[Xen-devel] Re: [PATCH] mini-os: lib/math.c: import FreeBSD 8 functions

[Keir Fraser <keir.xen@xxxxxxxxx>]

Should the license terms really be enumerated 1, 2, 4?

 -- Keir

On 30/04/2011 17:10, "Samuel Thibault" <samuel.thibault@xxxxxxxxxxxx> wrote:

> Import lib/math.c functions (and thus licence) from FreeBSD 8,
> and re-apply a few of our changes. Whitespaces left aside, this
> leads to almost no source change except s/int64_t/quad_t/ and
> s/uint64_t/u_quad_t/.
> 
> Signed-off-by: Samuel Thibault <samuel.thibault@xxxxxxxxxxxx>
> 
> diff -r 7745109e3c6e extras/mini-os/lib/math.c
> --- a/extras/mini-os/lib/math.c Wed Apr 27 13:36:15 2011 +0100
> +++ b/extras/mini-os/lib/math.c Sat Apr 30 18:06:08 2011 +0200
> @@ -13,10 +13,6 @@
>   * Description:  Library functions for 64bit arith and other
>   *               from freebsd, files in sys/libkern/ (qdivrem.c, etc)
>   *
> - ****************************************************************************
> - * $Id: c-insert.c,v 1.7 2002/11/08 16:04:34 rn Exp $
> - ****************************************************************************
> - *-
>   * Copyright (c) 1992, 1993
>   * The Regents of the University of California.  All rights reserved.
>   *
> @@ -32,10 +28,6 @@
>   * 2. Redistributions in binary form must reproduce the above copyright
>   *    notice, this list of conditions and the following disclaimer in the
>   *    documentation and/or other materials provided with the distribution.
> - * 3. All advertising materials mentioning features or use of this software
> - *    must display the following acknowledgement:
> - * This product includes software developed by the University of
> - * California, Berkeley and its contributors.
>   * 4. Neither the name of the University nor the names of its contributors
>   *    may be used to endorse or promote products derived from this software
>   *    without specific prior written permission.
> @@ -52,7 +44,6 @@
>   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
>   * SUCH DAMAGE.
>   *
> - * $FreeBSD: src/sys/libkern/divdi3.c,v 1.6 1999/08/28 00:46:31 peter Exp $
>  */
>  
>  #include <mini-os/types.h>
> @@ -63,49 +54,62 @@
> * assembler functions. */
>  #if !defined(__ia64__)
>  
> +/* XXX RN: Yuck hardcoded endianess :) */
> +#define _QUAD_HIGHWORD 1
> +#define _QUAD_LOWWORD 0
> +
> +/*
> + * From
> + * @(#)quad.h 8.1 (Berkeley) 6/4/93
> + */
> +
>  /*
>   * Depending on the desired operation, we view a `long long' (aka quad_t) in
>   * one or more of the following formats.
>   */
>  union uu {
> -        int64_t           q;              /* as a (signed) quad */
> -        int64_t          uq;             /* as an unsigned quad */
> -        int32_t        sl[2];          /* as two signed ints */
> -        uint32_t       ul[2];          /* as two unsigned ints */
> + quad_t q;  /* as a (signed) quad */
> + quad_t uq;  /* as an unsigned quad */
> + int32_t sl[2];  /* as two signed longs */
> + uint32_t ul[2];  /* as two unsigned longs */
>  };
> -/* XXX RN: Yuck hardcoded endianess :) */
> -#define _QUAD_HIGHWORD 1
> -#define _QUAD_LOWWORD 0
> +
>  /*
>   * Define high and low longwords.
>   */
> -#define H               _QUAD_HIGHWORD
> -#define L               _QUAD_LOWWORD
> +#define H  _QUAD_HIGHWORD
> +#define L  _QUAD_LOWWORD
>  
>  /*
> - * Total number of bits in a quad_t and in the pieces that make it up.
> + * Total number of bits in an quad_t and in the pieces that make it up.
>   * These are used for shifting, and also below for halfword extraction
>   * and assembly.
>   */
>  #ifndef HAVE_LIBC
>  #define CHAR_BIT        8               /* number of bits in a char */
>  #endif
> -#define QUAD_BITS       (sizeof(int64_t) * CHAR_BIT)
> -#define LONG_BITS       (sizeof(int32_t) * CHAR_BIT)
> -#define HALF_BITS       (sizeof(int32_t) * CHAR_BIT / 2)
> +#define QUAD_BITS (sizeof(quad_t) * CHAR_BIT)
> +#define LONG_BITS (sizeof(int32_t) * CHAR_BIT)
> +#define HALF_BITS (sizeof(int32_t) * CHAR_BIT / 2)
>  
>  /*
> - * Extract high and low shortwords from intword, and move low shortword of
> - * intword to upper half of int32_t, i.e., produce the upper intword of
> - * ((quad_t)(x) << (number_of_bits_in_int/2)).  (`x' must actually be
> uint32_t.)
> + * Extract high and low shortwords from longword, and move low shortword of
> + * longword to upper half of int32_t, i.e., produce the upper longword of
> + * ((quad_t)(x) << (number_of_bits_in_long/2)).  (`x' must actually be
> uint32_t.)
>   *
> - * These are used in the multiply code, to split a intword into upper
> + * These are used in the multiply code, to split a longword into upper
>   * and lower halves, and to reassemble a product as a quad_t, shifted left
>   * (sizeof(int32_t)*CHAR_BIT/2).
>   */
> -#define HHALF(x)        ((x) >> HALF_BITS)
> -#define LHALF(x)        ((x) & ((1UL << HALF_BITS) - 1))
> -#define LHUP(x)         ((x) << HALF_BITS)
> +#define HHALF(x) ((x) >> HALF_BITS)
> +#define LHALF(x) ((x) & ((1UL << HALF_BITS) - 1))
> +#define LHUP(x)  ((x) << HALF_BITS)
> +
> +
> +/*
> + * From
> + * qdivrem.c
> + */
>  
>  /*
>   * Multiprecision divide.  This algorithm is from Knuth vol. 2 (2nd ed),
> @@ -119,7 +123,6 @@
>  /* select a type for digits in base B: */
>  typedef uint16_t digit;
>  
> -
>  /*
>   * Shift p[0]..p[len] left `sh' bits, ignoring any bits that
>   * `fall out' the left (there never will be any such anyway).
> @@ -143,8 +146,8 @@
>   * divisor are 4 `digits' in this base (they are shorter if they have
>   * leading zeros).
>   */
> -uint64_t
> -__qdivrem(uint64_t uq, uint64_t vq, uint64_t *arq)
> +u_quad_t
> +__qdivrem(u_quad_t uq, u_quad_t vq, u_quad_t *arq)
>  {
> union uu tmp;
> digit *u, *v, *q;
> @@ -339,38 +342,51 @@
> return (tmp.q);
>  }
>  
> +/*
> + * From
> + * divdi3.c
> + */
>  
>  /*
>   * Divide two signed quads.
>   * ??? if -1/2 should produce -1 on this machine, this code is wrong
>   */
> -int64_t
> -__divdi3(int64_t a, int64_t b)
> +quad_t
> +__divdi3(quad_t a, quad_t b)
>  {
> - uint64_t ua, ub, uq;
> + u_quad_t ua, ub, uq;
> int neg;
>  
> if (a < 0)
> -  ua = -(uint64_t)a, neg = 1;
> +  ua = -(u_quad_t)a, neg = 1;
> else
> ua = a, neg = 0;
> if (b < 0)
> -  ub = -(uint64_t)b, neg ^= 1;
> +  ub = -(u_quad_t)b, neg ^= 1;
> else
> ub = b;
> - uq = __qdivrem(ua, ub, (uint64_t *)0);
> + uq = __qdivrem(ua, ub, (u_quad_t *)0);
> return (neg ? -uq : uq);
>  }
>  
>  /*
> + * From
> + * udivdi3.c
> + */
> +
> +/*
>   * Divide two unsigned quads.
>   */
> -uint64_t
> -__udivdi3(uint64_t a, uint64_t b)
> +u_quad_t
> +__udivdi3(u_quad_t a, u_quad_t b)
>  {
> -        return (__qdivrem(a, b, (uint64_t *)0));
> + return (__qdivrem(a, b, (u_quad_t *)0));
>  }
>  
> +/*
> + * From
> + * umoddi3.c
> + */
>  
>  /*
>   * Return remainder after dividing two unsigned quads.
> @@ -378,13 +394,18 @@
>  u_quad_t
>  __umoddi3(u_quad_t a, u_quad_t b)
>  {
> -        u_quad_t r;
> + u_quad_t r;
>  
> -        (void)__qdivrem(a, b, &r);
> -        return (r);
> + (void)__qdivrem(a, b, &r);
> + return (r);
>  }
>  
>  /*
> + * From
> + * moddi3.c
> + */
> +
> +/*
>   * Return remainder after dividing two signed quads.
>   *
>   * XXX



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