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view gen/abi.cpp @ 1317:4099548c80e0
Allocate objects on the stack if they (a) don't have a destructor, and
(b) don't override the delete operator (on top of the regular conditions for
stack allocation that also apply to arrays, structs, etc.).
The "no destructor" clause is not strictly necessary, but calling them at the
right time would be tricky to say the least; it would involve, among other
things, "manually" inserting a try-finally block around anything that might
throw exceptions not caught in the current function.
Note: objects with custom new operators are automatically ignored because they
don't use the regular allocation runtime call, so there's no need to pay special
attention to them.
author | Frits van Bommel <fvbommel wxs.nl> |
---|---|
date | Sat, 09 May 2009 00:50:15 +0200 |
parents | dc608dc33081 |
children | 15e9762bb620 |
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#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 "ir/irfunction.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 //////////////////////////// ////////////////////////////////////////////////////////////////////////////// ////////////////////////////////////////////////////////////////////////////// // simply swap of real/imag parts for proper x87 complex abi struct X87_complex_swap : ABIRewrite { LLValue* get(Type*, DValue* v) { return DtoAggrPairSwap(v->getRVal()); } LLValue* put(Type*, DValue* v) { return DtoAggrPairSwap(v->getRVal()); } const LLType* type(Type*, const LLType* t) { return t; } }; ////////////////////////////////////////////////////////////////////////////// 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::Int32Ty); rpart = gIR->ir->CreateBitCast(rpart, LLType::FloatTy, ".re"); // extract imag part LLValue* ipart = gIR->ir->CreateLShr(in, LLConstantInt::get(LLType::Int64Ty, 32, false)); ipart = gIR->ir->CreateTrunc(ipart, LLType::Int32Ty); ipart = gIR->ir->CreateBitCast(ipart, LLType::FloatTy, ".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::Int32Ty); // zext to i64 r = gIR->ir->CreateZExt(r, LLType::Int64Ty); // extract imag LLValue* i = gIR->ir->CreateExtractValue(v, 1); // cast to i32 i = gIR->ir->CreateBitCast(i, LLType::Int32Ty); // zext to i64 i = gIR->ir->CreateZExt(i, LLType::Int64Ty); // shift up i = gIR->ir->CreateShl(i, LLConstantInt::get(LLType::Int64Ty, 32, false)); // combine and return return v = gIR->ir->CreateOr(r, i); } // {float,float} -> i64 const LLType* type(Type*, const LLType* t) { return LLType::Int64Ty; } }; ////////////////////////////////////////////////////////////////////////////// // FIXME: try into eliminating the alloca or if at least check // if it gets optimized away // convert byval struct // when struct X86_struct_to_register : ABIRewrite { // int -> struct LLValue* get(Type* dty, DValue* dv) { Logger::println("rewriting int -> struct"); LLValue* mem = DtoAlloca(DtoType(dty), ".int_to_struct"); LLValue* v = dv->getRVal(); DtoStore(v, DtoBitCast(mem, getPtrToType(v->getType()))); return DtoLoad(mem); } // int -> struct (with dst lvalue given) void getL(Type* dty, DValue* dv, llvm::Value* lval) { Logger::println("rewriting int -> struct"); LLValue* v = dv->getRVal(); DtoStore(v, DtoBitCast(lval, getPtrToType(v->getType()))); } // struct -> int LLValue* put(Type* dty, DValue* dv) { Logger::println("rewriting struct -> int"); assert(dv->isLVal()); LLValue* mem = dv->getLVal(); const LLType* t = LLIntegerType::get(dty->size()*8); DtoLoad(DtoBitCast(mem, getPtrToType(t))); } const LLType* type(Type* t, const LLType*) { size_t sz = t->size()*8; return LLIntegerType::get(sz); } }; ////////////////////////////////////////////////////////////////////////////// struct X86TargetABI : TargetABI { X87_complex_swap swapComplex; X86_cfloat_rewrite cfloatToInt; X86_struct_to_register structToReg; bool returnInArg(TypeFunction* tf) { 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; } // otherwise try to mark the last param inreg else if (!fty.arg_sret && !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::Int64Ty; } // 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) { 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; } }