view gen/tocall.cpp @ 945:03d7c4aac654

SWITCHED TO LLVM 2.5 ! Applied patch from ticket #129 to compile against latest LLVM. Thanks Frits van Bommel. Fixed implicit return by asm block at the end of a function on x86-32. Other architectures will produce an error at the moment. Adding support for new targets is fairly simple. Fixed return calling convention for complex numbers, ST and ST(1) were switched around. Added some testcases. I've run a dstress test and there are no regressions. However, the runtime does not seem to compile with symbolic debug information. -O3 -release -inline works well and is what I used for the dstress run. Tango does not compile, a small workaround is needed in tango.io.digest.Digest.Digest.hexDigest. See ticket #206 .
author Tomas Lindquist Olsen <tomas.l.olsen@gmail.com>
date Sun, 08 Feb 2009 05:26:54 +0100
parents cac9895be400
children b2d27ddf8f45
line wrap: on
line source
#include "gen/llvm.h"

#include "mtype.h"
#include "declaration.h"

#include "gen/tollvm.h"
#include "gen/llvmhelpers.h"
#include "gen/irstate.h"
#include "gen/dvalue.h"
#include "gen/functions.h"

#include "gen/logger.h"

//////////////////////////////////////////////////////////////////////////////////////////

TypeFunction* DtoTypeFunction(DValue* fnval)
{
    Type* type = fnval->getType()->toBasetype();
    if (type->ty == Tfunction)
    {
         return (TypeFunction*)type;
    }
    else if (type->ty == Tdelegate)
    {
        Type* next = type->nextOf();
        assert(next->ty == Tfunction);
        return (TypeFunction*)next;
    }

    assert(0 && "cant get TypeFunction* from non lazy/function/delegate");
    return 0;
}

//////////////////////////////////////////////////////////////////////////////////////////

unsigned DtoCallingConv(Loc loc, LINK l)
{
    if (l == LINKc || l == LINKcpp || l == LINKintrinsic)
        return llvm::CallingConv::C;
    else if (l == LINKd || l == LINKdefault)
    {
        //TODO: StdCall is not a good base on Windows due to extra name mangling
        // applied there
        if (global.params.cpu == ARCHx86)
            return (global.params.os != OSWindows) ? llvm::CallingConv::X86_StdCall : llvm::CallingConv::C;
        else
            return llvm::CallingConv::Fast;
    }
    // on the other hand, here, it's exactly what we want!!! TODO: right?
    else if (l == LINKwindows)
        return llvm::CallingConv::X86_StdCall;
    else
    {
        error(loc, "unsupported calling convention");
        fatal();
    }
}

//////////////////////////////////////////////////////////////////////////////////////////

DValue* DtoVaArg(Loc& loc, Type* type, Expression* valistArg)
{
    DValue* expelem = valistArg->toElem(gIR);
    const LLType* llt = DtoType(type);
    if (DtoIsPassedByRef(type))
        llt = getPtrToType(llt);
    // issue a warning for broken va_arg instruction.
    if (global.params.cpu != ARCHx86)
        warning("%s: va_arg for C variadic functions is probably broken for anything but x86", loc.toChars());
    // done
    return new DImValue(type, gIR->ir->CreateVAArg(expelem->getLVal(), llt, "tmp"));
}

//////////////////////////////////////////////////////////////////////////////////////////

LLValue* DtoCallableValue(DValue* fn)
{
    Type* type = fn->getType()->toBasetype();
    if (type->ty == Tfunction)
    {
        return fn->getRVal();
    }
    else if (type->ty == Tdelegate)
    {
        if (fn->isLVal())
        {
            LLValue* dg = fn->getLVal();
            LLValue* funcptr = DtoGEPi(dg, 0, 1);
            return DtoLoad(funcptr);
        }
        else
        {
            LLValue* dg = fn->getRVal();
            assert(isaStruct(dg));
            return gIR->ir->CreateExtractValue(dg, 1, ".funcptr");
        }
    }
    else
    {
        assert(0 && "not a callable type");
        return NULL;
    }
}

//////////////////////////////////////////////////////////////////////////////////////////

const LLFunctionType* DtoExtractFunctionType(const LLType* type)
{
    if (const LLFunctionType* fty = isaFunction(type))
        return fty;
    else if (const LLPointerType* pty = isaPointer(type))
    {
        if (const LLFunctionType* fty = isaFunction(pty->getElementType()))
            return fty;
    }
    return NULL;
}

//////////////////////////////////////////////////////////////////////////////////////////

void DtoBuildDVarArgList(std::vector<LLValue*>& args, std::vector<llvm::AttributeWithIndex>& attrs, TypeFunction* tf, Expressions* arguments, size_t argidx)
{
    Logger::println("doing d-style variadic arguments");

    std::vector<const LLType*> vtypes;

    // number of non variadic args
    int begin = tf->parameters->dim;
    Logger::println("num non vararg params = %d", begin);

    // get n args in arguments list
    size_t n_arguments = arguments ? arguments->dim : 0;

    // build struct with argument types (non variadic args)
    for (int i=begin; i<n_arguments; i++)
    {
        Expression* argexp = (Expression*)arguments->data[i];
        vtypes.push_back(DtoType(argexp->type));
        size_t sz = getTypePaddedSize(vtypes.back());
        if (sz < PTRSIZE)
            vtypes.back() = DtoSize_t();
    }
    const LLStructType* vtype = LLStructType::get(vtypes);

    if (Logger::enabled())
        Logger::cout() << "d-variadic argument struct type:\n" << *vtype << '\n';

    LLValue* mem = DtoAlloca(vtype,"_argptr_storage");

    // store arguments in the struct
    for (int i=begin,k=0; i<n_arguments; i++,k++)
    {
        Expression* argexp = (Expression*)arguments->data[i];
        if (global.params.llvmAnnotate)
            DtoAnnotation(argexp->toChars());
        LLValue* argdst = DtoGEPi(mem,0,k);
        argdst = DtoBitCast(argdst, getPtrToType(DtoType(argexp->type)));
        DtoVariadicArgument(argexp, argdst);
    }

    // build type info array
    const LLType* typeinfotype = DtoType(Type::typeinfo->type);
    const LLArrayType* typeinfoarraytype = LLArrayType::get(typeinfotype,vtype->getNumElements());

    llvm::GlobalVariable* typeinfomem =
        new llvm::GlobalVariable(typeinfoarraytype, true, llvm::GlobalValue::InternalLinkage, NULL, "._arguments.storage", gIR->module);
    if (Logger::enabled())
        Logger::cout() << "_arguments storage: " << *typeinfomem << '\n';

    std::vector<LLConstant*> vtypeinfos;
    for (int i=begin,k=0; i<n_arguments; i++,k++)
    {
        Expression* argexp = (Expression*)arguments->data[i];
        vtypeinfos.push_back(DtoTypeInfoOf(argexp->type));
    }

    // apply initializer
    LLConstant* tiinits = llvm::ConstantArray::get(typeinfoarraytype, vtypeinfos);
    typeinfomem->setInitializer(tiinits);

    // put data in d-array
    std::vector<LLConstant*> pinits;
    pinits.push_back(DtoConstSize_t(vtype->getNumElements()));
    pinits.push_back(llvm::ConstantExpr::getBitCast(typeinfomem, getPtrToType(typeinfotype)));
    const LLType* tiarrty = DtoType(Type::typeinfo->type->arrayOf());
    tiinits = llvm::ConstantStruct::get(pinits);
    LLValue* typeinfoarrayparam = new llvm::GlobalVariable(tiarrty,
        true, llvm::GlobalValue::InternalLinkage, tiinits, "._arguments.array", gIR->module);

    // specify arguments
    args.push_back(DtoLoad(typeinfoarrayparam));
    ++argidx;
    args.push_back(gIR->ir->CreateBitCast(mem, getPtrToType(LLType::Int8Ty), "tmp"));
    ++argidx;

    // pass non variadic args
    for (int i=0; i<begin; i++)
    {
        Argument* fnarg = Argument::getNth(tf->parameters, i);
        DValue* argval = DtoArgument(fnarg, (Expression*)arguments->data[i]);
        args.push_back(argval->getRVal());

        if (fnarg->llvmAttrs)
        {
            llvm::AttributeWithIndex Attr;
            Attr.Index = argidx;
            Attr.Attrs = fnarg->llvmAttrs;
            attrs.push_back(Attr);
        }

        ++argidx;
    }
}


DValue* DtoCallFunction(Loc& loc, Type* resulttype, DValue* fnval, Expressions* arguments)
{
    // the callee D type
    Type* calleeType = fnval->getType();

    // if the type has not yet been processed, do so now
    if (calleeType->ir.type == NULL)
        DtoType(calleeType);

    // get func value if any
    DFuncValue* dfnval = fnval->isFunc();

    // handle special vararg intrinsics
    bool va_intrinsic = (dfnval && dfnval->func && dfnval->func->isVaIntrinsic());

    // get function type info
    TypeFunction* tf = DtoTypeFunction(fnval);

    // misc
    bool retinptr = tf->retInPtr;
    bool thiscall = tf->usesThis;
    bool delegatecall = (calleeType->toBasetype()->ty == Tdelegate);
    bool nestedcall = tf->usesNest;
    bool dvarargs = (tf->linkage == LINKd && tf->varargs == 1);

    unsigned callconv = DtoCallingConv(loc, tf->linkage);

    // get callee llvm value
    LLValue* callable = DtoCallableValue(fnval);
    const LLFunctionType* callableTy = DtoExtractFunctionType(callable->getType());
    assert(callableTy);

//     if (Logger::enabled())
//         Logger::cout() << "callable: " << *callable << '\n';

    // get n arguments
    size_t n_arguments = arguments ? arguments->dim : 0;

    // get llvm argument iterator, for types
    LLFunctionType::param_iterator argbegin = callableTy->param_begin();
    LLFunctionType::param_iterator argiter = argbegin;

    // parameter attributes
    std::vector<llvm::AttributeWithIndex> attrs;
    llvm::AttributeWithIndex Attr;

    // return attrs
    if (tf->retAttrs)
    {
        Attr.Index = 0;
        Attr.Attrs = tf->retAttrs;
        attrs.push_back(Attr);
    }

    // handle implicit arguments
    std::vector<LLValue*> args;

    // return in hidden ptr is first
    if (retinptr)
    {
        LLValue* retvar = DtoAlloca(argiter->get()->getContainedType(0), ".rettmp");
        ++argiter;
        args.push_back(retvar);

        // add attrs for hidden ptr
        Attr.Index = 1;
        Attr.Attrs = llvm::Attribute::StructRet;
        attrs.push_back(Attr);
    }

    // then comes a context argument...
    if(thiscall || delegatecall || nestedcall)
    {
        // ... which can be a 'this' argument
        if (thiscall && dfnval && dfnval->vthis)
        {
            LLValue* thisarg = DtoBitCast(dfnval->vthis, argiter->get());
            ++argiter;
            args.push_back(thisarg);
        }
        // ... or a delegate context arg
        else if (delegatecall)
        {
            LLValue* ctxarg;
            if (fnval->isLVal())
            {
                ctxarg = DtoLoad(DtoGEPi(fnval->getLVal(), 0,0));
            }
            else
            {
                ctxarg = gIR->ir->CreateExtractValue(fnval->getRVal(), 0, ".ptr");
            }
            assert(ctxarg->getType() == argiter->get());
            ++argiter;
            args.push_back(ctxarg);
        }
        // ... or a nested function context arg
        else if (nestedcall)
        {
            LLValue* contextptr = DtoNestedContext(loc, dfnval->func);
            contextptr = DtoBitCast(contextptr, getVoidPtrType());
            ++argiter;
            args.push_back(contextptr);
        }
        else
        {
            error(loc, "Context argument required but none given");
            fatal();
        }

        // add attributes for context argument
        if (tf->thisAttrs)
        {
            Attr.Index = retinptr ? 2 : 1;
            Attr.Attrs = tf->thisAttrs;
            attrs.push_back(Attr);
        }
    }

    // handle the rest of the arguments based on param passing style

    // variadic instrinsics need some custom casts
    if (va_intrinsic)
    {
        for (int i=0; i<n_arguments; i++)
        {
            Expression* exp = (Expression*)arguments->data[i];
            DValue* expelem = exp->toElem(gIR);
            // cast to va_list*
            LLValue* val = DtoBitCast(expelem->getLVal(), getVoidPtrType());
            ++argiter;
            args.push_back(val);
        }
    }

    // d style varargs needs a few more hidden arguments as well as special passing
    else if (dvarargs)
    {
        DtoBuildDVarArgList(args, attrs, tf, arguments, argiter-argbegin+1);
    }

    // otherwise we're looking at a normal function call
    // or a C style vararg call
    else
    {
        Logger::println("doing normal arguments");

        size_t n = Argument::dim(tf->parameters);

        LLSmallVector<unsigned, 10> attrptr(n, 0);

        // do formal params
        int beg = argiter-argbegin;
        for (int i=0; i<n; i++)
        {
            Argument* fnarg = Argument::getNth(tf->parameters, i);
            assert(fnarg);
            DValue* argval = DtoArgument(fnarg, (Expression*)arguments->data[i]);
            LLValue* arg = argval->getRVal();

            int j = tf->reverseParams ? beg + n - i - 1 : beg + i;

            // if it's a struct inreg arg, load first to pass as first-class value
            if (tf->structInregArg && i == (tf->reverseParams ? n - 1 : 0))
            {
                assert((fnarg->llvmAttrs & llvm::Attribute::InReg) && isaStruct(tf->structInregArg));
                arg = DtoBitCast(arg, getPtrToType(callableTy->getParamType(j)));
                arg = DtoLoad(arg);
            }

            // parameter type mismatch, this is hard to get rid of
            if (arg->getType() != callableTy->getParamType(j))
            {
            #if 0
                if (Logger::enabled())
                {
                    Logger::cout() << "arg:     " << *arg << '\n';
                    Logger::cout() << "expects: " << *callableTy->getParamType(j) << '\n';
                }
            #endif
                arg = DtoBitCast(arg, callableTy->getParamType(j));
            }

            // param attrs
            attrptr[i] = fnarg->llvmAttrs;

            ++argiter;
            args.push_back(arg);
        }

        // reverse the relevant params as well as the param attrs
        if (tf->reverseParams)
        {
            std::reverse(args.begin() + tf->firstRealArg, args.end());
            std::reverse(attrptr.begin(), attrptr.end());
        }

        // add attributes
        for (int i = 0; i < n; i++)
        {
            if (attrptr[i])
            {
                Attr.Index = beg + i + 1;
                Attr.Attrs = attrptr[i];
                attrs.push_back(Attr);
            }
        }

        // do C varargs
        if (n_arguments > n)
        {
            for (int i=n; i<n_arguments; i++)
            {
                Argument* fnarg = Argument::getNth(tf->parameters, i);
                DValue* argval = DtoArgument(fnarg, (Expression*)arguments->data[i]);
                LLValue* arg = argval->getRVal();

                // FIXME: do we need any param attrs here ?

                ++argiter;
                args.push_back(arg);
            }
        }
    }

    #if 1
    if (Logger::enabled())
    {
        Logger::println("%lu params passed", args.size());
        for (int i=0; i<args.size(); ++i) {
            assert(args[i]);
            Logger::cout() << "arg["<<i<<"] = " << *args[i] << '\n';
        }
    }
    #endif

    // void returns cannot not be named
    const char* varname = "";
    if (callableTy->getReturnType() != LLType::VoidTy)
        varname = "tmp";

    if (Logger::enabled())
        Logger::cout() << "Calling: " << *callable << '\n';

    // call the function
    CallOrInvoke* call = gIR->CreateCallOrInvoke(callable, args.begin(), args.end(), varname);

    // get return value
    LLValue* retllval = (retinptr) ? args[0] : call->get();

    // swap real/imag parts on a x87
    if (global.params.cpu == ARCHx86 && tf->nextOf()->toBasetype()->iscomplex())
    {
        retllval = DtoAggrPairSwap(retllval);
    }

    // repaint the type if necessary
    if (resulttype)
    {
        Type* rbase = resulttype->toBasetype();
        Type* nextbase = tf->nextOf()->toBasetype();
    #if DMDV2
        rbase = rbase->mutableOf();
        nextbase = nextbase->mutableOf();
    #endif
        if (!rbase->equals(nextbase))
        {
            Logger::println("repainting return value from '%s' to '%s'", tf->nextOf()->toChars(), rbase->toChars());
            switch(rbase->ty)
            {
            case Tarray:
                retllval = DtoAggrPaint(retllval, DtoType(rbase));
                break;

            case Tclass:
            case Taarray:
            case Tpointer:
                retllval = DtoBitCast(retllval, DtoType(rbase));
                break;

            default:
                assert(0 && "unhandled repainting of return value");
            }
            if (Logger::enabled())
                Logger::cout() << "final return value: " << *retllval << '\n';
        }
    }

    // set calling convention and parameter attributes
    llvm::AttrListPtr attrlist = llvm::AttrListPtr::get(attrs.begin(), attrs.end());
    if (dfnval && dfnval->func)
    {
        LLFunction* llfunc = llvm::dyn_cast<LLFunction>(dfnval->val);
        if (llfunc && llfunc->isIntrinsic()) // override intrinsic attrs
            attrlist = llvm::Intrinsic::getAttributes((llvm::Intrinsic::ID)llfunc->getIntrinsicID());
        else
            call->setCallingConv(callconv);
    }
    else
        call->setCallingConv(callconv);
    call->setAttributes(attrlist);

    return new DImValue(resulttype, retllval);
}