void AsmBlockStatement::toIR(IRState* p)
{
Logger::println("AsmBlockStatement::toIR(): %s", loc.toChars());
LOG_SCOPE;
// disable inlining by default
if (!p->func()->decl->allowInlining)
p->func()->setNeverInline();
// create asm block structure
assert(!p->asmBlock);
IRAsmBlock* asmblock = new IRAsmBlock(this);
assert(asmblock);
p->asmBlock = asmblock;
// do asm statements
for (unsigned i=0; i<statements->dim; i++)
{
Statement* s = static_cast<Statement*>(statements->data[i]);
if (s) {
s->toIR(p);
}
}
// build forwarder for in-asm branches to external labels
// this additional asm code sets the __llvm_jump_target variable
// to a unique value that will identify the jump target in
// a post-asm switch
// maps each goto destination to its special value
std::map<Identifier*, int> gotoToVal;
// location of the special value determining the goto label
// will be set if post-asm dispatcher block is needed
llvm::AllocaInst* jump_target = 0;
{
FuncDeclaration* fd = gIR->func()->decl;
const char* fdmangle = fd->mangle();
// we use a simple static counter to make sure the new end labels are unique
static size_t uniqueLabelsId = 0;
std::ostringstream asmGotoEndLabel;
printLabelName(asmGotoEndLabel, fdmangle, "_llvm_asm_end");
asmGotoEndLabel << uniqueLabelsId++;
// initialize the setter statement we're going to build
IRAsmStmt* outSetterStmt = new IRAsmStmt;
std::string asmGotoEnd = "\n\tjmp "+asmGotoEndLabel.str()+"\n";
std::ostringstream code;
code << asmGotoEnd;
int n_goto = 1;
size_t n = asmblock->s.size();
for(size_t i=0; i<n; ++i)
{
IRAsmStmt* a = asmblock->s[i];
// skip non-branch statements
if(!a->isBranchToLabel)
continue;
// if internal, no special handling is necessary, skip
std::vector<Identifier*>::const_iterator it, end;
end = asmblock->internalLabels.end();
bool skip = false;
for(it = asmblock->internalLabels.begin(); it != end; ++it)
if((*it)->equals(a->isBranchToLabel))
skip = true;
if(skip)
continue;
// if we already set things up for this branch target, skip
if(gotoToVal.find(a->isBranchToLabel) != gotoToVal.end())
continue;
// record that the jump needs to be handled in the post-asm dispatcher
gotoToVal[a->isBranchToLabel] = n_goto;
// provide an in-asm target for the branch and set value
Logger::println("statement '%s' references outer label '%s': creating forwarder", a->code.c_str(), a->isBranchToLabel->string);
printLabelName(code, fdmangle, a->isBranchToLabel->string);
code << ":\n\t";
code << "movl $<<in" << n_goto << ">>, $<<out0>>\n";
//FIXME: Store the value -> label mapping somewhere, so it can be referenced later
outSetterStmt->in.push_back(DtoConstUint(n_goto));
outSetterStmt->in_c += "i,";
code << asmGotoEnd;
++n_goto;
}
if(code.str() != asmGotoEnd)
{
// finalize code
outSetterStmt->code = code.str();
outSetterStmt->code += asmGotoEndLabel.str()+":\n";
// create storage for and initialize the temporary
jump_target = DtoAlloca(Type::tint32, "__llvm_jump_target");
gIR->ir->CreateStore(DtoConstUint(0), jump_target);
// setup variable for output from asm
outSetterStmt->out_c = "=*m,";
outSetterStmt->out.push_back(jump_target);
asmblock->s.push_back(outSetterStmt);
}
else
delete outSetterStmt;
}
// build a fall-off-end-properly asm statement
FuncDeclaration* thisfunc = p->func()->decl;
bool useabiret = false;
p->asmBlock->asmBlock->abiret = NULL;
if (thisfunc->fbody->endsWithAsm() == this && thisfunc->type->nextOf()->ty != Tvoid)
{
// there can't be goto forwarders in this case
assert(gotoToVal.empty());
emitABIReturnAsmStmt(asmblock, loc, thisfunc);
useabiret = true;
}
// build asm block
std::vector<LLValue*> outargs;
std::vector<LLValue*> inargs;
std::vector<LLType*> outtypes;
std::vector<LLType*> intypes;
std::string out_c;
std::string in_c;
std::string clobbers;
std::string code;
size_t asmIdx = asmblock->retn;
Logger::println("do outputs");
size_t n = asmblock->s.size();
for (size_t i=0; i<n; ++i)
{
IRAsmStmt* a = asmblock->s[i];
assert(a);
size_t onn = a->out.size();
for (size_t j=0; j<onn; ++j)
{
outargs.push_back(a->out[j]);
outtypes.push_back(a->out[j]->getType());
}
if (!a->out_c.empty())
{
out_c += a->out_c;
}
remap_outargs(a->code, onn+a->in.size(), asmIdx);
asmIdx += onn;
}
Logger::println("do inputs");
for (size_t i=0; i<n; ++i)
{
IRAsmStmt* a = asmblock->s[i];
assert(a);
size_t inn = a->in.size();
for (size_t j=0; j<inn; ++j)
{
inargs.push_back(a->in[j]);
intypes.push_back(a->in[j]->getType());
}
if (!a->in_c.empty())
{
in_c += a->in_c;
}
remap_inargs(a->code, inn+a->out.size(), asmIdx);
asmIdx += inn;
if (!code.empty())
code += "\n\t";
code += a->code;
}
asmblock->s.clear();
// append inputs
out_c += in_c;
// append clobbers
typedef std::set<std::string>::iterator clobs_it;
for (clobs_it i=asmblock->clobs.begin(); i!=asmblock->clobs.end(); ++i)
{
out_c += *i;
}
// remove excessive comma
if (!out_c.empty())
out_c.resize(out_c.size()-1);
Logger::println("code = \"%s\"", code.c_str());
Logger::println("constraints = \"%s\"", out_c.c_str());
// build return types
LLType* retty;
if (asmblock->retn)
retty = asmblock->retty;
else
retty = llvm::Type::getVoidTy(gIR->context());
// build argument types
std::vector<LLType*> types;
types.insert(types.end(), outtypes.begin(), outtypes.end());
types.insert(types.end(), intypes.begin(), intypes.end());
llvm::FunctionType* fty = llvm::FunctionType::get(retty, types, false);
if (Logger::enabled())
Logger::cout() << "function type = " << *fty << '\n';
std::vector<LLValue*> args;
args.insert(args.end(), outargs.begin(), outargs.end());
args.insert(args.end(), inargs.begin(), inargs.end());
if (Logger::enabled()) {
Logger::cout() << "Arguments:" << '\n';
Logger::indent();
for (std::vector<LLValue*>::iterator b = args.begin(), i = b, e = args.end(); i != e; ++i) {
Stream cout = Logger::cout();
cout << '$' << (i - b) << " ==> " << **i;
if (!llvm::isa<llvm::Instruction>(*i) && !llvm::isa<LLGlobalValue>(*i))
cout << '\n';
}
Logger::undent();
}
llvm::InlineAsm* ia = llvm::InlineAsm::get(fty, code, out_c, true);
llvm::CallInst* call = p->ir->CreateCall(ia, args,
retty == LLType::getVoidTy(gIR->context()) ? "" : "asm");
if (Logger::enabled())
Logger::cout() << "Complete asm statement: " << *call << '\n';
// capture abi return value
if (useabiret)
{
IRAsmBlock* block = p->asmBlock;
if (block->retfixup)
block->asmBlock->abiret = (*block->retfixup)(p->ir, call);
else if (p->asmBlock->retemu)
block->asmBlock->abiret = DtoLoad(block->asmBlock->abiret);
else
block->asmBlock->abiret = call;
}
p->asmBlock = NULL;
// if asm contained external branches, emit goto forwarder code
if(!gotoToVal.empty())
{
assert(jump_target);
// make new blocks
llvm::BasicBlock* oldend = gIR->scopeend();
llvm::BasicBlock* bb = llvm::BasicBlock::Create(gIR->context(), "afterasmgotoforwarder", p->topfunc(), oldend);
llvm::LoadInst* val = p->ir->CreateLoad(jump_target, "__llvm_jump_target_value");
llvm::SwitchInst* sw = p->ir->CreateSwitch(val, bb, gotoToVal.size());
// add all cases
std::map<Identifier*, int>::iterator it, end = gotoToVal.end();
for(it = gotoToVal.begin(); it != end; ++it)
{
llvm::BasicBlock* casebb = llvm::BasicBlock::Create(gIR->context(), "case", p->topfunc(), bb);
sw->addCase(LLConstantInt::get(llvm::IntegerType::get(gIR->context(), 32), it->second), casebb);
p->scope() = IRScope(casebb,bb);
DtoGoto(loc, it->first, enclosingFinally);
}
p->scope() = IRScope(bb,oldend);
}
}
llvm::GlobalVariable * IrAggr::getInterfaceVtbl(BaseClass * b, bool new_instance, size_t interfaces_index)
{
ClassGlobalMap::iterator it = interfaceVtblMap.find(b->base);
if (it != interfaceVtblMap.end())
return it->second;
IF_LOG Logger::println("Building vtbl for implementation of interface %s in class %s",
b->base->toPrettyChars(), aggrdecl->toPrettyChars());
LOG_SCOPE;
ClassDeclaration* cd = aggrdecl->isClassDeclaration();
assert(cd && "not a class aggregate");
FuncDeclarations vtbl_array;
b->fillVtbl(cd, &vtbl_array, new_instance);
std::vector<llvm::Constant*> constants;
constants.reserve(vtbl_array.dim);
if (!b->base->isCPPinterface()) { // skip interface info for CPP interfaces
// start with the interface info
VarDeclarationIter interfaces_idx(ClassDeclaration::classinfo->fields, 3);
// index into the interfaces array
llvm::Constant* idxs[2] = {
DtoConstSize_t(0),
DtoConstSize_t(interfaces_index)
};
llvm::Constant* c = llvm::ConstantExpr::getGetElementPtr(
getInterfaceArraySymbol(), idxs, true);
constants.push_back(c);
}
// add virtual function pointers
size_t n = vtbl_array.dim;
for (size_t i = b->base->vtblOffset(); i < n; i++)
{
Dsymbol* dsym = static_cast<Dsymbol*>(vtbl_array.data[i]);
if (dsym == NULL)
{
// FIXME
// why is this null?
// happens for mini/s.d
constants.push_back(getNullValue(getVoidPtrType()));
continue;
}
FuncDeclaration* fd = dsym->isFuncDeclaration();
assert(fd && "vtbl entry not a function");
assert((!fd->isAbstract() || fd->fbody) &&
"null symbol in interface implementation vtable");
fd->codegen(Type::sir);
assert(fd->ir.irFunc && "invalid vtbl function");
LLFunction *fn = fd->ir.irFunc->func;
// If the base is a cpp interface, 'this' parameter is a pointer to
// the interface not the underlying object as expected. Instead of
// the function, we place into the vtable a small wrapper, called thunk,
// that casts 'this' to the object and then pass it to the real function.
if (b->base->isCPPinterface()) {
TypeFunction *f = (TypeFunction*)fd->type->toBasetype();
assert(f->fty.arg_this);
// create the thunk function
OutBuffer name;
name.writestring("Th");
name.printf("%i", b->offset);
name.writestring(fd->mangle());
LLFunction *thunk = LLFunction::Create(isaFunction(fn->getType()->getContainedType(0)),
DtoLinkage(fd), name.toChars(), gIR->module);
// create entry and end blocks
llvm::BasicBlock* beginbb = llvm::BasicBlock::Create(gIR->context(), "entry", thunk);
llvm::BasicBlock* endbb = llvm::BasicBlock::Create(gIR->context(), "endentry", thunk);
gIR->scopes.push_back(IRScope(beginbb, endbb));
// copy the function parameters, so later we can pass them to the real function
std::vector<LLValue*> args;
llvm::Function::arg_iterator iarg = thunk->arg_begin();
for (; iarg != thunk->arg_end(); ++iarg)
args.push_back(iarg);
// cast 'this' to Object
LLValue* &thisArg = args[(f->fty.arg_sret == 0) ? 0 : 1];
LLType* thisType = thisArg->getType();
thisArg = DtoBitCast(thisArg, getVoidPtrType());
thisArg = DtoGEP1(thisArg, DtoConstInt(-b->offset));
thisArg = DtoBitCast(thisArg, thisType);
// call the real vtbl function.
LLValue *retVal = gIR->ir->CreateCall(fn, args);
// return from the thunk
if (thunk->getReturnType() == LLType::getVoidTy(gIR->context()))
llvm::ReturnInst::Create(gIR->context(), beginbb);
else
llvm::ReturnInst::Create(gIR->context(), retVal, beginbb);
// clean up
gIR->scopes.pop_back();
thunk->getBasicBlockList().pop_back();
fn = thunk;
}
constants.push_back(fn);
}
// build the vtbl constant
llvm::Constant* vtbl_constant = LLConstantStruct::getAnon(gIR->context(), constants, false);
// create the global variable to hold it
llvm::GlobalValue::LinkageTypes _linkage = DtoExternalLinkage(aggrdecl);
std::string mangle("_D");
mangle.append(cd->mangle());
mangle.append("11__interface");
mangle.append(b->base->mangle());
mangle.append("6__vtblZ");
llvm::GlobalVariable* GV = getOrCreateGlobal(cd->loc,
*gIR->module,
vtbl_constant->getType(),
true,
_linkage,
vtbl_constant,
mangle
);
// insert into the vtbl map
interfaceVtblMap.insert(std::make_pair(b->base, GV));
return GV;
}
