bool VolatileLoads,
Instruction *AllocaPoint) {
if (I.use_empty()) {
@@ -47,20 +46,19 @@ AllocaInst* llvm::DemoteRegToStack(Instruction &I, bool VolatileLoads,
F->getEntryBlock().begin());
}
- // Change all of the users of the instruction to read from the stack slot
- // instead.
+ // Change all of the users of the instruction to read from the stack slot.
while (!I.use_empty()) {
Instruction *U = cast<Instruction>(I.use_back());
if (PHINode *PN = dyn_cast<PHINode>(U)) {
// If this is a PHI node, we can't insert a load of the value before the
- // use. Instead, insert the load in the predecessor block corresponding
+ // use. Instead insert the load in the predecessor block corresponding
// to the incoming value.
//
// Note that if there are multiple edges from a basic block to this PHI
- // node that we cannot multiple loads. The problem is that the resultant
- // PHI node will have multiple values (from each load) coming in from the
- // same block, which is illegal SSA form. For this reason, we keep track
- // and reuse loads we insert.
+ // node that we cannot have multiple loads. The problem is that the
+ // resulting PHI node will have multiple values (from each load) coming in
+ // from the same block, which is illegal SSA form. For this reason, we
+ // keep track of and reuse loads we insert.
std::map<BasicBlock*, Value*> Loads;
for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
if (PN->getIncomingValue(i) == &I) {
@@ -81,9 +79,9 @@ AllocaInst* llvm::DemoteRegToStack(Instruction &I, bool VolatileLoads,
}
- // Insert stores of the computed value into the stack slot. We have to be
- // careful is I is an invoke instruction though, because we can't insert the
- // store AFTER the terminator instruction.
+ // Insert stores of the computed value into the stack slot. We have to be
+ // careful if I is an invoke instruction, because we can't insert the store
+ // AFTER the terminator instruction.
BasicBlock::iterator InsertPt;
if (!isa<TerminatorInst>(I)) {
InsertPt = &I;
@@ -98,16 +96,15 @@ AllocaInst* llvm::DemoteRegToStack(Instruction &I, bool VolatileLoads,
}
for (; isa<PHINode>(InsertPt) || isa<LandingPadInst>(InsertPt); ++InsertPt)
- /* empty */; // Don't insert before any PHI nodes or landingpad instrs.
- new StoreInst(&I, Slot, InsertPt);
+ /* empty */; // Don't insert before PHI nodes or landingpad instrs.
+ new StoreInst(&I, Slot, InsertPt);
return Slot;
}
-
-/// DemotePHIToStack - This function takes a virtual register computed by a phi
-/// node and replaces it with a slot in the stack frame, allocated via alloca.
-/// The phi node is deleted and it returns the pointer to the alloca inserted.
+/// DemotePHIToStack - This function takes a virtual register computed by a PHI
+/// node and replaces it with a slot in the stack frame allocated via alloca.
+/// The PHI node is deleted. It returns the pointer to the alloca inserted.
AllocaInst* llvm::DemotePHIToStack(PHINode *P, Instruction *AllocaPoint) {
if (P->use_empty()) {
P->eraseFromParent();
@@ -125,7 +122,7 @@ AllocaInst* llvm::DemotePHIToStack(PHINode *P, Instruction *AllocaPoint) {
F->getEntryBlock().begin());
}
- // Iterate over each operand, insert store in each predecessor.
+ // Iterate over each operand inserting a store in each predecessor.
for (unsigned i = 0, e = P->getNumIncomingValues(); i < e; ++i) {
if (InvokeInst *II = dyn_cast<InvokeInst>(P->getIncomingValue(i))) {
assert(II->getParent() != P->getIncomingBlock(i) &&
@@ -135,12 +132,11 @@ AllocaInst* llvm::DemotePHIToStack(PHINode *P, Instruction *AllocaPoint) {
P->getIncomingBlock(i)->getTerminator());
}
- // Insert load in place of the phi and replace all uses.
+ // Insert a load in place of the PHI and replace all uses.
Value *V = new LoadInst(Slot, P->getName()+".reload", P);
P->replaceAllUsesWith(V);
- // Delete phi.
+ // Delete PHI.
P->eraseFromParent();
-
return Slot;
}