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-rw-r--r--lib/Transforms/Utils/Local.cpp109
1 files changed, 63 insertions, 46 deletions
diff --git a/lib/Transforms/Utils/Local.cpp b/lib/Transforms/Utils/Local.cpp
index d7e2336..19c3c72 100644
--- a/lib/Transforms/Utils/Local.cpp
+++ b/lib/Transforms/Utils/Local.cpp
@@ -20,6 +20,8 @@
#include "llvm/Instructions.h"
#include "llvm/Intrinsics.h"
#include "llvm/IntrinsicInst.h"
+#include "llvm/Metadata.h"
+#include "llvm/Operator.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/Analysis/DebugInfo.h"
@@ -33,6 +35,7 @@
#include "llvm/Support/CFG.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/GetElementPtrTypeIterator.h"
+#include "llvm/Support/IRBuilder.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/ValueHandle.h"
#include "llvm/Support/raw_ostream.h"
@@ -42,12 +45,16 @@ using namespace llvm;
// Local constant propagation.
//
-// ConstantFoldTerminator - If a terminator instruction is predicated on a
-// constant value, convert it into an unconditional branch to the constant
-// destination.
-//
-bool llvm::ConstantFoldTerminator(BasicBlock *BB) {
+/// ConstantFoldTerminator - If a terminator instruction is predicated on a
+/// constant value, convert it into an unconditional branch to the constant
+/// destination. This is a nontrivial operation because the successors of this
+/// basic block must have their PHI nodes updated.
+/// Also calls RecursivelyDeleteTriviallyDeadInstructions() on any branch/switch
+/// conditions and indirectbr addresses this might make dead if
+/// DeleteDeadConditions is true.
+bool llvm::ConstantFoldTerminator(BasicBlock *BB, bool DeleteDeadConditions) {
TerminatorInst *T = BB->getTerminator();
+ IRBuilder<> Builder(T);
// Branch - See if we are conditional jumping on constant
if (BranchInst *BI = dyn_cast<BranchInst>(T)) {
@@ -67,11 +74,10 @@ bool llvm::ConstantFoldTerminator(BasicBlock *BB) {
// Let the basic block know that we are letting go of it. Based on this,
// it will adjust it's PHI nodes.
- assert(BI->getParent() && "Terminator not inserted in block!");
- OldDest->removePredecessor(BI->getParent());
+ OldDest->removePredecessor(BB);
// Replace the conditional branch with an unconditional one.
- BranchInst::Create(Destination, BI);
+ Builder.CreateBr(Destination);
BI->eraseFromParent();
return true;
}
@@ -86,8 +92,11 @@ bool llvm::ConstantFoldTerminator(BasicBlock *BB) {
Dest1->removePredecessor(BI->getParent());
// Replace the conditional branch with an unconditional one.
- BranchInst::Create(Dest1, BI);
+ Builder.CreateBr(Dest1);
+ Value *Cond = BI->getCondition();
BI->eraseFromParent();
+ if (DeleteDeadConditions)
+ RecursivelyDeleteTriviallyDeadInstructions(Cond);
return true;
}
return false;
@@ -136,7 +145,7 @@ bool llvm::ConstantFoldTerminator(BasicBlock *BB) {
// now.
if (TheOnlyDest) {
// Insert the new branch.
- BranchInst::Create(TheOnlyDest, SI);
+ Builder.CreateBr(TheOnlyDest);
BasicBlock *BB = SI->getParent();
// Remove entries from PHI nodes which we no longer branch to...
@@ -150,17 +159,21 @@ bool llvm::ConstantFoldTerminator(BasicBlock *BB) {
}
// Delete the old switch.
- BB->getInstList().erase(SI);
+ Value *Cond = SI->getCondition();
+ SI->eraseFromParent();
+ if (DeleteDeadConditions)
+ RecursivelyDeleteTriviallyDeadInstructions(Cond);
return true;
}
if (SI->getNumSuccessors() == 2) {
// Otherwise, we can fold this switch into a conditional branch
// instruction if it has only one non-default destination.
- Value *Cond = new ICmpInst(SI, ICmpInst::ICMP_EQ, SI->getCondition(),
- SI->getSuccessorValue(1), "cond");
+ Value *Cond = Builder.CreateICmpEQ(SI->getCondition(),
+ SI->getSuccessorValue(1), "cond");
+
// Insert the new branch.
- BranchInst::Create(SI->getSuccessor(1), SI->getSuccessor(0), Cond, SI);
+ Builder.CreateCondBr(Cond, SI->getSuccessor(1), SI->getSuccessor(0));
// Delete the old switch.
SI->eraseFromParent();
@@ -175,7 +188,7 @@ bool llvm::ConstantFoldTerminator(BasicBlock *BB) {
dyn_cast<BlockAddress>(IBI->getAddress()->stripPointerCasts())) {
BasicBlock *TheOnlyDest = BA->getBasicBlock();
// Insert the new branch.
- BranchInst::Create(TheOnlyDest, IBI);
+ Builder.CreateBr(TheOnlyDest);
for (unsigned i = 0, e = IBI->getNumDestinations(); i != e; ++i) {
if (IBI->getDestination(i) == TheOnlyDest)
@@ -183,7 +196,10 @@ bool llvm::ConstantFoldTerminator(BasicBlock *BB) {
else
IBI->getDestination(i)->removePredecessor(IBI->getParent());
}
+ Value *Address = IBI->getAddress();
IBI->eraseFromParent();
+ if (DeleteDeadConditions)
+ RecursivelyDeleteTriviallyDeadInstructions(Address);
// If we didn't find our destination in the IBI successor list, then we
// have undefined behavior. Replace the unconditional branch with an
@@ -690,39 +706,15 @@ bool llvm::EliminateDuplicatePHINodes(BasicBlock *BB) {
///
static unsigned enforceKnownAlignment(Value *V, unsigned Align,
unsigned PrefAlign) {
+ V = V->stripPointerCasts();
- User *U = dyn_cast<User>(V);
- if (!U) return Align;
-
- switch (Operator::getOpcode(U)) {
- default: break;
- case Instruction::BitCast:
- return enforceKnownAlignment(U->getOperand(0), Align, PrefAlign);
- case Instruction::GetElementPtr: {
- // If all indexes are zero, it is just the alignment of the base pointer.
- bool AllZeroOperands = true;
- for (User::op_iterator i = U->op_begin() + 1, e = U->op_end(); i != e; ++i)
- if (!isa<Constant>(*i) ||
- !cast<Constant>(*i)->isNullValue()) {
- AllZeroOperands = false;
- break;
- }
-
- if (AllZeroOperands) {
- // Treat this like a bitcast.
- return enforceKnownAlignment(U->getOperand(0), Align, PrefAlign);
- }
- return Align;
- }
- case Instruction::Alloca: {
- AllocaInst *AI = cast<AllocaInst>(V);
+ if (AllocaInst *AI = dyn_cast<AllocaInst>(V)) {
// If there is a requested alignment and if this is an alloca, round up.
if (AI->getAlignment() >= PrefAlign)
return AI->getAlignment();
AI->setAlignment(PrefAlign);
return PrefAlign;
}
- }
if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
// If there is a large requested alignment and we can, bump up the alignment
@@ -785,10 +777,19 @@ bool llvm::ConvertDebugDeclareToDebugValue(DbgDeclareInst *DDI,
if (!DIVar.Verify())
return false;
- Instruction *DbgVal =
- Builder.insertDbgValueIntrinsic(SI->getOperand(0), 0,
- DIVar, SI);
-
+ Instruction *DbgVal = NULL;
+ // If an argument is zero extended then use argument directly. The ZExt
+ // may be zapped by an optimization pass in future.
+ Argument *ExtendedArg = NULL;
+ if (ZExtInst *ZExt = dyn_cast<ZExtInst>(SI->getOperand(0)))
+ ExtendedArg = dyn_cast<Argument>(ZExt->getOperand(0));
+ if (SExtInst *SExt = dyn_cast<SExtInst>(SI->getOperand(0)))
+ ExtendedArg = dyn_cast<Argument>(SExt->getOperand(0));
+ if (ExtendedArg)
+ DbgVal = Builder.insertDbgValueIntrinsic(ExtendedArg, 0, DIVar, SI);
+ else
+ DbgVal = Builder.insertDbgValueIntrinsic(SI->getOperand(0), 0, DIVar, SI);
+
// Propagate any debug metadata from the store onto the dbg.value.
DebugLoc SIDL = SI->getDebugLoc();
if (!SIDL.isUnknown())
@@ -838,14 +839,30 @@ bool llvm::LowerDbgDeclare(Function &F) {
E = Dbgs.end(); I != E; ++I) {
DbgDeclareInst *DDI = *I;
if (AllocaInst *AI = dyn_cast_or_null<AllocaInst>(DDI->getAddress())) {
+ bool RemoveDDI = true;
for (Value::use_iterator UI = AI->use_begin(), E = AI->use_end();
UI != E; ++UI)
if (StoreInst *SI = dyn_cast<StoreInst>(*UI))
ConvertDebugDeclareToDebugValue(DDI, SI, DIB);
else if (LoadInst *LI = dyn_cast<LoadInst>(*UI))
ConvertDebugDeclareToDebugValue(DDI, LI, DIB);
+ else
+ RemoveDDI = false;
+ if (RemoveDDI)
+ DDI->eraseFromParent();
}
- DDI->eraseFromParent();
}
return true;
}
+
+/// FindAllocaDbgDeclare - Finds the llvm.dbg.declare intrinsic describing the
+/// alloca 'V', if any.
+DbgDeclareInst *llvm::FindAllocaDbgDeclare(Value *V) {
+ if (MDNode *DebugNode = MDNode::getIfExists(V->getContext(), V))
+ for (Value::use_iterator UI = DebugNode->use_begin(),
+ E = DebugNode->use_end(); UI != E; ++UI)
+ if (DbgDeclareInst *DDI = dyn_cast<DbgDeclareInst>(*UI))
+ return DDI;
+
+ return 0;
+}
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