//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "sink"
#include "llvm/Transforms/Scalar.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/IR/CFG.h"
+#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/Module.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
+#define DEBUG_TYPE "sink"
+
STATISTIC(NumSunk, "Number of instructions sunk");
STATISTIC(NumSinkIter, "Number of sinking iterations");
initializeSinkingPass(*PassRegistry::getPassRegistry());
}
- virtual bool runOnFunction(Function &F);
+ bool runOnFunction(Function &F) override;
- virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ void getAnalysisUsage(AnalysisUsage &AU) const override {
AU.setPreservesCFG();
FunctionPass::getAnalysisUsage(AU);
AU.addRequired<AliasAnalysis>();
AU.addRequired<DominatorTreeWrapperPass>();
- AU.addRequired<LoopInfo>();
+ AU.addRequired<LoopInfoWrapperPass>();
AU.addPreserved<DominatorTreeWrapperPass>();
- AU.addPreserved<LoopInfo>();
+ AU.addPreserved<LoopInfoWrapperPass>();
}
private:
bool ProcessBlock(BasicBlock &BB);
- bool SinkInstruction(Instruction *I, SmallPtrSet<Instruction *, 8> &Stores);
+ bool SinkInstruction(Instruction *I, SmallPtrSetImpl<Instruction*> &Stores);
bool AllUsesDominatedByBlock(Instruction *Inst, BasicBlock *BB) const;
bool IsAcceptableTarget(Instruction *Inst, BasicBlock *SuccToSinkTo) const;
};
char Sinking::ID = 0;
INITIALIZE_PASS_BEGIN(Sinking, "sink", "Code sinking", false, false)
-INITIALIZE_PASS_DEPENDENCY(LoopInfo)
+INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)
INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
INITIALIZE_AG_DEPENDENCY(AliasAnalysis)
INITIALIZE_PASS_END(Sinking, "sink", "Code sinking", false, false)
// This may leave a referencing dbg_value in the original block, before
// the definition of the vreg. Dwarf generator handles this although the
// user might not get the right info at runtime.
- for (Value::use_iterator I = Inst->use_begin(),
- E = Inst->use_end(); I != E; ++I) {
+ for (Use &U : Inst->uses()) {
// Determine the block of the use.
- Instruction *UseInst = cast<Instruction>(*I);
+ Instruction *UseInst = cast<Instruction>(U.getUser());
BasicBlock *UseBlock = UseInst->getParent();
if (PHINode *PN = dyn_cast<PHINode>(UseInst)) {
// PHI nodes use the operand in the predecessor block, not the block with
// the PHI.
- unsigned Num = PHINode::getIncomingValueNumForOperand(I.getOperandNo());
+ unsigned Num = PHINode::getIncomingValueNumForOperand(U.getOperandNo());
UseBlock = PN->getIncomingBlock(Num);
}
// Check that it dominates.
bool Sinking::runOnFunction(Function &F) {
DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
- LI = &getAnalysis<LoopInfo>();
+ LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
AA = &getAnalysis<AliasAnalysis>();
bool MadeChange, EverMadeChange = false;
}
static bool isSafeToMove(Instruction *Inst, AliasAnalysis *AA,
- SmallPtrSet<Instruction *, 8> &Stores) {
+ SmallPtrSetImpl<Instruction *> &Stores) {
if (Inst->mayWriteToMemory()) {
Stores.insert(Inst);
}
if (LoadInst *L = dyn_cast<LoadInst>(Inst)) {
- AliasAnalysis::Location Loc = AA->getLocation(L);
- for (SmallPtrSet<Instruction *, 8>::iterator I = Stores.begin(),
- E = Stores.end(); I != E; ++I)
- if (AA->getModRefInfo(*I, Loc) & AliasAnalysis::Mod)
+ AliasAnalysis::Location Loc = MemoryLocation::get(L);
+ for (Instruction *S : Stores)
+ if (AA->getModRefInfo(S, Loc) & AliasAnalysis::Mod)
return false;
}
if (isa<TerminatorInst>(Inst) || isa<PHINode>(Inst))
return false;
+ // Convergent operations can only be moved to control equivalent blocks.
+ if (auto CS = CallSite(Inst)) {
+ if (CS.hasFnAttr(Attribute::Convergent))
+ return false;
+ }
+
return true;
}
// Don't sink instructions into a loop.
Loop *succ = LI->getLoopFor(SuccToSinkTo);
Loop *cur = LI->getLoopFor(Inst->getParent());
- if (succ != 0 && succ != cur)
+ if (succ != nullptr && succ != cur)
return false;
}
/// SinkInstruction - Determine whether it is safe to sink the specified machine
/// instruction out of its current block into a successor.
bool Sinking::SinkInstruction(Instruction *Inst,
- SmallPtrSet<Instruction *, 8> &Stores) {
+ SmallPtrSetImpl<Instruction *> &Stores) {
+
+ // Don't sink static alloca instructions. CodeGen assumes allocas outside the
+ // entry block are dynamically sized stack objects.
+ if (AllocaInst *AI = dyn_cast<AllocaInst>(Inst))
+ if (AI->isStaticAlloca())
+ return false;
+
// Check if it's safe to move the instruction.
if (!isSafeToMove(Inst, AA, Stores))
return false;
// SuccToSinkTo - This is the successor to sink this instruction to, once we
// decide.
- BasicBlock *SuccToSinkTo = 0;
+ BasicBlock *SuccToSinkTo = nullptr;
// Instructions can only be sunk if all their uses are in blocks
// dominated by one of the successors.
// Look at all the postdominators and see if we can sink it in one.
DomTreeNode *DTN = DT->getNode(Inst->getParent());
for (DomTreeNode::iterator I = DTN->begin(), E = DTN->end();
- I != E && SuccToSinkTo == 0; ++I) {
+ I != E && SuccToSinkTo == nullptr; ++I) {
BasicBlock *Candidate = (*I)->getBlock();
if ((*I)->getIDom()->getBlock() == Inst->getParent() &&
IsAcceptableTarget(Inst, Candidate))
// If no suitable postdominator was found, look at all the successors and
// decide which one we should sink to, if any.
for (succ_iterator I = succ_begin(Inst->getParent()),
- E = succ_end(Inst->getParent()); I != E && SuccToSinkTo == 0; ++I) {
+ E = succ_end(Inst->getParent()); I != E && !SuccToSinkTo; ++I) {
if (IsAcceptableTarget(Inst, *I))
SuccToSinkTo = *I;
}
// If we couldn't find a block to sink to, ignore this instruction.
- if (SuccToSinkTo == 0)
+ if (!SuccToSinkTo)
return false;
DEBUG(dbgs() << "Sink" << *Inst << " (";