mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-12-14 11:32:34 +00:00
16fd27b2c3
This commit adds scoped noalias metadata. The primary motivations for this feature are: 1. To preserve noalias function attribute information when inlining 2. To provide the ability to model block-scope C99 restrict pointers Neither of these two abilities are added here, only the necessary infrastructure. In fact, there should be no change to existing functionality, only the addition of new features. The logic that converts noalias function parameters into this metadata during inlining will come in a follow-up commit. What is added here is the ability to generally specify noalias memory-access sets. Regarding the metadata, alias-analysis scopes are defined similar to TBAA nodes: !scope0 = metadata !{ metadata !"scope of foo()" } !scope1 = metadata !{ metadata !"scope 1", metadata !scope0 } !scope2 = metadata !{ metadata !"scope 2", metadata !scope0 } !scope3 = metadata !{ metadata !"scope 2.1", metadata !scope2 } !scope4 = metadata !{ metadata !"scope 2.2", metadata !scope2 } Loads and stores can be tagged with an alias-analysis scope, and also, with a noalias tag for a specific scope: ... = load %ptr1, !alias.scope !{ !scope1 } ... = load %ptr2, !alias.scope !{ !scope1, !scope2 }, !noalias !{ !scope1 } When evaluating an aliasing query, if one of the instructions is associated with an alias.scope id that is identical to the noalias scope associated with the other instruction, or is a descendant (in the scope hierarchy) of the noalias scope associated with the other instruction, then the two memory accesses are assumed not to alias. Note that is the first element of the scope metadata is a string, then it can be combined accross functions and translation units. The string can be replaced by a self-reference to create globally unqiue scope identifiers. [Note: This overview is slightly stylized, since the metadata nodes really need to just be numbers (!0 instead of !scope0), and the scope lists are also global unnamed metadata.] Existing noalias metadata in a callee is "cloned" for use by the inlined code. This is necessary because the aliasing scopes are unique to each call site (because of possible control dependencies on the aliasing properties). For example, consider a function: foo(noalias a, noalias b) { *a = *b; } that gets inlined into bar() { ... if (...) foo(a1, b1); ... if (...) foo(a2, b2); } -- now just because we know that a1 does not alias with b1 at the first call site, and a2 does not alias with b2 at the second call site, we cannot let inlining these functons have the metadata imply that a1 does not alias with b2. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213864 91177308-0d34-0410-b5e6-96231b3b80d8
175 lines
6.0 KiB
C++
175 lines
6.0 KiB
C++
//===---- IRBuilder.cpp - Builder for LLVM Instrs -------------------------===//
|
|
//
|
|
// 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 IRBuilder class, which is used as a convenient way
|
|
// to create LLVM instructions with a consistent and simplified interface.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "llvm/IR/Function.h"
|
|
#include "llvm/IR/GlobalVariable.h"
|
|
#include "llvm/IR/IRBuilder.h"
|
|
#include "llvm/IR/Intrinsics.h"
|
|
#include "llvm/IR/LLVMContext.h"
|
|
using namespace llvm;
|
|
|
|
/// CreateGlobalString - Make a new global variable with an initializer that
|
|
/// has array of i8 type filled in with the nul terminated string value
|
|
/// specified. If Name is specified, it is the name of the global variable
|
|
/// created.
|
|
Value *IRBuilderBase::CreateGlobalString(StringRef Str, const Twine &Name) {
|
|
Constant *StrConstant = ConstantDataArray::getString(Context, Str);
|
|
Module &M = *BB->getParent()->getParent();
|
|
GlobalVariable *GV = new GlobalVariable(M, StrConstant->getType(),
|
|
true, GlobalValue::PrivateLinkage,
|
|
StrConstant);
|
|
GV->setName(Name);
|
|
GV->setUnnamedAddr(true);
|
|
return GV;
|
|
}
|
|
|
|
Type *IRBuilderBase::getCurrentFunctionReturnType() const {
|
|
assert(BB && BB->getParent() && "No current function!");
|
|
return BB->getParent()->getReturnType();
|
|
}
|
|
|
|
Value *IRBuilderBase::getCastedInt8PtrValue(Value *Ptr) {
|
|
PointerType *PT = cast<PointerType>(Ptr->getType());
|
|
if (PT->getElementType()->isIntegerTy(8))
|
|
return Ptr;
|
|
|
|
// Otherwise, we need to insert a bitcast.
|
|
PT = getInt8PtrTy(PT->getAddressSpace());
|
|
BitCastInst *BCI = new BitCastInst(Ptr, PT, "");
|
|
BB->getInstList().insert(InsertPt, BCI);
|
|
SetInstDebugLocation(BCI);
|
|
return BCI;
|
|
}
|
|
|
|
static CallInst *createCallHelper(Value *Callee, ArrayRef<Value *> Ops,
|
|
IRBuilderBase *Builder) {
|
|
CallInst *CI = CallInst::Create(Callee, Ops, "");
|
|
Builder->GetInsertBlock()->getInstList().insert(Builder->GetInsertPoint(),CI);
|
|
Builder->SetInstDebugLocation(CI);
|
|
return CI;
|
|
}
|
|
|
|
CallInst *IRBuilderBase::
|
|
CreateMemSet(Value *Ptr, Value *Val, Value *Size, unsigned Align,
|
|
bool isVolatile, MDNode *TBAATag, MDNode *ScopeTag,
|
|
MDNode *NoAliasTag) {
|
|
Ptr = getCastedInt8PtrValue(Ptr);
|
|
Value *Ops[] = { Ptr, Val, Size, getInt32(Align), getInt1(isVolatile) };
|
|
Type *Tys[] = { Ptr->getType(), Size->getType() };
|
|
Module *M = BB->getParent()->getParent();
|
|
Value *TheFn = Intrinsic::getDeclaration(M, Intrinsic::memset, Tys);
|
|
|
|
CallInst *CI = createCallHelper(TheFn, Ops, this);
|
|
|
|
// Set the TBAA info if present.
|
|
if (TBAATag)
|
|
CI->setMetadata(LLVMContext::MD_tbaa, TBAATag);
|
|
|
|
if (ScopeTag)
|
|
CI->setMetadata(LLVMContext::MD_alias_scope, ScopeTag);
|
|
|
|
if (NoAliasTag)
|
|
CI->setMetadata(LLVMContext::MD_noalias, NoAliasTag);
|
|
|
|
return CI;
|
|
}
|
|
|
|
CallInst *IRBuilderBase::
|
|
CreateMemCpy(Value *Dst, Value *Src, Value *Size, unsigned Align,
|
|
bool isVolatile, MDNode *TBAATag, MDNode *TBAAStructTag,
|
|
MDNode *ScopeTag, MDNode *NoAliasTag) {
|
|
Dst = getCastedInt8PtrValue(Dst);
|
|
Src = getCastedInt8PtrValue(Src);
|
|
|
|
Value *Ops[] = { Dst, Src, Size, getInt32(Align), getInt1(isVolatile) };
|
|
Type *Tys[] = { Dst->getType(), Src->getType(), Size->getType() };
|
|
Module *M = BB->getParent()->getParent();
|
|
Value *TheFn = Intrinsic::getDeclaration(M, Intrinsic::memcpy, Tys);
|
|
|
|
CallInst *CI = createCallHelper(TheFn, Ops, this);
|
|
|
|
// Set the TBAA info if present.
|
|
if (TBAATag)
|
|
CI->setMetadata(LLVMContext::MD_tbaa, TBAATag);
|
|
|
|
// Set the TBAA Struct info if present.
|
|
if (TBAAStructTag)
|
|
CI->setMetadata(LLVMContext::MD_tbaa_struct, TBAAStructTag);
|
|
|
|
if (ScopeTag)
|
|
CI->setMetadata(LLVMContext::MD_alias_scope, ScopeTag);
|
|
|
|
if (NoAliasTag)
|
|
CI->setMetadata(LLVMContext::MD_noalias, NoAliasTag);
|
|
|
|
return CI;
|
|
}
|
|
|
|
CallInst *IRBuilderBase::
|
|
CreateMemMove(Value *Dst, Value *Src, Value *Size, unsigned Align,
|
|
bool isVolatile, MDNode *TBAATag, MDNode *ScopeTag,
|
|
MDNode *NoAliasTag) {
|
|
Dst = getCastedInt8PtrValue(Dst);
|
|
Src = getCastedInt8PtrValue(Src);
|
|
|
|
Value *Ops[] = { Dst, Src, Size, getInt32(Align), getInt1(isVolatile) };
|
|
Type *Tys[] = { Dst->getType(), Src->getType(), Size->getType() };
|
|
Module *M = BB->getParent()->getParent();
|
|
Value *TheFn = Intrinsic::getDeclaration(M, Intrinsic::memmove, Tys);
|
|
|
|
CallInst *CI = createCallHelper(TheFn, Ops, this);
|
|
|
|
// Set the TBAA info if present.
|
|
if (TBAATag)
|
|
CI->setMetadata(LLVMContext::MD_tbaa, TBAATag);
|
|
|
|
if (ScopeTag)
|
|
CI->setMetadata(LLVMContext::MD_alias_scope, ScopeTag);
|
|
|
|
if (NoAliasTag)
|
|
CI->setMetadata(LLVMContext::MD_noalias, NoAliasTag);
|
|
|
|
return CI;
|
|
}
|
|
|
|
CallInst *IRBuilderBase::CreateLifetimeStart(Value *Ptr, ConstantInt *Size) {
|
|
assert(isa<PointerType>(Ptr->getType()) &&
|
|
"lifetime.start only applies to pointers.");
|
|
Ptr = getCastedInt8PtrValue(Ptr);
|
|
if (!Size)
|
|
Size = getInt64(-1);
|
|
else
|
|
assert(Size->getType() == getInt64Ty() &&
|
|
"lifetime.start requires the size to be an i64");
|
|
Value *Ops[] = { Size, Ptr };
|
|
Module *M = BB->getParent()->getParent();
|
|
Value *TheFn = Intrinsic::getDeclaration(M, Intrinsic::lifetime_start);
|
|
return createCallHelper(TheFn, Ops, this);
|
|
}
|
|
|
|
CallInst *IRBuilderBase::CreateLifetimeEnd(Value *Ptr, ConstantInt *Size) {
|
|
assert(isa<PointerType>(Ptr->getType()) &&
|
|
"lifetime.end only applies to pointers.");
|
|
Ptr = getCastedInt8PtrValue(Ptr);
|
|
if (!Size)
|
|
Size = getInt64(-1);
|
|
else
|
|
assert(Size->getType() == getInt64Ty() &&
|
|
"lifetime.end requires the size to be an i64");
|
|
Value *Ops[] = { Size, Ptr };
|
|
Module *M = BB->getParent()->getParent();
|
|
Value *TheFn = Intrinsic::getDeclaration(M, Intrinsic::lifetime_end);
|
|
return createCallHelper(TheFn, Ops, this);
|
|
}
|