tinycc/libtcc1.c

/* TCC runtime library. 
   Parts of this code are (c) 2002 Fabrice Bellard 

   Copyright (C) 1987, 1988, 1992, 1994, 1995 Free Software Foundation, Inc.

This file is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 2, or (at your option) any
later version.

In addition to the permissions in the GNU General Public License, the
Free Software Foundation gives you unlimited permission to link the
compiled version of this file into combinations with other programs,
and to distribute those combinations without any restriction coming
from the use of this file.  (The General Public License restrictions
do apply in other respects; for example, they cover modification of
the file, and distribution when not linked into a combine
executable.)

This file is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; see the file COPYING.  If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  
*/

#define W_TYPE_SIZE   32
#define BITS_PER_UNIT 8

typedef int Wtype;
typedef unsigned int UWtype;
typedef unsigned int USItype;
typedef long long DWtype;
typedef unsigned long long UDWtype;

struct DWstruct {
    Wtype low, high;
};

typedef union
{
  struct DWstruct s;
  DWtype ll;
} DWunion;

typedef long double XFtype;
#define WORD_SIZE (sizeof (Wtype) * BITS_PER_UNIT)
#define HIGH_WORD_COEFF (((UDWtype) 1) << WORD_SIZE)

/* the following deal with IEEE single-precision numbers */
#define EXCESS		126
#define SIGNBIT		0x80000000
#define HIDDEN		(1 << 23)
#define SIGN(fp)	((fp) & SIGNBIT)
#define EXP(fp)		(((fp) >> 23) & 0xFF)
#define MANT(fp)	(((fp) & 0x7FFFFF) | HIDDEN)
#define PACK(s,e,m)	((s) | ((e) << 23) | (m))

/* the following deal with IEEE double-precision numbers */
#define EXCESSD		1022
#define HIDDEND		(1 << 20)
#define EXPD(fp)	(((fp.l.upper) >> 20) & 0x7FF)
#define SIGND(fp)	((fp.l.upper) & SIGNBIT)
#define MANTD(fp)	(((((fp.l.upper) & 0xFFFFF) | HIDDEND) << 10) | \
				(fp.l.lower >> 22))
#define HIDDEND_LL	((long long)1 << 52)
#define MANTD_LL(fp)	((fp.ll & (HIDDEND_LL-1)) | HIDDEND_LL)
#define PACKD_LL(s,e,m)	(((long long)((s)+((e)<<20))<<32)|(m))

/* the following deal with x86 long double-precision numbers */
#define EXCESSLD	16382
#define EXPLD(fp)	(fp.l.upper & 0x7fff)
#define SIGNLD(fp)	((fp.l.upper) & 0x8000)

/* only for x86 */
union ldouble_long {
    long double ld;
    struct {
        unsigned long long lower;
        unsigned short upper;
    } l;
};

union double_long {
    double d;
#if 1
    struct {
        unsigned long lower;
        long upper;
    } l;
#else
    struct {
        long upper;
        unsigned long lower;
    } l;
#endif
    long long ll;
};

union float_long {
    float f;
    long l;
};

/* XXX: use gcc/tcc intrinsic ? */
#if defined(__i386__)
#define sub_ddmmss(sh, sl, ah, al, bh, bl) \
  __asm__ ("subl %5,%1\n\tsbbl %3,%0"					\
	   : "=r" ((USItype) (sh)),					\
	     "=&r" ((USItype) (sl))					\
	   : "0" ((USItype) (ah)),					\
	     "g" ((USItype) (bh)),					\
	     "1" ((USItype) (al)),					\
	     "g" ((USItype) (bl)))
#define umul_ppmm(w1, w0, u, v) \
  __asm__ ("mull %3"							\
	   : "=a" ((USItype) (w0)),					\
	     "=d" ((USItype) (w1))					\
	   : "%0" ((USItype) (u)),					\
	     "rm" ((USItype) (v)))
#define udiv_qrnnd(q, r, n1, n0, dv) \
  __asm__ ("divl %4"							\
	   : "=a" ((USItype) (q)),					\
	     "=d" ((USItype) (r))					\
	   : "0" ((USItype) (n0)),					\
	     "1" ((USItype) (n1)),					\
	     "rm" ((USItype) (dv)))
#define count_leading_zeros(count, x) \
  do {									\
    USItype __cbtmp;							\
    __asm__ ("bsrl %1,%0"						\
	     : "=r" (__cbtmp) : "rm" ((USItype) (x)));			\
    (count) = __cbtmp ^ 31;						\
  } while (0)
#else
#error unsupported CPU type
#endif

/* most of this code is taken from libgcc2.c from gcc */

static UDWtype __udivmoddi4 (UDWtype n, UDWtype d, UDWtype *rp)
{
  DWunion ww;
  DWunion nn, dd;
  DWunion rr;
  UWtype d0, d1, n0, n1, n2;
  UWtype q0, q1;
  UWtype b, bm;

  nn.ll = n;
  dd.ll = d;

  d0 = dd.s.low;
  d1 = dd.s.high;
  n0 = nn.s.low;
  n1 = nn.s.high;

#if !UDIV_NEEDS_NORMALIZATION
  if (d1 == 0)
    {
      if (d0 > n1)
	{
	  /* 0q = nn / 0D */

	  udiv_qrnnd (q0, n0, n1, n0, d0);
	  q1 = 0;

	  /* Remainder in n0.  */
	}
      else
	{
	  /* qq = NN / 0d */

	  if (d0 == 0)
	    d0 = 1 / d0;	/* Divide intentionally by zero.  */

	  udiv_qrnnd (q1, n1, 0, n1, d0);
	  udiv_qrnnd (q0, n0, n1, n0, d0);

	  /* Remainder in n0.  */
	}

      if (rp != 0)
	{
	  rr.s.low = n0;
	  rr.s.high = 0;
	  *rp = rr.ll;
	}
    }

#else /* UDIV_NEEDS_NORMALIZATION */

  if (d1 == 0)
    {
      if (d0 > n1)
	{
	  /* 0q = nn / 0D */

	  count_leading_zeros (bm, d0);

	  if (bm != 0)
	    {
	      /* Normalize, i.e. make the most significant bit of the
		 denominator set.  */

	      d0 = d0 << bm;
	      n1 = (n1 << bm) | (n0 >> (W_TYPE_SIZE - bm));
	      n0 = n0 << bm;
	    }

	  udiv_qrnnd (q0, n0, n1, n0, d0);
	  q1 = 0;

	  /* Remainder in n0 >> bm.  */
	}
      else
	{
	  /* qq = NN / 0d */

	  if (d0 == 0)
	    d0 = 1 / d0;	/* Divide intentionally by zero.  */

	  count_leading_zeros (bm, d0);

	  if (bm == 0)
	    {
	      /* From (n1 >= d0) /\ (the most significant bit of d0 is set),
		 conclude (the most significant bit of n1 is set) /\ (the
		 leading quotient digit q1 = 1).

		 This special case is necessary, not an optimization.
		 (Shifts counts of W_TYPE_SIZE are undefined.)  */

	      n1 -= d0;
	      q1 = 1;
	    }
	  else
	    {
	      /* Normalize.  */

	      b = W_TYPE_SIZE - bm;

	      d0 = d0 << bm;
	      n2 = n1 >> b;
	      n1 = (n1 << bm) | (n0 >> b);
	      n0 = n0 << bm;

	      udiv_qrnnd (q1, n1, n2, n1, d0);
	    }

	  /* n1 != d0...  */

	  udiv_qrnnd (q0, n0, n1, n0, d0);

	  /* Remainder in n0 >> bm.  */
	}

      if (rp != 0)
	{
	  rr.s.low = n0 >> bm;
	  rr.s.high = 0;
	  *rp = rr.ll;
	}
    }
#endif /* UDIV_NEEDS_NORMALIZATION */

  else
    {
      if (d1 > n1)
	{
	  /* 00 = nn / DD */

	  q0 = 0;
	  q1 = 0;

	  /* Remainder in n1n0.  */
	  if (rp != 0)
	    {
	      rr.s.low = n0;
	      rr.s.high = n1;
	      *rp = rr.ll;
	    }
	}
      else
	{
	  /* 0q = NN / dd */

	  count_leading_zeros (bm, d1);
	  if (bm == 0)
	    {
	      /* From (n1 >= d1) /\ (the most significant bit of d1 is set),
		 conclude (the most significant bit of n1 is set) /\ (the
		 quotient digit q0 = 0 or 1).

		 This special case is necessary, not an optimization.  */

	      /* The condition on the next line takes advantage of that
		 n1 >= d1 (true due to program flow).  */
	      if (n1 > d1 || n0 >= d0)
		{
		  q0 = 1;
		  sub_ddmmss (n1, n0, n1, n0, d1, d0);
		}
	      else
		q0 = 0;

	      q1 = 0;

	      if (rp != 0)
		{
		  rr.s.low = n0;
		  rr.s.high = n1;
		  *rp = rr.ll;
		}
	    }
	  else
	    {
	      UWtype m1, m0;
	      /* Normalize.  */

	      b = W_TYPE_SIZE - bm;

	      d1 = (d1 << bm) | (d0 >> b);
	      d0 = d0 << bm;
	      n2 = n1 >> b;
	      n1 = (n1 << bm) | (n0 >> b);
	      n0 = n0 << bm;

	      udiv_qrnnd (q0, n1, n2, n1, d1);
	      umul_ppmm (m1, m0, q0, d0);

	      if (m1 > n1 || (m1 == n1 && m0 > n0))
		{
		  q0--;
		  sub_ddmmss (m1, m0, m1, m0, d1, d0);
		}

	      q1 = 0;

	      /* Remainder in (n1n0 - m1m0) >> bm.  */
	      if (rp != 0)
		{
		  sub_ddmmss (n1, n0, n1, n0, m1, m0);
		  rr.s.low = (n1 << b) | (n0 >> bm);
		  rr.s.high = n1 >> bm;
		  *rp = rr.ll;
		}
	    }
	}
    }

  ww.s.low = q0;
  ww.s.high = q1;
  return ww.ll;
}

#define __negdi2(a) (-(a))

long long __divdi3(long long u, long long v)
{
    int c = 0;
    DWunion uu, vv;
    DWtype w;
    
    uu.ll = u;
    vv.ll = v;
    
    if (uu.s.high < 0) {
        c = ~c;
        uu.ll = __negdi2 (uu.ll);
    }
    if (vv.s.high < 0) {
        c = ~c;
        vv.ll = __negdi2 (vv.ll);
    }
    w = __udivmoddi4 (uu.ll, vv.ll, (UDWtype *) 0);
    if (c)
        w = __negdi2 (w);
    return w;
}

long long __moddi3(long long u, long long v)
{
    int c = 0;
    DWunion uu, vv;
    DWtype w;
    
    uu.ll = u;
    vv.ll = v;
    
    if (uu.s.high < 0) {
        c = ~c;
        uu.ll = __negdi2 (uu.ll);
    }
    if (vv.s.high < 0)
        vv.ll = __negdi2 (vv.ll);
    
    __udivmoddi4 (uu.ll, vv.ll, &w);
    if (c)
        w = __negdi2 (w);
    return w;
}

unsigned long long __udivdi3(unsigned long long u, unsigned long long v)
{
    return __udivmoddi4 (u, v, (UDWtype *) 0);
}

unsigned long long __umoddi3(unsigned long long u, unsigned long long v)
{
    UDWtype w;
    
    __udivmoddi4 (u, v, &w);
    return w;
}

/* XXX: fix tcc's code generator to do this instead */
long long __sardi3(long long a, int b)
{
#ifdef __TINYC__
    DWunion u;
    u.ll = a;
    if (b >= 32) {
        u.s.low = u.s.high >> (b - 32);
        u.s.high = u.s.high >> 31;
    } else if (b != 0) {
        u.s.low = ((unsigned)u.s.low >> b) | (u.s.high << (32 - b));
        u.s.high = u.s.high >> b;
    }
    return u.ll;
#else
    return a >> b;
#endif
}

/* XXX: fix tcc's code generator to do this instead */
unsigned long long __shrdi3(unsigned long long a, int b)
{
#ifdef __TINYC__
    DWunion u;
    u.ll = a;
    if (b >= 32) {
        u.s.low = (unsigned)u.s.high >> (b - 32);
        u.s.high = 0;
    } else if (b != 0) {
        u.s.low = ((unsigned)u.s.low >> b) | (u.s.high << (32 - b));
        u.s.high = (unsigned)u.s.high >> b;
    }
    return u.ll;
#else
    return a >> b;
#endif
}

/* XXX: fix tcc's code generator to do this instead */
long long __shldi3(long long a, int b)
{
#ifdef __TINYC__
    DWunion u;
    u.ll = a;
    if (b >= 32) {
        u.s.high = (unsigned)u.s.low << (b - 32);
        u.s.low = 0;
    } else if (b != 0) {
        u.s.high = ((unsigned)u.s.high << b) | (u.s.low >> (32 - b));
        u.s.low = (unsigned)u.s.low << b;
    }
    return u.ll;
#else
    return a << b;
#endif
}

#if defined(__i386__)
/* FPU control word for rounding to nearest mode */
unsigned short __tcc_fpu_control = 0x137f;
/* FPU control word for round to zero mode for int conversion */
unsigned short __tcc_int_fpu_control = 0x137f | 0x0c00;
#endif

/* XXX: fix tcc's code generator to do this instead */
float __ulltof(unsigned long long a)
{
    DWunion uu; 
    XFtype r;

    uu.ll = a;
    if (uu.s.high >= 0) {
        return (float)uu.ll;
    } else {
        r = (XFtype)uu.ll;
        r += 18446744073709551616.0;
        return (float)r;
    }
}

double __ulltod(unsigned long long a)
{
    DWunion uu; 
    XFtype r;

    uu.ll = a;
    if (uu.s.high >= 0) {
        return (double)uu.ll;
    } else {
        r = (XFtype)uu.ll;
        r += 18446744073709551616.0;
        return (double)r;
    }
}

long double __ulltold(unsigned long long a)
{
    DWunion uu; 
    XFtype r;

    uu.ll = a;
    if (uu.s.high >= 0) {
        return (long double)uu.ll;
    } else {
        r = (XFtype)uu.ll;
        r += 18446744073709551616.0;
        return (long double)r;
    }
}

unsigned long long __fixunssfdi (float a1)
{
    register union float_long fl1;
    register int exp;
    register unsigned long l;

    fl1.f = a1;

    if (fl1.l == 0)
	return (0);

    exp = EXP (fl1.l) - EXCESS - 24;

    l = MANT(fl1.l);
    if (exp >= 41)
	return (unsigned long long)-1;
    else if (exp >= 0)
        return (unsigned long long)l << exp;
    else if (exp >= -23)
        return l >> -exp;
    else
        return 0;
}

unsigned long long __fixunsdfdi (double a1)
{
    register union double_long dl1;
    register int exp;
    register unsigned long long l;

    dl1.d = a1;

    if (dl1.ll == 0)
	return (0);

    exp = EXPD (dl1) - EXCESSD - 53;

    l = MANTD_LL(dl1);

    if (exp >= 12)
	return (unsigned long long)-1;
    else if (exp >= 0)
        return l << exp;
    else if (exp >= -52)
        return l >> -exp;
    else
        return 0;
}

unsigned long long __fixunsxfdi (long double a1)
{
    register union ldouble_long dl1;
    register int exp;
    register unsigned long long l;

    dl1.ld = a1;

    if (dl1.l.lower == 0 && dl1.l.upper == 0)
	return (0);

    exp = EXPLD (dl1) - EXCESSLD - 64;

    l = dl1.l.lower;

    if (exp > 0)
	return (unsigned long long)-1;
    else if (exp >= -63) 
        return l >> -exp;
    else
        return 0;
}