llvm/lib/IR/Instruction.cpp
Duncan P. N. Exon Smith eac309550f IR: Remove implicit iterator conversions from lib/IR, NFC
Stop converting implicitly between iterators and pointers/references in
lib/IR.  For convenience, I've added a `getIterator()` accessor to
`ilist_node` so that callers don't need to know how to spell the
iterator class (i.e., they can use `X.getIterator()` instead of
`Function::iterator(X)`).

I'll eventually disallow these implicit conversions entirely, but
there's a lot of code, so it doesn't make sense to do it all in one
patch.  One library or so at a time.

Why?  To root out cases of `getNextNode()` and `getPrevNode()` being
used in iterator logic.  The design of `ilist` makes that invalid when
the current node could be at the back of the list, but it happens to
"work" right now because of a bug where those functions never return
`nullptr` if you're using a half-node sentinel.  Before I can fix the
function, I have to remove uses of it that rely on it misbehaving.
(Maybe the function should just be deleted anyway?  But I don't want
deleting it -- potentially a huge project -- to block fixing
ilist/iplist.)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249782 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-08 23:49:46 +00:00

590 lines
21 KiB
C++

//===-- Instruction.cpp - Implement the Instruction class -----------------===//
//
// 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 Instruction class for the IR library.
//
//===----------------------------------------------------------------------===//
#include "llvm/IR/Instruction.h"
#include "llvm/IR/CallSite.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Operator.h"
#include "llvm/IR/Type.h"
using namespace llvm;
Instruction::Instruction(Type *ty, unsigned it, Use *Ops, unsigned NumOps,
Instruction *InsertBefore)
: User(ty, Value::InstructionVal + it, Ops, NumOps), Parent(nullptr) {
// If requested, insert this instruction into a basic block...
if (InsertBefore) {
BasicBlock *BB = InsertBefore->getParent();
assert(BB && "Instruction to insert before is not in a basic block!");
BB->getInstList().insert(InsertBefore->getIterator(), this);
}
}
Instruction::Instruction(Type *ty, unsigned it, Use *Ops, unsigned NumOps,
BasicBlock *InsertAtEnd)
: User(ty, Value::InstructionVal + it, Ops, NumOps), Parent(nullptr) {
// append this instruction into the basic block
assert(InsertAtEnd && "Basic block to append to may not be NULL!");
InsertAtEnd->getInstList().push_back(this);
}
// Out of line virtual method, so the vtable, etc has a home.
Instruction::~Instruction() {
assert(!Parent && "Instruction still linked in the program!");
if (hasMetadataHashEntry())
clearMetadataHashEntries();
}
void Instruction::setParent(BasicBlock *P) {
Parent = P;
}
const Module *Instruction::getModule() const {
return getParent()->getModule();
}
Module *Instruction::getModule() {
return getParent()->getModule();
}
void Instruction::removeFromParent() {
getParent()->getInstList().remove(getIterator());
}
iplist<Instruction>::iterator Instruction::eraseFromParent() {
return getParent()->getInstList().erase(getIterator());
}
/// insertBefore - Insert an unlinked instructions into a basic block
/// immediately before the specified instruction.
void Instruction::insertBefore(Instruction *InsertPos) {
InsertPos->getParent()->getInstList().insert(InsertPos->getIterator(), this);
}
/// insertAfter - Insert an unlinked instructions into a basic block
/// immediately after the specified instruction.
void Instruction::insertAfter(Instruction *InsertPos) {
InsertPos->getParent()->getInstList().insertAfter(InsertPos->getIterator(),
this);
}
/// moveBefore - Unlink this instruction from its current basic block and
/// insert it into the basic block that MovePos lives in, right before
/// MovePos.
void Instruction::moveBefore(Instruction *MovePos) {
MovePos->getParent()->getInstList().splice(
MovePos->getIterator(), getParent()->getInstList(), getIterator());
}
/// Set or clear the unsafe-algebra flag on this instruction, which must be an
/// operator which supports this flag. See LangRef.html for the meaning of this
/// flag.
void Instruction::setHasUnsafeAlgebra(bool B) {
assert(isa<FPMathOperator>(this) && "setting fast-math flag on invalid op");
cast<FPMathOperator>(this)->setHasUnsafeAlgebra(B);
}
/// Set or clear the NoNaNs flag on this instruction, which must be an operator
/// which supports this flag. See LangRef.html for the meaning of this flag.
void Instruction::setHasNoNaNs(bool B) {
assert(isa<FPMathOperator>(this) && "setting fast-math flag on invalid op");
cast<FPMathOperator>(this)->setHasNoNaNs(B);
}
/// Set or clear the no-infs flag on this instruction, which must be an operator
/// which supports this flag. See LangRef.html for the meaning of this flag.
void Instruction::setHasNoInfs(bool B) {
assert(isa<FPMathOperator>(this) && "setting fast-math flag on invalid op");
cast<FPMathOperator>(this)->setHasNoInfs(B);
}
/// Set or clear the no-signed-zeros flag on this instruction, which must be an
/// operator which supports this flag. See LangRef.html for the meaning of this
/// flag.
void Instruction::setHasNoSignedZeros(bool B) {
assert(isa<FPMathOperator>(this) && "setting fast-math flag on invalid op");
cast<FPMathOperator>(this)->setHasNoSignedZeros(B);
}
/// Set or clear the allow-reciprocal flag on this instruction, which must be an
/// operator which supports this flag. See LangRef.html for the meaning of this
/// flag.
void Instruction::setHasAllowReciprocal(bool B) {
assert(isa<FPMathOperator>(this) && "setting fast-math flag on invalid op");
cast<FPMathOperator>(this)->setHasAllowReciprocal(B);
}
/// Convenience function for setting all the fast-math flags on this
/// instruction, which must be an operator which supports these flags. See
/// LangRef.html for the meaning of these flats.
void Instruction::setFastMathFlags(FastMathFlags FMF) {
assert(isa<FPMathOperator>(this) && "setting fast-math flag on invalid op");
cast<FPMathOperator>(this)->setFastMathFlags(FMF);
}
void Instruction::copyFastMathFlags(FastMathFlags FMF) {
assert(isa<FPMathOperator>(this) && "copying fast-math flag on invalid op");
cast<FPMathOperator>(this)->copyFastMathFlags(FMF);
}
/// Determine whether the unsafe-algebra flag is set.
bool Instruction::hasUnsafeAlgebra() const {
assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
return cast<FPMathOperator>(this)->hasUnsafeAlgebra();
}
/// Determine whether the no-NaNs flag is set.
bool Instruction::hasNoNaNs() const {
assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
return cast<FPMathOperator>(this)->hasNoNaNs();
}
/// Determine whether the no-infs flag is set.
bool Instruction::hasNoInfs() const {
assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
return cast<FPMathOperator>(this)->hasNoInfs();
}
/// Determine whether the no-signed-zeros flag is set.
bool Instruction::hasNoSignedZeros() const {
assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
return cast<FPMathOperator>(this)->hasNoSignedZeros();
}
/// Determine whether the allow-reciprocal flag is set.
bool Instruction::hasAllowReciprocal() const {
assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
return cast<FPMathOperator>(this)->hasAllowReciprocal();
}
/// Convenience function for getting all the fast-math flags, which must be an
/// operator which supports these flags. See LangRef.html for the meaning of
/// these flags.
FastMathFlags Instruction::getFastMathFlags() const {
assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
return cast<FPMathOperator>(this)->getFastMathFlags();
}
/// Copy I's fast-math flags
void Instruction::copyFastMathFlags(const Instruction *I) {
copyFastMathFlags(I->getFastMathFlags());
}
const char *Instruction::getOpcodeName(unsigned OpCode) {
switch (OpCode) {
// Terminators
case Ret: return "ret";
case Br: return "br";
case Switch: return "switch";
case IndirectBr: return "indirectbr";
case Invoke: return "invoke";
case Resume: return "resume";
case Unreachable: return "unreachable";
case CleanupEndPad: return "cleanupendpad";
case CleanupRet: return "cleanupret";
case CatchEndPad: return "catchendpad";
case CatchRet: return "catchret";
case CatchPad: return "catchpad";
case TerminatePad: return "terminatepad";
// Standard binary operators...
case Add: return "add";
case FAdd: return "fadd";
case Sub: return "sub";
case FSub: return "fsub";
case Mul: return "mul";
case FMul: return "fmul";
case UDiv: return "udiv";
case SDiv: return "sdiv";
case FDiv: return "fdiv";
case URem: return "urem";
case SRem: return "srem";
case FRem: return "frem";
// Logical operators...
case And: return "and";
case Or : return "or";
case Xor: return "xor";
// Memory instructions...
case Alloca: return "alloca";
case Load: return "load";
case Store: return "store";
case AtomicCmpXchg: return "cmpxchg";
case AtomicRMW: return "atomicrmw";
case Fence: return "fence";
case GetElementPtr: return "getelementptr";
// Convert instructions...
case Trunc: return "trunc";
case ZExt: return "zext";
case SExt: return "sext";
case FPTrunc: return "fptrunc";
case FPExt: return "fpext";
case FPToUI: return "fptoui";
case FPToSI: return "fptosi";
case UIToFP: return "uitofp";
case SIToFP: return "sitofp";
case IntToPtr: return "inttoptr";
case PtrToInt: return "ptrtoint";
case BitCast: return "bitcast";
case AddrSpaceCast: return "addrspacecast";
// Other instructions...
case ICmp: return "icmp";
case FCmp: return "fcmp";
case PHI: return "phi";
case Select: return "select";
case Call: return "call";
case Shl: return "shl";
case LShr: return "lshr";
case AShr: return "ashr";
case VAArg: return "va_arg";
case ExtractElement: return "extractelement";
case InsertElement: return "insertelement";
case ShuffleVector: return "shufflevector";
case ExtractValue: return "extractvalue";
case InsertValue: return "insertvalue";
case LandingPad: return "landingpad";
case CleanupPad: return "cleanuppad";
default: return "<Invalid operator> ";
}
}
/// Return true if both instructions have the same special state
/// This must be kept in sync with lib/Transforms/IPO/MergeFunctions.cpp.
static bool haveSameSpecialState(const Instruction *I1, const Instruction *I2,
bool IgnoreAlignment = false) {
assert(I1->getOpcode() == I2->getOpcode() &&
"Can not compare special state of different instructions");
if (const LoadInst *LI = dyn_cast<LoadInst>(I1))
return LI->isVolatile() == cast<LoadInst>(I2)->isVolatile() &&
(LI->getAlignment() == cast<LoadInst>(I2)->getAlignment() ||
IgnoreAlignment) &&
LI->getOrdering() == cast<LoadInst>(I2)->getOrdering() &&
LI->getSynchScope() == cast<LoadInst>(I2)->getSynchScope();
if (const StoreInst *SI = dyn_cast<StoreInst>(I1))
return SI->isVolatile() == cast<StoreInst>(I2)->isVolatile() &&
(SI->getAlignment() == cast<StoreInst>(I2)->getAlignment() ||
IgnoreAlignment) &&
SI->getOrdering() == cast<StoreInst>(I2)->getOrdering() &&
SI->getSynchScope() == cast<StoreInst>(I2)->getSynchScope();
if (const CmpInst *CI = dyn_cast<CmpInst>(I1))
return CI->getPredicate() == cast<CmpInst>(I2)->getPredicate();
if (const CallInst *CI = dyn_cast<CallInst>(I1))
return CI->isTailCall() == cast<CallInst>(I2)->isTailCall() &&
CI->getCallingConv() == cast<CallInst>(I2)->getCallingConv() &&
CI->getAttributes() == cast<CallInst>(I2)->getAttributes();
if (const InvokeInst *CI = dyn_cast<InvokeInst>(I1))
return CI->getCallingConv() == cast<InvokeInst>(I2)->getCallingConv() &&
CI->getAttributes() ==
cast<InvokeInst>(I2)->getAttributes();
if (const InsertValueInst *IVI = dyn_cast<InsertValueInst>(I1))
return IVI->getIndices() == cast<InsertValueInst>(I2)->getIndices();
if (const ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(I1))
return EVI->getIndices() == cast<ExtractValueInst>(I2)->getIndices();
if (const FenceInst *FI = dyn_cast<FenceInst>(I1))
return FI->getOrdering() == cast<FenceInst>(I2)->getOrdering() &&
FI->getSynchScope() == cast<FenceInst>(I2)->getSynchScope();
if (const AtomicCmpXchgInst *CXI = dyn_cast<AtomicCmpXchgInst>(I1))
return CXI->isVolatile() == cast<AtomicCmpXchgInst>(I2)->isVolatile() &&
CXI->isWeak() == cast<AtomicCmpXchgInst>(I2)->isWeak() &&
CXI->getSuccessOrdering() ==
cast<AtomicCmpXchgInst>(I2)->getSuccessOrdering() &&
CXI->getFailureOrdering() ==
cast<AtomicCmpXchgInst>(I2)->getFailureOrdering() &&
CXI->getSynchScope() == cast<AtomicCmpXchgInst>(I2)->getSynchScope();
if (const AtomicRMWInst *RMWI = dyn_cast<AtomicRMWInst>(I1))
return RMWI->getOperation() == cast<AtomicRMWInst>(I2)->getOperation() &&
RMWI->isVolatile() == cast<AtomicRMWInst>(I2)->isVolatile() &&
RMWI->getOrdering() == cast<AtomicRMWInst>(I2)->getOrdering() &&
RMWI->getSynchScope() == cast<AtomicRMWInst>(I2)->getSynchScope();
return true;
}
/// isIdenticalTo - Return true if the specified instruction is exactly
/// identical to the current one. This means that all operands match and any
/// extra information (e.g. load is volatile) agree.
bool Instruction::isIdenticalTo(const Instruction *I) const {
return isIdenticalToWhenDefined(I) &&
SubclassOptionalData == I->SubclassOptionalData;
}
/// isIdenticalToWhenDefined - This is like isIdenticalTo, except that it
/// ignores the SubclassOptionalData flags, which specify conditions
/// under which the instruction's result is undefined.
bool Instruction::isIdenticalToWhenDefined(const Instruction *I) const {
if (getOpcode() != I->getOpcode() ||
getNumOperands() != I->getNumOperands() ||
getType() != I->getType())
return false;
// If both instructions have no operands, they are identical.
if (getNumOperands() == 0 && I->getNumOperands() == 0)
return haveSameSpecialState(this, I);
// We have two instructions of identical opcode and #operands. Check to see
// if all operands are the same.
if (!std::equal(op_begin(), op_end(), I->op_begin()))
return false;
if (const PHINode *thisPHI = dyn_cast<PHINode>(this)) {
const PHINode *otherPHI = cast<PHINode>(I);
return std::equal(thisPHI->block_begin(), thisPHI->block_end(),
otherPHI->block_begin());
}
return haveSameSpecialState(this, I);
}
// isSameOperationAs
// This should be kept in sync with isEquivalentOperation in
// lib/Transforms/IPO/MergeFunctions.cpp.
bool Instruction::isSameOperationAs(const Instruction *I,
unsigned flags) const {
bool IgnoreAlignment = flags & CompareIgnoringAlignment;
bool UseScalarTypes = flags & CompareUsingScalarTypes;
if (getOpcode() != I->getOpcode() ||
getNumOperands() != I->getNumOperands() ||
(UseScalarTypes ?
getType()->getScalarType() != I->getType()->getScalarType() :
getType() != I->getType()))
return false;
// We have two instructions of identical opcode and #operands. Check to see
// if all operands are the same type
for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
if (UseScalarTypes ?
getOperand(i)->getType()->getScalarType() !=
I->getOperand(i)->getType()->getScalarType() :
getOperand(i)->getType() != I->getOperand(i)->getType())
return false;
return haveSameSpecialState(this, I, IgnoreAlignment);
}
/// isUsedOutsideOfBlock - Return true if there are any uses of I outside of the
/// specified block. Note that PHI nodes are considered to evaluate their
/// operands in the corresponding predecessor block.
bool Instruction::isUsedOutsideOfBlock(const BasicBlock *BB) const {
for (const Use &U : uses()) {
// PHI nodes uses values in the corresponding predecessor block. For other
// instructions, just check to see whether the parent of the use matches up.
const Instruction *I = cast<Instruction>(U.getUser());
const PHINode *PN = dyn_cast<PHINode>(I);
if (!PN) {
if (I->getParent() != BB)
return true;
continue;
}
if (PN->getIncomingBlock(U) != BB)
return true;
}
return false;
}
/// mayReadFromMemory - Return true if this instruction may read memory.
///
bool Instruction::mayReadFromMemory() const {
switch (getOpcode()) {
default: return false;
case Instruction::VAArg:
case Instruction::Load:
case Instruction::Fence: // FIXME: refine definition of mayReadFromMemory
case Instruction::AtomicCmpXchg:
case Instruction::AtomicRMW:
case Instruction::CatchPad:
case Instruction::CatchRet:
case Instruction::TerminatePad:
return true;
case Instruction::Call:
return !cast<CallInst>(this)->doesNotAccessMemory();
case Instruction::Invoke:
return !cast<InvokeInst>(this)->doesNotAccessMemory();
case Instruction::Store:
return !cast<StoreInst>(this)->isUnordered();
}
}
/// mayWriteToMemory - Return true if this instruction may modify memory.
///
bool Instruction::mayWriteToMemory() const {
switch (getOpcode()) {
default: return false;
case Instruction::Fence: // FIXME: refine definition of mayWriteToMemory
case Instruction::Store:
case Instruction::VAArg:
case Instruction::AtomicCmpXchg:
case Instruction::AtomicRMW:
case Instruction::CatchPad:
case Instruction::CatchRet:
case Instruction::TerminatePad:
return true;
case Instruction::Call:
return !cast<CallInst>(this)->onlyReadsMemory();
case Instruction::Invoke:
return !cast<InvokeInst>(this)->onlyReadsMemory();
case Instruction::Load:
return !cast<LoadInst>(this)->isUnordered();
}
}
bool Instruction::isAtomic() const {
switch (getOpcode()) {
default:
return false;
case Instruction::AtomicCmpXchg:
case Instruction::AtomicRMW:
case Instruction::Fence:
return true;
case Instruction::Load:
return cast<LoadInst>(this)->getOrdering() != NotAtomic;
case Instruction::Store:
return cast<StoreInst>(this)->getOrdering() != NotAtomic;
}
}
bool Instruction::mayThrow() const {
if (const CallInst *CI = dyn_cast<CallInst>(this))
return !CI->doesNotThrow();
if (const auto *CRI = dyn_cast<CleanupReturnInst>(this))
return CRI->unwindsToCaller();
if (const auto *CEPI = dyn_cast<CleanupEndPadInst>(this))
return CEPI->unwindsToCaller();
if (const auto *CEPI = dyn_cast<CatchEndPadInst>(this))
return CEPI->unwindsToCaller();
if (const auto *TPI = dyn_cast<TerminatePadInst>(this))
return TPI->unwindsToCaller();
return isa<ResumeInst>(this);
}
bool Instruction::mayReturn() const {
if (const CallInst *CI = dyn_cast<CallInst>(this))
return !CI->doesNotReturn();
return true;
}
/// isAssociative - Return true if the instruction is associative:
///
/// Associative operators satisfy: x op (y op z) === (x op y) op z
///
/// In LLVM, the Add, Mul, And, Or, and Xor operators are associative.
///
bool Instruction::isAssociative(unsigned Opcode) {
return Opcode == And || Opcode == Or || Opcode == Xor ||
Opcode == Add || Opcode == Mul;
}
bool Instruction::isAssociative() const {
unsigned Opcode = getOpcode();
if (isAssociative(Opcode))
return true;
switch (Opcode) {
case FMul:
case FAdd:
return cast<FPMathOperator>(this)->hasUnsafeAlgebra();
default:
return false;
}
}
/// isCommutative - Return true if the instruction is commutative:
///
/// Commutative operators satisfy: (x op y) === (y op x)
///
/// In LLVM, these are the associative operators, plus SetEQ and SetNE, when
/// applied to any type.
///
bool Instruction::isCommutative(unsigned op) {
switch (op) {
case Add:
case FAdd:
case Mul:
case FMul:
case And:
case Or:
case Xor:
return true;
default:
return false;
}
}
/// isIdempotent - Return true if the instruction is idempotent:
///
/// Idempotent operators satisfy: x op x === x
///
/// In LLVM, the And and Or operators are idempotent.
///
bool Instruction::isIdempotent(unsigned Opcode) {
return Opcode == And || Opcode == Or;
}
/// isNilpotent - Return true if the instruction is nilpotent:
///
/// Nilpotent operators satisfy: x op x === Id,
///
/// where Id is the identity for the operator, i.e. a constant such that
/// x op Id === x and Id op x === x for all x.
///
/// In LLVM, the Xor operator is nilpotent.
///
bool Instruction::isNilpotent(unsigned Opcode) {
return Opcode == Xor;
}
Instruction *Instruction::cloneImpl() const {
llvm_unreachable("Subclass of Instruction failed to implement cloneImpl");
}
Instruction *Instruction::clone() const {
Instruction *New = nullptr;
switch (getOpcode()) {
default:
llvm_unreachable("Unhandled Opcode.");
#define HANDLE_INST(num, opc, clas) \
case Instruction::opc: \
New = cast<clas>(this)->cloneImpl(); \
break;
#include "llvm/IR/Instruction.def"
#undef HANDLE_INST
}
New->SubclassOptionalData = SubclassOptionalData;
if (!hasMetadata())
return New;
// Otherwise, enumerate and copy over metadata from the old instruction to the
// new one.
SmallVector<std::pair<unsigned, MDNode *>, 4> TheMDs;
getAllMetadataOtherThanDebugLoc(TheMDs);
for (const auto &MD : TheMDs)
New->setMetadata(MD.first, MD.second);
New->setDebugLoc(getDebugLoc());
return New;
}