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Update DtoConstFP() to be correct after LLVM r67562, which changed the way the APFloat constructor expects its i80 APInts to be formatted. (They're now actually consistent with the x87 format)
author Frits van Bommel <fvbommel wxs.nl>
date Tue, 24 Mar 2009 15:24:59 +0100
parents b30fe7e1dbb9
children e961851fb8be
line wrap: on
line source


// Compiler implementation of the D programming language
// Copyright (c) 1999-2007 by Digital Mars
// All Rights Reserved
// written by Walter Bright
// http://www.digitalmars.com
// License for redistribution is by either the Artistic License
// in artistic.txt, or the GNU General Public License in gnu.txt.
// See the included readme.txt for details.

#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <math.h>

#if __DMC__
#include <complex.h>
#endif

#include "rmem.h"
#include "root.h"

#include "mtype.h"
#include "expression.h"
#include "aggregate.h"
#include "declaration.h"

#ifdef IN_GCC
#include "d-gcc-real.h"

/* %% fix? */
extern "C" bool real_isnan (const real_t *);
#endif

static real_t zero;	// work around DMC bug for now

#define LOG 0

Expression *expType(Type *type, Expression *e)
{
    if (type != e->type)
    {
	e = e->copy();
	e->type = type;
    }
    return e;
}

/* ================================== isConst() ============================== */

int Expression::isConst()
{
    //printf("Expression::isConst(): %s\n", toChars());
    return 0;
}

int IntegerExp::isConst()
{
    return 1;
}

int RealExp::isConst()
{
    return 1;
}

int ComplexExp::isConst()
{
    return 1;
}

int SymOffExp::isConst()
{
    return 2;
}

/* =============================== constFold() ============================== */

/* The constFold() functions were redundant with the optimize() ones,
 * and so have been folded in with them.
 */

/* ========================================================================== */

Expression *Neg(Type *type, Expression *e1)
{   Expression *e;
    Loc loc = e1->loc;

    if (e1->type->isreal())
    {
	e = new RealExp(loc, -e1->toReal(), type);
    }
    else if (e1->type->isimaginary())
    {
	e = new RealExp(loc, -e1->toImaginary(), type);
    }
    else if (e1->type->iscomplex())
    {
	e = new ComplexExp(loc, -e1->toComplex(), type);
    }
    else
	e = new IntegerExp(loc, -e1->toInteger(), type);
    return e;
}

Expression *Com(Type *type, Expression *e1)
{   Expression *e;
    Loc loc = e1->loc;

    e = new IntegerExp(loc, ~e1->toInteger(), type);
    return e;
}

Expression *Not(Type *type, Expression *e1)
{   Expression *e;
    Loc loc = e1->loc;

    e = new IntegerExp(loc, e1->isBool(0), type);
    return e;
}

Expression *Bool(Type *type, Expression *e1)
{   Expression *e;
    Loc loc = e1->loc;

    e = new IntegerExp(loc, e1->isBool(1), type);
    return e;
}

Expression *Add(Type *type, Expression *e1, Expression *e2)
{   Expression *e;
    Loc loc = e1->loc;

#if LOG
    printf("Add(e1 = %s, e2 = %s)\n", e1->toChars(), e2->toChars());
#endif
    if (type->isreal())
    {
	e = new RealExp(loc, e1->toReal() + e2->toReal(), type);
    }
    else if (type->isimaginary())
    {
	e = new RealExp(loc, e1->toImaginary() + e2->toImaginary(), type);
    }
    else if (type->iscomplex())
    {
	// This rigamarole is necessary so that -0.0 doesn't get
	// converted to +0.0 by doing an extraneous add with +0.0
	complex_t c1;
	real_t r1;
	real_t i1;

	complex_t c2;
	real_t r2;
	real_t i2;

	complex_t v;
	int x;

	if (e1->type->isreal())
	{   r1 = e1->toReal();
	    x = 0;
	}
	else if (e1->type->isimaginary())
	{   i1 = e1->toImaginary();
	    x = 3;
	}
	else
	{   c1 = e1->toComplex();
	    x = 6;
	}

	if (e2->type->isreal())
	{   r2 = e2->toReal();
	}
	else if (e2->type->isimaginary())
	{   i2 = e2->toImaginary();
	    x += 1;
	}
	else
	{   c2 = e2->toComplex();
	    x += 2;
	}

	switch (x)
	{
#if __DMC__
	    case 0+0:	v = (complex_t) (r1 + r2);	break;
	    case 0+1:	v = r1 + i2 * I;		break;
	    case 0+2:	v = r1 + c2;			break;
	    case 3+0:	v = i1 * I + r2;		break;
	    case 3+1:	v = (complex_t) ((i1 + i2) * I); break;
	    case 3+2:	v = i1 * I + c2;		break;
	    case 6+0:	v = c1 + r2;			break;
	    case 6+1:	v = c1 + i2 * I;		break;
	    case 6+2:	v = c1 + c2;			break;
#else
	    case 0+0:	v = complex_t(r1 + r2, 0);	break;
	    case 0+1:	v = complex_t(r1, i2);		break;
	    case 0+2:	v = complex_t(r1 + creall(c2), cimagl(c2));	break;
	    case 3+0:	v = complex_t(r2, i1);		break;
	    case 3+1:	v = complex_t(0, i1 + i2);	break;
	    case 3+2:	v = complex_t(creall(c2), i1 + cimagl(c2));	break;
	    case 6+0:	v = complex_t(creall(c1) + r2, cimagl(c2));	break;
	    case 6+1:	v = complex_t(creall(c1), cimagl(c1) + i2);	break;
	    case 6+2:	v = c1 + c2;			break;
#endif
	    default: assert(0);
	}
	e = new ComplexExp(loc, v, type);
    }
    else if (e1->op == TOKsymoff)
    {
	SymOffExp *soe = (SymOffExp *)e1;
	e = new SymOffExp(loc, soe->var, soe->offset + e2->toInteger());
	e->type = type;
    }
    else if (e2->op == TOKsymoff)
    {
	SymOffExp *soe = (SymOffExp *)e2;
	e = new SymOffExp(loc, soe->var, soe->offset + e1->toInteger());
	e->type = type;
    }
    else
	e = new IntegerExp(loc, e1->toInteger() + e2->toInteger(), type);
    return e;
}


Expression *Min(Type *type, Expression *e1, Expression *e2)
{   Expression *e;
    Loc loc = e1->loc;

    if (type->isreal())
    {
	e = new RealExp(loc, e1->toReal() - e2->toReal(), type);
    }
    else if (type->isimaginary())
    {
	e = new RealExp(loc, e1->toImaginary() - e2->toImaginary(), type);
    }
    else if (type->iscomplex())
    {
	// This rigamarole is necessary so that -0.0 doesn't get
	// converted to +0.0 by doing an extraneous add with +0.0
	complex_t c1;
	real_t r1;
	real_t i1;

	complex_t c2;
	real_t r2;
	real_t i2;

	complex_t v;
	int x;

	if (e1->type->isreal())
	{   r1 = e1->toReal();
	    x = 0;
	}
	else if (e1->type->isimaginary())
	{   i1 = e1->toImaginary();
	    x = 3;
	}
	else
	{   c1 = e1->toComplex();
	    x = 6;
	}

	if (e2->type->isreal())
	{   r2 = e2->toReal();
	}
	else if (e2->type->isimaginary())
	{   i2 = e2->toImaginary();
	    x += 1;
	}
	else
	{   c2 = e2->toComplex();
	    x += 2;
	}

	switch (x)
	{
#if __DMC__
	    case 0+0:	v = (complex_t) (r1 - r2);	break;
	    case 0+1:	v = r1 - i2 * I;		break;
	    case 0+2:	v = r1 - c2;			break;
	    case 3+0:	v = i1 * I - r2;		break;
	    case 3+1:	v = (complex_t) ((i1 - i2) * I); break;
	    case 3+2:	v = i1 * I - c2;		break;
	    case 6+0:	v = c1 - r2;			break;
	    case 6+1:	v = c1 - i2 * I;		break;
	    case 6+2:	v = c1 - c2;			break;
#else
	    case 0+0:	v = complex_t(r1 - r2, 0);	break;
	    case 0+1:	v = complex_t(r1, -i2);		break;
	    case 0+2:	v = complex_t(r1 - creall(c2), -cimagl(c2));	break;
	    case 3+0:	v = complex_t(-r2, i1);		break;
	    case 3+1:	v = complex_t(0, i1 - i2);	break;
	    case 3+2:	v = complex_t(-creall(c2), i1 - cimagl(c2));	break;
	    case 6+0:	v = complex_t(creall(c1) - r2, cimagl(c1));	break;
	    case 6+1:	v = complex_t(creall(c1), cimagl(c1) - i2);	break;
	    case 6+2:	v = c1 - c2;			break;
#endif
	    default: assert(0);
	}
	e = new ComplexExp(loc, v, type);
    }
    else if (e1->op == TOKsymoff)
    {
	SymOffExp *soe = (SymOffExp *)e1;
	e = new SymOffExp(loc, soe->var, soe->offset - e2->toInteger());
	e->type = type;
    }
    else
    {
	e = new IntegerExp(loc, e1->toInteger() - e2->toInteger(), type);
    }
    return e;
}

Expression *Mul(Type *type, Expression *e1, Expression *e2)
{   Expression *e;
    Loc loc = e1->loc;

    if (type->isfloating())
    {   complex_t c;
#ifdef IN_GCC
	real_t r;
#else
	d_float80 r;
#endif

	if (e1->type->isreal())
	{
#if __DMC__
	    c = e1->toReal() * e2->toComplex();
#else
	    r = e1->toReal();
	    c = e2->toComplex();
	    c = complex_t(r * creall(c), r * cimagl(c));
#endif
	}
	else if (e1->type->isimaginary())
	{
#if __DMC__
	    c = e1->toImaginary() * I * e2->toComplex();
#else
	    r = e1->toImaginary();
	    c = e2->toComplex();
	    c = complex_t(-r * cimagl(c), r * creall(c));
#endif
	}
	else if (e2->type->isreal())
	{
#if __DMC__
	    c = e2->toReal() * e1->toComplex();
#else
	    r = e2->toReal();
	    c = e1->toComplex();
	    c = complex_t(r * creall(c), r * cimagl(c));
#endif
	}
	else if (e2->type->isimaginary())
	{
#if __DMC__
	    c = e1->toComplex() * e2->toImaginary() * I;
#else
	    r = e2->toImaginary();
	    c = e1->toComplex();
	    c = complex_t(-r * cimagl(c), r * creall(c));
#endif
	}
	else
	    c = e1->toComplex() * e2->toComplex();

	if (type->isreal())
	    e = new RealExp(loc, creall(c), type);
	else if (type->isimaginary())
	    e = new RealExp(loc, cimagl(c), type);
	else if (type->iscomplex())
	    e = new ComplexExp(loc, c, type);
	else
	    assert(0);
    }
    else
    {
	e = new IntegerExp(loc, e1->toInteger() * e2->toInteger(), type);
    }
    return e;
}

Expression *Div(Type *type, Expression *e1, Expression *e2)
{   Expression *e;
    Loc loc = e1->loc;

    if (type->isfloating())
    {   complex_t c;
#ifdef IN_GCC
	real_t r;
#else
	d_float80 r;
#endif

	//e1->type->print();
	//e2->type->print();
	if (e2->type->isreal())
	{
	    if (e1->type->isreal())
	    {
		e = new RealExp(loc, e1->toReal() / e2->toReal(), type);
		return e;
	    }
#if __DMC__
	    //r = e2->toReal();
	    //c = e1->toComplex();
	    //printf("(%Lg + %Lgi) / %Lg\n", creall(c), cimagl(c), r);

	    c = e1->toComplex() / e2->toReal();
#else
	    r = e2->toReal();
	    c = e1->toComplex();
	    c = complex_t(creall(c) / r, cimagl(c) / r);
#endif
	}
	else if (e2->type->isimaginary())
	{
#if __DMC__
	    //r = e2->toImaginary();
	    //c = e1->toComplex();
	    //printf("(%Lg + %Lgi) / %Lgi\n", creall(c), cimagl(c), r);

	    c = e1->toComplex() / (e2->toImaginary() * I);
#else
	    r = e2->toImaginary();
	    c = e1->toComplex();
	    c = complex_t(cimagl(c) / r, -creall(c) / r);
#endif
	}
	else
	{
	    c = e1->toComplex() / e2->toComplex();
	}

	if (type->isreal())
	    e = new RealExp(loc, creall(c), type);
	else if (type->isimaginary())
	    e = new RealExp(loc, cimagl(c), type);
	else if (type->iscomplex())
	    e = new ComplexExp(loc, c, type);
	else
	    assert(0);
    }
    else
    {   sinteger_t n1;
	sinteger_t n2;
	sinteger_t n;

	n1 = e1->toInteger();
	n2 = e2->toInteger();
	if (n2 == 0)
	{   e2->error("divide by 0");
	    e2 = new IntegerExp(0, 1, e2->type);
	    n2 = 1;
	}
	if (e1->type->isunsigned() || e2->type->isunsigned())
	    n = ((d_uns64) n1) / ((d_uns64) n2);
	else
	    n = n1 / n2;
	e = new IntegerExp(loc, n, type);
    }
    return e;
}

Expression *Mod(Type *type, Expression *e1, Expression *e2)
{   Expression *e;
    Loc loc = e1->loc;

    if (type->isfloating())
    {
	complex_t c;

	if (e2->type->isreal())
	{   real_t r2 = e2->toReal();

#ifdef __DMC__
	    c = fmodl(e1->toReal(), r2) + fmodl(e1->toImaginary(), r2) * I;
#elif defined(IN_GCC)
	    c = complex_t(e1->toReal() % r2, e1->toImaginary() % r2);
#elif (defined(__FreeBSD__) && __FreeBSD_version < 800000) || defined(__arm__) || defined(__thumb__)
	// freebsd is kinda messed up. the STABLE branch doesn't support C99's fmodl !?!
	// arm also doesn't like fmodl
	    c = complex_t(fmod(e1->toReal(), r2), fmod(e1->toImaginary(), r2));
#else
	    c = complex_t(fmodl(e1->toReal(), r2), fmodl(e1->toImaginary(), r2));
#endif
	}
	else if (e2->type->isimaginary())
	{   real_t i2 = e2->toImaginary();

#ifdef __DMC__
	    c = fmodl(e1->toReal(), i2) + fmodl(e1->toImaginary(), i2) * I;
#elif defined(IN_GCC)
	    c = complex_t(e1->toReal() % i2, e1->toImaginary() % i2);
#elif (defined(__FreeBSD__) && __FreeBSD_version < 800000) || defined(__arm__) || defined(__thumb__)
        // freebsd is kinda messed up. the STABLE branch doesn't support C99's fmodl !?!
	// arm also doesn't like fmodl
	    c = complex_t(fmod(e1->toReal(), i2), fmod(e1->toImaginary(), i2));
#else
	    c = complex_t(fmodl(e1->toReal(), i2), fmodl(e1->toImaginary(), i2));
#endif
	}
	else
	    assert(0);

	if (type->isreal())
	    e = new RealExp(loc, creall(c), type);
	else if (type->isimaginary())
	    e = new RealExp(loc, cimagl(c), type);
	else if (type->iscomplex())
	    e = new ComplexExp(loc, c, type);
	else
	    assert(0);
    }
    else
    {   sinteger_t n1;
	sinteger_t n2;
	sinteger_t n;

	n1 = e1->toInteger();
	n2 = e2->toInteger();
	if (n2 == 0)
	{   e2->error("divide by 0");
	    e2 = new IntegerExp(0, 1, e2->type);
	    n2 = 1;
	}
	if (e1->type->isunsigned() || e2->type->isunsigned())
	    n = ((d_uns64) n1) % ((d_uns64) n2);
	else
	    n = n1 % n2;
	e = new IntegerExp(loc, n, type);
    }
    return e;
}

Expression *Shl(Type *type, Expression *e1, Expression *e2)
{   Expression *e;
    Loc loc = e1->loc;

    e = new IntegerExp(loc, e1->toInteger() << e2->toInteger(), type);
    return e;
}

Expression *Shr(Type *type, Expression *e1, Expression *e2)
{   Expression *e;
    Loc loc = e1->loc;
    unsigned count;
    integer_t value;

    value = e1->toInteger();
    count = e2->toInteger();
    switch (e1->type->toBasetype()->ty)
    {
	case Tint8:
		value = (d_int8)(value) >> count;
		break;

	case Tuns8:
		value = (d_uns8)(value) >> count;
		break;

	case Tint16:
		value = (d_int16)(value) >> count;
		break;

	case Tuns16:
		value = (d_uns16)(value) >> count;
		break;

	case Tint32:
		value = (d_int32)(value) >> count;
		break;

	case Tuns32:
		value = (d_uns32)(value) >> count;
		break;

	case Tint64:
		value = (d_int64)(value) >> count;
		break;

	case Tuns64:
		value = (d_uns64)(value) >> count;
		break;

	default:
		assert(0);
    }
    e = new IntegerExp(loc, value, type);
    return e;
}

Expression *Ushr(Type *type, Expression *e1, Expression *e2)
{   Expression *e;
    Loc loc = e1->loc;
    unsigned count;
    integer_t value;

    value = e1->toInteger();
    count = e2->toInteger();
    switch (e1->type->toBasetype()->ty)
    {
	case Tint8:
	case Tuns8:
		assert(0);		// no way to trigger this
		value = (value & 0xFF) >> count;
		break;

	case Tint16:
	case Tuns16:
		assert(0);		// no way to trigger this
		value = (value & 0xFFFF) >> count;
		break;

	case Tint32:
	case Tuns32:
		value = (value & 0xFFFFFFFF) >> count;
		break;

	case Tint64:
	case Tuns64:
		value = (d_uns64)(value) >> count;
		break;

	default:
		assert(0);
    }
    e = new IntegerExp(loc, value, type);
    return e;
}

Expression *And(Type *type, Expression *e1, Expression *e2)
{   Expression *e;
    Loc loc = e1->loc;

    e = new IntegerExp(loc, e1->toInteger() & e2->toInteger(), type);
    return e;
}

Expression *Or(Type *type, Expression *e1, Expression *e2)
{   Expression *e;
    Loc loc = e1->loc;

    e = new IntegerExp(loc, e1->toInteger() | e2->toInteger(), type);
    return e;
}

Expression *Xor(Type *type, Expression *e1, Expression *e2)
{   Expression *e;
    Loc loc = e1->loc;

    e = new IntegerExp(loc, e1->toInteger() ^ e2->toInteger(), type);
    return e;
}

/* Also returns EXP_CANT_INTERPRET if cannot be computed.
 */
Expression *Equal(enum TOK op, Type *type, Expression *e1, Expression *e2)
{   Expression *e;
    Loc loc = e1->loc;
    int cmp;
    real_t r1;
    real_t r2;

    //printf("Equal(e1 = %s, e2 = %s)\n", e1->toChars(), e2->toChars());

    assert(op == TOKequal || op == TOKnotequal);

    if (e1->op == TOKnull)
    {
	if (e2->op == TOKnull)
	    cmp = 1;
	else if (e2->op == TOKstring)
	{   StringExp *es2 = (StringExp *)e2;
	    cmp = (0 == es2->len);
	}
	else if (e2->op == TOKarrayliteral)
	{   ArrayLiteralExp *es2 = (ArrayLiteralExp *)e2;
	    cmp = !es2->elements || (0 == es2->elements->dim);
	}
	else
	    return EXP_CANT_INTERPRET;
    }
    else if (e2->op == TOKnull)
    {
	if (e1->op == TOKstring)
	{   StringExp *es1 = (StringExp *)e1;
	    cmp = (0 == es1->len);
	}
	else if (e1->op == TOKarrayliteral)
	{   ArrayLiteralExp *es1 = (ArrayLiteralExp *)e1;
	    cmp = !es1->elements || (0 == es1->elements->dim);
	}
	else
	    return EXP_CANT_INTERPRET;
    }
    else if (e1->op == TOKstring && e2->op == TOKstring)
    {	StringExp *es1 = (StringExp *)e1;
	StringExp *es2 = (StringExp *)e2;

	if (es1->sz != es2->sz)
	{
	    assert(global.errors);
	    return EXP_CANT_INTERPRET;
	}
	if (es1->len == es2->len &&
	    memcmp(es1->string, es2->string, es1->sz * es1->len) == 0)
	    cmp = 1;
	else
	    cmp = 0;
    }
    else if (e1->op == TOKarrayliteral && e2->op == TOKarrayliteral)
    {   ArrayLiteralExp *es1 = (ArrayLiteralExp *)e1;
	ArrayLiteralExp *es2 = (ArrayLiteralExp *)e2;

	if ((!es1->elements || !es1->elements->dim) &&
	    (!es2->elements || !es2->elements->dim))
	    cmp = 1;		// both arrays are empty
	else if (!es1->elements || !es2->elements)
	    cmp = 0;
	else if (es1->elements->dim != es2->elements->dim)
	    cmp = 0;
	else
	{
	    for (size_t i = 0; i < es1->elements->dim; i++)
	    {   Expression *ee1 = (Expression *)es1->elements->data[i];
		Expression *ee2 = (Expression *)es2->elements->data[i];

		Expression *v = Equal(TOKequal, Type::tint32, ee1, ee2);
		if (v == EXP_CANT_INTERPRET)
		    return EXP_CANT_INTERPRET;
		cmp = v->toInteger();
		if (cmp == 0)
		    break;
	    }
	}
    }
    else if (e1->op == TOKarrayliteral && e2->op == TOKstring)
    {	// Swap operands and use common code
	Expression *e = e1;
	e1 = e2;
	e2 = e;
	goto Lsa;
    }
    else if (e1->op == TOKstring && e2->op == TOKarrayliteral)
    {
     Lsa:
	StringExp *es1 = (StringExp *)e1;
	ArrayLiteralExp *es2 = (ArrayLiteralExp *)e2;
	size_t dim1 = es1->len;
	size_t dim2 = es2->elements ? es2->elements->dim : 0;
	if (dim1 != dim2)
	    cmp = 0;
	else
	{
	    for (size_t i = 0; i < dim1; i++)
	    {
		uinteger_t c = es1->charAt(i);
		Expression *ee2 = (Expression *)es2->elements->data[i];
		if (ee2->isConst() != 1)
		    return EXP_CANT_INTERPRET;
		cmp = (c == ee2->toInteger());
		if (cmp == 0)
		    break;
	    }
	}
    }
    else if (e1->op == TOKstructliteral && e2->op == TOKstructliteral)
    {   StructLiteralExp *es1 = (StructLiteralExp *)e1;
	StructLiteralExp *es2 = (StructLiteralExp *)e2;

	if (es1->sd != es2->sd)
	    cmp = 0;
	else if ((!es1->elements || !es1->elements->dim) &&
	    (!es2->elements || !es2->elements->dim))
	    cmp = 1;		// both arrays are empty
	else if (!es1->elements || !es2->elements)
	    cmp = 0;
	else if (es1->elements->dim != es2->elements->dim)
	    cmp = 0;
	else
	{
	    cmp = 1;
	    for (size_t i = 0; i < es1->elements->dim; i++)
	    {   Expression *ee1 = (Expression *)es1->elements->data[i];
		Expression *ee2 = (Expression *)es2->elements->data[i];

		if (ee1 == ee2)
		    continue;
		if (!ee1 || !ee2)
		{   cmp = 0;
		    break;
		}
		Expression *v = Equal(TOKequal, Type::tint32, ee1, ee2);
		if (v == EXP_CANT_INTERPRET)
		    return EXP_CANT_INTERPRET;
		cmp = v->toInteger();
		if (cmp == 0)
		    break;
	    }
	}
    }
#if 0 // Should handle this
    else if (e1->op == TOKarrayliteral && e2->op == TOKstring)
    {
    }
#endif
    else if (e1->isConst() != 1 || e2->isConst() != 1)
	return EXP_CANT_INTERPRET;
    else if (e1->type->isreal())
    {
	r1 = e1->toReal();
	r2 = e2->toReal();
	goto L1;
    }
    else if (e1->type->isimaginary())
    {
	r1 = e1->toImaginary();
	r2 = e2->toImaginary();
     L1:
#if __DMC__
	cmp = (r1 == r2);
#else
	if (isnan(r1) || isnan(r2))	// if unordered
	{
	    cmp = 0;
	}
	else
	{
	    cmp = (r1 == r2);
	}
#endif
    }
    else if (e1->type->iscomplex())
    {
	cmp = e1->toComplex() == e2->toComplex();
    }
    else if (e1->type->isintegral())
    {
	cmp = (e1->toInteger() == e2->toInteger());
    }
    else
	return EXP_CANT_INTERPRET;
    if (op == TOKnotequal)
	cmp ^= 1;
    e = new IntegerExp(loc, cmp, type);
    return e;
}

Expression *Identity(enum TOK op, Type *type, Expression *e1, Expression *e2)
{   Expression *e;
    Loc loc = e1->loc;
    int cmp;

    if (e1->op == TOKnull && e2->op == TOKnull)
    {
	cmp = 1;
    }
    else if (e1->op == TOKsymoff && e2->op == TOKsymoff)
    {
	SymOffExp *es1 = (SymOffExp *)e1;
	SymOffExp *es2 = (SymOffExp *)e2;

	cmp = (es1->var == es2->var && es1->offset == es2->offset);
    }
    else if (e1->isConst() == 1 && e2->isConst() == 1)
	return Equal((op == TOKidentity) ? TOKequal : TOKnotequal,
		type, e1, e2);
    else
	assert(0);
    if (op == TOKnotidentity)
	cmp ^= 1;
    return new IntegerExp(loc, cmp, type);
}


Expression *Cmp(enum TOK op, Type *type, Expression *e1, Expression *e2)
{   Expression *e;
    Loc loc = e1->loc;
    integer_t n;
    real_t r1;
    real_t r2;

    if (e1->type->isreal())
    {
	r1 = e1->toReal();
	r2 = e2->toReal();
	goto L1;
    }
    else if (e1->type->isimaginary())
    {
	r1 = e1->toImaginary();
	r2 = e2->toImaginary();
     L1:
#if __DMC__
	// DMC is the only compiler I know of that handles NAN arguments
	// correctly in comparisons.
	switch (op)
	{
	    case TOKlt:	   n = r1 <  r2;	break;
	    case TOKle:	   n = r1 <= r2;	break;
	    case TOKgt:	   n = r1 >  r2;	break;
	    case TOKge:	   n = r1 >= r2;	break;

	    case TOKleg:   n = r1 <>=  r2;	break;
	    case TOKlg:	   n = r1 <>   r2;	break;
	    case TOKunord: n = r1 !<>= r2;	break;
	    case TOKue:	   n = r1 !<>  r2;	break;
	    case TOKug:	   n = r1 !<=  r2;	break;
	    case TOKuge:   n = r1 !<   r2;	break;
	    case TOKul:	   n = r1 !>=  r2;	break;
	    case TOKule:   n = r1 !>   r2;	break;

	    default:
		assert(0);
	}
#else
	// Don't rely on compiler, handle NAN arguments separately
#if IN_GCC
	if (real_isnan(&r1) || real_isnan(&r2))	// if unordered
#else
	if (isnan(r1) || isnan(r2))	// if unordered
#endif
	{
	    switch (op)
	    {
		case TOKlt:	n = 0;	break;
		case TOKle:	n = 0;	break;
		case TOKgt:	n = 0;	break;
		case TOKge:	n = 0;	break;

		case TOKleg:	n = 0;	break;
		case TOKlg:	n = 0;	break;
		case TOKunord:	n = 1;	break;
		case TOKue:	n = 1;	break;
		case TOKug:	n = 1;	break;
		case TOKuge:	n = 1;	break;
		case TOKul:	n = 1;	break;
		case TOKule:	n = 1;	break;

		default:
		    assert(0);
	    }
	}
	else
	{
	    switch (op)
	    {
		case TOKlt:	n = r1 <  r2;	break;
		case TOKle:	n = r1 <= r2;	break;
		case TOKgt:	n = r1 >  r2;	break;
		case TOKge:	n = r1 >= r2;	break;

		case TOKleg:	n = 1;		break;
		case TOKlg:	n = r1 != r2;	break;
		case TOKunord:	n = 0;		break;
		case TOKue:	n = r1 == r2;	break;
		case TOKug:	n = r1 >  r2;	break;
		case TOKuge:	n = r1 >= r2;	break;
		case TOKul:	n = r1 <  r2;	break;
		case TOKule:	n = r1 <= r2;	break;

		default:
		    assert(0);
	    }
	}
#endif
    }
    else if (e1->type->iscomplex())
    {
	assert(0);
    }
    else
    {   sinteger_t n1;
	sinteger_t n2;

	n1 = e1->toInteger();
	n2 = e2->toInteger();
	if (e1->type->isunsigned() || e2->type->isunsigned())
	{
	    switch (op)
	    {
		case TOKlt:	n = ((d_uns64) n1) <  ((d_uns64) n2);	break;
		case TOKle:	n = ((d_uns64) n1) <= ((d_uns64) n2);	break;
		case TOKgt:	n = ((d_uns64) n1) >  ((d_uns64) n2);	break;
		case TOKge:	n = ((d_uns64) n1) >= ((d_uns64) n2);	break;

		case TOKleg:	n = 1;					break;
		case TOKlg:	n = ((d_uns64) n1) != ((d_uns64) n2);	break;
		case TOKunord:	n = 0;					break;
		case TOKue:	n = ((d_uns64) n1) == ((d_uns64) n2);	break;
		case TOKug:	n = ((d_uns64) n1) >  ((d_uns64) n2);	break;
		case TOKuge:	n = ((d_uns64) n1) >= ((d_uns64) n2);	break;
		case TOKul:	n = ((d_uns64) n1) <  ((d_uns64) n2);	break;
		case TOKule:	n = ((d_uns64) n1) <= ((d_uns64) n2);	break;

		default:
		    assert(0);
	    }
	}
	else
	{
	    switch (op)
	    {
		case TOKlt:	n = n1 <  n2;	break;
		case TOKle:	n = n1 <= n2;	break;
		case TOKgt:	n = n1 >  n2;	break;
		case TOKge:	n = n1 >= n2;	break;

		case TOKleg:	n = 1;		break;
		case TOKlg:	n = n1 != n2;	break;
		case TOKunord:	n = 0;		break;
		case TOKue:	n = n1 == n2;	break;
		case TOKug:	n = n1 >  n2;	break;
		case TOKuge:	n = n1 >= n2;	break;
		case TOKul:	n = n1 <  n2;	break;
		case TOKule:	n = n1 <= n2;	break;

		default:
		    assert(0);
	    }
	}
    }
    e = new IntegerExp(loc, n, type);
    return e;
}

/* Also returns EXP_CANT_INTERPRET if cannot be computed.
 *  to:	type to cast to
 *  type: type to paint the result
 */

Expression *Cast(Type *type, Type *to, Expression *e1)
{   Expression *e = EXP_CANT_INTERPRET;
    Loc loc = e1->loc;

    //printf("Cast(type = %s, to = %s, e1 = %s)\n", type->toChars(), to->toChars(), e1->toChars());
    //printf("e1->type = %s\n", e1->type->toChars());
    if (type->equals(e1->type) && to->equals(type))
	return e1;

    if (e1->isConst() != 1)
	return EXP_CANT_INTERPRET;

    Type *tb = to->toBasetype();
    if (tb->ty == Tbool)
	e = new IntegerExp(loc, e1->toInteger() != 0, type);
    else if (type->isintegral())
    {
	if (e1->type->isfloating())
	{   integer_t result;
	    real_t r = e1->toReal();

	    switch (type->toBasetype()->ty)
	    {
		case Tint8:	result = (d_int8)r;	break;
		case Tchar:
		case Tuns8:	result = (d_uns8)r;	break;
		case Tint16:	result = (d_int16)r;	break;
		case Twchar:
		case Tuns16:	result = (d_uns16)r;	break;
		case Tint32:	result = (d_int32)r;	break;
		case Tdchar:
		case Tuns32:	result = (d_uns32)r;	break;
		case Tint64:	result = (d_int64)r;	break;
		case Tuns64:	result = (d_uns64)r;	break;
		default:
		    assert(0);
	    }

	    e = new IntegerExp(loc, result, type);
	}
	else if (type->isunsigned())
	    e = new IntegerExp(loc, e1->toUInteger(), type);
	else
	    e = new IntegerExp(loc, e1->toInteger(), type);
    }
    else if (tb->isreal())
    {   real_t value = e1->toReal();

	e = new RealExp(loc, value, type);
    }
    else if (tb->isimaginary())
    {   real_t value = e1->toImaginary();

	e = new RealExp(loc, value, type);
    }
    else if (tb->iscomplex())
    {   complex_t value = e1->toComplex();

	e = new ComplexExp(loc, value, type);
    }
    else if (tb->isscalar())
	e = new IntegerExp(loc, e1->toInteger(), type);
    else if (tb->ty == Tvoid)
	e = EXP_CANT_INTERPRET;
    else if (tb->ty == Tstruct && e1->op == TOKint64)
    {	// Struct = 0;
	StructDeclaration *sd = tb->toDsymbol(NULL)->isStructDeclaration();
	assert(sd);
	Expressions *elements = new Expressions;
	for (size_t i = 0; i < sd->fields.dim; i++)
	{   Dsymbol *s = (Dsymbol *)sd->fields.data[i];
	    VarDeclaration *v = s->isVarDeclaration();
	    assert(v);

	    Expression *exp = new IntegerExp(0);
	    exp = Cast(v->type, v->type, exp);
	    if (exp == EXP_CANT_INTERPRET)
		return exp;
	    elements->push(exp);
	}
	e = new StructLiteralExp(loc, sd, elements);
	e->type = type;
    }
    else
    {
	error(loc, "cannot cast %s to %s", e1->type->toChars(), type->toChars());
	e = new IntegerExp(loc, 0, type);
    }
    return e;
}


Expression *ArrayLength(Type *type, Expression *e1)
{   Expression *e;
    Loc loc = e1->loc;

    if (e1->op == TOKstring)
    {	StringExp *es1 = (StringExp *)e1;

	e = new IntegerExp(loc, es1->len, type);
    }
    else if (e1->op == TOKarrayliteral)
    {	ArrayLiteralExp *ale = (ArrayLiteralExp *)e1;
	size_t dim;

	dim = ale->elements ? ale->elements->dim : 0;
	e = new IntegerExp(loc, dim, type);
    }
    else if (e1->op == TOKassocarrayliteral)
    {	AssocArrayLiteralExp *ale = (AssocArrayLiteralExp *)e1;
	size_t dim = ale->keys->dim;

	e = new IntegerExp(loc, dim, type);
    }
    else
	e = EXP_CANT_INTERPRET;
    return e;
}

/* Also return EXP_CANT_INTERPRET if this fails
 */
Expression *Index(Type *type, Expression *e1, Expression *e2)
{   Expression *e = EXP_CANT_INTERPRET;
    Loc loc = e1->loc;

    //printf("Index(e1 = %s, e2 = %s)\n", e1->toChars(), e2->toChars());
    assert(e1->type);
    if (e1->op == TOKstring && e2->op == TOKint64)
    {	StringExp *es1 = (StringExp *)e1;
	uinteger_t i = e2->toInteger();

	if (i >= es1->len)
	    e1->error("string index %ju is out of bounds [0 .. %zu]", i, es1->len);
	else
	{   unsigned value = es1->charAt(i);
	    e = new IntegerExp(loc, value, type);
	}
    }
    else if (e1->type->toBasetype()->ty == Tsarray && e2->op == TOKint64)
    {	TypeSArray *tsa = (TypeSArray *)e1->type->toBasetype();
	uinteger_t length = tsa->dim->toInteger();
	uinteger_t i = e2->toInteger();

	if (i >= length)
	{   e2->error("array index %ju is out of bounds %s[0 .. %ju]", i, e1->toChars(), length);
	}
	else if (e1->op == TOKarrayliteral && !e1->checkSideEffect(2))
	{   ArrayLiteralExp *ale = (ArrayLiteralExp *)e1;
	    e = (Expression *)ale->elements->data[i];
	    e->type = type;
	}
    }
    else if (e1->type->toBasetype()->ty == Tarray && e2->op == TOKint64)
    {
	uinteger_t i = e2->toInteger();

	if (e1->op == TOKarrayliteral && !e1->checkSideEffect(2))
	{   ArrayLiteralExp *ale = (ArrayLiteralExp *)e1;
	    if (i >= ale->elements->dim)
	    {   e2->error("array index %ju is out of bounds %s[0 .. %u]", i, e1->toChars(), ale->elements->dim);
	    }
	    else
	    {	e = (Expression *)ale->elements->data[i];
		e->type = type;
	    }
	}
    }
    else if (e1->op == TOKassocarrayliteral && !e1->checkSideEffect(2))
    {
	AssocArrayLiteralExp *ae = (AssocArrayLiteralExp *)e1;
	/* Search the keys backwards, in case there are duplicate keys
	 */
	for (size_t i = ae->keys->dim; i;)
	{
	    i--;
	    Expression *ekey = (Expression *)ae->keys->data[i];
	    Expression *ex = Equal(TOKequal, Type::tbool, ekey, e2);
	    if (ex == EXP_CANT_INTERPRET)
		return ex;
	    if (ex->isBool(TRUE))
	    {	e = (Expression *)ae->values->data[i];
		e->type = type;
		break;
	    }
	}
    }
    return e;
}

/* Also return EXP_CANT_INTERPRET if this fails
 */
Expression *Slice(Type *type, Expression *e1, Expression *lwr, Expression *upr)
{   Expression *e = EXP_CANT_INTERPRET;
    Loc loc = e1->loc;

#if LOG
    printf("Slice()\n");
    if (lwr)
    {	printf("\te1 = %s\n", e1->toChars());
	printf("\tlwr = %s\n", lwr->toChars());
	printf("\tupr = %s\n", upr->toChars());
    }
#endif
    if (e1->op == TOKstring && lwr->op == TOKint64 && upr->op == TOKint64)
    {	StringExp *es1 = (StringExp *)e1;
	uinteger_t ilwr = lwr->toInteger();
	uinteger_t iupr = upr->toInteger();

	if (iupr > es1->len || ilwr > iupr)
	    e1->error("string slice [%ju .. %ju] is out of bounds", ilwr, iupr);
	else
	{   integer_t value;
	    void *s;
	    size_t len = iupr - ilwr;
	    int sz = es1->sz;
	    StringExp *es;

	    s = mem.malloc((len + 1) * sz);
	    memcpy((unsigned char *)s, (unsigned char *)es1->string + ilwr * sz, len * sz);
	    memset((unsigned char *)s + len * sz, 0, sz);

	    es = new StringExp(loc, s, len, es1->postfix);
	    es->sz = sz;
	    es->committed = 1;
	    es->type = type;
	    e = es;
	}
    }
    else if (e1->op == TOKarrayliteral &&
	    lwr->op == TOKint64 && upr->op == TOKint64 &&
	    !e1->checkSideEffect(2))
    {	ArrayLiteralExp *es1 = (ArrayLiteralExp *)e1;
	uinteger_t ilwr = lwr->toInteger();
	uinteger_t iupr = upr->toInteger();

	if (iupr > es1->elements->dim || ilwr > iupr)
	    e1->error("array slice [%ju .. %ju] is out of bounds", ilwr, iupr);
	else
	{
	    Expressions *elements = new Expressions();
	    elements->setDim(iupr - ilwr);
	    memcpy(elements->data,
		   es1->elements->data + ilwr,
		   (iupr - ilwr) * sizeof(es1->elements->data[0]));
	    e = new ArrayLiteralExp(e1->loc, elements);
	    e->type = type;
	}
    }
    return e;
}

/* Also return EXP_CANT_INTERPRET if this fails
 */
Expression *Cat(Type *type, Expression *e1, Expression *e2)
{   Expression *e = EXP_CANT_INTERPRET;
    Loc loc = e1->loc;
    Type *t;
    Type *t1 = e1->type->toBasetype();
    Type *t2 = e2->type->toBasetype();

    //printf("Cat(e1 = %s, e2 = %s)\n", e1->toChars(), e2->toChars());

    if (e1->op == TOKnull && (e2->op == TOKint64 || e2->op == TOKstructliteral))
    {	e = e2;
	goto L2;
    }
    else if ((e1->op == TOKint64 || e1->op == TOKstructliteral) && e2->op == TOKnull)
    {	e = e1;
     L2:
	Type *tn = e->type->toBasetype();
	if (tn->ty == Tchar || tn->ty == Twchar || tn->ty == Tdchar)
	{
	    // Create a StringExp
	    void *s;
	    StringExp *es;
	    size_t len = 1;
	    int sz = tn->size();
	    integer_t v = e->toInteger();

	    s = mem.malloc((len + 1) * sz);
	    memcpy((unsigned char *)s, &v, sz);

	    // Add terminating 0
	    memset((unsigned char *)s + len * sz, 0, sz);

	    es = new StringExp(loc, s, len);
	    es->sz = sz;
	    es->committed = 1;
	    e = es;
	}
	else
	{   // Create an ArrayLiteralExp
	    Expressions *elements = new Expressions();
	    elements->push(e);
	    e = new ArrayLiteralExp(e->loc, elements);
	}
	e->type = type;
	return e;
    }
    else if (e1->op == TOKstring && e2->op == TOKstring)
    {
	// Concatenate the strings
	void *s;
	StringExp *es1 = (StringExp *)e1;
	StringExp *es2 = (StringExp *)e2;
	StringExp *es;
	Type *t;
	size_t len = es1->len + es2->len;
	int sz = es1->sz;

	if (sz != es2->sz)
	{
	    /* Can happen with:
	     *   auto s = "foo"d ~ "bar"c;
	     */
	    assert(global.errors);
	    return e;
	}
	s = mem.malloc((len + 1) * sz);
	memcpy(s, es1->string, es1->len * sz);
	memcpy((unsigned char *)s + es1->len * sz, es2->string, es2->len * sz);

	// Add terminating 0
	memset((unsigned char *)s + len * sz, 0, sz);

	es = new StringExp(loc, s, len);
	es->sz = sz;
	es->committed = es1->committed | es2->committed;
	if (es1->committed)
	    t = es1->type;
	else
	    t = es2->type;
	es->type = type;
	e = es;
    }
    else if (e1->op == TOKstring && e2->op == TOKint64)
    {
	// Concatenate the strings
	void *s;
	StringExp *es1 = (StringExp *)e1;
	StringExp *es;
	Type *t;
	size_t len = es1->len + 1;
	int sz = es1->sz;
	integer_t v = e2->toInteger();

	s = mem.malloc((len + 1) * sz);
	memcpy(s, es1->string, es1->len * sz);
	memcpy((unsigned char *)s + es1->len * sz, &v, sz);

	// Add terminating 0
	memset((unsigned char *)s + len * sz, 0, sz);

	es = new StringExp(loc, s, len);
	es->sz = sz;
	es->committed = es1->committed;
	t = es1->type;
	es->type = type;
	e = es;
    }
    else if (e1->op == TOKint64 && e2->op == TOKstring)
    {
	// Concatenate the strings
	void *s;
	StringExp *es2 = (StringExp *)e2;
	StringExp *es;
	Type *t;
	size_t len = 1 + es2->len;
	int sz = es2->sz;
	integer_t v = e1->toInteger();

	s = mem.malloc((len + 1) * sz);
	memcpy((unsigned char *)s, &v, sz);
	memcpy((unsigned char *)s + sz, es2->string, es2->len * sz);

	// Add terminating 0
	memset((unsigned char *)s + len * sz, 0, sz);

	es = new StringExp(loc, s, len);
	es->sz = sz;
	es->committed = es2->committed;
	t = es2->type;
	es->type = type;
	e = es;
    }
    else if (e1->op == TOKarrayliteral && e2->op == TOKarrayliteral &&
	e1->type->equals(e2->type))
    {
	// Concatenate the arrays
	ArrayLiteralExp *es1 = (ArrayLiteralExp *)e1;
	ArrayLiteralExp *es2 = (ArrayLiteralExp *)e2;

	es1 = new ArrayLiteralExp(es1->loc, (Expressions *)es1->elements->copy());
	es1->elements->insert(es1->elements->dim, es2->elements);
	e = es1;

	if (type->toBasetype()->ty == Tsarray)
	{
	    e->type = new TypeSArray(e1->type->toBasetype()->next, new IntegerExp(0, es1->elements->dim, Type::tindex));
	    e->type = e->type->semantic(loc, NULL);
	}
	else
	    e->type = type;
    }
    else if (e1->op == TOKarrayliteral && e2->op == TOKnull &&
	t1->nextOf()->equals(t2->nextOf()))
    {
	e = e1;
	goto L3;
    }
    else if (e1->op == TOKnull && e2->op == TOKarrayliteral &&
	t1->nextOf()->equals(t2->nextOf()))
    {
	e = e2;
     L3:
	// Concatenate the array with null
	ArrayLiteralExp *es = (ArrayLiteralExp *)e;

	es = new ArrayLiteralExp(es->loc, (Expressions *)es->elements->copy());
	e = es;

	if (type->toBasetype()->ty == Tsarray)
	{
	    e->type = new TypeSArray(t1->nextOf(), new IntegerExp(loc, es->elements->dim, Type::tindex));
	    e->type = e->type->semantic(loc, NULL);
	}
	else
	    e->type = type;
    }
    else if ((e1->op == TOKarrayliteral || e1->op == TOKnull) &&
	e1->type->toBasetype()->nextOf()->equals(e2->type))
    {
	ArrayLiteralExp *es1;
	if (e1->op == TOKarrayliteral)
	{   es1 = (ArrayLiteralExp *)e1;
	    es1 = new ArrayLiteralExp(es1->loc, (Expressions *)es1->elements->copy());
	    es1->elements->push(e2);
	}
	else
	{
	    es1 = new ArrayLiteralExp(e1->loc, e2);
	}
	e = es1;

	if (type->toBasetype()->ty == Tsarray)
	{
	    e->type = new TypeSArray(e2->type, new IntegerExp(0, es1->elements->dim, Type::tindex));
	    e->type = e->type->semantic(loc, NULL);
	}
	else
	    e->type = type;
    }
    else if (e2->op == TOKarrayliteral &&
	e2->type->toBasetype()->nextOf()->equals(e1->type))
    {
	ArrayLiteralExp *es2 = (ArrayLiteralExp *)e2;

	es2 = new ArrayLiteralExp(es2->loc, (Expressions *)es2->elements->copy());
	es2->elements->shift(e1);
	e = es2;

	if (type->toBasetype()->ty == Tsarray)
	{
	    e->type = new TypeSArray(e1->type, new IntegerExp(0, es2->elements->dim, Type::tindex));
	    e->type = e->type->semantic(loc, NULL);
	}
	else
	    e->type = type;
    }
    else if (e1->op == TOKnull && e2->op == TOKstring)
    {
	t = e1->type;
	e = e2;
	goto L1;
    }
    else if (e1->op == TOKstring && e2->op == TOKnull)
    {	e = e1;
	t = e2->type;
      L1:
	Type *tb = t->toBasetype();
	if (tb->ty == Tarray && tb->nextOf()->equals(e->type))
	{   Expressions *expressions = new Expressions();
	    expressions->push(e);
	    e = new ArrayLiteralExp(loc, expressions);
	    e->type = t;
	}
	if (!e->type->equals(type))
	{   StringExp *se = (StringExp *)e->copy();
	    e = se->castTo(NULL, type);
	}
    }
    return e;
}

Expression *Ptr(Type *type, Expression *e1)
{
    //printf("Ptr(e1 = %s)\n", e1->toChars());
    if (e1->op == TOKadd)
    {	AddExp *ae = (AddExp *)e1;
	if (ae->e1->op == TOKaddress && ae->e2->op == TOKint64)
	{   AddrExp *ade = (AddrExp *)ae->e1;
	    if (ade->e1->op == TOKstructliteral)
	    {	StructLiteralExp *se = (StructLiteralExp *)ade->e1;
		unsigned offset = ae->e2->toInteger();
		Expression *e = se->getField(type, offset);
		if (!e)
		    e = EXP_CANT_INTERPRET;
		return e;
	    }
	}
    }
    return EXP_CANT_INTERPRET;
}