ldc/gen/abi.cpp
2011-03-26 19:30:17 +03:00

347 lines
11 KiB
C++

#include "gen/llvm.h"
#include <algorithm>
#include "mars.h"
#include "gen/irstate.h"
#include "gen/llvmhelpers.h"
#include "gen/tollvm.h"
#include "gen/abi.h"
#include "gen/logger.h"
#include "gen/dvalue.h"
#include "gen/abi-generic.h"
#include "ir/irfunction.h"
#include "ir/irfuncty.h"
//////////////////////////////////////////////////////////////////////////////
void ABIRewrite::getL(Type* dty, DValue* v, llvm::Value* lval)
{
LLValue* rval = get(dty, v);
assert(rval->getType() == lval->getType()->getContainedType(0));
DtoStore(rval, lval);
}
//////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////
///////////////////// X86 ////////////////////////////
//////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////
struct X86_cfloat_rewrite : ABIRewrite
{
// i64 -> {float,float}
LLValue* get(Type*, DValue* dv)
{
LLValue* in = dv->getRVal();
// extract real part
LLValue* rpart = gIR->ir->CreateTrunc(in, LLType::getInt32Ty(gIR->context()));
rpart = gIR->ir->CreateBitCast(rpart, LLType::getFloatTy(gIR->context()), ".re");
// extract imag part
LLValue* ipart = gIR->ir->CreateLShr(in, LLConstantInt::get(LLType::getInt64Ty(gIR->context()), 32, false));
ipart = gIR->ir->CreateTrunc(ipart, LLType::getInt32Ty(gIR->context()));
ipart = gIR->ir->CreateBitCast(ipart, LLType::getFloatTy(gIR->context()), ".im");
// return {float,float} aggr pair with same bits
return DtoAggrPair(rpart, ipart, ".final_cfloat");
}
// {float,float} -> i64
LLValue* put(Type*, DValue* dv)
{
LLValue* v = dv->getRVal();
// extract real
LLValue* r = gIR->ir->CreateExtractValue(v, 0);
// cast to i32
r = gIR->ir->CreateBitCast(r, LLType::getInt32Ty(gIR->context()));
// zext to i64
r = gIR->ir->CreateZExt(r, LLType::getInt64Ty(gIR->context()));
// extract imag
LLValue* i = gIR->ir->CreateExtractValue(v, 1);
// cast to i32
i = gIR->ir->CreateBitCast(i, LLType::getInt32Ty(gIR->context()));
// zext to i64
i = gIR->ir->CreateZExt(i, LLType::getInt64Ty(gIR->context()));
// shift up
i = gIR->ir->CreateShl(i, LLConstantInt::get(LLType::getInt64Ty(gIR->context()), 32, false));
// combine and return
return v = gIR->ir->CreateOr(r, i);
}
// {float,float} -> i64
const LLType* type(Type*, const LLType* t)
{
return LLType::getInt64Ty(gIR->context());
}
};
//////////////////////////////////////////////////////////////////////////////
struct X86TargetABI : TargetABI
{
X87_complex_swap swapComplex;
X86_cfloat_rewrite cfloatToInt;
X86_struct_to_register structToReg;
bool returnInArg(TypeFunction* tf)
{
#if DMDV2
if (tf->isref)
return false;
#endif
Type* rt = tf->next->toBasetype();
// D only returns structs on the stack
if (tf->linkage == LINKd)
return (rt->ty == Tstruct);
// other ABI's follow C, which is cdouble and creal returned on the stack
// as well as structs
else
return (rt->ty == Tstruct || rt->ty == Tcomplex64 || rt->ty == Tcomplex80);
}
bool passByVal(Type* t)
{
return t->toBasetype()->ty == Tstruct;
}
void rewriteFunctionType(TypeFunction* tf)
{
IrFuncTy& fty = tf->fty;
Type* rt = fty.ret->type->toBasetype();
// extern(D)
if (tf->linkage == LINKd)
{
// RETURN VALUE
// complex {re,im} -> {im,re}
if (rt->iscomplex())
{
Logger::println("Rewriting complex return value");
fty.ret->rewrite = &swapComplex;
}
// IMPLICIT PARAMETERS
// mark this/nested params inreg
if (fty.arg_this)
{
Logger::println("Putting 'this' in register");
fty.arg_this->attrs = llvm::Attribute::InReg;
}
else if (fty.arg_nest)
{
Logger::println("Putting context ptr in register");
fty.arg_nest->attrs = llvm::Attribute::InReg;
}
else if (IrFuncTyArg* sret = fty.arg_sret)
{
Logger::println("Putting sret ptr in register");
// sret and inreg are incompatible, but the ABI requires the
// sret parameter to be in EAX in this situation...
sret->attrs = (sret->attrs | llvm::Attribute::InReg)
& ~llvm::Attribute::StructRet;
}
// otherwise try to mark the last param inreg
else if (!fty.args.empty())
{
// The last parameter is passed in EAX rather than being pushed on the stack if the following conditions are met:
// * It fits in EAX.
// * It is not a 3 byte struct.
// * It is not a floating point type.
IrFuncTyArg* last = fty.args.back();
Type* lastTy = last->type->toBasetype();
unsigned sz = lastTy->size();
if (last->byref && !last->isByVal())
{
Logger::println("Putting last (byref) parameter in register");
last->attrs |= llvm::Attribute::InReg;
}
else if (!lastTy->isfloating() && (sz == 1 || sz == 2 || sz == 4)) // right?
{
// rewrite the struct into an integer to make inreg work
if (lastTy->ty == Tstruct)
{
last->rewrite = &structToReg;
last->ltype = structToReg.type(last->type, last->ltype);
last->byref = false;
// erase previous attributes
last->attrs = 0;
}
last->attrs |= llvm::Attribute::InReg;
}
}
// FIXME: tf->varargs == 1 need to use C calling convention and vararg mechanism to live up to the spec:
// "The caller is expected to clean the stack. _argptr is not passed, it is computed by the callee."
// EXPLICIT PARAMETERS
// reverse parameter order
// for non variadics
if (!fty.args.empty() && tf->varargs != 1)
{
fty.reverseParams = true;
}
}
// extern(C) and all others
else
{
// RETURN VALUE
// cfloat -> i64
if (tf->next->toBasetype() == Type::tcomplex32)
{
fty.ret->rewrite = &cfloatToInt;
fty.ret->ltype = LLType::getInt64Ty(gIR->context());
}
// IMPLICIT PARAMETERS
// EXPLICIT PARAMETERS
}
}
};
//////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////
/////////////////// X86-64 //////////////////////////
//////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////
#include "gen/abi-x86-64.h"
//////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////
/////////////////// Unknown targets //////////////////////////
//////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////
// Some reasonable defaults for when we don't know what ABI to use.
struct UnknownTargetABI : TargetABI
{
bool returnInArg(TypeFunction* tf)
{
#if DMDV2
if (tf->isref)
return false;
#endif
return (tf->next->toBasetype()->ty == Tstruct);
}
bool passByVal(Type* t)
{
return t->toBasetype()->ty == Tstruct;
}
void rewriteFunctionType(TypeFunction* t)
{
// why?
}
};
//////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////
TargetABI * TargetABI::getTarget()
{
switch(global.params.cpu)
{
case ARCHx86:
return new X86TargetABI;
case ARCHx86_64:
return getX86_64TargetABI();
default:
Logger::cout() << "WARNING: Unknown ABI, guessing...\n";
return new UnknownTargetABI;
}
}
//////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////
// A simple ABI for LLVM intrinsics.
struct IntrinsicABI : TargetABI
{
RemoveStructPadding remove_padding;
bool returnInArg(TypeFunction* tf)
{
return false;
}
bool passByVal(Type* t)
{
return false;
}
void fixup(IrFuncTyArg& arg) {
assert(arg.type->ty == Tstruct);
// TODO: Check that no unions are passed in or returned.
LLType* abiTy = DtoUnpaddedStructType(arg.type);
if (abiTy && abiTy != arg.ltype) {
arg.ltype = abiTy;
arg.rewrite = &remove_padding;
}
}
void rewriteFunctionType(TypeFunction* tf)
{
assert(tf->linkage == LINKintrinsic);
IrFuncTy& fty = tf->fty;
if (!fty.arg_sret) {
Type* rt = fty.ret->type->toBasetype();
if (rt->ty == Tstruct) {
Logger::println("Intrinsic ABI: Transforming return type");
fixup(*fty.ret);
}
}
Logger::println("Intrinsic ABI: Transforming arguments");
LOG_SCOPE;
for (IrFuncTy::ArgIter I = fty.args.begin(), E = fty.args.end(); I != E; ++I) {
IrFuncTyArg& arg = **I;
if (Logger::enabled())
Logger::cout() << "Arg: " << arg.type->toChars() << '\n';
// Arguments that are in memory are of no interest to us.
if (arg.byref)
continue;
Type* ty = arg.type->toBasetype();
if (ty->ty == Tstruct)
fixup(arg);
if (Logger::enabled())
Logger::cout() << "New arg type: " << *arg.ltype << '\n';
}
}
};
TargetABI * TargetABI::getIntrinsic()
{
static IntrinsicABI iabi;
return &iabi;
}