src/abi_win64.cpp

//===-- abi_win64.cpp - Windows x86_64 ABI description ----------*- C++ -*-===//
//
//                         LDC &ndash; the LLVM D compiler
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//===----------------------------------------------------------------------===//
//
// The ABI implementation used for 64 bit x86 (i.e. x86_64/AMD64/x64) targets
// on Windows.
//
//===----------------------------------------------------------------------===//

// whether the argument can be passed in register
static bool win64_reg_size(size_t size)
{
    return size <= 2 || size == 4 || size == 8;
}

struct ABI_Win64Layout : AbiLayout {
int nargs;
ABI_Win64Layout() : nargs(0) { }

bool use_sret(jl_datatype_t *dt, LLVMContext &ctx) override
{
    size_t size = jl_datatype_size(dt);
    if (win64_reg_size(size) || is_native_simd_type(dt))
        return false;
    nargs++;
    return true;
}

bool needPassByRef(jl_datatype_t *dt, AttrBuilder &ab, LLVMContext &ctx, Type *Ty) override
{
    nargs++;
    size_t size = jl_datatype_size(dt);
    if (win64_reg_size(size))
        return false;
    if (nargs <= 4) {
        ab.addByValAttr(Ty);
    }
    return true;
}

Type *preferred_llvm_type(jl_datatype_t *dt, bool isret, LLVMContext &ctx) const override
{
    size_t size = jl_datatype_size(dt);
    if (size > 0 && win64_reg_size(size) && !jl_is_primitivetype(dt))
        return Type::getIntNTy(ctx, jl_datatype_nbits(dt));
    return NULL;
}

};