llvm/lib/VMCore/AutoUpgrade.cpp
Bill Wendling 884fb72f15 Only delete instructions once.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@138700 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-27 06:10:02 +00:00

484 lines
17 KiB
C++

//===-- AutoUpgrade.cpp - Implement auto-upgrade helper functions ---------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the auto-upgrade helper functions
//
//===----------------------------------------------------------------------===//
#include "llvm/AutoUpgrade.h"
#include "llvm/Constants.h"
#include "llvm/Function.h"
#include "llvm/Instruction.h"
#include "llvm/LLVMContext.h"
#include "llvm/Module.h"
#include "llvm/IntrinsicInst.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Support/CallSite.h"
#include "llvm/Support/CFG.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/IRBuilder.h"
#include <cstring>
using namespace llvm;
static bool UpgradeIntrinsicFunction1(Function *F, Function *&NewFn) {
assert(F && "Illegal to upgrade a non-existent Function.");
// Quickly eliminate it, if it's not a candidate.
StringRef Name = F->getName();
if (Name.size() <= 8 || !Name.startswith("llvm."))
return false;
Name = Name.substr(5); // Strip off "llvm."
FunctionType *FTy = F->getFunctionType();
Module *M = F->getParent();
switch (Name[0]) {
default: break;
case 'p':
// This upgrades the llvm.prefetch intrinsic to accept one more parameter,
// which is a instruction / data cache identifier. The old version only
// implicitly accepted the data version.
if (Name == "prefetch") {
// Don't do anything if it has the correct number of arguments already
if (FTy->getNumParams() == 4)
break;
assert(FTy->getNumParams() == 3 && "old prefetch takes 3 args!");
// We first need to change the name of the old (bad) intrinsic, because
// its type is incorrect, but we cannot overload that name. We
// arbitrarily unique it here allowing us to construct a correctly named
// and typed function below.
std::string NameTmp = F->getName();
F->setName("");
NewFn = cast<Function>(M->getOrInsertFunction(NameTmp,
FTy->getReturnType(),
FTy->getParamType(0),
FTy->getParamType(1),
FTy->getParamType(2),
FTy->getParamType(2),
(Type*)0));
return true;
}
break;
case 'x': {
const char *NewFnName = NULL;
// This fixes the poorly named crc32 intrinsics.
if (Name == "x86.sse42.crc32.8")
NewFnName = "llvm.x86.sse42.crc32.32.8";
else if (Name == "x86.sse42.crc32.16")
NewFnName = "llvm.x86.sse42.crc32.32.16";
else if (Name == "x86.sse42.crc32.32")
NewFnName = "llvm.x86.sse42.crc32.32.32";
else if (Name == "x86.sse42.crc64.8")
NewFnName = "llvm.x86.sse42.crc32.64.8";
else if (Name == "x86.sse42.crc64.64")
NewFnName = "llvm.x86.sse42.crc32.64.64";
if (NewFnName) {
F->setName(NewFnName);
NewFn = F;
return true;
}
// Calls to these instructions are transformed into unaligned loads.
if (Name == "x86.sse.loadu.ps" || Name == "x86.sse2.loadu.dq" ||
Name == "x86.sse2.loadu.pd")
return true;
// Calls to these instructions are transformed into nontemporal stores.
if (Name == "x86.sse.movnt.ps" || Name == "x86.sse2.movnt.dq" ||
Name == "x86.sse2.movnt.pd" || Name == "x86.sse2.movnt.i")
return true;
break;
}
}
// This may not belong here. This function is effectively being overloaded
// to both detect an intrinsic which needs upgrading, and to provide the
// upgraded form of the intrinsic. We should perhaps have two separate
// functions for this.
return false;
}
bool llvm::UpgradeIntrinsicFunction(Function *F, Function *&NewFn) {
NewFn = 0;
bool Upgraded = UpgradeIntrinsicFunction1(F, NewFn);
// Upgrade intrinsic attributes. This does not change the function.
if (NewFn)
F = NewFn;
if (unsigned id = F->getIntrinsicID())
F->setAttributes(Intrinsic::getAttributes((Intrinsic::ID)id));
return Upgraded;
}
bool llvm::UpgradeGlobalVariable(GlobalVariable *GV) {
// Nothing to do yet.
return false;
}
// UpgradeIntrinsicCall - Upgrade a call to an old intrinsic to be a call the
// upgraded intrinsic. All argument and return casting must be provided in
// order to seamlessly integrate with existing context.
void llvm::UpgradeIntrinsicCall(CallInst *CI, Function *NewFn) {
Function *F = CI->getCalledFunction();
LLVMContext &C = CI->getContext();
ImmutableCallSite CS(CI);
assert(F && "CallInst has no function associated with it.");
if (!NewFn) {
if (F->getName() == "llvm.x86.sse.loadu.ps" ||
F->getName() == "llvm.x86.sse2.loadu.dq" ||
F->getName() == "llvm.x86.sse2.loadu.pd") {
// Convert to a native, unaligned load.
Type *VecTy = CI->getType();
Type *IntTy = IntegerType::get(C, 128);
IRBuilder<> Builder(C);
Builder.SetInsertPoint(CI->getParent(), CI);
Value *BC = Builder.CreateBitCast(CI->getArgOperand(0),
PointerType::getUnqual(IntTy),
"cast");
LoadInst *LI = Builder.CreateLoad(BC, CI->getName());
LI->setAlignment(1); // Unaligned load.
BC = Builder.CreateBitCast(LI, VecTy, "new.cast");
// Fix up all the uses with our new load.
if (!CI->use_empty())
CI->replaceAllUsesWith(BC);
// Remove intrinsic.
CI->eraseFromParent();
} else if (F->getName() == "llvm.x86.sse.movnt.ps" ||
F->getName() == "llvm.x86.sse2.movnt.dq" ||
F->getName() == "llvm.x86.sse2.movnt.pd" ||
F->getName() == "llvm.x86.sse2.movnt.i") {
IRBuilder<> Builder(C);
Builder.SetInsertPoint(CI->getParent(), CI);
Module *M = F->getParent();
SmallVector<Value *, 1> Elts;
Elts.push_back(ConstantInt::get(Type::getInt32Ty(C), 1));
MDNode *Node = MDNode::get(C, Elts);
Value *Arg0 = CI->getArgOperand(0);
Value *Arg1 = CI->getArgOperand(1);
// Convert the type of the pointer to a pointer to the stored type.
Value *BC = Builder.CreateBitCast(Arg0,
PointerType::getUnqual(Arg1->getType()),
"cast");
StoreInst *SI = Builder.CreateStore(Arg1, BC);
SI->setMetadata(M->getMDKindID("nontemporal"), Node);
SI->setAlignment(16);
// Remove intrinsic.
CI->eraseFromParent();
} else {
llvm_unreachable("Unknown function for CallInst upgrade.");
}
return;
}
switch (NewFn->getIntrinsicID()) {
case Intrinsic::prefetch: {
IRBuilder<> Builder(C);
Builder.SetInsertPoint(CI->getParent(), CI);
llvm::Type *I32Ty = llvm::Type::getInt32Ty(CI->getContext());
// Add the extra "data cache" argument
Value *Operands[4] = { CI->getArgOperand(0), CI->getArgOperand(1),
CI->getArgOperand(2),
llvm::ConstantInt::get(I32Ty, 1) };
CallInst *NewCI = CallInst::Create(NewFn, Operands,
CI->getName(), CI);
NewCI->setTailCall(CI->isTailCall());
NewCI->setCallingConv(CI->getCallingConv());
// Handle any uses of the old CallInst.
if (!CI->use_empty())
// Replace all uses of the old call with the new cast which has the
// correct type.
CI->replaceAllUsesWith(NewCI);
// Clean up the old call now that it has been completely upgraded.
CI->eraseFromParent();
break;
}
}
}
// This tests each Function to determine if it needs upgrading. When we find
// one we are interested in, we then upgrade all calls to reflect the new
// function.
void llvm::UpgradeCallsToIntrinsic(Function* F) {
assert(F && "Illegal attempt to upgrade a non-existent intrinsic.");
// Upgrade the function and check if it is a totaly new function.
Function *NewFn;
if (UpgradeIntrinsicFunction(F, NewFn)) {
if (NewFn != F) {
// Replace all uses to the old function with the new one if necessary.
for (Value::use_iterator UI = F->use_begin(), UE = F->use_end();
UI != UE; ) {
if (CallInst *CI = dyn_cast<CallInst>(*UI++))
UpgradeIntrinsicCall(CI, NewFn);
}
// Remove old function, no longer used, from the module.
F->eraseFromParent();
}
}
}
/// This function strips all debug info intrinsics, except for llvm.dbg.declare.
/// If an llvm.dbg.declare intrinsic is invalid, then this function simply
/// strips that use.
void llvm::CheckDebugInfoIntrinsics(Module *M) {
if (Function *FuncStart = M->getFunction("llvm.dbg.func.start")) {
while (!FuncStart->use_empty())
cast<CallInst>(FuncStart->use_back())->eraseFromParent();
FuncStart->eraseFromParent();
}
if (Function *StopPoint = M->getFunction("llvm.dbg.stoppoint")) {
while (!StopPoint->use_empty())
cast<CallInst>(StopPoint->use_back())->eraseFromParent();
StopPoint->eraseFromParent();
}
if (Function *RegionStart = M->getFunction("llvm.dbg.region.start")) {
while (!RegionStart->use_empty())
cast<CallInst>(RegionStart->use_back())->eraseFromParent();
RegionStart->eraseFromParent();
}
if (Function *RegionEnd = M->getFunction("llvm.dbg.region.end")) {
while (!RegionEnd->use_empty())
cast<CallInst>(RegionEnd->use_back())->eraseFromParent();
RegionEnd->eraseFromParent();
}
if (Function *Declare = M->getFunction("llvm.dbg.declare")) {
if (!Declare->use_empty()) {
DbgDeclareInst *DDI = cast<DbgDeclareInst>(Declare->use_back());
if (!isa<MDNode>(DDI->getArgOperand(0)) ||
!isa<MDNode>(DDI->getArgOperand(1))) {
while (!Declare->use_empty()) {
CallInst *CI = cast<CallInst>(Declare->use_back());
CI->eraseFromParent();
}
Declare->eraseFromParent();
}
}
}
}
/// FindExnAndSelIntrinsics - Find the eh_exception and eh_selector intrinsic
/// calls reachable from the unwind basic block.
static void FindExnAndSelIntrinsics(BasicBlock *BB, CallInst *&Exn,
CallInst *&Sel,
SmallPtrSet<BasicBlock*, 8> &Visited) {
if (!Visited.insert(BB)) return;
for (BasicBlock::iterator
I = BB->begin(), E = BB->end(); I != E; ++I) {
if (CallInst *CI = dyn_cast<CallInst>(I)) {
switch (CI->getCalledFunction()->getIntrinsicID()) {
default: break;
case Intrinsic::eh_exception:
assert(!Exn && "Found more than one eh.exception call!");
Exn = CI;
break;
case Intrinsic::eh_selector:
assert(!Sel && "Found more than one eh.selector call!");
Sel = CI;
break;
}
if (Exn && Sel) return;
}
}
if (Exn && Sel) return;
for (succ_iterator I = succ_begin(BB), E = succ_end(BB); I != E; ++I) {
FindExnAndSelIntrinsics(*I, Exn, Sel, Visited);
if (Exn && Sel) return;
}
}
/// TransferClausesToLandingPadInst - Transfer the exception handling clauses
/// from the eh_selector call to the new landingpad instruction.
static void TransferClausesToLandingPadInst(LandingPadInst *LPI,
CallInst *EHSel) {
LLVMContext &Context = LPI->getContext();
unsigned N = EHSel->getNumArgOperands();
for (unsigned i = N - 1; i > 1; --i) {
if (const ConstantInt *CI = dyn_cast<ConstantInt>(EHSel->getArgOperand(i))){
unsigned FilterLength = CI->getZExtValue();
unsigned FirstCatch = i + FilterLength + !FilterLength;
assert(FirstCatch <= N && "Invalid filter length");
if (FirstCatch < N)
for (unsigned j = FirstCatch; j < N; ++j) {
Value *Val = EHSel->getArgOperand(j);
if (!Val->hasName() || Val->getName() != "llvm.eh.catch.all.value") {
LPI->addClause(EHSel->getArgOperand(j));
} else {
GlobalVariable *GV = cast<GlobalVariable>(Val);
LPI->addClause(GV->getInitializer());
}
}
if (!FilterLength) {
// Cleanup.
LPI->setCleanup(true);
} else {
// Filter.
SmallVector<Constant *, 4> TyInfo;
TyInfo.reserve(FilterLength - 1);
for (unsigned j = i + 1; j < FirstCatch; ++j)
TyInfo.push_back(cast<Constant>(EHSel->getArgOperand(j)));
ArrayType *AType =
ArrayType::get(!TyInfo.empty() ? TyInfo[0]->getType() :
PointerType::getUnqual(Type::getInt8Ty(Context)),
TyInfo.size());
LPI->addClause(ConstantArray::get(AType, TyInfo));
}
N = i;
}
}
if (N > 2)
for (unsigned j = 2; j < N; ++j) {
Value *Val = EHSel->getArgOperand(j);
if (!Val->hasName() || Val->getName() != "llvm.eh.catch.all.value") {
LPI->addClause(EHSel->getArgOperand(j));
} else {
GlobalVariable *GV = cast<GlobalVariable>(Val);
LPI->addClause(GV->getInitializer());
}
}
}
/// This function upgrades the old pre-3.0 exception handling system to the new
/// one. N.B. This will be removed in 3.1.
void llvm::UpgradeExceptionHandling(Module *M) {
Function *EHException = M->getFunction("llvm.eh.exception");
Function *EHSelector = M->getFunction("llvm.eh.selector");
if (!EHException || !EHSelector)
return;
LLVMContext &Context = M->getContext();
Type *ExnTy = PointerType::getUnqual(Type::getInt8Ty(Context));
Type *SelTy = Type::getInt32Ty(Context);
Type *LPadSlotTy = StructType::get(ExnTy, SelTy, NULL);
// This map stores the slots where the exception object and selector value are
// stored within a function.
SmallPtrSet<Instruction*, 32> DeadInsts;
DenseMap<Function*, std::pair<Value*, Value*> > FnToLPadSlotMap;
for (Module::iterator
I = M->begin(), E = M->end(); I != E; ++I) {
Function &F = *I;
for (Function::iterator
II = F.begin(), IE = F.end(); II != IE; ++II) {
BasicBlock *BB = &*II;
InvokeInst *Inst = dyn_cast<InvokeInst>(BB->getTerminator());
if (!Inst) continue;
BasicBlock *UnwindDest = Inst->getUnwindDest();
if (UnwindDest->isLandingPad()) continue; // All ready converted.
// Store the exception object and selector value in the entry block.
Value *ExnSlot = 0;
Value *SelSlot = 0;
if (!FnToLPadSlotMap[&F].first) {
BasicBlock *Entry = &F.front();
ExnSlot = new AllocaInst(ExnTy, "exn", Entry->getTerminator());
SelSlot = new AllocaInst(SelTy, "sel", Entry->getTerminator());
FnToLPadSlotMap[&F] = std::make_pair(ExnSlot, SelSlot);
} else {
ExnSlot = FnToLPadSlotMap[&F].first;
SelSlot = FnToLPadSlotMap[&F].second;
}
// We're in an unwind block. Try to find the eh.exception and eh.selector
// calls.
IRBuilder<> Builder(Context);
Builder.SetInsertPoint(UnwindDest, UnwindDest->getFirstNonPHI());
SmallPtrSet<BasicBlock*, 8> Visited;
CallInst *Exn = 0;
CallInst *Sel = 0;
FindExnAndSelIntrinsics(UnwindDest, Exn, Sel, Visited);
assert(Exn && Sel && "Cannot find eh.exception and eh.selector calls!");
Value *PersFn = Sel->getArgOperand(1);
LandingPadInst *LPI = Builder.CreateLandingPad(LPadSlotTy, PersFn, 0);
Value *LPExn = Builder.CreateExtractValue(LPI, 0);
Value *LPSel = Builder.CreateExtractValue(LPI, 1);
Builder.CreateStore(LPExn, ExnSlot);
Builder.CreateStore(LPSel, SelSlot);
TransferClausesToLandingPadInst(LPI, Sel);
Exn->replaceAllUsesWith(LPExn);
Sel->replaceAllUsesWith(LPSel);
DeadInsts.insert(Exn);
DeadInsts.insert(Sel);
}
}
// Remove the dead instructions.
for (SmallPtrSet<Instruction*, 32>::iterator
I = DeadInsts.begin(), E = DeadInsts.end(); I != E; ++I) {
Instruction *Inst = *I;
Inst->eraseFromParent();
}
// Replace calls to "llvm.eh.resume" with the 'resume' instruction. Load the
// exception and selector values from the stored place.
Function *EHResume = M->getFunction("llvm.eh.resume");
if (!EHResume) return;
while (!EHResume->use_empty()) {
CallInst *Resume = cast<CallInst>(EHResume->use_back());
BasicBlock *BB = Resume->getParent();
Function *Fn = BB->getParent();
std::pair<Value*, Value*> &ExnSel = FnToLPadSlotMap[Fn];
IRBuilder<> Builder(Context);
Builder.SetInsertPoint(BB, Resume);
Value *Exn = Builder.CreateLoad(ExnSel.first, "exn");
Value *Sel = Builder.CreateLoad(ExnSel.second, "sel");
Value *LPadVal =
Builder.CreateInsertValue(UndefValue::get(LPadSlotTy),
Exn, 0, "lpad.val");
LPadVal = Builder.CreateInsertValue(LPadVal, Sel, 1, "lpad.val");
Builder.CreateResume(LPadVal);
// Remove all instructions after the 'resume.'
BasicBlock::iterator I = Resume;
while (I != BB->end()) {
Instruction *Inst = &*I++;
Inst->eraseFromParent();
}
}
}