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llvm / llvm-archive / cfaec05de39adb34392b8c7b1ad4b32abbf3663d / . / llvm-gcc-4.2 / gcc / llvm-backend.cpp
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/* LLVM LOCAL begin (ENTIRE FILE!) */
/* High-level LLVM backend interface
Copyright (C) 2005, 2006, 2007 Free Software Foundation, Inc.
Contributed by Chris Lattner (sabre@nondot.org)
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING. If not, write to the Free
Software Foundation, 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA. */
#include "llvm-internal.h"
#include "llvm-debug.h"
#include "llvm-file-ostream.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Module.h"
#include "llvm/ModuleProvider.h"
#include "llvm/PassManager.h"
#include "llvm/ValueSymbolTable.h"
#include "llvm/Analysis/LoopPass.h"
#include "llvm/Analysis/Verifier.h"
#include "llvm/Assembly/Writer.h"
#include "llvm/Assembly/PrintModulePass.h"
#include "llvm/Bitcode/ReaderWriter.h"
#include "llvm/CodeGen/RegAllocRegistry.h"
#include "llvm/Target/SubtargetFeature.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetLowering.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetMachineRegistry.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Transforms/Scalar.h"
#include "llvm/Transforms/IPO.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/Support/Streams.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/System/Program.h"
#include <cassert>
#undef VISIBILITY_HIDDEN
extern "C" {
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "flags.h"
#include "tree.h"
#include "diagnostic.h"
#include "output.h"
#include "target.h"
#include "toplev.h"
#include "timevar.h"
#include "tm.h"
#include "function.h"
#include "tree-inline.h"
#include "langhooks.h"
#include "cgraph.h"
#include "params.h"
}
// Non-zero if bytecode from PCH is successfully read.
int flag_llvm_pch_read;
// Non-zero if libcalls should not be simplified.
int flag_no_simplify_libcalls;
// Global state for the LLVM backend.
Module *TheModule = 0;
DebugInfo *TheDebugInfo = 0;
TargetMachine *TheTarget = 0;
TargetFolder *TheFolder = 0;
TypeConverter *TheTypeConverter = 0;
llvm::OStream *AsmOutFile = 0;
llvm::OStream *AsmIntermediateOutFile = 0;
/// DisableLLVMOptimizations - Allow the user to specify:
/// "-mllvm -disable-llvm-optzns" on the llvm-gcc command line to force llvm
/// optimizations off.
static cl::opt<bool> DisableLLVMOptimizations("disable-llvm-optzns");
std::vector<std::pair<Constant*, int> > StaticCtors, StaticDtors;
SmallSetVector<Constant*, 32> AttributeUsedGlobals;
std::vector<Constant*> AttributeAnnotateGlobals;
/// PerFunctionPasses - This is the list of cleanup passes run per-function
/// as each is compiled. In cases where we are not doing IPO, it includes the
/// code generator.
static FunctionPassManager *PerFunctionPasses = 0;
static PassManager *PerModulePasses = 0;
static FunctionPassManager *CodeGenPasses = 0;
static void createPerFunctionOptimizationPasses();
static void createPerModuleOptimizationPasses();
static void destroyOptimizationPasses();
//===----------------------------------------------------------------------===//
// Matching LLVM Values with GCC DECL trees
//===----------------------------------------------------------------------===//
//
// LLVMValues is a vector of LLVM Values. GCC tree nodes keep track of LLVM
// Values using this vector's index. It is easier to save and restore the index
// than the LLVM Value pointer while using PCH.
// Collection of LLVM Values
static std::vector<Value *> LLVMValues;
typedef DenseMap<Value *, unsigned> LLVMValuesMapTy;
static LLVMValuesMapTy LLVMValuesMap;
/// LocalLLVMValueIDs - This is the set of local IDs we have in our mapping,
/// this allows us to efficiently identify and remove them. Local IDs are IDs
/// for values that are local to the current function being processed. These do
/// not need to go into the PCH file, but DECL_LLVM still needs a valid index
/// while converting the function. Using "Local IDs" allows the IDs for
/// function-local decls to be recycled after the function is done.
static std::vector<unsigned> LocalLLVMValueIDs;
// Remember the LLVM value for GCC tree node.
void llvm_set_decl(tree Tr, Value *V) {
// If there is not any value then do not add new LLVMValues entry.
// However clear Tr index if it is non zero.
if (!V) {
if (GET_DECL_LLVM_INDEX(Tr))
SET_DECL_LLVM_INDEX(Tr, 0);
return;
}
unsigned &ValueSlot = LLVMValuesMap[V];
if (ValueSlot) {
// Already in map
SET_DECL_LLVM_INDEX(Tr, ValueSlot);
return;
}
LLVMValues.push_back(V);
unsigned Index = LLVMValues.size();
SET_DECL_LLVM_INDEX(Tr, Index);
LLVMValuesMap[V] = Index;
// Remember local values.
if (!isa<Constant>(V))
LocalLLVMValueIDs.push_back(Index);
}
// Return TRUE if there is a LLVM Value associate with GCC tree node.
bool llvm_set_decl_p(tree Tr) {
unsigned Index = GET_DECL_LLVM_INDEX(Tr);
if (Index == 0)
return false;
return LLVMValues[Index - 1] != 0;
}
// Get LLVM Value for the GCC tree node based on LLVMValues vector index.
// If there is not any value associated then use make_decl_llvm() to
// make LLVM value. When GCC tree node is initialized, it has 0 as the
// index value. This is why all recorded indices are offset by 1.
Value *llvm_get_decl(tree Tr) {
unsigned Index = GET_DECL_LLVM_INDEX(Tr);
if (Index == 0) {
make_decl_llvm(Tr);
Index = GET_DECL_LLVM_INDEX(Tr);
// If there was an error, we may have disabled creating LLVM values.
if (Index == 0) return 0;
}
assert((Index - 1) < LLVMValues.size() && "Invalid LLVM value index");
assert(LLVMValues[Index - 1] && "Trying to use deleted LLVM value!");
return LLVMValues[Index - 1];
}
/// changeLLVMConstant - Replace Old with New everywhere, updating all maps
/// (except for AttributeAnnotateGlobals, which is a different kind of animal).
/// At this point we know that New is not in any of these maps.
void changeLLVMConstant(Constant *Old, Constant *New) {
assert(Old->use_empty() && "Old value has uses!");
if (AttributeUsedGlobals.count(Old)) {
AttributeUsedGlobals.remove(Old);
AttributeUsedGlobals.insert(New);
}
for (unsigned i = 0, e = StaticCtors.size(); i != e; ++i) {
if (StaticCtors[i].first == Old)
StaticCtors[i].first = New;
}
for (unsigned i = 0, e = StaticDtors.size(); i != e; ++i) {
if (StaticDtors[i].first == Old)
StaticDtors[i].first = New;
}
assert(!LLVMValuesMap.count(New) && "New cannot be in the LLVMValues map!");
// Find Old in the table.
LLVMValuesMapTy::iterator I = LLVMValuesMap.find(Old);
if (I == LLVMValuesMap.end()) return;
unsigned Idx = I->second-1;
assert(Idx < LLVMValues.size() && "Out of range index!");
assert(LLVMValues[Idx] == Old && "Inconsistent LLVMValues mapping!");
LLVMValues[Idx] = New;
// Remove the old value from the value map.
LLVMValuesMap.erase(I);
// Insert the new value into the value map. We know that it can't already
// exist in the mapping.
if (New)
LLVMValuesMap[New] = Idx+1;
}
// Read LLVM Types string table
void readLLVMValues() {
GlobalValue *V = TheModule->getNamedGlobal("llvm.pch.values");
if (!V)
return;
GlobalVariable *GV = cast<GlobalVariable>(V);
ConstantStruct *ValuesFromPCH = cast<ConstantStruct>(GV->getOperand(0));
for (unsigned i = 0; i < ValuesFromPCH->getNumOperands(); ++i) {
Value *Va = ValuesFromPCH->getOperand(i);
if (!Va) {
// If V is empty then insert NULL to represent empty entries.
LLVMValues.push_back(Va);
continue;
}
if (ConstantArray *CA = dyn_cast<ConstantArray>(Va)) {
std::string Str = CA->getAsString();
Va = TheModule->getValueSymbolTable().lookup(Str);
}
assert (Va != NULL && "Invalid Value in LLVMValues string table");
LLVMValues.push_back(Va);
}
// Now, llvm.pch.values is not required so remove it from the symbol table.
GV->eraseFromParent();
}
// GCC tree's uses LLVMValues vector's index to reach LLVM Values.
// Create a string table to hold these LLVM Values' names. This string
// table will be used to recreate LTypes vector after loading PCH.
void writeLLVMValues() {
if (LLVMValues.empty())
return;
std::vector<Constant *> ValuesForPCH;
for (std::vector<Value *>::iterator I = LLVMValues.begin(),
E = LLVMValues.end(); I != E; ++I) {
if (Constant *C = dyn_cast_or_null<Constant>(*I))
ValuesForPCH.push_back(C);
else
// Non constant values, e.g. arguments, are not at global scope.
// When PCH is read, only global scope values are used.
ValuesForPCH.push_back(Constant::getNullValue(Type::Int32Ty));
}
// Create string table.
Constant *LLVMValuesTable = ConstantStruct::get(ValuesForPCH, false);
// Create variable to hold this string table.
new GlobalVariable(LLVMValuesTable->getType(), true,
GlobalValue::ExternalLinkage,
LLVMValuesTable,
"llvm.pch.values", TheModule);
}
/// eraseLocalLLVMValues - drop all non-global values from the LLVM values map.
void eraseLocalLLVMValues() {
// Erase all the local values, these are stored in LocalLLVMValueIDs.
while (!LocalLLVMValueIDs.empty()) {
unsigned Idx = LocalLLVMValueIDs.back()-1;
LocalLLVMValueIDs.pop_back();
if (Value *V = LLVMValues[Idx]) {
assert(!isa<Constant>(V) && "Found global value");
LLVMValuesMap.erase(V);
}
if (Idx == LLVMValues.size()-1)
LLVMValues.pop_back();
else
LLVMValues[Idx] = 0;
}
}
// Forward decl visibility style to global.
void handleVisibility(tree decl, GlobalValue *GV) {
// If decl has visibility specified explicitely (via attribute) - honour
// it. Otherwise (e.g. visibility specified via -fvisibility=hidden) honour
// only if symbol is local.
if (TREE_PUBLIC(decl) &&
(DECL_VISIBILITY_SPECIFIED(decl) || !DECL_EXTERNAL(decl))) {
if (DECL_VISIBILITY(decl) == VISIBILITY_HIDDEN)
GV->setVisibility(GlobalValue::HiddenVisibility);
else if (DECL_VISIBILITY(decl) == VISIBILITY_PROTECTED)
GV->setVisibility(GlobalValue::ProtectedVisibility);
else if (DECL_VISIBILITY(decl) == VISIBILITY_DEFAULT)
GV->setVisibility(Function::DefaultVisibility);
}
}
void llvm_initialize_backend(void) {
// Initialize LLVM options.
std::vector<const char*> Args;
Args.push_back(progname); // program name
// Allow targets to specify PIC options and other stuff to the corresponding
// LLVM backends.
#ifdef LLVM_SET_ARCH_OPTIONS
LLVM_SET_ARCH_OPTIONS(Args);
#endif
#ifdef LLVM_SET_TARGET_OPTIONS
LLVM_SET_TARGET_OPTIONS(Args);
#endif
#ifdef LLVM_SET_MACHINE_OPTIONS
LLVM_SET_MACHINE_OPTIONS(Args);
#endif
if (time_report)
Args.push_back("--time-passes");
if (fast_math_flags_set_p())
Args.push_back("--enable-unsafe-fp-math");
if (!flag_omit_frame_pointer)
Args.push_back("--disable-fp-elim");
if (!flag_zero_initialized_in_bss)
Args.push_back("--nozero-initialized-in-bss");
if (flag_debug_asm)
Args.push_back("--asm-verbose");
if (flag_debug_pass_structure)
Args.push_back("--debug-pass=Structure");
if (flag_debug_pass_arguments)
Args.push_back("--debug-pass=Arguments");
if (optimize_size || optimize < 3)
// Reduce inline limit. Default limit is 200.
Args.push_back("--inline-threshold=50");
if (flag_unwind_tables)
Args.push_back("--unwind-tables");
// If there are options that should be passed through to the LLVM backend
// directly from the command line, do so now. This is mainly for debugging
// purposes, and shouldn't really be for general use.
std::vector<std::string> ArgStrings;
if (flag_limited_precision > 0) {
std::string Arg("--limit-float-precision="+utostr(flag_limited_precision));
ArgStrings.push_back(Arg);
}
if (flag_stack_protect > 0) {
std::string Arg("--stack-protector-buffer-size=" +
utostr(PARAM_VALUE(PARAM_SSP_BUFFER_SIZE)));
ArgStrings.push_back(Arg);
}
for (unsigned i = 0, e = ArgStrings.size(); i != e; ++i)
Args.push_back(ArgStrings[i].c_str());
std::vector<std::string> LLVM_Optns; // Avoid deallocation before opts parsed!
if (llvm_optns) {
SplitString(llvm_optns, LLVM_Optns);
for(unsigned i = 0, e = LLVM_Optns.size(); i != e; ++i)
Args.push_back(LLVM_Optns[i].c_str());
}
Args.push_back(0); // Null terminator.
int pseudo_argc = Args.size()-1;
cl::ParseCommandLineOptions(pseudo_argc, (char**)&Args[0]);
TheModule = new Module("");
// If the target wants to override the architecture, e.g. turning
// powerpc-darwin-... into powerpc64-darwin-... when -m64 is enabled, do so
// now.
std::string TargetTriple = TARGET_NAME;
#ifdef LLVM_OVERRIDE_TARGET_ARCH
std::string Arch = LLVM_OVERRIDE_TARGET_ARCH();
if (!Arch.empty()) {
std::string::size_type DashPos = TargetTriple.find('-');
if (DashPos != std::string::npos)// If we have a sane t-t, replace the arch.
TargetTriple = Arch + TargetTriple.substr(DashPos);
}
#endif
#ifdef LLVM_OVERRIDE_TARGET_VERSION
char *NewTriple;
bool OverRidden = LLVM_OVERRIDE_TARGET_VERSION(TargetTriple.c_str(),
&NewTriple);
if (OverRidden)
TargetTriple = std::string(NewTriple);
#endif
TheModule->setTargetTriple(TargetTriple);
TheTypeConverter = new TypeConverter();
// Create the TargetMachine we will be generating code with.
// FIXME: Figure out how to select the target and pass down subtarget info.
std::string Err;
const TargetMachineRegistry::entry *TME =
TargetMachineRegistry::getClosestStaticTargetForModule(*TheModule, Err);
if (!TME) {
cerr << "Did not get a target machine! Triplet is " << TargetTriple << '\n';
exit(1);
}
// Figure out the subtarget feature string we pass to the target.
std::string FeatureStr;
// The target can set LLVM_SET_SUBTARGET_FEATURES to configure the LLVM
// backend.
#ifdef LLVM_SET_SUBTARGET_FEATURES
SubtargetFeatures Features;
LLVM_SET_SUBTARGET_FEATURES(Features);
FeatureStr = Features.getString();
#endif
TheTarget = TME->CtorFn(*TheModule, FeatureStr);
assert(TheTarget->getTargetData()->isBigEndian() == BYTES_BIG_ENDIAN);
TheFolder = new TargetFolder(*TheTarget->getTargetData());
// Install information about target datalayout stuff into the module for
// optimizer use.
TheModule->setDataLayout(TheTarget->getTargetData()->
getStringRepresentation());
if (optimize)
RegisterRegAlloc::setDefault(createLinearScanRegisterAllocator);
else
RegisterRegAlloc::setDefault(createLocalRegisterAllocator);
// FIXME - Do not disable debug info while writing pch.
if (!flag_pch_file &&
debug_info_level > DINFO_LEVEL_NONE)
TheDebugInfo = new DebugInfo(TheModule);
}
/// Set backend options that may only be known at codegen time.
void performLateBackendInitialization(void) {
// The Ada front-end sets flag_exceptions only after processing the file.
ExceptionHandling = flag_exceptions;
}
void llvm_lang_dependent_init(const char *Name) {
if (TheDebugInfo)
TheDebugInfo->Initialize();
if (Name)
TheModule->setModuleIdentifier(Name);
}
oFILEstream *AsmOutStream = 0;
static raw_ostream *AsmOutRawStream = 0;
oFILEstream *AsmIntermediateOutStream = 0;
/// Read bytecode from PCH file. Initialize TheModule and setup
/// LTypes vector.
void llvm_pch_read(const unsigned char *Buffer, unsigned Size) {
std::string ModuleName = TheModule->getModuleIdentifier();
delete TheModule;
delete TheDebugInfo;
clearTargetBuiltinCache();
MemoryBuffer *MB = MemoryBuffer::getNewMemBuffer(Size, ModuleName.c_str());
memcpy((char*)MB->getBufferStart(), Buffer, Size);
std::string ErrMsg;
TheModule = ParseBitcodeFile(MB, &ErrMsg);
delete MB;
// FIXME - Do not disable debug info while writing pch.
if (!flag_pch_file && debug_info_level > DINFO_LEVEL_NONE) {
TheDebugInfo = new DebugInfo(TheModule);
TheDebugInfo->Initialize();
}
if (!TheModule) {
cerr << "Error reading bytecodes from PCH file\n";
cerr << ErrMsg << "\n";
exit(1);
}
if (PerFunctionPasses || PerModulePasses) {
destroyOptimizationPasses();
// Don't run codegen, when we should output PCH
if (flag_pch_file)
llvm_pch_write_init();
}
// Read LLVM Types string table
readLLVMTypesStringTable();
readLLVMValues();
flag_llvm_pch_read = 1;
}
// Initialize PCH writing.
void llvm_pch_write_init(void) {
timevar_push(TV_LLVM_INIT);
AsmOutStream = new oFILEstream(asm_out_file);
// FIXME: disentangle ostream madness here. Kill off ostream and FILE.
AsmOutRawStream = new raw_os_ostream(*AsmOutStream);
AsmOutFile = new OStream(*AsmOutStream);
PerModulePasses = new PassManager();
PerModulePasses->add(new TargetData(*TheTarget->getTargetData()));
// If writing to stdout, set binary mode.
if (asm_out_file == stdout)
sys::Program::ChangeStdoutToBinary();
// Emit an LLVM .bc file to the output. This is used when passed
// -emit-llvm -c to the GCC driver.
PerModulePasses->add(CreateBitcodeWriterPass(*AsmOutStream));
// Disable emission of .ident into the output file... which is completely
// wrong for llvm/.bc emission cases.
flag_no_ident = 1;
flag_llvm_pch_read = 0;
timevar_pop(TV_LLVM_INIT);
}
static void destroyOptimizationPasses() {
delete PerFunctionPasses;
delete PerModulePasses;
delete CodeGenPasses;
PerFunctionPasses = 0;
PerModulePasses = 0;
CodeGenPasses = 0;
}
static void createPerFunctionOptimizationPasses() {
if (PerFunctionPasses)
return;
// Create and set up the per-function pass manager.
// FIXME: Move the code generator to be function-at-a-time.
PerFunctionPasses =
new FunctionPassManager(new ExistingModuleProvider(TheModule));
PerFunctionPasses->add(new TargetData(*TheTarget->getTargetData()));
// In -O0 if checking is disabled, we don't even have per-function passes.
bool HasPerFunctionPasses = false;
#ifdef ENABLE_CHECKING
PerFunctionPasses->add(createVerifierPass());
HasPerFunctionPasses = true;
#endif
if (optimize > 0 && !DisableLLVMOptimizations) {
HasPerFunctionPasses = true;
PerFunctionPasses->add(createCFGSimplificationPass());
if (optimize == 1)
PerFunctionPasses->add(createPromoteMemoryToRegisterPass());
else
PerFunctionPasses->add(createScalarReplAggregatesPass());
PerFunctionPasses->add(createInstructionCombiningPass());
}
// If there are no module-level passes that have to be run, we codegen as
// each function is parsed.
// FIXME: We can't figure this out until we know there are no always-inline
// functions.
// FIXME: This is disabled right now until bugs can be worked out. Reenable
// this for fast -O0 compiles!
if (!emit_llvm_bc && !emit_llvm && 0) {
FunctionPassManager *PM = PerFunctionPasses;
HasPerFunctionPasses = true;
CodeGenOpt::Level OptLevel = CodeGenOpt::Default;
switch (optimize) {
default: break;
case 0: OptLevel = CodeGenOpt::None; break;
case 3: OptLevel = CodeGenOpt::Aggressive; break;
}
// Normal mode, emit a .s file by running the code generator.
// Note, this also adds codegenerator level optimization passes.
switch (TheTarget->addPassesToEmitFile(*PM, *AsmOutRawStream,
TargetMachine::AssemblyFile,
OptLevel)) {
default:
case FileModel::Error:
cerr << "Error interfacing to target machine!\n";
exit(1);
case FileModel::AsmFile:
break;
}
if (TheTarget->addPassesToEmitFileFinish(*PM, 0, OptLevel)) {
cerr << "Error interfacing to target machine!\n";
exit(1);
}
}
if (HasPerFunctionPasses) {
PerFunctionPasses->doInitialization();
} else {
delete PerFunctionPasses;
PerFunctionPasses = 0;
}
}
static void createPerModuleOptimizationPasses() {
if (PerModulePasses)
// llvm_pch_write_init has already created the per module passes.
return;
// FIXME: AT -O0/O1, we should stream out functions at a time.
PerModulePasses = new PassManager();
PerModulePasses->add(new TargetData(*TheTarget->getTargetData()));
bool HasPerModulePasses = false;
bool NeedAlwaysInliner = false;
if (flag_inline_trees <= 1) {
// If full inliner is not run, check if always-inline is needed to handle
// functions that are marked as always_inline.
for (Module::iterator I = TheModule->begin(), E = TheModule->end();
I != E; ++I)
if (I->hasFnAttr(Attribute::AlwaysInline)) {
NeedAlwaysInliner = true;
break;
}
}
if (!DisableLLVMOptimizations) {
HasPerModulePasses = true;
PassManager *PM = PerModulePasses;
if (optimize == 0) {
if (flag_inline_trees > 1) // respect -fno-inline-functions
PM->add(createFunctionInliningPass()); // Inline small functions
else if (NeedAlwaysInliner)
PM->add(createAlwaysInlinerPass()); // Inline always_inline funcs
} else {
if (flag_unit_at_a_time)
PM->add(createRaiseAllocationsPass()); // call %malloc -> malloc inst
PM->add(createCFGSimplificationPass()); // Clean up disgusting code
PM->add(createPromoteMemoryToRegisterPass()); // Kill useless allocas
if (flag_unit_at_a_time) {
PM->add(createGlobalOptimizerPass()); // Optimize out global vars
PM->add(createGlobalDCEPass()); // Remove unused fns and globs
PM->add(createIPConstantPropagationPass()); // IP Constant Propagation
PM->add(createDeadArgEliminationPass()); // Dead argument elimination
}
PM->add(createInstructionCombiningPass()); // Clean up after IPCP & DAE
PM->add(createCFGSimplificationPass()); // Clean up after IPCP & DAE
if (flag_unit_at_a_time) {
if (flag_exceptions)
PM->add(createPruneEHPass()); // Remove dead EH info
PM->add(createFunctionAttrsPass()); // Deduce function attrs
}
if (flag_inline_trees > 1) // respect -fno-inline-functions
PM->add(createFunctionInliningPass()); // Inline small functions
else if (NeedAlwaysInliner)
PM->add(createAlwaysInlinerPass()); // Inline always_inline funcs
if (optimize > 2)
PM->add(createArgumentPromotionPass()); // Scalarize uninlined fn args
if (!flag_no_simplify_libcalls)
PM->add(createSimplifyLibCallsPass()); // Library Call Optimizations
PM->add(createInstructionCombiningPass()); // Cleanup for scalarrepl.
PM->add(createJumpThreadingPass()); // Thread jumps.
PM->add(createCFGSimplificationPass()); // Merge & remove BBs
PM->add(createScalarReplAggregatesPass()); // Break up aggregate allocas
PM->add(createInstructionCombiningPass()); // Combine silly seq's
PM->add(createCondPropagationPass()); // Propagate conditionals
PM->add(createTailCallEliminationPass()); // Eliminate tail calls
PM->add(createCFGSimplificationPass()); // Merge & remove BBs
PM->add(createReassociatePass()); // Reassociate expressions
PM->add(createLoopRotatePass()); // Rotate Loop
PM->add(createLICMPass()); // Hoist loop invariants
// At -O2, loop unswitch should not increase code size.
PM->add(createLoopUnswitchPass(optimize_size || optimize < 3));
PM->add(createLoopIndexSplitPass()); // Split loop index
PM->add(createInstructionCombiningPass());
PM->add(createIndVarSimplifyPass()); // Canonicalize indvars
PM->add(createLoopDeletionPass()); // Delete dead loops
if (flag_unroll_loops)
PM->add(createLoopUnrollPass()); // Unroll small loops
PM->add(createInstructionCombiningPass()); // Clean up after the unroller
PM->add(createGVNPass()); // Remove redundancies
PM->add(createMemCpyOptPass()); // Remove memcpy / form memset
PM->add(createSCCPPass()); // Constant prop with SCCP
// Run instcombine after redundancy elimination to exploit opportunities
// opened up by them.
PM->add(createInstructionCombiningPass());
PM->add(createCondPropagationPass()); // Propagate conditionals
PM->add(createDeadStoreEliminationPass()); // Delete dead stores
PM->add(createAggressiveDCEPass()); // Delete dead instructions
PM->add(createCFGSimplificationPass()); // Merge & remove BBs
if (flag_unit_at_a_time) {
PM->add(createStripDeadPrototypesPass()); // Get rid of dead prototypes
PM->add(createDeadTypeEliminationPass()); // Eliminate dead types
}
if (optimize > 1 && flag_unit_at_a_time)
PM->add(createConstantMergePass()); // Merge dup global constants
}
}
if (emit_llvm_bc) {
// Emit an LLVM .bc file to the output. This is used when passed
// -emit-llvm -c to the GCC driver.
PerModulePasses->add(CreateBitcodeWriterPass(*AsmOutStream));
HasPerModulePasses = true;
} else if (emit_llvm) {
// Emit an LLVM .ll file to the output. This is used when passed
// -emit-llvm -S to the GCC driver.
PerModulePasses->add(createPrintModulePass(AsmOutRawStream));
HasPerModulePasses = true;
} else {
// If there are passes we have to run on the entire module, we do codegen
// as a separate "pass" after that happens.
// However if there are no module-level passes that have to be run, we
// codegen as each function is parsed.
// FIXME: This is disabled right now until bugs can be worked out. Reenable
// this for fast -O0 compiles!
if (PerModulePasses || 1) {
FunctionPassManager *PM = CodeGenPasses =
new FunctionPassManager(new ExistingModuleProvider(TheModule));
PM->add(new TargetData(*TheTarget->getTargetData()));
CodeGenOpt::Level OptLevel = CodeGenOpt::Default;
switch (optimize) {
default: break;
case 0: OptLevel = CodeGenOpt::None; break;
case 3: OptLevel = CodeGenOpt::Aggressive; break;
}
// Normal mode, emit a .s file by running the code generator.
// Note, this also adds codegenerator level optimization passes.
switch (TheTarget->addPassesToEmitFile(*PM, *AsmOutRawStream,
TargetMachine::AssemblyFile,
OptLevel)) {
default:
case FileModel::Error:
cerr << "Error interfacing to target machine!\n";
exit(1);
case FileModel::AsmFile:
break;
}
if (TheTarget->addPassesToEmitFileFinish(*PM, 0, OptLevel)) {
cerr << "Error interfacing to target machine!\n";
exit(1);
}
}
}
if (!HasPerModulePasses) {
delete PerModulePasses;
PerModulePasses = 0;
}
}
// llvm_asm_file_start - Start the .s file.
void llvm_asm_file_start(void) {
timevar_push(TV_LLVM_INIT);
AsmOutStream = new oFILEstream(asm_out_file);
// FIXME: disentangle ostream madness here. Kill off ostream and FILE.
AsmOutRawStream = new raw_os_ostream(*AsmOutStream);
AsmOutFile = new OStream(*AsmOutStream);
flag_llvm_pch_read = 0;
if (emit_llvm_bc || emit_llvm)
// Disable emission of .ident into the output file... which is completely
// wrong for llvm/.bc emission cases.
flag_no_ident = 1;
// If writing to stdout, set binary mode.
if (asm_out_file == stdout)
sys::Program::ChangeStdoutToBinary();
AttributeUsedGlobals.clear();
timevar_pop(TV_LLVM_INIT);
}
/// ConvertStructorsList - Convert a list of static ctors/dtors to an
/// initializer suitable for the llvm.global_[cd]tors globals.
static void CreateStructorsList(std::vector<std::pair<Constant*, int> > &Tors,
const char *Name) {
std::vector<Constant*> InitList;
std::vector<Constant*> StructInit;
StructInit.resize(2);
const Type *FPTy = FunctionType::get(Type::VoidTy, std::vector<const Type*>(),
false);
FPTy = PointerType::getUnqual(FPTy);
for (unsigned i = 0, e = Tors.size(); i != e; ++i) {
StructInit[0] = ConstantInt::get(Type::Int32Ty, Tors[i].second);
// __attribute__(constructor) can be on a function with any type. Make sure
// the pointer is void()*.
StructInit[1] = TheFolder->CreateBitCast(Tors[i].first, FPTy);
InitList.push_back(ConstantStruct::get(StructInit, false));
}
Constant *Array =
ConstantArray::get(ArrayType::get(InitList[0]->getType(), InitList.size()),
InitList);
new GlobalVariable(Array->getType(), false, GlobalValue::AppendingLinkage,
Array, Name, TheModule);
}
// llvm_asm_file_end - Finish the .s file.
void llvm_asm_file_end(void) {
timevar_push(TV_LLVM_PERFILE);
performLateBackendInitialization();
createPerFunctionOptimizationPasses();
if (flag_pch_file) {
writeLLVMTypesStringTable();
writeLLVMValues();
}
// Add an llvm.global_ctors global if needed.
if (!StaticCtors.empty())
CreateStructorsList(StaticCtors, "llvm.global_ctors");
// Add an llvm.global_dtors global if needed.
if (!StaticDtors.empty())
CreateStructorsList(StaticDtors, "llvm.global_dtors");
if (!AttributeUsedGlobals.empty()) {
std::vector<Constant *> AUGs;
const Type *SBP= PointerType::getUnqual(Type::Int8Ty);
for (SmallSetVector<Constant *,32>::iterator AI = AttributeUsedGlobals.begin(),
AE = AttributeUsedGlobals.end(); AI != AE; ++AI) {
Constant *C = *AI;
AUGs.push_back(TheFolder->CreateBitCast(C, SBP));
}
ArrayType *AT = ArrayType::get(SBP, AUGs.size());
Constant *Init = ConstantArray::get(AT, AUGs);
GlobalValue *gv = new GlobalVariable(AT, false,
GlobalValue::AppendingLinkage, Init,
"llvm.used", TheModule);
gv->setSection("llvm.metadata");
AttributeUsedGlobals.clear();
}
// Add llvm.global.annotations
if (!AttributeAnnotateGlobals.empty()) {
Constant *Array =
ConstantArray::get(ArrayType::get(AttributeAnnotateGlobals[0]->getType(),
AttributeAnnotateGlobals.size()),
AttributeAnnotateGlobals);
GlobalValue *gv = new GlobalVariable(Array->getType(), false,
GlobalValue::AppendingLinkage, Array,
"llvm.global.annotations", TheModule);
gv->setSection("llvm.metadata");
AttributeAnnotateGlobals.clear();
}
// Finish off the per-function pass.
if (PerFunctionPasses)
PerFunctionPasses->doFinalization();
// Emit intermediate file before module level optimization passes are run.
if (flag_debug_llvm_module_opt) {
static PassManager *IntermediatePM = new PassManager();
IntermediatePM->add(new TargetData(*TheTarget->getTargetData()));
char asm_intermediate_out_filename[MAXPATHLEN];
strcpy(&asm_intermediate_out_filename[0], asm_file_name);
strcat(&asm_intermediate_out_filename[0],".0");
FILE *asm_intermediate_out_file = fopen(asm_intermediate_out_filename, "w+b");
AsmIntermediateOutStream = new oFILEstream(asm_intermediate_out_file);
AsmIntermediateOutFile = new OStream(*AsmIntermediateOutStream);
raw_ostream *AsmIntermediateRawOutStream =
new raw_os_ostream(*AsmIntermediateOutStream);
if (emit_llvm_bc)
IntermediatePM->add(CreateBitcodeWriterPass(*AsmIntermediateOutStream));
if (emit_llvm)
IntermediatePM->add(createPrintModulePass(AsmIntermediateRawOutStream));
IntermediatePM->run(*TheModule);
AsmIntermediateRawOutStream->flush();
delete AsmIntermediateRawOutStream;
AsmIntermediateRawOutStream = 0;
AsmIntermediateOutStream->flush();
fflush(asm_intermediate_out_file);
delete AsmIntermediateOutStream;
AsmIntermediateOutStream = 0;
delete AsmIntermediateOutFile;
AsmIntermediateOutFile = 0;
}
// Run module-level optimizers, if any are present.
createPerModuleOptimizationPasses();
if (PerModulePasses)
PerModulePasses->run(*TheModule);
// Run the code generator, if present.
if (CodeGenPasses) {
CodeGenPasses->doInitialization();
for (Module::iterator I = TheModule->begin(), E = TheModule->end();
I != E; ++I)
if (!I->isDeclaration())
CodeGenPasses->run(*I);
CodeGenPasses->doFinalization();
}
AsmOutRawStream->flush();
AsmOutStream->flush();
fflush(asm_out_file);
delete AsmOutRawStream;
AsmOutRawStream = 0;
delete AsmOutStream;
AsmOutStream = 0;
delete AsmOutFile;
AsmOutFile = 0;
timevar_pop(TV_LLVM_PERFILE);
}
// llvm_call_llvm_shutdown - Release LLVM global state.
void llvm_call_llvm_shutdown(void) {
llvm_shutdown();
}
// llvm_emit_code_for_current_function - Top level interface for emitting a
// function to the .s file.
void llvm_emit_code_for_current_function(tree fndecl) {
if (cfun->nonlocal_goto_save_area)
sorry("%Jnon-local gotos not supported by LLVM", fndecl);
if (errorcount || sorrycount) {
TREE_ASM_WRITTEN(fndecl) = 1;
return; // Do not process broken code.
}
timevar_push(TV_LLVM_FUNCS);
// Convert the AST to raw/ugly LLVM code.
Function *Fn;
{
TreeToLLVM Emitter(fndecl);
enum symbol_visibility vis = DECL_VISIBILITY (fndecl);
if (vis != VISIBILITY_DEFAULT)
// "asm_out.visibility" emits an important warning if we're using a
// visibility that's not supported by the target.
targetm.asm_out.visibility(fndecl, vis);
Fn = Emitter.EmitFunction();
}
#if 0
if (dump_file) {
fprintf (dump_file,
"\n\n;;\n;; Full LLVM generated for this function:\n;;\n");
Fn->dump();
}
#endif
performLateBackendInitialization();
createPerFunctionOptimizationPasses();
if (PerFunctionPasses)
PerFunctionPasses->run(*Fn);
// TODO: Nuke the .ll code for the function at -O[01] if we don't want to
// inline it or something else.
// There's no need to defer outputting this function any more; we
// know we want to output it.
DECL_DEFER_OUTPUT(fndecl) = 0;
// Finally, we have written out this function!
TREE_ASM_WRITTEN(fndecl) = 1;
timevar_pop(TV_LLVM_FUNCS);
}
// emit_alias_to_llvm - Given decl and target emit alias to target.
void emit_alias_to_llvm(tree decl, tree target, tree target_decl) {
if (errorcount || sorrycount) {
TREE_ASM_WRITTEN(decl) = 1;
return; // Do not process broken code.
}
timevar_push(TV_LLVM_GLOBALS);
// Get or create LLVM global for our alias.
GlobalValue *V = cast<GlobalValue>(DECL_LLVM(decl));
GlobalValue *Aliasee = NULL;
if (target_decl)
Aliasee = cast<GlobalValue>(DECL_LLVM(target_decl));
else {
// This is something insane. Probably only LTHUNKs can be here
// Try to grab decl from IDENTIFIER_NODE
// Query SymTab for aliasee
const char* AliaseeName = IDENTIFIER_POINTER(target);
Aliasee =
dyn_cast_or_null<GlobalValue>(TheModule->
getValueSymbolTable().lookup(AliaseeName));
// Last resort. Query for name set via __asm__
if (!Aliasee) {
std::string starred = std::string("\001") + AliaseeName;
Aliasee =
dyn_cast_or_null<GlobalValue>(TheModule->
getValueSymbolTable().lookup(starred));
}
if (!Aliasee) {
if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl))) {
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V))
Aliasee = new GlobalVariable(GV->getType(), GV->isConstant(),
GlobalVariable::ExternalWeakLinkage,
NULL, AliaseeName, TheModule);
else if (Function *F = dyn_cast<Function>(V))
Aliasee = Function::Create(F->getFunctionType(),
Function::ExternalWeakLinkage,
AliaseeName, TheModule);
else
assert(0 && "Unsuported global value");
} else {
error ("%J%qD aliased to undefined symbol %qs", decl, decl, AliaseeName);
timevar_pop(TV_LLVM_GLOBALS);
return;
}
}
}
GlobalValue::LinkageTypes Linkage;
// A weak alias has TREE_PUBLIC set but not the other bits.
if (DECL_LLVM_PRIVATE(decl))
Linkage = GlobalValue::PrivateLinkage;
else if (DECL_WEAK(decl))
// The user may have explicitly asked for weak linkage - ignore flag_odr.
Linkage = GlobalValue::WeakAnyLinkage;
else if (!TREE_PUBLIC(decl))
Linkage = GlobalValue::InternalLinkage;
else
Linkage = GlobalValue::ExternalLinkage;
GlobalAlias* GA = new GlobalAlias(Aliasee->getType(), Linkage, "",
Aliasee, TheModule);
handleVisibility(decl, GA);
if (GA->getType()->canLosslesslyBitCastTo(V->getType()))
V->replaceAllUsesWith(ConstantExpr::getBitCast(GA, V->getType()));
else if (!V->use_empty()) {
error ("%J Alias %qD used with invalid type!", decl, decl);
timevar_pop(TV_LLVM_GLOBALS);
return;
}
changeLLVMConstant(V, GA);
GA->takeName(V);
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V))
GV->eraseFromParent();
else if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V))
GA->eraseFromParent();
else if (Function *F = dyn_cast<Function>(V))
F->eraseFromParent();
else
assert(0 && "Unsuported global value");
TREE_ASM_WRITTEN(decl) = 1;
timevar_pop(TV_LLVM_GLOBALS);
return;
}
// Convert string to global value. Use existing global if possible.
Constant* ConvertMetadataStringToGV(const char *str) {
Constant *Init = ConstantArray::get(std::string(str));
// Use cached string if it exists.
static std::map<Constant*, GlobalVariable*> StringCSTCache;
GlobalVariable *&Slot = StringCSTCache[Init];
if (Slot) return Slot;
// Create a new string global.
GlobalVariable *GV = new GlobalVariable(Init->getType(), true,
GlobalVariable::InternalLinkage,
Init, ".str", TheModule);
GV->setSection("llvm.metadata");
Slot = GV;
return GV;
}
/// AddAnnotateAttrsToGlobal - Adds decls that have a
/// annotate attribute to a vector to be emitted later.
void AddAnnotateAttrsToGlobal(GlobalValue *GV, tree decl) {
// Handle annotate attribute on global.
tree annotateAttr = lookup_attribute("annotate", DECL_ATTRIBUTES (decl));
if (annotateAttr == 0)
return;
// Get file and line number
Constant *lineNo = ConstantInt::get(Type::Int32Ty, DECL_SOURCE_LINE(decl));
Constant *file = ConvertMetadataStringToGV(DECL_SOURCE_FILE(decl));
const Type *SBP= PointerType::getUnqual(Type::Int8Ty);
file = TheFolder->CreateBitCast(file, SBP);
// There may be multiple annotate attributes. Pass return of lookup_attr
// to successive lookups.
while (annotateAttr) {
// Each annotate attribute is a tree list.
// Get value of list which is our linked list of args.
tree args = TREE_VALUE(annotateAttr);
// Each annotate attribute may have multiple args.
// Treat each arg as if it were a separate annotate attribute.
for (tree a = args; a; a = TREE_CHAIN(a)) {
// Each element of the arg list is a tree list, so get value
tree val = TREE_VALUE(a);
// Assert its a string, and then get that string.
assert(TREE_CODE(val) == STRING_CST &&
"Annotate attribute arg should always be a string");
Constant *strGV = TreeConstantToLLVM::EmitLV_STRING_CST(val);
Constant *Element[4] = {
TheFolder->CreateBitCast(GV,SBP),
TheFolder->CreateBitCast(strGV,SBP),
file,
lineNo
};
AttributeAnnotateGlobals.push_back(ConstantStruct::get(Element, 4, false));
}
// Get next annotate attribute.
annotateAttr = TREE_CHAIN(annotateAttr);
if (annotateAttr)
annotateAttr = lookup_attribute("annotate", annotateAttr);
}
}
/// reset_initializer_llvm - Change the initializer for a global variable.
void reset_initializer_llvm(tree decl) {
// If there were earlier errors we can get here when DECL_LLVM has not
// been set. Don't crash.
// We can also get here when DECL_LLVM has not been set for some object
// referenced in the initializer. Don't crash then either.
if (errorcount || sorrycount)
return;
// Get or create the global variable now.
GlobalVariable *GV = cast<GlobalVariable>(DECL_LLVM(decl));
// Visibility may also have changed.
handleVisibility(decl, GV);
// Convert the initializer over.
Constant *Init = TreeConstantToLLVM::Convert(DECL_INITIAL(decl));
// Set the initializer.
GV->setInitializer(Init);
}
/// reset_type_and_initializer_llvm - Change the type and initializer for
/// a global variable.
void reset_type_and_initializer_llvm(tree decl) {
// If there were earlier errors we can get here when DECL_LLVM has not
// been set. Don't crash.
// We can also get here when DECL_LLVM has not been set for some object
// referenced in the initializer. Don't crash then either.
if (errorcount || sorrycount)
return;
// Get or create the global variable now.
GlobalVariable *GV = cast<GlobalVariable>(DECL_LLVM(decl));
// Visibility may also have changed.
handleVisibility(decl, GV);
// Temporary to avoid infinite recursion (see comments emit_global_to_llvm)
GV->setInitializer(UndefValue::get(GV->getType()->getElementType()));
// Convert the initializer over.
Constant *Init = TreeConstantToLLVM::Convert(DECL_INITIAL(decl));
// If we had a forward definition that has a type that disagrees with our
// initializer, insert a cast now. This sort of thing occurs when we have a
// global union, and the LLVM type followed a union initializer that is
// different from the union element used for the type.
if (GV->getType()->getElementType() != Init->getType()) {
GV->removeFromParent();
GlobalVariable *NGV = new GlobalVariable(Init->getType(), GV->isConstant(),
GV->getLinkage(), 0,
GV->getName(), TheModule);
NGV->setVisibility(GV->getVisibility());
NGV->setSection(GV->getSection());
NGV->setAlignment(GV->getAlignment());
GV->replaceAllUsesWith(TheFolder->CreateBitCast(NGV, GV->getType()));
changeLLVMConstant(GV, NGV);
delete GV;
SET_DECL_LLVM(decl, NGV);
GV = NGV;
}
// Set the initializer.
GV->setInitializer(Init);
}
/// emit_global_to_llvm - Emit the specified VAR_DECL or aggregate CONST_DECL to
/// LLVM as a global variable. This function implements the end of
/// assemble_variable.
void emit_global_to_llvm(tree decl) {
if (errorcount || sorrycount) {
TREE_ASM_WRITTEN(decl) = 1;
return; // Do not process broken code.
}
// FIXME: Support alignment on globals: DECL_ALIGN.
// FIXME: DECL_PRESERVE_P indicates the var is marked with attribute 'used'.
// Global register variables don't turn into LLVM GlobalVariables.
if (TREE_CODE(decl) == VAR_DECL && DECL_REGISTER(decl))
return;
// If tree nodes says defer output then do not emit global yet.
if (CODE_CONTAINS_STRUCT (TREE_CODE (decl), TS_DECL_WITH_VIS)
&& (DECL_DEFER_OUTPUT(decl)))
return;
// If we encounter a forward declaration then do not emit the global yet.
if (!TYPE_SIZE(TREE_TYPE(decl)))
return;
timevar_push(TV_LLVM_GLOBALS);
// Get or create the global variable now.
GlobalVariable *GV = cast<GlobalVariable>(DECL_LLVM(decl));
// Convert the initializer over.
Constant *Init;
if (DECL_INITIAL(decl) == 0 || DECL_INITIAL(decl) == error_mark_node) {
// This global should be zero initialized. Reconvert the type in case the
// forward def of the global and the real def differ in type (e.g. declared
// as 'int A[]', and defined as 'int A[100]').
Init = Constant::getNullValue(ConvertType(TREE_TYPE(decl)));
} else {
assert((TREE_CONSTANT(DECL_INITIAL(decl)) ||
TREE_CODE(DECL_INITIAL(decl)) == STRING_CST) &&
"Global initializer should be constant!");
// Temporarily set an initializer for the global, so we don't infinitely
// recurse. If we don't do this, we can hit cases where we see "oh a global
// with an initializer hasn't been initialized yet, call emit_global_to_llvm
// on it". When constructing the initializer it might refer to itself.
// this can happen for things like void *G = &G;
//
GV->setInitializer(UndefValue::get(GV->getType()->getElementType()));
Init = TreeConstantToLLVM::Convert(DECL_INITIAL(decl));
}
// If we had a forward definition that has a type that disagrees with our
// initializer, insert a cast now. This sort of thing occurs when we have a
// global union, and the LLVM type followed a union initializer that is
// different from the union element used for the type.
if (GV->getType()->getElementType() != Init->getType()) {
GV->removeFromParent();
GlobalVariable *NGV = new GlobalVariable(Init->getType(), GV->isConstant(),
GlobalValue::ExternalLinkage, 0,
GV->getName(), TheModule);
GV->replaceAllUsesWith(TheFolder->CreateBitCast(NGV, GV->getType()));
changeLLVMConstant(GV, NGV);
delete GV;
SET_DECL_LLVM(decl, NGV);
GV = NGV;
}
// Set the initializer.
GV->setInitializer(Init);
// Set thread local (TLS)
if (TREE_CODE(decl) == VAR_DECL && DECL_THREAD_LOCAL_P(decl))
GV->setThreadLocal(true);
// Set the linkage.
GlobalValue::LinkageTypes Linkage = GV->getLinkage();
if (CODE_CONTAINS_STRUCT (TREE_CODE (decl), TS_DECL_WITH_VIS)
&& DECL_LLVM_PRIVATE(decl)) {
Linkage = GlobalValue::PrivateLinkage;
} else if (!TREE_PUBLIC(decl)) {
Linkage = GlobalValue::InternalLinkage;
} else if (DECL_WEAK(decl)) {
// The user may have explicitly asked for weak linkage - ignore flag_odr.
Linkage = GlobalValue::WeakAnyLinkage;
} else if (DECL_ONE_ONLY(decl)) {
Linkage = GlobalValue::getWeakLinkage(flag_odr);
} else if (DECL_COMMON(decl) && // DECL_COMMON is only meaningful if no init
(!DECL_INITIAL(decl) || DECL_INITIAL(decl) == error_mark_node)) {
// llvm-gcc also includes DECL_VIRTUAL_P here.
Linkage = GlobalValue::CommonLinkage;
} else if (DECL_COMDAT(decl)) {
Linkage = GlobalValue::getLinkOnceLinkage(flag_odr);
}
// Allow loads from constants to be folded even if the constant has weak
// linkage. Do this by giving the constant weak_odr linkage rather than
// weak linkage. It is not clear whether this optimization is valid (see
// gcc bug 36685), but mainline gcc chooses to do it, and fold may already
// have done it, so we might as well join in with gusto.
if (GV->isConstant()) {
if (Linkage == GlobalValue::WeakAnyLinkage)
Linkage = GlobalValue::WeakODRLinkage;
else if (Linkage == GlobalValue::LinkOnceAnyLinkage)
Linkage = GlobalValue::LinkOnceODRLinkage;
}
GV->setLinkage(Linkage);
#ifdef TARGET_ADJUST_LLVM_LINKAGE
TARGET_ADJUST_LLVM_LINKAGE(GV, decl);
#endif /* TARGET_ADJUST_LLVM_LINKAGE */
handleVisibility(decl, GV);
// Set the section for the global.
if (TREE_CODE(decl) == VAR_DECL) {
if (DECL_SECTION_NAME(decl)) {
GV->setSection(TREE_STRING_POINTER(DECL_SECTION_NAME(decl)));
#ifdef LLVM_IMPLICIT_TARGET_GLOBAL_VAR_SECTION
} else if (const char *Section =
LLVM_IMPLICIT_TARGET_GLOBAL_VAR_SECTION(decl)) {
GV->setSection(Section);
#endif
}
// Set the alignment for the global if one of the following condition is met
// 1) DECL_ALIGN is better than the alignment as per ABI specification
// 2) DECL_ALIGN is set by user.
if (DECL_ALIGN(decl)) {
unsigned TargetAlign =
getTargetData().getABITypeAlignment(GV->getType()->getElementType());
if (DECL_USER_ALIGN(decl) ||
8 * TargetAlign < (unsigned)DECL_ALIGN(decl))
GV->setAlignment(DECL_ALIGN(decl) / 8);
}
// Handle used decls
if (DECL_PRESERVE_P (decl))
AttributeUsedGlobals.insert(GV);
// Add annotate attributes for globals
if (DECL_ATTRIBUTES(decl))
AddAnnotateAttrsToGlobal(GV, decl);
#ifdef LLVM_IMPLICIT_TARGET_GLOBAL_VAR_SECTION
} else if (TREE_CODE(decl) == CONST_DECL) {
if (const char *Section =
LLVM_IMPLICIT_TARGET_GLOBAL_VAR_SECTION(decl)) {
GV->setSection(Section);
/* LLVM LOCAL - begin radar 6389998 */
#ifdef TARGET_ADJUST_CFSTRING_NAME
TARGET_ADJUST_CFSTRING_NAME(GV, Section);
#endif
/* LLVM LOCAL - end radar 6389998 */
}
#endif
}
// No debug info for globals when optimization is on. While this is
// something that would be accurate and useful to a user, it currently
// affects some optimizations that, e.g., count uses.
if (TheDebugInfo && !optimize) {
const char *Name = GV->getName().c_str();
const char LPrefix[] = "\01L_OBJC_";
const char lPrefix[] = "\01l_OBJC_";
if (flag_objc_abi == -1 || flag_objc_abi == 0 ||
(strncmp(Name, LPrefix, sizeof(LPrefix) - 1) != 0 &&
strncmp(Name, lPrefix, sizeof(lPrefix) - 1) != 0))
TheDebugInfo->EmitGlobalVariable(GV, decl);
}
TREE_ASM_WRITTEN(decl) = 1;
timevar_pop(TV_LLVM_GLOBALS);
}
/// ValidateRegisterVariable - Check that a static "asm" variable is
/// well-formed. If not, emit error messages and return true. If so, return
/// false.
bool ValidateRegisterVariable(tree decl) {
int RegNumber = decode_reg_name(extractRegisterName(decl));
const Type *Ty = ConvertType(TREE_TYPE(decl));
// If this has already been processed, don't emit duplicate error messages.
if (DECL_LLVM_SET_P(decl)) {
// Error state encoded into DECL_LLVM.
return cast<ConstantInt>(DECL_LLVM(decl))->getZExtValue();
}
/* Detect errors in declaring global registers. */
if (RegNumber == -1)
error("%Jregister name not specified for %qD", decl, decl);
else if (RegNumber < 0)
error("%Jinvalid register name for %qD", decl, decl);
else if (TYPE_MODE(TREE_TYPE(decl)) == BLKmode)
error("%Jdata type of %qD isn%'t suitable for a register", decl, decl);
#if 0 // FIXME: enable this.
else if (!HARD_REGNO_MODE_OK(RegNumber, TYPE_MODE(TREE_TYPE(decl))))
error("%Jregister specified for %qD isn%'t suitable for data type",
decl, decl);
#endif
else if (DECL_INITIAL(decl) != 0 && TREE_STATIC(decl))
error("global register variable has initial value");
else if (!Ty->isSingleValueType())
sorry("%JLLVM cannot handle register variable %qD, report a bug",
decl, decl);
else {
if (TREE_THIS_VOLATILE(decl))
warning(0, "volatile register variables don%'t work as you might wish");
SET_DECL_LLVM(decl, ConstantInt::getFalse());
return false; // Everything ok.
}
SET_DECL_LLVM(decl, ConstantInt::getTrue());
return true;
}
// make_decl_llvm - Create the DECL_RTL for a VAR_DECL or FUNCTION_DECL. DECL
// should have static storage duration. In other words, it should not be an
// automatic variable, including PARM_DECLs.
//
// There is, however, one exception: this function handles variables explicitly
// placed in a particular register by the user.
//
// This function corresponds to make_decl_rtl in varasm.c, and is implicitly
// called by DECL_LLVM if a decl doesn't have an LLVM set.
//
void make_decl_llvm(tree decl) {
#ifdef ENABLE_CHECKING
// Check that we are not being given an automatic variable.
// A weak alias has TREE_PUBLIC set but not the other bits.
if (TREE_CODE(decl) == PARM_DECL || TREE_CODE(decl) == RESULT_DECL
|| (TREE_CODE(decl) == VAR_DECL && !TREE_STATIC(decl) &&
!TREE_PUBLIC(decl) && !DECL_EXTERNAL(decl) && !DECL_REGISTER(decl)))
abort();
// And that we were not given a type or a label. */
else if (TREE_CODE(decl) == TYPE_DECL || TREE_CODE(decl) == LABEL_DECL)
abort ();
#endif
// For a duplicate declaration, we can be called twice on the
// same DECL node. Don't discard the LLVM already made.
if (DECL_LLVM_SET_P(decl)) return;
if (errorcount || sorrycount)
return; // Do not process broken code.
// Global register variable with asm name, e.g.:
// register unsigned long esp __asm__("ebp");
if (TREE_CODE(decl) != FUNCTION_DECL && DECL_REGISTER(decl)) {
// This just verifies that the variable is ok. The actual "load/store"
// code paths handle accesses to the variable.
ValidateRegisterVariable(decl);
return;
}
timevar_push(TV_LLVM_GLOBALS);
const char *Name = "";
if (DECL_NAME(decl))
if (tree AssemblerName = DECL_ASSEMBLER_NAME(decl))
Name = IDENTIFIER_POINTER(AssemblerName);
// Now handle ordinary static variables and functions (in memory).
// Also handle vars declared register invalidly.
if (Name[0] == 1) {
#ifdef REGISTER_PREFIX
if (strlen (REGISTER_PREFIX) != 0) {
int reg_number = decode_reg_name(Name);
if (reg_number >= 0 || reg_number == -3)
error("%Jregister name given for non-register variable %qD",
decl, decl);
}
#endif
}
// Specifying a section attribute on a variable forces it into a
// non-.bss section, and thus it cannot be common.
if (TREE_CODE(decl) == VAR_DECL && DECL_SECTION_NAME(decl) != NULL_TREE &&
DECL_INITIAL(decl) == NULL_TREE && DECL_COMMON(decl))
DECL_COMMON(decl) = 0;
// Variables can't be both common and weak.
if (TREE_CODE(decl) == VAR_DECL && DECL_WEAK(decl))
DECL_COMMON(decl) = 0;
// Okay, now we need to create an LLVM global variable or function for this
// object. Note that this is quite possibly a forward reference to the
// object, so its type may change later.
if (TREE_CODE(decl) == FUNCTION_DECL) {
assert(Name[0] && "Function with empty name!");
// If this function has already been created, reuse the decl. This happens
// when we have something like __builtin_memset and memset in the same file.
Function *FnEntry = TheModule->getFunction(Name);
if (FnEntry == 0) {
unsigned CC;
AttrListPtr PAL;
const FunctionType *Ty =
TheTypeConverter->ConvertFunctionType(TREE_TYPE(decl), decl, NULL,
CC, PAL);
FnEntry = Function::Create(Ty, Function::ExternalLinkage, Name, TheModule);
FnEntry->setCallingConv(CC);
FnEntry->setAttributes(PAL);
// Check for external weak linkage.
if (DECL_EXTERNAL(decl) && DECL_WEAK(decl))
FnEntry->setLinkage(Function::ExternalWeakLinkage);
#ifdef TARGET_ADJUST_LLVM_LINKAGE
TARGET_ADJUST_LLVM_LINKAGE(FnEntry,decl);
#endif /* TARGET_ADJUST_LLVM_LINKAGE */
handleVisibility(decl, FnEntry);
// If FnEntry got renamed, then there is already an object with this name
// in the symbol table. If this happens, the old one must be a forward
// decl, just replace it with a cast of the new one.
if (FnEntry->getName() != Name) {
GlobalVariable *G = TheModule->getGlobalVariable(Name, true);
assert(G && G->isDeclaration() && "A global turned into a function?");
// Replace any uses of "G" with uses of FnEntry.
Constant *GInNewType = TheFolder->CreateBitCast(FnEntry, G->getType());
G->replaceAllUsesWith(GInNewType);
// Update the decl that points to G.
changeLLVMConstant(G, GInNewType);
// Now we can give GV the proper name.
FnEntry->takeName(G);
// G is now dead, nuke it.
G->eraseFromParent();
}
}
SET_DECL_LLVM(decl, FnEntry);
} else {
assert((TREE_CODE(decl) == VAR_DECL ||
TREE_CODE(decl) == CONST_DECL) && "Not a function or var decl?");
const Type *Ty = ConvertType(TREE_TYPE(decl));
GlobalVariable *GV ;
// If we have "extern void foo", make the global have type {} instead of
// type void.
if (Ty == Type::VoidTy) Ty = StructType::get(NULL, NULL);
if (Name[0] == 0) { // Global has no name.
GV = new GlobalVariable(Ty, false, GlobalValue::ExternalLinkage, 0,
"", TheModule);
// Check for external weak linkage.
if (DECL_EXTERNAL(decl) && DECL_WEAK(decl))
GV->setLinkage(GlobalValue::ExternalWeakLinkage);
#ifdef TARGET_ADJUST_LLVM_LINKAGE
TARGET_ADJUST_LLVM_LINKAGE(GV,decl);
#endif /* TARGET_ADJUST_LLVM_LINKAGE */
handleVisibility(decl, GV);
} else {
// If the global has a name, prevent multiple vars with the same name from
// being created.
GlobalVariable *GVE = TheModule->getGlobalVariable(Name, true);
if (GVE == 0) {
GV = new GlobalVariable(Ty, false, GlobalValue::ExternalLinkage,0,
Name, TheModule);
// Check for external weak linkage.
if (DECL_EXTERNAL(decl) && DECL_WEAK(decl))
GV->setLinkage(GlobalValue::ExternalWeakLinkage);
#ifdef TARGET_ADJUST_LLVM_LINKAGE
TARGET_ADJUST_LLVM_LINKAGE(GV,decl);
#endif /* TARGET_ADJUST_LLVM_LINKAGE */
handleVisibility(decl, GV);
// If GV got renamed, then there is already an object with this name in
// the symbol table. If this happens, the old one must be a forward
// decl, just replace it with a cast of the new one.
if (GV->getName() != Name) {
Function *F = TheModule->getFunction(Name);
assert(F && F->isDeclaration() && "A function turned into a global?");
// Replace any uses of "F" with uses of GV.
Constant *FInNewType = TheFolder->CreateBitCast(GV, F->getType());
F->replaceAllUsesWith(FInNewType);
// Update the decl that points to F.
changeLLVMConstant(F, FInNewType);
// Now we can give GV the proper name.
GV->takeName(F);
// F is now dead, nuke it.
F->eraseFromParent();
}
} else {
GV = GVE; // Global already created, reuse it.
}
}
if ((TREE_READONLY(decl) && !TREE_SIDE_EFFECTS(decl)) ||
TREE_CODE(decl) == CONST_DECL) {
if (DECL_EXTERNAL(decl)) {
// Mark external globals constant even though they could be marked
// non-constant in the defining translation unit. The definition of the
// global determines whether the global is ultimately constant or not,
// marking this constant will allow us to do some extra (legal)
// optimizations that we would otherwise not be able to do. (In C++,
// any global that is 'C++ const' may not be readonly: it could have a
// dynamic initializer.
//
GV->setConstant(true);
} else {
// Mark readonly globals with constant initializers constant.
if (DECL_INITIAL(decl) != error_mark_node && // uninitialized?
DECL_INITIAL(decl) &&
(TREE_CONSTANT(DECL_INITIAL(decl)) ||
TREE_CODE(DECL_INITIAL(decl)) == STRING_CST))
GV->setConstant(true);
}
}
// Set thread local (TLS)
if (TREE_CODE(decl) == VAR_DECL && DECL_THREAD_LOCAL_P(decl))
GV->setThreadLocal(true);
SET_DECL_LLVM(decl, GV);
}
timevar_pop(TV_LLVM_GLOBALS);
}
/// llvm_get_decl_name - Used by varasm.c, returns the specified declaration's
/// name.
const char *llvm_get_decl_name(void *LLVM) {
if (LLVM)
if (const ValueName *VN = ((Value*)LLVM)->getValueName())
return VN->getKeyData();
return "";
}
// llvm_mark_decl_weak - Used by varasm.c, called when a decl is found to be
// weak, but it already had an llvm object created for it. This marks the LLVM
// object weak as well.
void llvm_mark_decl_weak(tree decl) {
assert(DECL_LLVM_SET_P(decl) && DECL_WEAK(decl) &&
isa<GlobalValue>(DECL_LLVM(decl)) && "Decl isn't marked weak!");
GlobalValue *GV = cast<GlobalValue>(DECL_LLVM(decl));
// Do not mark something that is already known to be linkonce or internal.
// The user may have explicitly asked for weak linkage - ignore flag_odr.
if (GV->hasExternalLinkage()) {
GlobalValue::LinkageTypes Linkage;
if (GV->isDeclaration()) {
Linkage = GlobalValue::ExternalWeakLinkage;
} else {
Linkage = GlobalValue::WeakAnyLinkage;
// Allow loads from constants to be folded even if the constant has weak
// linkage. Do this by giving the constant weak_odr linkage rather than
// weak linkage. It is not clear whether this optimization is valid (see
// gcc bug 36685), but mainline gcc chooses to do it, and fold may already
// have done it, so we might as well join in with gusto.
if (GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
if (GVar->isConstant())
Linkage = GlobalValue::WeakODRLinkage;
}
GV->setLinkage(Linkage);
}
}
// llvm_emit_ctor_dtor - Called to emit static ctors/dtors to LLVM code. fndecl
// is a 'void()' FUNCTION_DECL for the code, initprio is the init priority, and
// isCtor indicates whether this is a ctor or dtor.
//
void llvm_emit_ctor_dtor(tree FnDecl, int InitPrio, int isCtor) {
mark_decl_referenced(FnDecl); // Inform cgraph that we used the global.
if (errorcount || sorrycount) return;
Constant *C = cast<Constant>(DECL_LLVM(FnDecl));
(isCtor ? &StaticCtors:&StaticDtors)->push_back(std::make_pair(C, InitPrio));
}
void llvm_emit_typedef(tree decl) {
// Need hooks for debug info?
return;
}
// llvm_emit_file_scope_asm - Emit the specified string as a file-scope inline
// asm block.
//
void llvm_emit_file_scope_asm(const char *string) {
if (TheModule->getModuleInlineAsm().empty())
TheModule->setModuleInlineAsm(string);
else
TheModule->setModuleInlineAsm(TheModule->getModuleInlineAsm() + "\n" +
string);
}
// print_llvm - Print the specified LLVM chunk like an operand, called by
// print-tree.c for tree dumps.
//
void print_llvm(FILE *file, void *LLVM) {
oFILEstream FS(file);
FS << "LLVM: ";
WriteAsOperand(FS, (Value*)LLVM, true, TheModule);
}
// print_llvm_type - Print the specified LLVM type symbolically, called by
// print-tree.c for tree dumps.
//
void print_llvm_type(FILE *file, void *LLVM) {
oFILEstream FS(file);
FS << "LLVM: ";
// FIXME: oFILEstream can probably be removed in favor of a new raw_ostream
// adaptor which would be simpler and more efficient. In the meantime, just
// adapt the adaptor.
raw_os_ostream RO(FS);
WriteTypeSymbolic(RO, (const Type*)LLVM, TheModule);
}
// Get a register name given its decl. In 4.2 unlike 4.0 these names
// have been run through set_user_assembler_name which means they may
// have a leading \1 at this point; compensate.
const char* extractRegisterName(tree decl) {
const char* Name = IDENTIFIER_POINTER(DECL_ASSEMBLER_NAME(decl));
return (*Name==1) ? Name+1 : Name;
}
/* LLVM LOCAL end (ENTIRE FILE!) */