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view gen/abi.cpp @ 1479:4f7d50c744ed
Rewrite `StructLiteralExp::toElem` to store individual fields instead of
generating a constant to fill the entire struct with a single `store`.
This is much more efficient at compile time (fixing #320) and vastly reduces
the size of the emitted code. Since LLVM no longer needs to keep the data for
all fields in "registers" until the store happens, it should also be more
efficient at run time in cases where the fields aren't assigned with constants.
There's also some code clean-up by removing duplicated logic.
author | Frits van Bommel <fvbommel wxs.nl> |
---|---|
date | Sat, 06 Jun 2009 20:16:13 +0200 |
parents | a5526b7a5ae6 |
children | 2292878925f4 |
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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 "gen/abi-generic.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(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); return 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; } 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::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; } } ////////////////////////////////////////////////////////////////////////////// ////////////////////////////////////////////////////////////////////////////// ////////////////////////////////////////////////////////////////////////////// ////////////////////////////////////////////////////////////////////////////// ////////////////////////////////////////////////////////////////////////////// // 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 0 if (Logger::enabled()) Logger::cout() << "New arg type: " << *arg.ltype << '\n'; #endif } } }; TargetABI * TargetABI::getIntrinsic() { static IntrinsicABI iabi; return &iabi; }