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author | upstream source tree <ports@midipix.org> | 2015-03-15 20:14:05 -0400 |
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committer | upstream source tree <ports@midipix.org> | 2015-03-15 20:14:05 -0400 |
commit | 554fd8c5195424bdbcabf5de30fdc183aba391bd (patch) | |
tree | 976dc5ab7fddf506dadce60ae936f43f58787092 /gcc/config/cris/arit.c | |
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Diffstat (limited to 'gcc/config/cris/arit.c')
-rw-r--r-- | gcc/config/cris/arit.c | 304 |
1 files changed, 304 insertions, 0 deletions
diff --git a/gcc/config/cris/arit.c b/gcc/config/cris/arit.c new file mode 100644 index 000000000..32255f99d --- /dev/null +++ b/gcc/config/cris/arit.c @@ -0,0 +1,304 @@ +/* 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: + */ |