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//===--- CGExprComplex.cpp - Emit LLVM Code for Complex Exprs -------------===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by Chris Lattner and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This contains code to emit Expr nodes with complex types as LLVM code.
//
//===----------------------------------------------------------------------===//
#include "CodeGenFunction.h"
#include "CodeGenModule.h"
#include "clang/AST/AST.h"
#include "llvm/Constants.h"
#include "llvm/Function.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/Support/Compiler.h"
using namespace clang;
using namespace CodeGen;
//===----------------------------------------------------------------------===//
// Complex Expression Emitter
//===----------------------------------------------------------------------===//
typedef CodeGenFunction::ComplexPairTy ComplexPairTy;
namespace {
class VISIBILITY_HIDDEN ComplexExprEmitter
: public StmtVisitor<ComplexExprEmitter, ComplexPairTy> {
CodeGenFunction &CGF;
llvm::LLVMBuilder &Builder;
public:
ComplexExprEmitter(CodeGenFunction &cgf) : CGF(cgf), Builder(CGF.Builder) {
}
//===--------------------------------------------------------------------===//
// Utilities
//===--------------------------------------------------------------------===//
/// EmitLoadOfLValue - Given an expression with complex type that represents a
/// value l-value, this method emits the address of the l-value, then loads
/// and returns the result.
ComplexPairTy EmitLoadOfLValue(const Expr *E) {
LValue LV = CGF.EmitLValue(E);
// FIXME: Volatile
return EmitLoadOfComplex(LV.getAddress(), false);
}
/// EmitLoadOfComplex - Given a pointer to a complex value, emit code to load
/// the real and imaginary pieces.
ComplexPairTy EmitLoadOfComplex(llvm::Value *SrcPtr, bool isVolatile);
/// EmitStoreOfComplex - Store the specified real/imag parts into the
/// specified value pointer.
void EmitStoreOfComplex(ComplexPairTy Val, llvm::Value *ResPtr, bool isVol);
/// EmitComplexToComplexCast - Emit a cast from complex value Val to DestType.
ComplexPairTy EmitComplexToComplexCast(ComplexPairTy Val, QualType SrcType,
QualType DestType);
//===--------------------------------------------------------------------===//
// Visitor Methods
//===--------------------------------------------------------------------===//
ComplexPairTy VisitStmt(Stmt *S) {
S->dump();
assert(0 && "Stmt can't have complex result type!");
return ComplexPairTy();
}
ComplexPairTy VisitExpr(Expr *S);
ComplexPairTy VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr());}
ComplexPairTy VisitImaginaryLiteral(const ImaginaryLiteral *IL);
// l-values.
ComplexPairTy VisitDeclRefExpr(const Expr *E) { return EmitLoadOfLValue(E); }
ComplexPairTy VisitArraySubscriptExpr(Expr *E) { return EmitLoadOfLValue(E); }
ComplexPairTy VisitMemberExpr(const Expr *E) { return EmitLoadOfLValue(E); }
// FIXME: CompoundLiteralExpr
ComplexPairTy EmitCast(Expr *Op, QualType DestTy);
ComplexPairTy VisitImplicitCastExpr(ImplicitCastExpr *E) {
// Unlike for scalars, we don't have to worry about function->ptr demotion
// here.
return EmitCast(E->getSubExpr(), E->getType());
}
ComplexPairTy VisitCastExpr(CastExpr *E) {
return EmitCast(E->getSubExpr(), E->getType());
}
ComplexPairTy VisitCallExpr(const CallExpr *E);
// Operators.
ComplexPairTy VisitPrePostIncDec(const UnaryOperator *E,
bool isInc, bool isPre);
ComplexPairTy VisitUnaryPostDec(const UnaryOperator *E) {
return VisitPrePostIncDec(E, false, false);
}
ComplexPairTy VisitUnaryPostInc(const UnaryOperator *E) {
return VisitPrePostIncDec(E, true, false);
}
ComplexPairTy VisitUnaryPreDec(const UnaryOperator *E) {
return VisitPrePostIncDec(E, false, true);
}
ComplexPairTy VisitUnaryPreInc(const UnaryOperator *E) {
return VisitPrePostIncDec(E, true, true);
}
ComplexPairTy VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); }
ComplexPairTy VisitUnaryPlus (const UnaryOperator *E) {
return Visit(E->getSubExpr());
}
ComplexPairTy VisitUnaryMinus (const UnaryOperator *E);
ComplexPairTy VisitUnaryNot (const UnaryOperator *E);
// LNot,SizeOf,AlignOf,Real,Imag never return complex.
ComplexPairTy VisitUnaryExtension(const UnaryOperator *E) {
return Visit(E->getSubExpr());
}
struct BinOpInfo {
ComplexPairTy LHS;
ComplexPairTy RHS;
QualType Ty; // Computation Type.
};
BinOpInfo EmitBinOps(const BinaryOperator *E);
ComplexPairTy EmitCompoundAssign(const CompoundAssignOperator *E,
ComplexPairTy (ComplexExprEmitter::*Func)
(const BinOpInfo &));
ComplexPairTy EmitBinAdd(const BinOpInfo &Op);
ComplexPairTy EmitBinSub(const BinOpInfo &Op);
ComplexPairTy EmitBinMul(const BinOpInfo &Op);
ComplexPairTy EmitBinDiv(const BinOpInfo &Op);
ComplexPairTy VisitBinMul(const BinaryOperator *E) {
return EmitBinMul(EmitBinOps(E));
}
ComplexPairTy VisitBinAdd(const BinaryOperator *E) {
return EmitBinAdd(EmitBinOps(E));
}
ComplexPairTy VisitBinSub(const BinaryOperator *E) {
return EmitBinSub(EmitBinOps(E));
}
ComplexPairTy VisitBinDiv(const BinaryOperator *E) {
return EmitBinDiv(EmitBinOps(E));
}
// Compound assignments.
ComplexPairTy VisitBinAddAssign(const CompoundAssignOperator *E) {
return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinAdd);
}
ComplexPairTy VisitBinSubAssign(const CompoundAssignOperator *E) {
return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinSub);
}
ComplexPairTy VisitBinMulAssign(const CompoundAssignOperator *E) {
return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinMul);
}
ComplexPairTy VisitBinDivAssign(const CompoundAssignOperator *E) {
return EmitCompoundAssign(E, &ComplexExprEmitter::EmitBinDiv);
}
// GCC rejects rem/and/or/xor for integer complex.
// Logical and/or always return int, never complex.
// No comparisons produce a complex result.
ComplexPairTy VisitBinAssign (const BinaryOperator *E);
ComplexPairTy VisitBinComma (const BinaryOperator *E);
ComplexPairTy VisitConditionalOperator(const ConditionalOperator *CO);
ComplexPairTy VisitChooseExpr(ChooseExpr *CE);
};
} // end anonymous namespace.
//===----------------------------------------------------------------------===//
// Utilities
//===----------------------------------------------------------------------===//
/// EmitLoadOfComplex - Given an RValue reference for a complex, emit code to
/// load the real and imaginary pieces, returning them as Real/Imag.
ComplexPairTy ComplexExprEmitter::EmitLoadOfComplex(llvm::Value *SrcPtr,
bool isVolatile) {
llvm::Constant *Zero = llvm::ConstantInt::get(llvm::Type::Int32Ty, 0);
llvm::Constant *One = llvm::ConstantInt::get(llvm::Type::Int32Ty, 1);
llvm::SmallString<64> Name(SrcPtr->getNameStart(),
SrcPtr->getNameStart()+SrcPtr->getNameLen());
Name += ".realp";
llvm::Value *RealPtr = Builder.CreateGEP(SrcPtr, Zero, Zero, Name.c_str());
Name.pop_back(); // .realp -> .real
llvm::Value *Real = Builder.CreateLoad(RealPtr, isVolatile, Name.c_str());
Name.resize(Name.size()-4); // .real -> .imagp
Name += "imagp";
llvm::Value *ImagPtr = Builder.CreateGEP(SrcPtr, Zero, One, Name.c_str());
Name.pop_back(); // .imagp -> .imag
llvm::Value *Imag = Builder.CreateLoad(ImagPtr, isVolatile, Name.c_str());
return ComplexPairTy(Real, Imag);
}
/// EmitStoreOfComplex - Store the specified real/imag parts into the
/// specified value pointer.
void ComplexExprEmitter::EmitStoreOfComplex(ComplexPairTy Val, llvm::Value *Ptr,
bool isVolatile) {
llvm::Constant *Zero = llvm::ConstantInt::get(llvm::Type::Int32Ty, 0);
llvm::Constant *One = llvm::ConstantInt::get(llvm::Type::Int32Ty, 1);
llvm::Value *RealPtr = Builder.CreateGEP(Ptr, Zero, Zero, "real");
llvm::Value *ImagPtr = Builder.CreateGEP(Ptr, Zero, One, "imag");
Builder.CreateStore(Val.first, RealPtr, isVolatile);
Builder.CreateStore(Val.second, ImagPtr, isVolatile);
}
//===----------------------------------------------------------------------===//
// Visitor Methods
//===----------------------------------------------------------------------===//
ComplexPairTy ComplexExprEmitter::VisitExpr(Expr *E) {
fprintf(stderr, "Unimplemented complex expr!\n");
E->dump();
const llvm::Type *EltTy =
CGF.ConvertType(E->getType()->getAsComplexType()->getElementType());
llvm::Value *U = llvm::UndefValue::get(EltTy);
return ComplexPairTy(U, U);
}
ComplexPairTy ComplexExprEmitter::
VisitImaginaryLiteral(const ImaginaryLiteral *IL) {
llvm::Value *Imag = CGF.EmitScalarExpr(IL->getSubExpr());
return ComplexPairTy(llvm::Constant::getNullValue(Imag->getType()), Imag);
}
ComplexPairTy ComplexExprEmitter::VisitCallExpr(const CallExpr *E) {
llvm::Value *AggPtr = CGF.EmitCallExpr(E).getAggregateAddr();
return EmitLoadOfComplex(AggPtr, false);
}
/// EmitComplexToComplexCast - Emit a cast from complex value Val to DestType.
ComplexPairTy ComplexExprEmitter::EmitComplexToComplexCast(ComplexPairTy Val,
QualType SrcType,
QualType DestType) {
// Get the src/dest element type.
SrcType = cast<ComplexType>(SrcType.getCanonicalType())->getElementType();
DestType = cast<ComplexType>(DestType.getCanonicalType())->getElementType();
// C99 6.3.1.6: When a value of complextype is converted to another
// complex type, both the real and imaginary parts followthe conversion
// rules for the corresponding real types.
Val.first = CGF.EmitScalarConversion(Val.first, SrcType, DestType);
Val.second = CGF.EmitScalarConversion(Val.second, SrcType, DestType);
return Val;
}
ComplexPairTy ComplexExprEmitter::EmitCast(Expr *Op, QualType DestTy) {
// Two cases here: cast from (complex to complex) and (scalar to complex).
if (Op->getType()->isComplexType())
return EmitComplexToComplexCast(Visit(Op), Op->getType(), DestTy);
// C99 6.3.1.7: When a value of real type is converted to a complex type, the
// real part of the complex result value is determined by the rules of
// conversion to the corresponding real type and the imaginary part of the
// complex result value is a positive zero or an unsigned zero.
llvm::Value *Elt = CGF.EmitScalarExpr(Op);
// Convert the input element to the element type of the complex.
DestTy = cast<ComplexType>(DestTy.getCanonicalType())->getElementType();
Elt = CGF.EmitScalarConversion(Elt, Op->getType(), DestTy);
// Return (realval, 0).
return ComplexPairTy(Elt, llvm::Constant::getNullValue(Elt->getType()));
}
ComplexPairTy ComplexExprEmitter::VisitPrePostIncDec(const UnaryOperator *E,
bool isInc, bool isPre) {
LValue LV = CGF.EmitLValue(E->getSubExpr());
// FIXME: Handle volatile!
ComplexPairTy InVal = EmitLoadOfComplex(LV.getAddress(), false);
int AmountVal = isInc ? 1 : -1;
llvm::Value *NextVal;
if (isa<llvm::IntegerType>(InVal.first->getType()))
NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal);
else
NextVal = llvm::ConstantFP::get(InVal.first->getType(), AmountVal);
// Add the inc/dec to the real part.
NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
ComplexPairTy IncVal(NextVal, InVal.second);
// Store the updated result through the lvalue.
EmitStoreOfComplex(IncVal, LV.getAddress(), false); /* FIXME: Volatile */
// If this is a postinc, return the value read from memory, otherwise use the
// updated value.
return isPre ? IncVal : InVal;
}
ComplexPairTy ComplexExprEmitter::VisitUnaryMinus(const UnaryOperator *E) {
ComplexPairTy Op = Visit(E->getSubExpr());
llvm::Value *ResR = Builder.CreateNeg(Op.first, "neg.r");
llvm::Value *ResI = Builder.CreateNeg(Op.second, "neg.i");
return ComplexPairTy(ResR, ResI);
}
ComplexPairTy ComplexExprEmitter::VisitUnaryNot(const UnaryOperator *E) {
// ~(a+ib) = a + i*-b
ComplexPairTy Op = Visit(E->getSubExpr());
llvm::Value *ResI = Builder.CreateNeg(Op.second, "conj.i");
return ComplexPairTy(Op.first, ResI);
}
ComplexPairTy ComplexExprEmitter::EmitBinAdd(const BinOpInfo &Op) {
llvm::Value *ResR = Builder.CreateAdd(Op.LHS.first, Op.RHS.first, "add.r");
llvm::Value *ResI = Builder.CreateAdd(Op.LHS.second, Op.RHS.second, "add.i");
return ComplexPairTy(ResR, ResI);
}
ComplexPairTy ComplexExprEmitter::EmitBinSub(const BinOpInfo &Op) {
llvm::Value *ResR = Builder.CreateSub(Op.LHS.first, Op.RHS.first, "sub.r");
llvm::Value *ResI = Builder.CreateSub(Op.LHS.second, Op.RHS.second, "sub.i");
return ComplexPairTy(ResR, ResI);
}
ComplexPairTy ComplexExprEmitter::EmitBinMul(const BinOpInfo &Op) {
llvm::Value *ResRl = Builder.CreateMul(Op.LHS.first, Op.RHS.first, "mul.rl");
llvm::Value *ResRr = Builder.CreateMul(Op.LHS.second, Op.RHS.second,"mul.rr");
llvm::Value *ResR = Builder.CreateSub(ResRl, ResRr, "mul.r");
llvm::Value *ResIl = Builder.CreateMul(Op.LHS.second, Op.RHS.first, "mul.il");
llvm::Value *ResIr = Builder.CreateMul(Op.LHS.first, Op.RHS.second, "mul.ir");
llvm::Value *ResI = Builder.CreateAdd(ResIl, ResIr, "mul.i");
return ComplexPairTy(ResR, ResI);
}
ComplexPairTy ComplexExprEmitter::EmitBinDiv(const BinOpInfo &Op) {
llvm::Value *LHSr = Op.LHS.first, *LHSi = Op.LHS.second;
llvm::Value *RHSr = Op.RHS.first, *RHSi = Op.RHS.second;
// (a+ib) / (c+id) = ((ac+bd)/(cc+dd)) + i((bc-ad)/(cc+dd))
llvm::Value *Tmp1 = Builder.CreateMul(LHSr, RHSr, "tmp"); // a*c
llvm::Value *Tmp2 = Builder.CreateMul(LHSi, RHSi, "tmp"); // b*d
llvm::Value *Tmp3 = Builder.CreateAdd(Tmp1, Tmp2, "tmp"); // ac+bd
llvm::Value *Tmp4 = Builder.CreateMul(RHSr, RHSr, "tmp"); // c*c
llvm::Value *Tmp5 = Builder.CreateMul(RHSi, RHSi, "tmp"); // d*d
llvm::Value *Tmp6 = Builder.CreateAdd(Tmp4, Tmp5, "tmp"); // cc+dd
llvm::Value *Tmp7 = Builder.CreateMul(LHSi, RHSr, "tmp"); // b*c
llvm::Value *Tmp8 = Builder.CreateMul(LHSr, RHSi, "tmp"); // a*d
llvm::Value *Tmp9 = Builder.CreateSub(Tmp7, Tmp8, "tmp"); // bc-ad
llvm::Value *DSTr, *DSTi;
if (Tmp3->getType()->isFloatingPoint()) {
DSTr = Builder.CreateFDiv(Tmp3, Tmp6, "tmp");
DSTi = Builder.CreateFDiv(Tmp9, Tmp6, "tmp");
} else {
if (Op.Ty->getAsComplexType()->getElementType()->isUnsignedIntegerType()) {
DSTr = Builder.CreateUDiv(Tmp3, Tmp6, "tmp");
DSTi = Builder.CreateUDiv(Tmp9, Tmp6, "tmp");
} else {
DSTr = Builder.CreateSDiv(Tmp3, Tmp6, "tmp");
DSTi = Builder.CreateSDiv(Tmp9, Tmp6, "tmp");
}
}
return ComplexPairTy(DSTr, DSTi);
}
ComplexExprEmitter::BinOpInfo
ComplexExprEmitter::EmitBinOps(const BinaryOperator *E) {
BinOpInfo Ops;
Ops.LHS = Visit(E->getLHS());
Ops.RHS = Visit(E->getRHS());
Ops.Ty = E->getType();
return Ops;
}
// Compound assignments.
ComplexPairTy ComplexExprEmitter::
EmitCompoundAssign(const CompoundAssignOperator *E,
ComplexPairTy (ComplexExprEmitter::*Func)(const BinOpInfo&)){
QualType LHSTy = E->getLHS()->getType(), RHSTy = E->getRHS()->getType();
// Load the LHS and RHS operands.
LValue LHSLV = CGF.EmitLValue(E->getLHS());
BinOpInfo OpInfo;
OpInfo.Ty = E->getComputationType();
// We know the LHS is a complex lvalue.
OpInfo.LHS = EmitLoadOfComplex(LHSLV.getAddress(), false);// FIXME: Volatile.
OpInfo.LHS = EmitComplexToComplexCast(OpInfo.LHS, LHSTy, OpInfo.Ty);
// It is possible for the RHS to be complex or scalar.
OpInfo.RHS = EmitCast(E->getRHS(), OpInfo.Ty);
// Expand the binary operator.
ComplexPairTy Result = (this->*Func)(OpInfo);
// Truncate the result back to the LHS type.
Result = EmitComplexToComplexCast(Result, OpInfo.Ty, LHSTy);
// Store the result value into the LHS lvalue.
EmitStoreOfComplex(Result, LHSLV.getAddress(), false); // FIXME: VOLATILE
return Result;
}
ComplexPairTy ComplexExprEmitter::VisitBinAssign(const BinaryOperator *E) {
assert(E->getLHS()->getType().getCanonicalType() ==
E->getRHS()->getType().getCanonicalType() && "Invalid assignment");
// Emit the RHS.
ComplexPairTy Val = Visit(E->getRHS());
// Compute the address to store into.
LValue LHS = CGF.EmitLValue(E->getLHS());
// Store into it.
// FIXME: Volatility!
EmitStoreOfComplex(Val, LHS.getAddress(), false);
return Val;
}
ComplexPairTy ComplexExprEmitter::VisitBinComma(const BinaryOperator *E) {
CGF.EmitStmt(E->getLHS());
return Visit(E->getRHS());
}
ComplexPairTy ComplexExprEmitter::
VisitConditionalOperator(const ConditionalOperator *E) {
llvm::BasicBlock *LHSBlock = new llvm::BasicBlock("cond.?");
llvm::BasicBlock *RHSBlock = new llvm::BasicBlock("cond.:");
llvm::BasicBlock *ContBlock = new llvm::BasicBlock("cond.cont");
llvm::Value *Cond = CGF.EvaluateExprAsBool(E->getCond());
Builder.CreateCondBr(Cond, LHSBlock, RHSBlock);
CGF.EmitBlock(LHSBlock);
// Handle the GNU extension for missing LHS.
assert(E->getLHS() && "Must have LHS for complex value");
ComplexPairTy LHS = Visit(E->getLHS());
Builder.CreateBr(ContBlock);
LHSBlock = Builder.GetInsertBlock();
CGF.EmitBlock(RHSBlock);
ComplexPairTy RHS = Visit(E->getRHS());
Builder.CreateBr(ContBlock);
RHSBlock = Builder.GetInsertBlock();
CGF.EmitBlock(ContBlock);
// Create a PHI node for the real part.
llvm::PHINode *RealPN = Builder.CreatePHI(LHS.first->getType(), "cond.r");
RealPN->reserveOperandSpace(2);
RealPN->addIncoming(LHS.first, LHSBlock);
RealPN->addIncoming(RHS.first, RHSBlock);
// Create a PHI node for the imaginary part.
llvm::PHINode *ImagPN = Builder.CreatePHI(LHS.first->getType(), "cond.i");
ImagPN->reserveOperandSpace(2);
ImagPN->addIncoming(LHS.second, LHSBlock);
ImagPN->addIncoming(RHS.second, RHSBlock);
return ComplexPairTy(RealPN, ImagPN);
}
ComplexPairTy ComplexExprEmitter::VisitChooseExpr(ChooseExpr *E) {
llvm::APSInt CondVal(32);
bool IsConst = E->getCond()->isIntegerConstantExpr(CondVal, CGF.getContext());
assert(IsConst && "Condition of choose expr must be i-c-e"); IsConst=IsConst;
// Emit the LHS or RHS as appropriate.
return Visit(CondVal != 0 ? E->getLHS() : E->getRHS());
}
//===----------------------------------------------------------------------===//
// Entry Point into this File
//===----------------------------------------------------------------------===//
/// EmitComplexExpr - Emit the computation of the specified expression of
/// complex type, ignoring the result.
ComplexPairTy CodeGenFunction::EmitComplexExpr(const Expr *E) {
assert(E && E->getType()->isComplexType() &&
"Invalid complex expression to emit");
return ComplexExprEmitter(*this).Visit(const_cast<Expr*>(E));
}
/// EmitComplexExprIntoAddr - Emit the computation of the specified expression
/// of complex type, storing into the specified Value*.
void CodeGenFunction::EmitComplexExprIntoAddr(const Expr *E,
llvm::Value *DestAddr,
bool DestIsVolatile) {
assert(E && E->getType()->isComplexType() &&
"Invalid complex expression to emit");
ComplexExprEmitter Emitter(*this);
ComplexPairTy Val = Emitter.Visit(const_cast<Expr*>(E));
Emitter.EmitStoreOfComplex(Val, DestAddr, DestIsVolatile);
}