mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-12-14 11:32:34 +00:00
953c681473
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239657 91177308-0d34-0410-b5e6-96231b3b80d8
366 lines
11 KiB
C++
366 lines
11 KiB
C++
//===-- SIAnnotateControlFlow.cpp - ------------------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
/// \file
|
|
/// Annotates the control flow with hardware specific intrinsics.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "AMDGPU.h"
|
|
#include "llvm/ADT/DepthFirstIterator.h"
|
|
#include "llvm/Analysis/LoopInfo.h"
|
|
#include "llvm/IR/Constants.h"
|
|
#include "llvm/IR/Dominators.h"
|
|
#include "llvm/IR/Instructions.h"
|
|
#include "llvm/IR/Module.h"
|
|
#include "llvm/Pass.h"
|
|
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
|
|
#include "llvm/Transforms/Utils/SSAUpdater.h"
|
|
|
|
using namespace llvm;
|
|
|
|
#define DEBUG_TYPE "si-annotate-control-flow"
|
|
|
|
namespace {
|
|
|
|
// Complex types used in this pass
|
|
typedef std::pair<BasicBlock *, Value *> StackEntry;
|
|
typedef SmallVector<StackEntry, 16> StackVector;
|
|
|
|
// Intrinsic names the control flow is annotated with
|
|
static const char *const IfIntrinsic = "llvm.SI.if";
|
|
static const char *const ElseIntrinsic = "llvm.SI.else";
|
|
static const char *const BreakIntrinsic = "llvm.SI.break";
|
|
static const char *const IfBreakIntrinsic = "llvm.SI.if.break";
|
|
static const char *const ElseBreakIntrinsic = "llvm.SI.else.break";
|
|
static const char *const LoopIntrinsic = "llvm.SI.loop";
|
|
static const char *const EndCfIntrinsic = "llvm.SI.end.cf";
|
|
|
|
class SIAnnotateControlFlow : public FunctionPass {
|
|
|
|
static char ID;
|
|
|
|
Type *Boolean;
|
|
Type *Void;
|
|
Type *Int64;
|
|
Type *ReturnStruct;
|
|
|
|
ConstantInt *BoolTrue;
|
|
ConstantInt *BoolFalse;
|
|
UndefValue *BoolUndef;
|
|
Constant *Int64Zero;
|
|
|
|
Constant *If;
|
|
Constant *Else;
|
|
Constant *Break;
|
|
Constant *IfBreak;
|
|
Constant *ElseBreak;
|
|
Constant *Loop;
|
|
Constant *EndCf;
|
|
|
|
DominatorTree *DT;
|
|
StackVector Stack;
|
|
|
|
LoopInfo *LI;
|
|
|
|
bool isTopOfStack(BasicBlock *BB);
|
|
|
|
Value *popSaved();
|
|
|
|
void push(BasicBlock *BB, Value *Saved);
|
|
|
|
bool isElse(PHINode *Phi);
|
|
|
|
void eraseIfUnused(PHINode *Phi);
|
|
|
|
void openIf(BranchInst *Term);
|
|
|
|
void insertElse(BranchInst *Term);
|
|
|
|
Value *handleLoopCondition(Value *Cond, PHINode *Broken, llvm::Loop *L);
|
|
|
|
void handleLoop(BranchInst *Term);
|
|
|
|
void closeControlFlow(BasicBlock *BB);
|
|
|
|
public:
|
|
SIAnnotateControlFlow():
|
|
FunctionPass(ID) { }
|
|
|
|
bool doInitialization(Module &M) override;
|
|
|
|
bool runOnFunction(Function &F) override;
|
|
|
|
const char *getPassName() const override {
|
|
return "SI annotate control flow";
|
|
}
|
|
|
|
void getAnalysisUsage(AnalysisUsage &AU) const override {
|
|
AU.addRequired<LoopInfoWrapperPass>();
|
|
AU.addRequired<DominatorTreeWrapperPass>();
|
|
AU.addPreserved<DominatorTreeWrapperPass>();
|
|
FunctionPass::getAnalysisUsage(AU);
|
|
}
|
|
|
|
};
|
|
|
|
} // end anonymous namespace
|
|
|
|
char SIAnnotateControlFlow::ID = 0;
|
|
|
|
/// \brief Initialize all the types and constants used in the pass
|
|
bool SIAnnotateControlFlow::doInitialization(Module &M) {
|
|
LLVMContext &Context = M.getContext();
|
|
|
|
Void = Type::getVoidTy(Context);
|
|
Boolean = Type::getInt1Ty(Context);
|
|
Int64 = Type::getInt64Ty(Context);
|
|
ReturnStruct = StructType::get(Boolean, Int64, (Type *)nullptr);
|
|
|
|
BoolTrue = ConstantInt::getTrue(Context);
|
|
BoolFalse = ConstantInt::getFalse(Context);
|
|
BoolUndef = UndefValue::get(Boolean);
|
|
Int64Zero = ConstantInt::get(Int64, 0);
|
|
|
|
If = M.getOrInsertFunction(
|
|
IfIntrinsic, ReturnStruct, Boolean, (Type *)nullptr);
|
|
|
|
Else = M.getOrInsertFunction(
|
|
ElseIntrinsic, ReturnStruct, Int64, (Type *)nullptr);
|
|
|
|
Break = M.getOrInsertFunction(
|
|
BreakIntrinsic, Int64, Int64, (Type *)nullptr);
|
|
|
|
IfBreak = M.getOrInsertFunction(
|
|
IfBreakIntrinsic, Int64, Boolean, Int64, (Type *)nullptr);
|
|
|
|
ElseBreak = M.getOrInsertFunction(
|
|
ElseBreakIntrinsic, Int64, Int64, Int64, (Type *)nullptr);
|
|
|
|
Loop = M.getOrInsertFunction(
|
|
LoopIntrinsic, Boolean, Int64, (Type *)nullptr);
|
|
|
|
EndCf = M.getOrInsertFunction(
|
|
EndCfIntrinsic, Void, Int64, (Type *)nullptr);
|
|
|
|
return false;
|
|
}
|
|
|
|
/// \brief Is BB the last block saved on the stack ?
|
|
bool SIAnnotateControlFlow::isTopOfStack(BasicBlock *BB) {
|
|
return !Stack.empty() && Stack.back().first == BB;
|
|
}
|
|
|
|
/// \brief Pop the last saved value from the control flow stack
|
|
Value *SIAnnotateControlFlow::popSaved() {
|
|
return Stack.pop_back_val().second;
|
|
}
|
|
|
|
/// \brief Push a BB and saved value to the control flow stack
|
|
void SIAnnotateControlFlow::push(BasicBlock *BB, Value *Saved) {
|
|
Stack.push_back(std::make_pair(BB, Saved));
|
|
}
|
|
|
|
/// \brief Can the condition represented by this PHI node treated like
|
|
/// an "Else" block?
|
|
bool SIAnnotateControlFlow::isElse(PHINode *Phi) {
|
|
BasicBlock *IDom = DT->getNode(Phi->getParent())->getIDom()->getBlock();
|
|
for (unsigned i = 0, e = Phi->getNumIncomingValues(); i != e; ++i) {
|
|
if (Phi->getIncomingBlock(i) == IDom) {
|
|
|
|
if (Phi->getIncomingValue(i) != BoolTrue)
|
|
return false;
|
|
|
|
} else {
|
|
if (Phi->getIncomingValue(i) != BoolFalse)
|
|
return false;
|
|
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
// \brief Erase "Phi" if it is not used any more
|
|
void SIAnnotateControlFlow::eraseIfUnused(PHINode *Phi) {
|
|
if (!Phi->hasNUsesOrMore(1))
|
|
Phi->eraseFromParent();
|
|
}
|
|
|
|
/// \brief Open a new "If" block
|
|
void SIAnnotateControlFlow::openIf(BranchInst *Term) {
|
|
Value *Ret = CallInst::Create(If, Term->getCondition(), "", Term);
|
|
Term->setCondition(ExtractValueInst::Create(Ret, 0, "", Term));
|
|
push(Term->getSuccessor(1), ExtractValueInst::Create(Ret, 1, "", Term));
|
|
}
|
|
|
|
/// \brief Close the last "If" block and open a new "Else" block
|
|
void SIAnnotateControlFlow::insertElse(BranchInst *Term) {
|
|
Value *Ret = CallInst::Create(Else, popSaved(), "", Term);
|
|
Term->setCondition(ExtractValueInst::Create(Ret, 0, "", Term));
|
|
push(Term->getSuccessor(1), ExtractValueInst::Create(Ret, 1, "", Term));
|
|
}
|
|
|
|
/// \brief Recursively handle the condition leading to a loop
|
|
Value *SIAnnotateControlFlow::handleLoopCondition(Value *Cond, PHINode *Broken,
|
|
llvm::Loop *L) {
|
|
|
|
// Only search through PHI nodes which are inside the loop. If we try this
|
|
// with PHI nodes that are outside of the loop, we end up inserting new PHI
|
|
// nodes outside of the loop which depend on values defined inside the loop.
|
|
// This will break the module with
|
|
// 'Instruction does not dominate all users!' errors.
|
|
PHINode *Phi = nullptr;
|
|
if ((Phi = dyn_cast<PHINode>(Cond)) && L->contains(Phi)) {
|
|
|
|
BasicBlock *Parent = Phi->getParent();
|
|
PHINode *NewPhi = PHINode::Create(Int64, 0, "", &Parent->front());
|
|
Value *Ret = NewPhi;
|
|
|
|
// Handle all non-constant incoming values first
|
|
for (unsigned i = 0, e = Phi->getNumIncomingValues(); i != e; ++i) {
|
|
Value *Incoming = Phi->getIncomingValue(i);
|
|
BasicBlock *From = Phi->getIncomingBlock(i);
|
|
if (isa<ConstantInt>(Incoming)) {
|
|
NewPhi->addIncoming(Broken, From);
|
|
continue;
|
|
}
|
|
|
|
Phi->setIncomingValue(i, BoolFalse);
|
|
Value *PhiArg = handleLoopCondition(Incoming, Broken, L);
|
|
NewPhi->addIncoming(PhiArg, From);
|
|
}
|
|
|
|
BasicBlock *IDom = DT->getNode(Parent)->getIDom()->getBlock();
|
|
|
|
for (unsigned i = 0, e = Phi->getNumIncomingValues(); i != e; ++i) {
|
|
|
|
Value *Incoming = Phi->getIncomingValue(i);
|
|
if (Incoming != BoolTrue)
|
|
continue;
|
|
|
|
BasicBlock *From = Phi->getIncomingBlock(i);
|
|
if (From == IDom) {
|
|
CallInst *OldEnd = dyn_cast<CallInst>(Parent->getFirstInsertionPt());
|
|
if (OldEnd && OldEnd->getCalledFunction() == EndCf) {
|
|
Value *Args[] = { OldEnd->getArgOperand(0), NewPhi };
|
|
Ret = CallInst::Create(ElseBreak, Args, "", OldEnd);
|
|
continue;
|
|
}
|
|
}
|
|
TerminatorInst *Insert = From->getTerminator();
|
|
Value *PhiArg = CallInst::Create(Break, Broken, "", Insert);
|
|
NewPhi->setIncomingValue(i, PhiArg);
|
|
}
|
|
eraseIfUnused(Phi);
|
|
return Ret;
|
|
|
|
} else if (Instruction *Inst = dyn_cast<Instruction>(Cond)) {
|
|
BasicBlock *Parent = Inst->getParent();
|
|
Instruction *Insert;
|
|
if (L->contains(Inst)) {
|
|
Insert = Parent->getTerminator();
|
|
} else {
|
|
Insert = L->getHeader()->getFirstNonPHIOrDbgOrLifetime();
|
|
}
|
|
Value *Args[] = { Cond, Broken };
|
|
return CallInst::Create(IfBreak, Args, "", Insert);
|
|
|
|
} else {
|
|
llvm_unreachable("Unhandled loop condition!");
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/// \brief Handle a back edge (loop)
|
|
void SIAnnotateControlFlow::handleLoop(BranchInst *Term) {
|
|
BasicBlock *BB = Term->getParent();
|
|
llvm::Loop *L = LI->getLoopFor(BB);
|
|
BasicBlock *Target = Term->getSuccessor(1);
|
|
PHINode *Broken = PHINode::Create(Int64, 0, "", &Target->front());
|
|
|
|
Value *Cond = Term->getCondition();
|
|
Term->setCondition(BoolTrue);
|
|
Value *Arg = handleLoopCondition(Cond, Broken, L);
|
|
|
|
for (pred_iterator PI = pred_begin(Target), PE = pred_end(Target);
|
|
PI != PE; ++PI) {
|
|
|
|
Broken->addIncoming(*PI == BB ? Arg : Int64Zero, *PI);
|
|
}
|
|
|
|
Term->setCondition(CallInst::Create(Loop, Arg, "", Term));
|
|
push(Term->getSuccessor(0), Arg);
|
|
}/// \brief Close the last opened control flow
|
|
void SIAnnotateControlFlow::closeControlFlow(BasicBlock *BB) {
|
|
llvm::Loop *L = LI->getLoopFor(BB);
|
|
|
|
if (L && L->getHeader() == BB) {
|
|
// We can't insert an EndCF call into a loop header, because it will
|
|
// get executed on every iteration of the loop, when it should be
|
|
// executed only once before the loop.
|
|
SmallVector <BasicBlock*, 8> Latches;
|
|
L->getLoopLatches(Latches);
|
|
|
|
std::vector<BasicBlock*> Preds;
|
|
for (pred_iterator PI = pred_begin(BB), PE = pred_end(BB); PI != PE; ++PI) {
|
|
if (std::find(Latches.begin(), Latches.end(), *PI) == Latches.end())
|
|
Preds.push_back(*PI);
|
|
}
|
|
BB = llvm::SplitBlockPredecessors(BB, Preds, "endcf.split", nullptr, DT,
|
|
LI, false);
|
|
}
|
|
|
|
CallInst::Create(EndCf, popSaved(), "", BB->getFirstInsertionPt());
|
|
}
|
|
|
|
/// \brief Annotate the control flow with intrinsics so the backend can
|
|
/// recognize if/then/else and loops.
|
|
bool SIAnnotateControlFlow::runOnFunction(Function &F) {
|
|
DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
|
|
LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
|
|
|
|
for (df_iterator<BasicBlock *> I = df_begin(&F.getEntryBlock()),
|
|
E = df_end(&F.getEntryBlock()); I != E; ++I) {
|
|
|
|
BranchInst *Term = dyn_cast<BranchInst>((*I)->getTerminator());
|
|
|
|
if (!Term || Term->isUnconditional()) {
|
|
if (isTopOfStack(*I))
|
|
closeControlFlow(*I);
|
|
continue;
|
|
}
|
|
|
|
if (I.nodeVisited(Term->getSuccessor(1))) {
|
|
if (isTopOfStack(*I))
|
|
closeControlFlow(*I);
|
|
handleLoop(Term);
|
|
continue;
|
|
}
|
|
|
|
if (isTopOfStack(*I)) {
|
|
PHINode *Phi = dyn_cast<PHINode>(Term->getCondition());
|
|
if (Phi && Phi->getParent() == *I && isElse(Phi)) {
|
|
insertElse(Term);
|
|
eraseIfUnused(Phi);
|
|
continue;
|
|
}
|
|
closeControlFlow(*I);
|
|
}
|
|
openIf(Term);
|
|
}
|
|
|
|
assert(Stack.empty());
|
|
return true;
|
|
}
|
|
|
|
/// \brief Create the annotation pass
|
|
FunctionPass *llvm::createSIAnnotateControlFlowPass() {
|
|
return new SIAnnotateControlFlow();
|
|
}
|