mirror of
https://github.com/autc04/Retro68.git
synced 2024-11-27 14:50:23 +00:00
305 lines
7.3 KiB
C
305 lines
7.3 KiB
C
/* Signed and unsigned multiplication and division and modulus for CRIS.
|
|
Contributed by Axis Communications.
|
|
Written by Hans-Peter Nilsson <hp@axis.se>, c:a 1992.
|
|
|
|
Copyright (C) 1998, 1999, 2000, 2001, 2002,
|
|
2005, 2009 Free Software Foundation, Inc.
|
|
|
|
This file is part of GCC.
|
|
|
|
GCC 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 3, or (at your option) any
|
|
later version.
|
|
|
|
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.
|
|
|
|
Under Section 7 of GPL version 3, you are granted additional
|
|
permissions described in the GCC Runtime Library Exception, version
|
|
3.1, as published by the Free Software Foundation.
|
|
|
|
You should have received a copy of the GNU General Public License and
|
|
a copy of the GCC Runtime Library Exception along with this program;
|
|
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
|
|
/* Note that we provide prototypes for all "const" functions, to attach
|
|
the const attribute. This is necessary in 2.7.2 - adding the
|
|
attribute to the function *definition* is a syntax error.
|
|
This did not work with e.g. 2.1; back then, the return type had to
|
|
be "const". */
|
|
|
|
#include "config.h"
|
|
|
|
#if defined (__CRIS_arch_version) && __CRIS_arch_version >= 3
|
|
#define LZ(v) __builtin_clz (v)
|
|
#endif
|
|
|
|
|
|
#if defined (L_udivsi3) || defined (L_divsi3) || defined (L_umodsi3) \
|
|
|| defined (L_modsi3)
|
|
/* Result type of divmod worker function. */
|
|
struct quot_rem
|
|
{
|
|
long quot;
|
|
long rem;
|
|
};
|
|
|
|
/* This is the worker function for div and mod. It is inlined into the
|
|
respective library function. Parameter A must have bit 31 == 0. */
|
|
|
|
static __inline__ struct quot_rem
|
|
do_31div (unsigned long a, unsigned long b)
|
|
__attribute__ ((__const__, __always_inline__));
|
|
|
|
static __inline__ struct quot_rem
|
|
do_31div (unsigned long a, unsigned long b)
|
|
{
|
|
/* Adjust operands and result if a is 31 bits. */
|
|
long extra = 0;
|
|
int quot_digits = 0;
|
|
|
|
if (b == 0)
|
|
{
|
|
struct quot_rem ret;
|
|
ret.quot = 0xffffffff;
|
|
ret.rem = 0xffffffff;
|
|
return ret;
|
|
}
|
|
|
|
if (a < b)
|
|
return (struct quot_rem) { 0, a };
|
|
|
|
#ifdef LZ
|
|
if (b <= a)
|
|
{
|
|
quot_digits = LZ (b) - LZ (a);
|
|
quot_digits += (a >= (b << quot_digits));
|
|
b <<= quot_digits;
|
|
}
|
|
#else
|
|
while (b <= a)
|
|
{
|
|
b <<= 1;
|
|
quot_digits++;
|
|
}
|
|
#endif
|
|
|
|
/* Is a 31 bits? Note that bit 31 is handled by the caller. */
|
|
if (a & 0x40000000)
|
|
{
|
|
/* Then make b:s highest bit max 0x40000000, because it must have
|
|
been 0x80000000 to be 1 bit higher than a. */
|
|
b >>= 1;
|
|
|
|
/* Adjust a to be maximum 0x3fffffff, i.e. two upper bits zero. */
|
|
if (a >= b)
|
|
{
|
|
a -= b;
|
|
extra = 1 << (quot_digits - 1);
|
|
}
|
|
else
|
|
{
|
|
a -= b >> 1;
|
|
|
|
/* Remember that we adjusted a by subtracting b * 2 ** Something. */
|
|
extra = 1 << quot_digits;
|
|
}
|
|
|
|
/* The number of quotient digits will be one less, because
|
|
we just adjusted b. */
|
|
quot_digits--;
|
|
}
|
|
|
|
/* Now do the division part. */
|
|
|
|
/* Subtract b and add ones to the right when a >= b
|
|
i.e. "a - (b - 1) == (a - b) + 1". */
|
|
b--;
|
|
|
|
#define DS __asm__ ("dstep %2,%0" : "=r" (a) : "0" (a), "r" (b))
|
|
|
|
switch (quot_digits)
|
|
{
|
|
case 32: DS; case 31: DS; case 30: DS; case 29: DS;
|
|
case 28: DS; case 27: DS; case 26: DS; case 25: DS;
|
|
case 24: DS; case 23: DS; case 22: DS; case 21: DS;
|
|
case 20: DS; case 19: DS; case 18: DS; case 17: DS;
|
|
case 16: DS; case 15: DS; case 14: DS; case 13: DS;
|
|
case 12: DS; case 11: DS; case 10: DS; case 9: DS;
|
|
case 8: DS; case 7: DS; case 6: DS; case 5: DS;
|
|
case 4: DS; case 3: DS; case 2: DS; case 1: DS;
|
|
case 0:;
|
|
}
|
|
|
|
{
|
|
struct quot_rem ret;
|
|
ret.quot = (a & ((1 << quot_digits) - 1)) + extra;
|
|
ret.rem = a >> quot_digits;
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
#ifdef L_udivsi3
|
|
unsigned long
|
|
__Udiv (unsigned long a, unsigned long b) __attribute__ ((__const__));
|
|
|
|
unsigned long
|
|
__Udiv (unsigned long a, unsigned long b)
|
|
{
|
|
long extra = 0;
|
|
|
|
/* Adjust operands and result, if a and/or b is 32 bits. */
|
|
/* Effectively: b & 0x80000000. */
|
|
if ((long) b < 0)
|
|
return a >= b;
|
|
|
|
/* Effectively: a & 0x80000000. */
|
|
if ((long) a < 0)
|
|
{
|
|
int tmp = 0;
|
|
|
|
if (b == 0)
|
|
return 0xffffffff;
|
|
#ifdef LZ
|
|
tmp = LZ (b);
|
|
#else
|
|
for (tmp = 31; (((long) b & (1 << tmp)) == 0); tmp--)
|
|
;
|
|
|
|
tmp = 31 - tmp;
|
|
#endif
|
|
|
|
if ((b << tmp) > a)
|
|
{
|
|
extra = 1 << (tmp-1);
|
|
a -= b << (tmp - 1);
|
|
}
|
|
else
|
|
{
|
|
extra = 1 << tmp;
|
|
a -= b << tmp;
|
|
}
|
|
}
|
|
|
|
return do_31div (a, b).quot+extra;
|
|
}
|
|
#endif /* L_udivsi3 */
|
|
|
|
#ifdef L_divsi3
|
|
long
|
|
__Div (long a, long b) __attribute__ ((__const__));
|
|
|
|
long
|
|
__Div (long a, long b)
|
|
{
|
|
long extra = 0;
|
|
long sign = (b < 0) ? -1 : 1;
|
|
|
|
/* We need to handle a == -2147483648 as expected and must while
|
|
doing that avoid producing a sequence like "abs (a) < 0" as GCC
|
|
may optimize out the test. That sequence may not be obvious as
|
|
we call inline functions. Testing for a being negative and
|
|
handling (presumably much rarer than positive) enables us to get
|
|
a bit of optimization for an (accumulated) reduction of the
|
|
penalty of the 0x80000000 special-case. */
|
|
if (a < 0)
|
|
{
|
|
sign = -sign;
|
|
|
|
if ((a & 0x7fffffff) == 0)
|
|
{
|
|
/* We're at 0x80000000. Tread carefully. */
|
|
a -= b * sign;
|
|
extra = sign;
|
|
}
|
|
a = -a;
|
|
}
|
|
|
|
/* We knowingly penalize pre-v10 models by multiplication with the
|
|
sign. */
|
|
return sign * do_31div (a, __builtin_labs (b)).quot + extra;
|
|
}
|
|
#endif /* L_divsi3 */
|
|
|
|
|
|
#ifdef L_umodsi3
|
|
unsigned long
|
|
__Umod (unsigned long a, unsigned long b) __attribute__ ((__const__));
|
|
|
|
unsigned long
|
|
__Umod (unsigned long a, unsigned long b)
|
|
{
|
|
/* Adjust operands and result if a and/or b is 32 bits. */
|
|
if ((long) b < 0)
|
|
return a >= b ? a - b : a;
|
|
|
|
if ((long) a < 0)
|
|
{
|
|
int tmp = 0;
|
|
|
|
if (b == 0)
|
|
return a;
|
|
#ifdef LZ
|
|
tmp = LZ (b);
|
|
#else
|
|
for (tmp = 31; (((long) b & (1 << tmp)) == 0); tmp--)
|
|
;
|
|
tmp = 31 - tmp;
|
|
#endif
|
|
|
|
if ((b << tmp) > a)
|
|
{
|
|
a -= b << (tmp - 1);
|
|
}
|
|
else
|
|
{
|
|
a -= b << tmp;
|
|
}
|
|
}
|
|
|
|
return do_31div (a, b).rem;
|
|
}
|
|
#endif /* L_umodsi3 */
|
|
|
|
#ifdef L_modsi3
|
|
long
|
|
__Mod (long a, long b) __attribute__ ((__const__));
|
|
|
|
long
|
|
__Mod (long a, long b)
|
|
{
|
|
long sign = 1;
|
|
|
|
/* We need to handle a == -2147483648 as expected and must while
|
|
doing that avoid producing a sequence like "abs (a) < 0" as GCC
|
|
may optimize out the test. That sequence may not be obvious as
|
|
we call inline functions. Testing for a being negative and
|
|
handling (presumably much rarer than positive) enables us to get
|
|
a bit of optimization for an (accumulated) reduction of the
|
|
penalty of the 0x80000000 special-case. */
|
|
if (a < 0)
|
|
{
|
|
sign = -1;
|
|
if ((a & 0x7fffffff) == 0)
|
|
/* We're at 0x80000000. Tread carefully. */
|
|
a += __builtin_labs (b);
|
|
a = -a;
|
|
}
|
|
|
|
return sign * do_31div (a, __builtin_labs (b)).rem;
|
|
}
|
|
#endif /* L_modsi3 */
|
|
#endif /* L_udivsi3 || L_divsi3 || L_umodsi3 || L_modsi3 */
|
|
|
|
/*
|
|
* Local variables:
|
|
* eval: (c-set-style "gnu")
|
|
* indent-tabs-mode: t
|
|
* End:
|
|
*/
|