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authorUlrich Drepper <drepper@redhat.com>1999-11-23 04:15:27 +0000
committerUlrich Drepper <drepper@redhat.com>1999-11-23 04:15:27 +0000
commit62818cfd92d7b749399a48bdcaea7569f32efa62 (patch)
tree8773314808bb89570f12402fbd310a897a9e2519 /stdlib/longlong.h
parent1da2d51aebf6dc722aaf1793d8608b028eec12ed (diff)
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Update.
* stdlib/longlong.h: Add count_trailing_zeros back.
Diffstat (limited to 'stdlib/longlong.h')
-rw-r--r--stdlib/longlong.h34
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