llvm-project/llvm/tools/llvm-stress/llvm-stress.cpp

720 lines
22 KiB
C++

//===-- llvm-stress.cpp - Generate random LL files to stress-test LLVM ----===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This program is a utility that generates random .ll files to stress-test
// different components in LLVM.
//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/CallGraphSCCPass.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/IRPrintingPasses.h"
#include "llvm/IR/Instruction.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/LegacyPassManager.h"
#include "llvm/IR/LegacyPassNameParser.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Verifier.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/PluginLoader.h"
#include "llvm/Support/PrettyStackTrace.h"
#include "llvm/Support/ToolOutputFile.h"
#include <algorithm>
#include <vector>
namespace llvm {
static cl::opt<unsigned> SeedCL("seed",
cl::desc("Seed used for randomness"), cl::init(0));
static cl::opt<unsigned> SizeCL("size",
cl::desc("The estimated size of the generated function (# of instrs)"),
cl::init(100));
static cl::opt<std::string>
OutputFilename("o", cl::desc("Override output filename"),
cl::value_desc("filename"));
static LLVMContext Context;
namespace cl {
template <> class parser<Type*> final : public basic_parser<Type*> {
public:
parser(Option &O) : basic_parser(O) {}
// Parse options as IR types. Return true on error.
bool parse(Option &O, StringRef, StringRef Arg, Type *&Value) {
if (Arg == "half") Value = Type::getHalfTy(Context);
else if (Arg == "fp128") Value = Type::getFP128Ty(Context);
else if (Arg == "x86_fp80") Value = Type::getX86_FP80Ty(Context);
else if (Arg == "ppc_fp128") Value = Type::getPPC_FP128Ty(Context);
else if (Arg == "x86_mmx") Value = Type::getX86_MMXTy(Context);
else if (Arg.startswith("i")) {
unsigned N = 0;
Arg.drop_front().getAsInteger(10, N);
if (N > 0)
Value = Type::getIntNTy(Context, N);
}
if (!Value)
return O.error("Invalid IR scalar type: '" + Arg + "'!");
return false;
}
const char *getValueName() const override { return "IR scalar type"; }
};
}
static cl::list<Type*> AdditionalScalarTypes("types", cl::CommaSeparated,
cl::desc("Additional IR scalar types "
"(always includes i1, i8, i16, i32, i64, float and double)"));
namespace {
/// A utility class to provide a pseudo-random number generator which is
/// the same across all platforms. This is somewhat close to the libc
/// implementation. Note: This is not a cryptographically secure pseudorandom
/// number generator.
class Random {
public:
/// C'tor
Random(unsigned _seed):Seed(_seed) {}
/// Return a random integer, up to a
/// maximum of 2**19 - 1.
uint32_t Rand() {
uint32_t Val = Seed + 0x000b07a1;
Seed = (Val * 0x3c7c0ac1);
// Only lowest 19 bits are random-ish.
return Seed & 0x7ffff;
}
/// Return a random 32 bit integer.
uint32_t Rand32() {
uint32_t Val = Rand();
Val &= 0xffff;
return Val | (Rand() << 16);
}
/// Return a random 64 bit integer.
uint64_t Rand64() {
uint64_t Val = Rand32();
return Val | (uint64_t(Rand32()) << 32);
}
/// Rand operator for STL algorithms.
ptrdiff_t operator()(ptrdiff_t y) {
return Rand64() % y;
}
private:
unsigned Seed;
};
/// Generate an empty function with a default argument list.
Function *GenEmptyFunction(Module *M) {
// Define a few arguments
LLVMContext &Context = M->getContext();
Type* ArgsTy[] = {
Type::getInt8PtrTy(Context),
Type::getInt32PtrTy(Context),
Type::getInt64PtrTy(Context),
Type::getInt32Ty(Context),
Type::getInt64Ty(Context),
Type::getInt8Ty(Context)
};
auto *FuncTy = FunctionType::get(Type::getVoidTy(Context), ArgsTy, false);
// Pick a unique name to describe the input parameters
Twine Name = "autogen_SD" + Twine{SeedCL};
auto *Func = Function::Create(FuncTy, GlobalValue::ExternalLinkage, Name, M);
Func->setCallingConv(CallingConv::C);
return Func;
}
/// A base class, implementing utilities needed for
/// modifying and adding new random instructions.
struct Modifier {
/// Used to store the randomly generated values.
typedef std::vector<Value*> PieceTable;
public:
/// C'tor
Modifier(BasicBlock *Block, PieceTable *PT, Random *R):
BB(Block),PT(PT),Ran(R),Context(BB->getContext()) {}
/// virtual D'tor to silence warnings.
virtual ~Modifier() {}
/// Add a new instruction.
virtual void Act() = 0;
/// Add N new instructions,
virtual void ActN(unsigned n) {
for (unsigned i=0; i<n; ++i)
Act();
}
protected:
/// Return a random value from the list of known values.
Value *getRandomVal() {
assert(PT->size());
return PT->at(Ran->Rand() % PT->size());
}
Constant *getRandomConstant(Type *Tp) {
if (Tp->isIntegerTy()) {
if (Ran->Rand() & 1)
return ConstantInt::getAllOnesValue(Tp);
return ConstantInt::getNullValue(Tp);
} else if (Tp->isFloatingPointTy()) {
if (Ran->Rand() & 1)
return ConstantFP::getAllOnesValue(Tp);
return ConstantFP::getNullValue(Tp);
}
return UndefValue::get(Tp);
}
/// Return a random value with a known type.
Value *getRandomValue(Type *Tp) {
unsigned index = Ran->Rand();
for (unsigned i=0; i<PT->size(); ++i) {
Value *V = PT->at((index + i) % PT->size());
if (V->getType() == Tp)
return V;
}
// If the requested type was not found, generate a constant value.
if (Tp->isIntegerTy()) {
if (Ran->Rand() & 1)
return ConstantInt::getAllOnesValue(Tp);
return ConstantInt::getNullValue(Tp);
} else if (Tp->isFloatingPointTy()) {
if (Ran->Rand() & 1)
return ConstantFP::getAllOnesValue(Tp);
return ConstantFP::getNullValue(Tp);
} else if (Tp->isVectorTy()) {
VectorType *VTp = cast<VectorType>(Tp);
std::vector<Constant*> TempValues;
TempValues.reserve(VTp->getNumElements());
for (unsigned i = 0; i < VTp->getNumElements(); ++i)
TempValues.push_back(getRandomConstant(VTp->getScalarType()));
ArrayRef<Constant*> VectorValue(TempValues);
return ConstantVector::get(VectorValue);
}
return UndefValue::get(Tp);
}
/// Return a random value of any pointer type.
Value *getRandomPointerValue() {
unsigned index = Ran->Rand();
for (unsigned i=0; i<PT->size(); ++i) {
Value *V = PT->at((index + i) % PT->size());
if (V->getType()->isPointerTy())
return V;
}
return UndefValue::get(pickPointerType());
}
/// Return a random value of any vector type.
Value *getRandomVectorValue() {
unsigned index = Ran->Rand();
for (unsigned i=0; i<PT->size(); ++i) {
Value *V = PT->at((index + i) % PT->size());
if (V->getType()->isVectorTy())
return V;
}
return UndefValue::get(pickVectorType());
}
/// Pick a random type.
Type *pickType() {
return (Ran->Rand() & 1 ? pickVectorType() : pickScalarType());
}
/// Pick a random pointer type.
Type *pickPointerType() {
Type *Ty = pickType();
return PointerType::get(Ty, 0);
}
/// Pick a random vector type.
Type *pickVectorType(unsigned len = (unsigned)-1) {
// Pick a random vector width in the range 2**0 to 2**4.
// by adding two randoms we are generating a normal-like distribution
// around 2**3.
unsigned width = 1<<((Ran->Rand() % 3) + (Ran->Rand() % 3));
Type *Ty;
// Vectors of x86mmx are illegal; keep trying till we get something else.
do {
Ty = pickScalarType();
} while (Ty->isX86_MMXTy());
if (len != (unsigned)-1)
width = len;
return VectorType::get(Ty, width);
}
/// Pick a random scalar type.
Type *pickScalarType() {
static std::vector<Type*> ScalarTypes;
if (ScalarTypes.empty()) {
ScalarTypes.assign({
Type::getInt1Ty(Context),
Type::getInt8Ty(Context),
Type::getInt16Ty(Context),
Type::getInt32Ty(Context),
Type::getInt64Ty(Context),
Type::getFloatTy(Context),
Type::getDoubleTy(Context)
});
ScalarTypes.insert(ScalarTypes.end(),
AdditionalScalarTypes.begin(), AdditionalScalarTypes.end());
}
return ScalarTypes[Ran->Rand() % ScalarTypes.size()];
}
/// Basic block to populate
BasicBlock *BB;
/// Value table
PieceTable *PT;
/// Random number generator
Random *Ran;
/// Context
LLVMContext &Context;
};
struct LoadModifier: public Modifier {
LoadModifier(BasicBlock *BB, PieceTable *PT, Random *R):Modifier(BB, PT, R) {}
void Act() override {
// Try to use predefined pointers. If non-exist, use undef pointer value;
Value *Ptr = getRandomPointerValue();
Value *V = new LoadInst(Ptr, "L", BB->getTerminator());
PT->push_back(V);
}
};
struct StoreModifier: public Modifier {
StoreModifier(BasicBlock *BB, PieceTable *PT, Random *R):Modifier(BB, PT, R) {}
void Act() override {
// Try to use predefined pointers. If non-exist, use undef pointer value;
Value *Ptr = getRandomPointerValue();
Type *Tp = Ptr->getType();
Value *Val = getRandomValue(Tp->getContainedType(0));
Type *ValTy = Val->getType();
// Do not store vectors of i1s because they are unsupported
// by the codegen.
if (ValTy->isVectorTy() && ValTy->getScalarSizeInBits() == 1)
return;
new StoreInst(Val, Ptr, BB->getTerminator());
}
};
struct BinModifier: public Modifier {
BinModifier(BasicBlock *BB, PieceTable *PT, Random *R):Modifier(BB, PT, R) {}
void Act() override {
Value *Val0 = getRandomVal();
Value *Val1 = getRandomValue(Val0->getType());
// Don't handle pointer types.
if (Val0->getType()->isPointerTy() ||
Val1->getType()->isPointerTy())
return;
// Don't handle i1 types.
if (Val0->getType()->getScalarSizeInBits() == 1)
return;
bool isFloat = Val0->getType()->getScalarType()->isFloatingPointTy();
Instruction* Term = BB->getTerminator();
unsigned R = Ran->Rand() % (isFloat ? 7 : 13);
Instruction::BinaryOps Op;
switch (R) {
default: llvm_unreachable("Invalid BinOp");
case 0:{Op = (isFloat?Instruction::FAdd : Instruction::Add); break; }
case 1:{Op = (isFloat?Instruction::FSub : Instruction::Sub); break; }
case 2:{Op = (isFloat?Instruction::FMul : Instruction::Mul); break; }
case 3:{Op = (isFloat?Instruction::FDiv : Instruction::SDiv); break; }
case 4:{Op = (isFloat?Instruction::FDiv : Instruction::UDiv); break; }
case 5:{Op = (isFloat?Instruction::FRem : Instruction::SRem); break; }
case 6:{Op = (isFloat?Instruction::FRem : Instruction::URem); break; }
case 7: {Op = Instruction::Shl; break; }
case 8: {Op = Instruction::LShr; break; }
case 9: {Op = Instruction::AShr; break; }
case 10:{Op = Instruction::And; break; }
case 11:{Op = Instruction::Or; break; }
case 12:{Op = Instruction::Xor; break; }
}
PT->push_back(BinaryOperator::Create(Op, Val0, Val1, "B", Term));
}
};
/// Generate constant values.
struct ConstModifier: public Modifier {
ConstModifier(BasicBlock *BB, PieceTable *PT, Random *R):Modifier(BB, PT, R) {}
void Act() override {
Type *Ty = pickType();
if (Ty->isVectorTy()) {
switch (Ran->Rand() % 2) {
case 0: if (Ty->getScalarType()->isIntegerTy())
return PT->push_back(ConstantVector::getAllOnesValue(Ty));
case 1: if (Ty->getScalarType()->isIntegerTy())
return PT->push_back(ConstantVector::getNullValue(Ty));
}
}
if (Ty->isFloatingPointTy()) {
// Generate 128 random bits, the size of the (currently)
// largest floating-point types.
uint64_t RandomBits[2];
for (unsigned i = 0; i < 2; ++i)
RandomBits[i] = Ran->Rand64();
APInt RandomInt(Ty->getPrimitiveSizeInBits(), makeArrayRef(RandomBits));
APFloat RandomFloat(Ty->getFltSemantics(), RandomInt);
if (Ran->Rand() & 1)
return PT->push_back(ConstantFP::getNullValue(Ty));
return PT->push_back(ConstantFP::get(Ty->getContext(), RandomFloat));
}
if (Ty->isIntegerTy()) {
switch (Ran->Rand() % 7) {
case 0: if (Ty->isIntegerTy())
return PT->push_back(ConstantInt::get(Ty,
APInt::getAllOnesValue(Ty->getPrimitiveSizeInBits())));
case 1: if (Ty->isIntegerTy())
return PT->push_back(ConstantInt::get(Ty,
APInt::getNullValue(Ty->getPrimitiveSizeInBits())));
case 2: case 3: case 4: case 5:
case 6: if (Ty->isIntegerTy())
PT->push_back(ConstantInt::get(Ty, Ran->Rand()));
}
}
}
};
struct AllocaModifier: public Modifier {
AllocaModifier(BasicBlock *BB, PieceTable *PT, Random *R):Modifier(BB, PT, R){}
void Act() override {
Type *Tp = pickType();
PT->push_back(new AllocaInst(Tp, "A", BB->getFirstNonPHI()));
}
};
struct ExtractElementModifier: public Modifier {
ExtractElementModifier(BasicBlock *BB, PieceTable *PT, Random *R):
Modifier(BB, PT, R) {}
void Act() override {
Value *Val0 = getRandomVectorValue();
Value *V = ExtractElementInst::Create(Val0,
ConstantInt::get(Type::getInt32Ty(BB->getContext()),
Ran->Rand() % cast<VectorType>(Val0->getType())->getNumElements()),
"E", BB->getTerminator());
return PT->push_back(V);
}
};
struct ShuffModifier: public Modifier {
ShuffModifier(BasicBlock *BB, PieceTable *PT, Random *R):Modifier(BB, PT, R) {}
void Act() override {
Value *Val0 = getRandomVectorValue();
Value *Val1 = getRandomValue(Val0->getType());
unsigned Width = cast<VectorType>(Val0->getType())->getNumElements();
std::vector<Constant*> Idxs;
Type *I32 = Type::getInt32Ty(BB->getContext());
for (unsigned i=0; i<Width; ++i) {
Constant *CI = ConstantInt::get(I32, Ran->Rand() % (Width*2));
// Pick some undef values.
if (!(Ran->Rand() % 5))
CI = UndefValue::get(I32);
Idxs.push_back(CI);
}
Constant *Mask = ConstantVector::get(Idxs);
Value *V = new ShuffleVectorInst(Val0, Val1, Mask, "Shuff",
BB->getTerminator());
PT->push_back(V);
}
};
struct InsertElementModifier: public Modifier {
InsertElementModifier(BasicBlock *BB, PieceTable *PT, Random *R):
Modifier(BB, PT, R) {}
void Act() override {
Value *Val0 = getRandomVectorValue();
Value *Val1 = getRandomValue(Val0->getType()->getScalarType());
Value *V = InsertElementInst::Create(Val0, Val1,
ConstantInt::get(Type::getInt32Ty(BB->getContext()),
Ran->Rand() % cast<VectorType>(Val0->getType())->getNumElements()),
"I", BB->getTerminator());
return PT->push_back(V);
}
};
struct CastModifier: public Modifier {
CastModifier(BasicBlock *BB, PieceTable *PT, Random *R):Modifier(BB, PT, R) {}
void Act() override {
Value *V = getRandomVal();
Type *VTy = V->getType();
Type *DestTy = pickScalarType();
// Handle vector casts vectors.
if (VTy->isVectorTy()) {
VectorType *VecTy = cast<VectorType>(VTy);
DestTy = pickVectorType(VecTy->getNumElements());
}
// no need to cast.
if (VTy == DestTy) return;
// Pointers:
if (VTy->isPointerTy()) {
if (!DestTy->isPointerTy())
DestTy = PointerType::get(DestTy, 0);
return PT->push_back(
new BitCastInst(V, DestTy, "PC", BB->getTerminator()));
}
unsigned VSize = VTy->getScalarType()->getPrimitiveSizeInBits();
unsigned DestSize = DestTy->getScalarType()->getPrimitiveSizeInBits();
// Generate lots of bitcasts.
if ((Ran->Rand() & 1) && VSize == DestSize) {
return PT->push_back(
new BitCastInst(V, DestTy, "BC", BB->getTerminator()));
}
// Both types are integers:
if (VTy->getScalarType()->isIntegerTy() &&
DestTy->getScalarType()->isIntegerTy()) {
if (VSize > DestSize) {
return PT->push_back(
new TruncInst(V, DestTy, "Tr", BB->getTerminator()));
} else {
assert(VSize < DestSize && "Different int types with the same size?");
if (Ran->Rand() & 1)
return PT->push_back(
new ZExtInst(V, DestTy, "ZE", BB->getTerminator()));
return PT->push_back(new SExtInst(V, DestTy, "Se", BB->getTerminator()));
}
}
// Fp to int.
if (VTy->getScalarType()->isFloatingPointTy() &&
DestTy->getScalarType()->isIntegerTy()) {
if (Ran->Rand() & 1)
return PT->push_back(
new FPToSIInst(V, DestTy, "FC", BB->getTerminator()));
return PT->push_back(new FPToUIInst(V, DestTy, "FC", BB->getTerminator()));
}
// Int to fp.
if (VTy->getScalarType()->isIntegerTy() &&
DestTy->getScalarType()->isFloatingPointTy()) {
if (Ran->Rand() & 1)
return PT->push_back(
new SIToFPInst(V, DestTy, "FC", BB->getTerminator()));
return PT->push_back(new UIToFPInst(V, DestTy, "FC", BB->getTerminator()));
}
// Both floats.
if (VTy->getScalarType()->isFloatingPointTy() &&
DestTy->getScalarType()->isFloatingPointTy()) {
if (VSize > DestSize) {
return PT->push_back(
new FPTruncInst(V, DestTy, "Tr", BB->getTerminator()));
} else if (VSize < DestSize) {
return PT->push_back(
new FPExtInst(V, DestTy, "ZE", BB->getTerminator()));
}
// If VSize == DestSize, then the two types must be fp128 and ppc_fp128,
// for which there is no defined conversion. So do nothing.
}
}
};
struct SelectModifier: public Modifier {
SelectModifier(BasicBlock *BB, PieceTable *PT, Random *R):
Modifier(BB, PT, R) {}
void Act() override {
// Try a bunch of different select configuration until a valid one is found.
Value *Val0 = getRandomVal();
Value *Val1 = getRandomValue(Val0->getType());
Type *CondTy = Type::getInt1Ty(Context);
// If the value type is a vector, and we allow vector select, then in 50%
// of the cases generate a vector select.
if (Val0->getType()->isVectorTy() && (Ran->Rand() % 1)) {
unsigned NumElem = cast<VectorType>(Val0->getType())->getNumElements();
CondTy = VectorType::get(CondTy, NumElem);
}
Value *Cond = getRandomValue(CondTy);
Value *V = SelectInst::Create(Cond, Val0, Val1, "Sl", BB->getTerminator());
return PT->push_back(V);
}
};
struct CmpModifier: public Modifier {
CmpModifier(BasicBlock *BB, PieceTable *PT, Random *R):Modifier(BB, PT, R) {}
void Act() override {
Value *Val0 = getRandomVal();
Value *Val1 = getRandomValue(Val0->getType());
if (Val0->getType()->isPointerTy()) return;
bool fp = Val0->getType()->getScalarType()->isFloatingPointTy();
int op;
if (fp) {
op = Ran->Rand() %
(CmpInst::LAST_FCMP_PREDICATE - CmpInst::FIRST_FCMP_PREDICATE) +
CmpInst::FIRST_FCMP_PREDICATE;
} else {
op = Ran->Rand() %
(CmpInst::LAST_ICMP_PREDICATE - CmpInst::FIRST_ICMP_PREDICATE) +
CmpInst::FIRST_ICMP_PREDICATE;
}
Value *V = CmpInst::Create(fp ? Instruction::FCmp : Instruction::ICmp,
(CmpInst::Predicate)op, Val0, Val1, "Cmp",
BB->getTerminator());
return PT->push_back(V);
}
};
} // end anonymous namespace
static void FillFunction(Function *F, Random &R) {
// Create a legal entry block.
BasicBlock *BB = BasicBlock::Create(F->getContext(), "BB", F);
ReturnInst::Create(F->getContext(), BB);
// Create the value table.
Modifier::PieceTable PT;
// Consider arguments as legal values.
for (auto &arg : F->args())
PT.push_back(&arg);
// List of modifiers which add new random instructions.
std::vector<std::unique_ptr<Modifier>> Modifiers;
Modifiers.emplace_back(new LoadModifier(BB, &PT, &R));
Modifiers.emplace_back(new StoreModifier(BB, &PT, &R));
auto SM = Modifiers.back().get();
Modifiers.emplace_back(new ExtractElementModifier(BB, &PT, &R));
Modifiers.emplace_back(new ShuffModifier(BB, &PT, &R));
Modifiers.emplace_back(new InsertElementModifier(BB, &PT, &R));
Modifiers.emplace_back(new BinModifier(BB, &PT, &R));
Modifiers.emplace_back(new CastModifier(BB, &PT, &R));
Modifiers.emplace_back(new SelectModifier(BB, &PT, &R));
Modifiers.emplace_back(new CmpModifier(BB, &PT, &R));
// Generate the random instructions
AllocaModifier{BB, &PT, &R}.ActN(5); // Throw in a few allocas
ConstModifier{BB, &PT, &R}.ActN(40); // Throw in a few constants
for (unsigned i = 0; i < SizeCL / Modifiers.size(); ++i)
for (auto &Mod : Modifiers)
Mod->Act();
SM->ActN(5); // Throw in a few stores.
}
static void IntroduceControlFlow(Function *F, Random &R) {
std::vector<Instruction*> BoolInst;
for (auto &Instr : F->front()) {
if (Instr.getType() == IntegerType::getInt1Ty(F->getContext()))
BoolInst.push_back(&Instr);
}
std::random_shuffle(BoolInst.begin(), BoolInst.end(), R);
for (auto *Instr : BoolInst) {
BasicBlock *Curr = Instr->getParent();
BasicBlock::iterator Loc = Instr->getIterator();
BasicBlock *Next = Curr->splitBasicBlock(Loc, "CF");
Instr->moveBefore(Curr->getTerminator());
if (Curr != &F->getEntryBlock()) {
BranchInst::Create(Curr, Next, Instr, Curr->getTerminator());
Curr->getTerminator()->eraseFromParent();
}
}
}
}
int main(int argc, char **argv) {
using namespace llvm;
// Init LLVM, call llvm_shutdown() on exit, parse args, etc.
PrettyStackTraceProgram X(argc, argv);
cl::ParseCommandLineOptions(argc, argv, "llvm codegen stress-tester\n");
llvm_shutdown_obj Y;
auto M = make_unique<Module>("/tmp/autogen.bc", Context);
Function *F = GenEmptyFunction(M.get());
// Pick an initial seed value
Random R(SeedCL);
// Generate lots of random instructions inside a single basic block.
FillFunction(F, R);
// Break the basic block into many loops.
IntroduceControlFlow(F, R);
// Figure out what stream we are supposed to write to...
std::unique_ptr<tool_output_file> Out;
// Default to standard output.
if (OutputFilename.empty())
OutputFilename = "-";
std::error_code EC;
Out.reset(new tool_output_file(OutputFilename, EC, sys::fs::F_None));
if (EC) {
errs() << EC.message() << '\n';
return 1;
}
legacy::PassManager Passes;
Passes.add(createVerifierPass());
Passes.add(createPrintModulePass(Out->os()));
Passes.run(*M.get());
Out->keep();
return 0;
}