view gen/aa.cpp @ 1117:4c20fcc4252b

Fun with parameter attributes: For several of the "synthetic" parameters added to D functions, we can apply noalias and nocapture. They are sret parameters, 'nest' pointers passed to nested functions, and _argptr: Nocapture: - Sret and nest are nocapture because they don't represent D-level variables, and thus the callee can't (validly) obtain a pointer to them, let alone keep it around after it returns. - _argptr is nocapture because although the callee has access to it as a pointer, that pointer is invalidated when it returns. All three are noalias because they're function-local variables - Sret and _argptr are noalias because they're freshly alloca'd memory only used for a single function call that's not allowed to keep an aliasing pointer to it around (since the parameter is nocapture). - 'Nest' is noalias because the callee only ever has access to one such pointer per parent function, and every parent function has a different one. This commit also ensures attributes set on sret, _arguments and _argptr are propagated to calls to such functions. It also adds one exception to the general rule that attributes on function types should propagate to calls: the type of a delegate's function pointer has a 'nest' parameter, but this can either be a true 'nest' (for delegates to nested functions) or a 'this' (for delegates to member functions). Since 'this' is neither noalias nor nocapture, and there's generally no way to tell which one it is, we remove these attributes at the call site if the callee is a delegate.
author Frits van Bommel <fvbommel wxs.nl>
date Sat, 14 Mar 2009 22:15:31 +0100
parents d584cda84b00
children 0686701178d3
line wrap: on
line source

#include "gen/llvm.h"

#include "mtype.h"
#include "module.h"
#include "declaration.h"
#include "aggregate.h"

#include "gen/aa.h"
#include "gen/runtime.h"
#include "gen/tollvm.h"
#include "gen/llvmhelpers.h"
#include "gen/logger.h"
#include "gen/irstate.h"
#include "gen/dvalue.h"
#include "ir/irmodule.h"

// makes sure the key value lives in memory so it can be passed to the runtime functions without problems
// returns the pointer
static LLValue* to_pkey(Loc& loc, DValue* key)
{
    Type* keytype = key->getType();
    bool needmem = !DtoIsPassedByRef(keytype);
    LLValue* pkey;
    if (key->isIm()) {
        pkey = key->getRVal();
    }
    else if (DVarValue* var = key->isVar()) {
        pkey = key->getLVal();
        needmem = false;
    }
    else if (key->isConst()) {
        needmem = true;
        pkey = key->getRVal();
    }
    else {
        LLValue* tmp = DtoAlloca(DtoType(keytype), "aatmpkeystorage");
        DVarValue var(keytype, tmp);
        DtoAssign(loc, &var, key);
        return tmp;
    }

    // give memory
    if (needmem) {
        LLValue* tmp = DtoAlloca(DtoType(keytype), "aatmpkeystorage");
        DtoStore(pkey, tmp);
        pkey = tmp;
    }

    return pkey;
}

// returns the keytype typeinfo
static LLValue* to_keyti(DValue* key)
{
    // keyti param
    Type* keytype = key->getType();
    return DtoTypeInfoOf(keytype, false);
}

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

DValue* DtoAAIndex(Loc& loc, Type* type, DValue* aa, DValue* key, bool lvalue)
{
    // call:
    // extern(C) void* _aaGet(AA* aa, TypeInfo keyti, size_t valuesize, void* pkey)
    // or
    // extern(C) void* _aaGetRvalue(AA aa, TypeInfo keyti, size_t valuesize, void* pkey)

    // first get the runtime function
    llvm::Function* func = LLVM_D_GetRuntimeFunction(gIR->module, lvalue?"_aaGet":"_aaGetRvalue");
    const llvm::FunctionType* funcTy = func->getFunctionType();

    // aa param
    LLValue* aaval = lvalue ? aa->getLVal() : aa->getRVal();
    aaval = DtoBitCast(aaval, funcTy->getParamType(0));

    // keyti param
    LLValue* keyti = to_keyti(key);
    keyti = DtoBitCast(keyti, funcTy->getParamType(1));

    // valuesize param
    LLValue* valsize = DtoConstSize_t(getTypePaddedSize(DtoType(type)));

    // pkey param
    LLValue* pkey = to_pkey(loc, key);
    pkey = DtoBitCast(pkey, funcTy->getParamType(3));

    // call runtime
    LLValue* ret = gIR->CreateCallOrInvoke4(func, aaval, keyti, valsize, pkey, "aa.index").getInstruction();

    // cast return value
    const LLType* targettype = getPtrToType(DtoType(type));
    if (ret->getType() != targettype)
        ret = DtoBitCast(ret, targettype);

    // Only check bounds for rvalues ('aa[key]').
    // Lvalue use ('aa[key] = value') auto-adds an element.
    if (!lvalue && global.params.useArrayBounds) {
        llvm::BasicBlock* oldend = gIR->scopeend();
        llvm::BasicBlock* failbb = llvm::BasicBlock::Create("aaboundscheckfail", gIR->topfunc(), oldend);
        llvm::BasicBlock* okbb = llvm::BasicBlock::Create("aaboundsok", gIR->topfunc(), oldend);

        LLValue* nullaa = LLConstant::getNullValue(ret->getType());
        LLValue* cond = gIR->ir->CreateICmpNE(nullaa, ret, "aaboundscheck");
        gIR->ir->CreateCondBr(cond, okbb, failbb);

        // set up failbb to call the array bounds error runtime function

        gIR->scope() = IRScope(failbb, okbb);

        std::vector<LLValue*> args;

        // file param
        args.push_back(DtoLoad(gIR->dmodule->ir.irModule->fileName));

        // line param
        LLConstant* c = DtoConstUint(loc.linnum);
        args.push_back(c);

        // call
        llvm::Function* errorfn = LLVM_D_GetRuntimeFunction(gIR->module, "_d_array_bounds");
        gIR->CreateCallOrInvoke(errorfn, args.begin(), args.end());

        // the function does not return
        gIR->ir->CreateUnreachable();

        // if ok, proceed in okbb
        gIR->scope() = IRScope(okbb, oldend);
    }
    return new DVarValue(type, ret);
}

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

DValue* DtoAAIn(Loc& loc, Type* type, DValue* aa, DValue* key)
{
    // call:
    // extern(C) void* _aaIn(AA aa*, TypeInfo keyti, void* pkey)

    // first get the runtime function
    llvm::Function* func = LLVM_D_GetRuntimeFunction(gIR->module, "_aaIn");
    const llvm::FunctionType* funcTy = func->getFunctionType();

    if (Logger::enabled())
        Logger::cout() << "_aaIn = " << *func << '\n';

    // aa param
    LLValue* aaval = aa->getRVal();
    if (Logger::enabled())
    {
        Logger::cout() << "aaval: " << *aaval << '\n';
        Logger::cout() << "totype: " << *funcTy->getParamType(0) << '\n';
    }
    aaval = DtoBitCast(aaval, funcTy->getParamType(0));

    // keyti param
    LLValue* keyti = to_keyti(key);
    keyti = DtoBitCast(keyti, funcTy->getParamType(1));

    // pkey param
    LLValue* pkey = to_pkey(loc, key);
    pkey = DtoBitCast(pkey, funcTy->getParamType(2));

    // call runtime
    LLValue* ret = gIR->CreateCallOrInvoke3(func, aaval, keyti, pkey, "aa.in").getInstruction();

    // cast return value
    const LLType* targettype = DtoType(type);
    if (ret->getType() != targettype)
        ret = DtoBitCast(ret, targettype);

    return new DImValue(type, ret);
}

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

void DtoAARemove(Loc& loc, DValue* aa, DValue* key)
{
    // call:
    // extern(C) void _aaDel(AA aa, TypeInfo keyti, void* pkey)

    // first get the runtime function
    llvm::Function* func = LLVM_D_GetRuntimeFunction(gIR->module, "_aaDel");
    const llvm::FunctionType* funcTy = func->getFunctionType();

    if (Logger::enabled())
        Logger::cout() << "_aaDel = " << *func << '\n';

    // aa param
    LLValue* aaval = aa->getRVal();
    if (Logger::enabled())
    {
        Logger::cout() << "aaval: " << *aaval << '\n';
        Logger::cout() << "totype: " << *funcTy->getParamType(0) << '\n';
    }
    aaval = DtoBitCast(aaval, funcTy->getParamType(0));

    // keyti param
    LLValue* keyti = to_keyti(key);
    keyti = DtoBitCast(keyti, funcTy->getParamType(1));

    // pkey param
    LLValue* pkey = to_pkey(loc, key);
    pkey = DtoBitCast(pkey, funcTy->getParamType(2));

    // build arg vector
    LLSmallVector<LLValue*, 3> args;
    args.push_back(aaval);
    args.push_back(keyti);
    args.push_back(pkey);

    // call runtime
    gIR->CreateCallOrInvoke(func, args.begin(), args.end());
}