diff options
Diffstat (limited to 'stdlib')
| -rw-r--r-- | stdlib/longlong.h | 34 |
1 files changed, 29 insertions, 5 deletions
diff --git a/stdlib/longlong.h b/stdlib/longlong.h index d1859ef58f..de2b19ce81 100644 --- a/stdlib/longlong.h +++ b/stdlib/longlong.h @@ -1,5 +1,5 @@ /* longlong.h -- definitions for mixed size 32/64 bit arithmetic. - Copyright (C) 1991, 92, 94, 95, 96, 1997, 1998 Free Software Foundation, Inc. + Copyright (C) 1991,92,94,95,96,97,98,99 Free Software Foundation, Inc. This definition file is free software; you can redistribute it and/or modify it under the terms of the GNU General Public @@ -51,14 +51,17 @@ the msb to the first non-zero bit. This is the number of steps X needs to be shifted left to set the msb. Undefined for X == 0. - 6) add_ssaaaa(high_sum, low_sum, high_addend_1, low_addend_1, + 6) count_trailing_zeros(count, x) like count_leading_zeros, but counts + from the least significant end. + + 7) add_ssaaaa(high_sum, low_sum, high_addend_1, low_addend_1, high_addend_2, low_addend_2) adds two two-word unsigned integers, composed by HIGH_ADDEND_1 and LOW_ADDEND_1, and HIGH_ADDEND_2 and LOW_ADDEND_2 respectively. The result is placed in HIGH_SUM and LOW_SUM. Overflow (i.e. carry out) is not stored anywhere, and is lost. - 7) sub_ddmmss(high_difference, low_difference, high_minuend, + 8) sub_ddmmss(high_difference, low_difference, high_minuend, low_minuend, high_subtrahend, low_subtrahend) subtracts two two-word unsigned integers, composed by HIGH_MINUEND_1 and LOW_MINUEND_1, and HIGH_SUBTRAHEND_2 and LOW_SUBTRAHEND_2 @@ -373,6 +376,8 @@ UDItype __umulsidi3 (USItype, USItype); : "=r" (__cbtmp) : "rm" ((USItype) (x))); \ (count) = __cbtmp ^ 31; \ } while (0) +#define count_trailing_zeros(count, x) \ + __asm__ ("bsfl %1,%0" : "=r" (count) : "rm" ((USItype)(x))) #define UMUL_TIME 40 #define UDIV_TIME 40 #endif /* 80x86 */ @@ -434,7 +439,7 @@ UDItype __umulsidi3 (USItype, USItype); : "=d" (__w) \ : "%dI" ((USItype) (u)), \ "dI" ((USItype) (v))); \ - __w; }) + __w; }) #endif /* __i960__ */ #if defined (__M32R__) @@ -663,6 +668,13 @@ UDItype __umulsidi3 (USItype, USItype); : "0" (__xx.__ll), \ "g" ((USItype) (d))); \ (r) = __xx.__i.__l; (q) = __xx.__i.__h; }) +#define count_trailing_zeros(count,x) \ + do { + __asm__ ("ffsd %2,%0" \ + : "=r" ((USItype) (count)) \ + : "0" ((USItype) 0), \ + "r" ((USItype) (x))); \ + } while (0) #endif /* __ns32000__ */ #if (defined (_ARCH_PPC) || defined (_IBMR2)) && W_TYPE_SIZE == 32 @@ -982,7 +994,7 @@ UDItype __umulsidi3 (USItype, USItype); __asm__ ("scan %1,1,%0" \ : "=r" ((USItype) (count)) \ : "r" ((USItype) (x))); \ - } while (0) + } while (0) #else /* SPARC without integer multiplication and divide instructions. (i.e. at least Sun4/20,40,60,65,75,110,260,280,330,360,380,470,490) */ @@ -1253,6 +1265,18 @@ extern const UQItype __clz_tab[]; } while (0) #endif +#if !defined (count_trailing_zeros) +/* Define count_trailing_zeros using count_leading_zeros. The latter might be + defined in asm, but if it is not, the C version above is good enough. */ +#define count_trailing_zeros(count, x) \ + do { \ + USItype __ctz_x = (x); \ + USItype __ctz_c; \ + count_leading_zeros (__ctz_c, __ctz_x & -__ctz_x); \ + (count) = SI_TYPE_SIZE - 1 - __ctz_c; \ + } while (0) +#endif + #ifndef UDIV_NEEDS_NORMALIZATION #define UDIV_NEEDS_NORMALIZATION 0 #endif |