llvm-project/llvm/lib/IR/Instruction.cpp

755 lines
26 KiB
C++
Raw Normal View History

//===-- Instruction.cpp - Implement the Instruction class -----------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
2001-06-07 04:29:01 +08:00
//
// This file implements the Instruction class for the IR library.
2001-06-07 04:29:01 +08:00
//
//===----------------------------------------------------------------------===//
#include "llvm/IR/Instruction.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/ADT/DenseSet.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/MDBuilder.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);
}
2001-06-07 04:29:01 +08:00
}
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);
}
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();
}
const Function *Instruction::getFunction() const {
return getParent()->getParent();
}
void Instruction::removeFromParent() {
getParent()->getInstList().remove(getIterator());
}
iplist<Instruction>::iterator Instruction::eraseFromParent() {
return getParent()->getInstList().erase(getIterator());
}
2016-01-06 08:18:29 +08:00
/// Insert an unlinked instruction into a basic block immediately before the
/// specified instruction.
void Instruction::insertBefore(Instruction *InsertPos) {
InsertPos->getParent()->getInstList().insert(InsertPos->getIterator(), this);
}
2016-01-06 08:18:29 +08:00
/// Insert an unlinked instruction into a basic block immediately after the
/// specified instruction.
void Instruction::insertAfter(Instruction *InsertPos) {
InsertPos->getParent()->getInstList().insertAfter(InsertPos->getIterator(),
this);
}
2016-01-06 08:18:29 +08:00
/// 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) {
moveBefore(*MovePos->getParent(), MovePos->getIterator());
}
void Instruction::moveAfter(Instruction *MovePos) {
moveBefore(*MovePos->getParent(), ++MovePos->getIterator());
}
void Instruction::moveBefore(BasicBlock &BB,
SymbolTableList<Instruction>::iterator I) {
assert(I == BB.end() || I->getParent() == &BB);
BB.getInstList().splice(I, getParent()->getInstList(), getIterator());
}
void Instruction::setHasNoUnsignedWrap(bool b) {
cast<OverflowingBinaryOperator>(this)->setHasNoUnsignedWrap(b);
}
void Instruction::setHasNoSignedWrap(bool b) {
cast<OverflowingBinaryOperator>(this)->setHasNoSignedWrap(b);
}
void Instruction::setIsExact(bool b) {
cast<PossiblyExactOperator>(this)->setIsExact(b);
}
bool Instruction::hasNoUnsignedWrap() const {
return cast<OverflowingBinaryOperator>(this)->hasNoUnsignedWrap();
}
bool Instruction::hasNoSignedWrap() const {
return cast<OverflowingBinaryOperator>(this)->hasNoSignedWrap();
}
void Instruction::dropPoisonGeneratingFlags() {
switch (getOpcode()) {
case Instruction::Add:
case Instruction::Sub:
case Instruction::Mul:
case Instruction::Shl:
cast<OverflowingBinaryOperator>(this)->setHasNoUnsignedWrap(false);
cast<OverflowingBinaryOperator>(this)->setHasNoSignedWrap(false);
break;
case Instruction::UDiv:
case Instruction::SDiv:
case Instruction::AShr:
case Instruction::LShr:
cast<PossiblyExactOperator>(this)->setIsExact(false);
break;
case Instruction::GetElementPtr:
cast<GetElementPtrInst>(this)->setIsInBounds(false);
break;
}
// TODO: FastMathFlags!
}
bool Instruction::isExact() const {
return cast<PossiblyExactOperator>(this)->isExact();
}
[IR] redefine 'UnsafeAlgebra' / 'reassoc' fast-math-flags and add 'trans' fast-math-flag As discussed on llvm-dev: http://lists.llvm.org/pipermail/llvm-dev/2016-November/107104.html and again more recently: http://lists.llvm.org/pipermail/llvm-dev/2017-October/118118.html ...this is a step in cleaning up our fast-math-flags implementation in IR to better match the capabilities of both clang's user-visible flags and the backend's flags for SDNode. As proposed in the above threads, we're replacing the 'UnsafeAlgebra' bit (which had the 'umbrella' meaning that all flags are set) with a new bit that only applies to algebraic reassociation - 'AllowReassoc'. We're also adding a bit to allow approximations for library functions called 'ApproxFunc' (this was initially proposed as 'libm' or similar). ...and we're out of bits. 7 bits ought to be enough for anyone, right? :) FWIW, I did look at getting this out of SubclassOptionalData via SubclassData (spacious 16-bits), but that's apparently already used for other purposes. Also, I don't think we can just add a field to FPMathOperator because Operator is not intended to be instantiated. We'll defer movement of FMF to another day. We keep the 'fast' keyword. I thought about removing that, but seeing IR like this: %f.fast = fadd reassoc nnan ninf nsz arcp contract afn float %op1, %op2 ...made me think we want to keep the shortcut synonym. Finally, this change is binary incompatible with existing IR as seen in the compatibility tests. This statement: "Newer releases can ignore features from older releases, but they cannot miscompile them. For example, if nsw is ever replaced with something else, dropping it would be a valid way to upgrade the IR." ( http://llvm.org/docs/DeveloperPolicy.html#ir-backwards-compatibility ) ...provides the flexibility we want to make this change without requiring a new IR version. Ie, we're not loosening the FP strictness of existing IR. At worst, we will fail to optimize some previously 'fast' code because it's no longer recognized as 'fast'. This should get fixed as we audit/squash all of the uses of 'isFast()'. Note: an inter-dependent clang commit to use the new API name should closely follow commit. Differential Revision: https://reviews.llvm.org/D39304 llvm-svn: 317488
2017-11-07 00:27:15 +08:00
void Instruction::setFast(bool B) {
assert(isa<FPMathOperator>(this) && "setting fast-math flag on invalid op");
[IR] redefine 'UnsafeAlgebra' / 'reassoc' fast-math-flags and add 'trans' fast-math-flag As discussed on llvm-dev: http://lists.llvm.org/pipermail/llvm-dev/2016-November/107104.html and again more recently: http://lists.llvm.org/pipermail/llvm-dev/2017-October/118118.html ...this is a step in cleaning up our fast-math-flags implementation in IR to better match the capabilities of both clang's user-visible flags and the backend's flags for SDNode. As proposed in the above threads, we're replacing the 'UnsafeAlgebra' bit (which had the 'umbrella' meaning that all flags are set) with a new bit that only applies to algebraic reassociation - 'AllowReassoc'. We're also adding a bit to allow approximations for library functions called 'ApproxFunc' (this was initially proposed as 'libm' or similar). ...and we're out of bits. 7 bits ought to be enough for anyone, right? :) FWIW, I did look at getting this out of SubclassOptionalData via SubclassData (spacious 16-bits), but that's apparently already used for other purposes. Also, I don't think we can just add a field to FPMathOperator because Operator is not intended to be instantiated. We'll defer movement of FMF to another day. We keep the 'fast' keyword. I thought about removing that, but seeing IR like this: %f.fast = fadd reassoc nnan ninf nsz arcp contract afn float %op1, %op2 ...made me think we want to keep the shortcut synonym. Finally, this change is binary incompatible with existing IR as seen in the compatibility tests. This statement: "Newer releases can ignore features from older releases, but they cannot miscompile them. For example, if nsw is ever replaced with something else, dropping it would be a valid way to upgrade the IR." ( http://llvm.org/docs/DeveloperPolicy.html#ir-backwards-compatibility ) ...provides the flexibility we want to make this change without requiring a new IR version. Ie, we're not loosening the FP strictness of existing IR. At worst, we will fail to optimize some previously 'fast' code because it's no longer recognized as 'fast'. This should get fixed as we audit/squash all of the uses of 'isFast()'. Note: an inter-dependent clang commit to use the new API name should closely follow commit. Differential Revision: https://reviews.llvm.org/D39304 llvm-svn: 317488
2017-11-07 00:27:15 +08:00
cast<FPMathOperator>(this)->setFast(B);
}
void Instruction::setHasAllowReassoc(bool B) {
assert(isa<FPMathOperator>(this) && "setting fast-math flag on invalid op");
cast<FPMathOperator>(this)->setHasAllowReassoc(B);
}
void Instruction::setHasNoNaNs(bool B) {
assert(isa<FPMathOperator>(this) && "setting fast-math flag on invalid op");
cast<FPMathOperator>(this)->setHasNoNaNs(B);
}
void Instruction::setHasNoInfs(bool B) {
assert(isa<FPMathOperator>(this) && "setting fast-math flag on invalid op");
cast<FPMathOperator>(this)->setHasNoInfs(B);
}
void Instruction::setHasNoSignedZeros(bool B) {
assert(isa<FPMathOperator>(this) && "setting fast-math flag on invalid op");
cast<FPMathOperator>(this)->setHasNoSignedZeros(B);
}
void Instruction::setHasAllowReciprocal(bool B) {
assert(isa<FPMathOperator>(this) && "setting fast-math flag on invalid op");
cast<FPMathOperator>(this)->setHasAllowReciprocal(B);
}
[IR] redefine 'UnsafeAlgebra' / 'reassoc' fast-math-flags and add 'trans' fast-math-flag As discussed on llvm-dev: http://lists.llvm.org/pipermail/llvm-dev/2016-November/107104.html and again more recently: http://lists.llvm.org/pipermail/llvm-dev/2017-October/118118.html ...this is a step in cleaning up our fast-math-flags implementation in IR to better match the capabilities of both clang's user-visible flags and the backend's flags for SDNode. As proposed in the above threads, we're replacing the 'UnsafeAlgebra' bit (which had the 'umbrella' meaning that all flags are set) with a new bit that only applies to algebraic reassociation - 'AllowReassoc'. We're also adding a bit to allow approximations for library functions called 'ApproxFunc' (this was initially proposed as 'libm' or similar). ...and we're out of bits. 7 bits ought to be enough for anyone, right? :) FWIW, I did look at getting this out of SubclassOptionalData via SubclassData (spacious 16-bits), but that's apparently already used for other purposes. Also, I don't think we can just add a field to FPMathOperator because Operator is not intended to be instantiated. We'll defer movement of FMF to another day. We keep the 'fast' keyword. I thought about removing that, but seeing IR like this: %f.fast = fadd reassoc nnan ninf nsz arcp contract afn float %op1, %op2 ...made me think we want to keep the shortcut synonym. Finally, this change is binary incompatible with existing IR as seen in the compatibility tests. This statement: "Newer releases can ignore features from older releases, but they cannot miscompile them. For example, if nsw is ever replaced with something else, dropping it would be a valid way to upgrade the IR." ( http://llvm.org/docs/DeveloperPolicy.html#ir-backwards-compatibility ) ...provides the flexibility we want to make this change without requiring a new IR version. Ie, we're not loosening the FP strictness of existing IR. At worst, we will fail to optimize some previously 'fast' code because it's no longer recognized as 'fast'. This should get fixed as we audit/squash all of the uses of 'isFast()'. Note: an inter-dependent clang commit to use the new API name should closely follow commit. Differential Revision: https://reviews.llvm.org/D39304 llvm-svn: 317488
2017-11-07 00:27:15 +08:00
void Instruction::setHasApproxFunc(bool B) {
assert(isa<FPMathOperator>(this) && "setting fast-math flag on invalid op");
cast<FPMathOperator>(this)->setHasApproxFunc(B);
}
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);
}
[IR] redefine 'UnsafeAlgebra' / 'reassoc' fast-math-flags and add 'trans' fast-math-flag As discussed on llvm-dev: http://lists.llvm.org/pipermail/llvm-dev/2016-November/107104.html and again more recently: http://lists.llvm.org/pipermail/llvm-dev/2017-October/118118.html ...this is a step in cleaning up our fast-math-flags implementation in IR to better match the capabilities of both clang's user-visible flags and the backend's flags for SDNode. As proposed in the above threads, we're replacing the 'UnsafeAlgebra' bit (which had the 'umbrella' meaning that all flags are set) with a new bit that only applies to algebraic reassociation - 'AllowReassoc'. We're also adding a bit to allow approximations for library functions called 'ApproxFunc' (this was initially proposed as 'libm' or similar). ...and we're out of bits. 7 bits ought to be enough for anyone, right? :) FWIW, I did look at getting this out of SubclassOptionalData via SubclassData (spacious 16-bits), but that's apparently already used for other purposes. Also, I don't think we can just add a field to FPMathOperator because Operator is not intended to be instantiated. We'll defer movement of FMF to another day. We keep the 'fast' keyword. I thought about removing that, but seeing IR like this: %f.fast = fadd reassoc nnan ninf nsz arcp contract afn float %op1, %op2 ...made me think we want to keep the shortcut synonym. Finally, this change is binary incompatible with existing IR as seen in the compatibility tests. This statement: "Newer releases can ignore features from older releases, but they cannot miscompile them. For example, if nsw is ever replaced with something else, dropping it would be a valid way to upgrade the IR." ( http://llvm.org/docs/DeveloperPolicy.html#ir-backwards-compatibility ) ...provides the flexibility we want to make this change without requiring a new IR version. Ie, we're not loosening the FP strictness of existing IR. At worst, we will fail to optimize some previously 'fast' code because it's no longer recognized as 'fast'. This should get fixed as we audit/squash all of the uses of 'isFast()'. Note: an inter-dependent clang commit to use the new API name should closely follow commit. Differential Revision: https://reviews.llvm.org/D39304 llvm-svn: 317488
2017-11-07 00:27:15 +08:00
bool Instruction::isFast() const {
assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
[IR] redefine 'UnsafeAlgebra' / 'reassoc' fast-math-flags and add 'trans' fast-math-flag As discussed on llvm-dev: http://lists.llvm.org/pipermail/llvm-dev/2016-November/107104.html and again more recently: http://lists.llvm.org/pipermail/llvm-dev/2017-October/118118.html ...this is a step in cleaning up our fast-math-flags implementation in IR to better match the capabilities of both clang's user-visible flags and the backend's flags for SDNode. As proposed in the above threads, we're replacing the 'UnsafeAlgebra' bit (which had the 'umbrella' meaning that all flags are set) with a new bit that only applies to algebraic reassociation - 'AllowReassoc'. We're also adding a bit to allow approximations for library functions called 'ApproxFunc' (this was initially proposed as 'libm' or similar). ...and we're out of bits. 7 bits ought to be enough for anyone, right? :) FWIW, I did look at getting this out of SubclassOptionalData via SubclassData (spacious 16-bits), but that's apparently already used for other purposes. Also, I don't think we can just add a field to FPMathOperator because Operator is not intended to be instantiated. We'll defer movement of FMF to another day. We keep the 'fast' keyword. I thought about removing that, but seeing IR like this: %f.fast = fadd reassoc nnan ninf nsz arcp contract afn float %op1, %op2 ...made me think we want to keep the shortcut synonym. Finally, this change is binary incompatible with existing IR as seen in the compatibility tests. This statement: "Newer releases can ignore features from older releases, but they cannot miscompile them. For example, if nsw is ever replaced with something else, dropping it would be a valid way to upgrade the IR." ( http://llvm.org/docs/DeveloperPolicy.html#ir-backwards-compatibility ) ...provides the flexibility we want to make this change without requiring a new IR version. Ie, we're not loosening the FP strictness of existing IR. At worst, we will fail to optimize some previously 'fast' code because it's no longer recognized as 'fast'. This should get fixed as we audit/squash all of the uses of 'isFast()'. Note: an inter-dependent clang commit to use the new API name should closely follow commit. Differential Revision: https://reviews.llvm.org/D39304 llvm-svn: 317488
2017-11-07 00:27:15 +08:00
return cast<FPMathOperator>(this)->isFast();
}
bool Instruction::hasAllowReassoc() const {
assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
return cast<FPMathOperator>(this)->hasAllowReassoc();
}
bool Instruction::hasNoNaNs() const {
assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
return cast<FPMathOperator>(this)->hasNoNaNs();
}
bool Instruction::hasNoInfs() const {
assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
return cast<FPMathOperator>(this)->hasNoInfs();
}
bool Instruction::hasNoSignedZeros() const {
assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
return cast<FPMathOperator>(this)->hasNoSignedZeros();
}
bool Instruction::hasAllowReciprocal() const {
assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
return cast<FPMathOperator>(this)->hasAllowReciprocal();
}
bool Instruction::hasAllowContract() const {
assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
return cast<FPMathOperator>(this)->hasAllowContract();
}
[IR] redefine 'UnsafeAlgebra' / 'reassoc' fast-math-flags and add 'trans' fast-math-flag As discussed on llvm-dev: http://lists.llvm.org/pipermail/llvm-dev/2016-November/107104.html and again more recently: http://lists.llvm.org/pipermail/llvm-dev/2017-October/118118.html ...this is a step in cleaning up our fast-math-flags implementation in IR to better match the capabilities of both clang's user-visible flags and the backend's flags for SDNode. As proposed in the above threads, we're replacing the 'UnsafeAlgebra' bit (which had the 'umbrella' meaning that all flags are set) with a new bit that only applies to algebraic reassociation - 'AllowReassoc'. We're also adding a bit to allow approximations for library functions called 'ApproxFunc' (this was initially proposed as 'libm' or similar). ...and we're out of bits. 7 bits ought to be enough for anyone, right? :) FWIW, I did look at getting this out of SubclassOptionalData via SubclassData (spacious 16-bits), but that's apparently already used for other purposes. Also, I don't think we can just add a field to FPMathOperator because Operator is not intended to be instantiated. We'll defer movement of FMF to another day. We keep the 'fast' keyword. I thought about removing that, but seeing IR like this: %f.fast = fadd reassoc nnan ninf nsz arcp contract afn float %op1, %op2 ...made me think we want to keep the shortcut synonym. Finally, this change is binary incompatible with existing IR as seen in the compatibility tests. This statement: "Newer releases can ignore features from older releases, but they cannot miscompile them. For example, if nsw is ever replaced with something else, dropping it would be a valid way to upgrade the IR." ( http://llvm.org/docs/DeveloperPolicy.html#ir-backwards-compatibility ) ...provides the flexibility we want to make this change without requiring a new IR version. Ie, we're not loosening the FP strictness of existing IR. At worst, we will fail to optimize some previously 'fast' code because it's no longer recognized as 'fast'. This should get fixed as we audit/squash all of the uses of 'isFast()'. Note: an inter-dependent clang commit to use the new API name should closely follow commit. Differential Revision: https://reviews.llvm.org/D39304 llvm-svn: 317488
2017-11-07 00:27:15 +08:00
bool Instruction::hasApproxFunc() const {
assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
return cast<FPMathOperator>(this)->hasApproxFunc();
}
FastMathFlags Instruction::getFastMathFlags() const {
assert(isa<FPMathOperator>(this) && "getting fast-math flag on invalid op");
return cast<FPMathOperator>(this)->getFastMathFlags();
}
void Instruction::copyFastMathFlags(const Instruction *I) {
copyFastMathFlags(I->getFastMathFlags());
}
void Instruction::copyIRFlags(const Value *V, bool IncludeWrapFlags) {
// Copy the wrapping flags.
if (IncludeWrapFlags && isa<OverflowingBinaryOperator>(this)) {
if (auto *OB = dyn_cast<OverflowingBinaryOperator>(V)) {
setHasNoSignedWrap(OB->hasNoSignedWrap());
setHasNoUnsignedWrap(OB->hasNoUnsignedWrap());
}
}
// Copy the exact flag.
if (auto *PE = dyn_cast<PossiblyExactOperator>(V))
if (isa<PossiblyExactOperator>(this))
setIsExact(PE->isExact());
// Copy the fast-math flags.
if (auto *FP = dyn_cast<FPMathOperator>(V))
if (isa<FPMathOperator>(this))
copyFastMathFlags(FP->getFastMathFlags());
if (auto *SrcGEP = dyn_cast<GetElementPtrInst>(V))
if (auto *DestGEP = dyn_cast<GetElementPtrInst>(this))
DestGEP->setIsInBounds(SrcGEP->isInBounds() | DestGEP->isInBounds());
}
void Instruction::andIRFlags(const Value *V) {
if (auto *OB = dyn_cast<OverflowingBinaryOperator>(V)) {
if (isa<OverflowingBinaryOperator>(this)) {
setHasNoSignedWrap(hasNoSignedWrap() & OB->hasNoSignedWrap());
setHasNoUnsignedWrap(hasNoUnsignedWrap() & OB->hasNoUnsignedWrap());
}
}
if (auto *PE = dyn_cast<PossiblyExactOperator>(V))
if (isa<PossiblyExactOperator>(this))
setIsExact(isExact() & PE->isExact());
if (auto *FP = dyn_cast<FPMathOperator>(V)) {
if (isa<FPMathOperator>(this)) {
FastMathFlags FM = getFastMathFlags();
FM &= FP->getFastMathFlags();
copyFastMathFlags(FM);
}
}
if (auto *SrcGEP = dyn_cast<GetElementPtrInst>(V))
if (auto *DestGEP = dyn_cast<GetElementPtrInst>(this))
DestGEP->setIsInBounds(SrcGEP->isInBounds() & DestGEP->isInBounds());
}
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 CleanupRet: return "cleanupret";
case CatchRet: return "catchret";
case CatchPad: return "catchpad";
[IR] Reformulate LLVM's EH funclet IR While we have successfully implemented a funclet-oriented EH scheme on top of LLVM IR, our scheme has some notable deficiencies: - catchendpad and cleanupendpad are necessary in the current design but they are difficult to explain to others, even to seasoned LLVM experts. - catchendpad and cleanupendpad are optimization barriers. They cannot be split and force all potentially throwing call-sites to be invokes. This has a noticable effect on the quality of our code generation. - catchpad, while similar in some aspects to invoke, is fairly awkward. It is unsplittable, starts a funclet, and has control flow to other funclets. - The nesting relationship between funclets is currently a property of control flow edges. Because of this, we are forced to carefully analyze the flow graph to see if there might potentially exist illegal nesting among funclets. While we have logic to clone funclets when they are illegally nested, it would be nicer if we had a representation which forbade them upfront. Let's clean this up a bit by doing the following: - Instead, make catchpad more like cleanuppad and landingpad: no control flow, just a bunch of simple operands; catchpad would be splittable. - Introduce catchswitch, a control flow instruction designed to model the constraints of funclet oriented EH. - Make funclet scoping explicit by having funclet instructions consume the token produced by the funclet which contains them. - Remove catchendpad and cleanupendpad. Their presence can be inferred implicitly using coloring information. N.B. The state numbering code for the CLR has been updated but the veracity of it's output cannot be spoken for. An expert should take a look to make sure the results are reasonable. Reviewers: rnk, JosephTremoulet, andrew.w.kaylor Differential Revision: http://reviews.llvm.org/D15139 llvm-svn: 255422
2015-12-12 13:38:55 +08:00
case CatchSwitch: return "catchswitch";
case CallBr: return "callbr";
// Standard unary operators...
case FNeg: return "fneg";
// 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 FunctionComparator::cmpOperations in
/// 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 AllocaInst *AI = dyn_cast<AllocaInst>(I1))
return AI->getAllocatedType() == cast<AllocaInst>(I2)->getAllocatedType() &&
(AI->getAlignment() == cast<AllocaInst>(I2)->getAlignment() ||
IgnoreAlignment);
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->getSyncScopeID() == cast<LoadInst>(I2)->getSyncScopeID();
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->getSyncScopeID() == cast<StoreInst>(I2)->getSyncScopeID();
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() &&
CI->hasIdenticalOperandBundleSchema(*cast<CallInst>(I2));
if (const InvokeInst *CI = dyn_cast<InvokeInst>(I1))
return CI->getCallingConv() == cast<InvokeInst>(I2)->getCallingConv() &&
CI->getAttributes() == cast<InvokeInst>(I2)->getAttributes() &&
CI->hasIdenticalOperandBundleSchema(*cast<InvokeInst>(I2));
if (const CallBrInst *CI = dyn_cast<CallBrInst>(I1))
return CI->getCallingConv() == cast<CallBrInst>(I2)->getCallingConv() &&
CI->getAttributes() == cast<CallBrInst>(I2)->getAttributes() &&
CI->hasIdenticalOperandBundleSchema(*cast<CallBrInst>(I2));
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->getSyncScopeID() == cast<FenceInst>(I2)->getSyncScopeID();
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->getSyncScopeID() ==
cast<AtomicCmpXchgInst>(I2)->getSyncScopeID();
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->getSyncScopeID() == cast<AtomicRMWInst>(I2)->getSyncScopeID();
return true;
}
bool Instruction::isIdenticalTo(const Instruction *I) const {
return isIdenticalToWhenDefined(I) &&
SubclassOptionalData == I->SubclassOptionalData;
}
bool Instruction::isIdenticalToWhenDefined(const Instruction *I) const {
2004-11-30 10:51:53 +08:00
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);
2004-11-30 10:51:53 +08:00
// 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;
2004-11-30 10:51:53 +08:00
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);
}
// Keep this in sync with FunctionComparator::cmpOperations 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);
2004-11-30 10:51:53 +08:00
}
bool Instruction::isUsedOutsideOfBlock(const BasicBlock *BB) const {
[C++11] Add range based accessors for the Use-Def chain of a Value. This requires a number of steps. 1) Move value_use_iterator into the Value class as an implementation detail 2) Change it to actually be a *Use* iterator rather than a *User* iterator. 3) Add an adaptor which is a User iterator that always looks through the Use to the User. 4) Wrap these in Value::use_iterator and Value::user_iterator typedefs. 5) Add the range adaptors as Value::uses() and Value::users(). 6) Update *all* of the callers to correctly distinguish between whether they wanted a use_iterator (and to explicitly dig out the User when needed), or a user_iterator which makes the Use itself totally opaque. Because #6 requires churning essentially everything that walked the Use-Def chains, I went ahead and added all of the range adaptors and switched them to range-based loops where appropriate. Also because the renaming requires at least churning every line of code, it didn't make any sense to split these up into multiple commits -- all of which would touch all of the same lies of code. The result is still not quite optimal. The Value::use_iterator is a nice regular iterator, but Value::user_iterator is an iterator over User*s rather than over the User objects themselves. As a consequence, it fits a bit awkwardly into the range-based world and it has the weird extra-dereferencing 'operator->' that so many of our iterators have. I think this could be fixed by providing something which transforms a range of T&s into a range of T*s, but that *can* be separated into another patch, and it isn't yet 100% clear whether this is the right move. However, this change gets us most of the benefit and cleans up a substantial amount of code around Use and User. =] llvm-svn: 203364
2014-03-09 11:16:01 +08:00
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.
[C++11] Add range based accessors for the Use-Def chain of a Value. This requires a number of steps. 1) Move value_use_iterator into the Value class as an implementation detail 2) Change it to actually be a *Use* iterator rather than a *User* iterator. 3) Add an adaptor which is a User iterator that always looks through the Use to the User. 4) Wrap these in Value::use_iterator and Value::user_iterator typedefs. 5) Add the range adaptors as Value::uses() and Value::users(). 6) Update *all* of the callers to correctly distinguish between whether they wanted a use_iterator (and to explicitly dig out the User when needed), or a user_iterator which makes the Use itself totally opaque. Because #6 requires churning essentially everything that walked the Use-Def chains, I went ahead and added all of the range adaptors and switched them to range-based loops where appropriate. Also because the renaming requires at least churning every line of code, it didn't make any sense to split these up into multiple commits -- all of which would touch all of the same lies of code. The result is still not quite optimal. The Value::use_iterator is a nice regular iterator, but Value::user_iterator is an iterator over User*s rather than over the User objects themselves. As a consequence, it fits a bit awkwardly into the range-based world and it has the weird extra-dereferencing 'operator->' that so many of our iterators have. I think this could be fixed by providing something which transforms a range of T&s into a range of T*s, but that *can* be separated into another patch, and it isn't yet 100% clear whether this is the right move. However, this change gets us most of the benefit and cleans up a substantial amount of code around Use and User. =] llvm-svn: 203364
2014-03-09 11:16:01 +08:00
const Instruction *I = cast<Instruction>(U.getUser());
const PHINode *PN = dyn_cast<PHINode>(I);
if (!PN) {
[C++11] Add range based accessors for the Use-Def chain of a Value. This requires a number of steps. 1) Move value_use_iterator into the Value class as an implementation detail 2) Change it to actually be a *Use* iterator rather than a *User* iterator. 3) Add an adaptor which is a User iterator that always looks through the Use to the User. 4) Wrap these in Value::use_iterator and Value::user_iterator typedefs. 5) Add the range adaptors as Value::uses() and Value::users(). 6) Update *all* of the callers to correctly distinguish between whether they wanted a use_iterator (and to explicitly dig out the User when needed), or a user_iterator which makes the Use itself totally opaque. Because #6 requires churning essentially everything that walked the Use-Def chains, I went ahead and added all of the range adaptors and switched them to range-based loops where appropriate. Also because the renaming requires at least churning every line of code, it didn't make any sense to split these up into multiple commits -- all of which would touch all of the same lies of code. The result is still not quite optimal. The Value::use_iterator is a nice regular iterator, but Value::user_iterator is an iterator over User*s rather than over the User objects themselves. As a consequence, it fits a bit awkwardly into the range-based world and it has the weird extra-dereferencing 'operator->' that so many of our iterators have. I think this could be fixed by providing something which transforms a range of T&s into a range of T*s, but that *can* be separated into another patch, and it isn't yet 100% clear whether this is the right move. However, this change gets us most of the benefit and cleans up a substantial amount of code around Use and User. =] llvm-svn: 203364
2014-03-09 11:16:01 +08:00
if (I->getParent() != BB)
return true;
continue;
}
[C++11] Add range based accessors for the Use-Def chain of a Value. This requires a number of steps. 1) Move value_use_iterator into the Value class as an implementation detail 2) Change it to actually be a *Use* iterator rather than a *User* iterator. 3) Add an adaptor which is a User iterator that always looks through the Use to the User. 4) Wrap these in Value::use_iterator and Value::user_iterator typedefs. 5) Add the range adaptors as Value::uses() and Value::users(). 6) Update *all* of the callers to correctly distinguish between whether they wanted a use_iterator (and to explicitly dig out the User when needed), or a user_iterator which makes the Use itself totally opaque. Because #6 requires churning essentially everything that walked the Use-Def chains, I went ahead and added all of the range adaptors and switched them to range-based loops where appropriate. Also because the renaming requires at least churning every line of code, it didn't make any sense to split these up into multiple commits -- all of which would touch all of the same lies of code. The result is still not quite optimal. The Value::use_iterator is a nice regular iterator, but Value::user_iterator is an iterator over User*s rather than over the User objects themselves. As a consequence, it fits a bit awkwardly into the range-based world and it has the weird extra-dereferencing 'operator->' that so many of our iterators have. I think this could be fixed by providing something which transforms a range of T&s into a range of T*s, but that *can* be separated into another patch, and it isn't yet 100% clear whether this is the right move. However, this change gets us most of the benefit and cleans up a substantial amount of code around Use and User. =] llvm-svn: 203364
2014-03-09 11:16:01 +08:00
if (PN->getIncomingBlock(U) != BB)
return true;
}
return false;
}
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:
return true;
case Instruction::Call:
case Instruction::Invoke:
case Instruction::CallBr:
return !cast<CallBase>(this)->doesNotAccessMemory();
case Instruction::Store:
return !cast<StoreInst>(this)->isUnordered();
}
}
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:
return true;
case Instruction::Call:
case Instruction::Invoke:
case Instruction::CallBr:
return !cast<CallBase>(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() != AtomicOrdering::NotAtomic;
case Instruction::Store:
return cast<StoreInst>(this)->getOrdering() != AtomicOrdering::NotAtomic;
}
}
bool Instruction::hasAtomicLoad() const {
assert(isAtomic());
switch (getOpcode()) {
default:
return false;
case Instruction::AtomicCmpXchg:
case Instruction::AtomicRMW:
case Instruction::Load:
return true;
}
}
bool Instruction::hasAtomicStore() const {
assert(isAtomic());
switch (getOpcode()) {
default:
return false;
case Instruction::AtomicCmpXchg:
case Instruction::AtomicRMW:
case Instruction::Store:
return true;
}
}
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();
[IR] Reformulate LLVM's EH funclet IR While we have successfully implemented a funclet-oriented EH scheme on top of LLVM IR, our scheme has some notable deficiencies: - catchendpad and cleanupendpad are necessary in the current design but they are difficult to explain to others, even to seasoned LLVM experts. - catchendpad and cleanupendpad are optimization barriers. They cannot be split and force all potentially throwing call-sites to be invokes. This has a noticable effect on the quality of our code generation. - catchpad, while similar in some aspects to invoke, is fairly awkward. It is unsplittable, starts a funclet, and has control flow to other funclets. - The nesting relationship between funclets is currently a property of control flow edges. Because of this, we are forced to carefully analyze the flow graph to see if there might potentially exist illegal nesting among funclets. While we have logic to clone funclets when they are illegally nested, it would be nicer if we had a representation which forbade them upfront. Let's clean this up a bit by doing the following: - Instead, make catchpad more like cleanuppad and landingpad: no control flow, just a bunch of simple operands; catchpad would be splittable. - Introduce catchswitch, a control flow instruction designed to model the constraints of funclet oriented EH. - Make funclet scoping explicit by having funclet instructions consume the token produced by the funclet which contains them. - Remove catchendpad and cleanupendpad. Their presence can be inferred implicitly using coloring information. N.B. The state numbering code for the CLR has been updated but the veracity of it's output cannot be spoken for. An expert should take a look to make sure the results are reasonable. Reviewers: rnk, JosephTremoulet, andrew.w.kaylor Differential Revision: http://reviews.llvm.org/D15139 llvm-svn: 255422
2015-12-12 13:38:55 +08:00
if (const auto *CatchSwitch = dyn_cast<CatchSwitchInst>(this))
return CatchSwitch->unwindsToCaller();
return isa<ResumeInst>(this);
}
bool Instruction::isSafeToRemove() const {
return (!isa<CallInst>(this) || !this->mayHaveSideEffects()) &&
!this->isTerminator();
}
bool Instruction::isLifetimeStartOrEnd() const {
auto II = dyn_cast<IntrinsicInst>(this);
if (!II)
return false;
Intrinsic::ID ID = II->getIntrinsicID();
return ID == Intrinsic::lifetime_start || ID == Intrinsic::lifetime_end;
}
const Instruction *Instruction::getNextNonDebugInstruction() const {
for (const Instruction *I = getNextNode(); I; I = I->getNextNode())
if (!isa<DbgInfoIntrinsic>(I))
return I;
return nullptr;
}
const Instruction *Instruction::getPrevNonDebugInstruction() const {
for (const Instruction *I = getPrevNode(); I; I = I->getPrevNode())
if (!isa<DbgInfoIntrinsic>(I))
return I;
return nullptr;
}
bool Instruction::isAssociative() const {
unsigned Opcode = getOpcode();
if (isAssociative(Opcode))
return true;
switch (Opcode) {
case FMul:
case FAdd:
return cast<FPMathOperator>(this)->hasAllowReassoc() &&
cast<FPMathOperator>(this)->hasNoSignedZeros();
default:
return false;
}
}
unsigned Instruction::getNumSuccessors() const {
switch (getOpcode()) {
#define HANDLE_TERM_INST(N, OPC, CLASS) \
case Instruction::OPC: \
return static_cast<const CLASS *>(this)->getNumSuccessors();
#include "llvm/IR/Instruction.def"
default:
break;
}
llvm_unreachable("not a terminator");
}
BasicBlock *Instruction::getSuccessor(unsigned idx) const {
switch (getOpcode()) {
#define HANDLE_TERM_INST(N, OPC, CLASS) \
case Instruction::OPC: \
return static_cast<const CLASS *>(this)->getSuccessor(idx);
#include "llvm/IR/Instruction.def"
default:
break;
}
llvm_unreachable("not a terminator");
}
void Instruction::setSuccessor(unsigned idx, BasicBlock *B) {
switch (getOpcode()) {
#define HANDLE_TERM_INST(N, OPC, CLASS) \
case Instruction::OPC: \
return static_cast<CLASS *>(this)->setSuccessor(idx, B);
#include "llvm/IR/Instruction.def"
default:
break;
}
llvm_unreachable("not a terminator");
}
void Instruction::replaceSuccessorWith(BasicBlock *OldBB, BasicBlock *NewBB) {
for (unsigned Idx = 0, NumSuccessors = Instruction::getNumSuccessors();
Idx != NumSuccessors; ++Idx)
if (getSuccessor(Idx) == OldBB)
setSuccessor(Idx, NewBB);
}
Instruction *Instruction::cloneImpl() const {
llvm_unreachable("Subclass of Instruction failed to implement cloneImpl");
}
void Instruction::swapProfMetadata() {
MDNode *ProfileData = getMetadata(LLVMContext::MD_prof);
if (!ProfileData || ProfileData->getNumOperands() != 3 ||
!isa<MDString>(ProfileData->getOperand(0)))
return;
MDString *MDName = cast<MDString>(ProfileData->getOperand(0));
if (MDName->getString() != "branch_weights")
return;
// The first operand is the name. Fetch them backwards and build a new one.
Metadata *Ops[] = {ProfileData->getOperand(0), ProfileData->getOperand(2),
ProfileData->getOperand(1)};
setMetadata(LLVMContext::MD_prof,
MDNode::get(ProfileData->getContext(), Ops));
}
void Instruction::copyMetadata(const Instruction &SrcInst,
ArrayRef<unsigned> WL) {
if (!SrcInst.hasMetadata())
return;
DenseSet<unsigned> WLS;
for (unsigned M : WL)
WLS.insert(M);
// Otherwise, enumerate and copy over metadata from the old instruction to the
// new one.
SmallVector<std::pair<unsigned, MDNode *>, 4> TheMDs;
SrcInst.getAllMetadataOtherThanDebugLoc(TheMDs);
for (const auto &MD : TheMDs) {
if (WL.empty() || WLS.count(MD.first))
setMetadata(MD.first, MD.second);
}
if (WL.empty() || WLS.count(LLVMContext::MD_dbg))
setDebugLoc(SrcInst.getDebugLoc());
}
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;
New->copyMetadata(*this);
return New;
}
void Instruction::setProfWeight(uint64_t W) {
assert(isa<CallBase>(this) &&
"Can only set weights for call like instructions");
SmallVector<uint32_t, 1> Weights;
Weights.push_back(W);
MDBuilder MDB(getContext());
setMetadata(LLVMContext::MD_prof, MDB.createBranchWeights(Weights));
}