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authoriap10@labyrinth.cl.cam.ac.uk <iap10@labyrinth.cl.cam.ac.uk>2003-02-24 16:59:11 +0000
committeriap10@labyrinth.cl.cam.ac.uk <iap10@labyrinth.cl.cam.ac.uk>2003-02-24 16:59:11 +0000
commit0b109673722dd825609e7cc51ca124693f0b8240 (patch)
treeba95c49e5ebe85976c365b232c8f48634784cca1 /xen/common/lib.c
parenta48212cb65e09669ed243581556529681cebba0a (diff)
downloadxen-0b109673722dd825609e7cc51ca124693f0b8240.tar.gz
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bitkeeper revision 1.94 (3e5a4f5fzVaxemjfCt0N0OH8PYPiuw)
Rename xen-2.4.16 to just "xen" to reflect that it hasn't got any relation to the Linux kernel version.
Diffstat (limited to 'xen/common/lib.c')
-rw-r--r--xen/common/lib.c526
1 files changed, 526 insertions, 0 deletions
diff --git a/xen/common/lib.c b/xen/common/lib.c
new file mode 100644
index 0000000000..ae75196ffd
--- /dev/null
+++ b/xen/common/lib.c
@@ -0,0 +1,526 @@
+
+#include <xeno/ctype.h>
+#include <xeno/lib.h>
+
+int memcmp(const void * cs,const void * ct,size_t count)
+{
+ const unsigned char *su1, *su2;
+ signed char res = 0;
+
+ for( su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--)
+ if ((res = *su1 - *su2) != 0)
+ break;
+ return res;
+}
+
+void * memcpy(void * dest,const void *src,size_t count)
+{
+ char *tmp = (char *) dest, *s = (char *) src;
+
+ while (count--)
+ *tmp++ = *s++;
+
+ return dest;
+}
+
+int strncmp(const char * cs,const char * ct,size_t count)
+{
+ register signed char __res = 0;
+
+ while (count) {
+ if ((__res = *cs - *ct++) != 0 || !*cs++)
+ break;
+ count--;
+ }
+
+ return __res;
+}
+
+int strcmp(const char * cs,const char * ct)
+{
+ register signed char __res;
+
+ while (1) {
+ if ((__res = *cs - *ct++) != 0 || !*cs++)
+ break;
+ }
+
+ return __res;
+}
+
+char * strcpy(char * dest,const char *src)
+{
+ char *tmp = dest;
+
+ while ((*dest++ = *src++) != '\0')
+ /* nothing */;
+ return tmp;
+}
+
+char * strncpy(char * dest,const char *src,size_t count)
+{
+ char *tmp = dest;
+
+ while (count-- && (*dest++ = *src++) != '\0')
+ /* nothing */;
+
+ return tmp;
+}
+
+void * memset(void * s,int c,size_t count)
+{
+ char *xs = (char *) s;
+
+ while (count--)
+ *xs++ = c;
+
+ return s;
+}
+
+size_t strnlen(const char * s, size_t count)
+{
+ const char *sc;
+
+ for (sc = s; count-- && *sc != '\0'; ++sc)
+ /* nothing */;
+ return sc - s;
+}
+
+size_t strlen(const char * s)
+{
+ const char *sc;
+
+ for (sc = s; *sc != '\0'; ++sc)
+ /* nothing */;
+ return sc - s;
+}
+
+char * strchr(const char * s, int c)
+{
+ for(; *s != (char) c; ++s)
+ if (*s == '\0')
+ return NULL;
+ return (char *) s;
+}
+
+char * strstr(const char * s1,const char * s2)
+{
+ int l1, l2;
+
+ l2 = strlen(s2);
+ if (!l2)
+ return (char *) s1;
+ l1 = strlen(s1);
+ while (l1 >= l2) {
+ l1--;
+ if (!memcmp(s1,s2,l2))
+ return (char *) s1;
+ s1++;
+ }
+ return NULL;
+}
+
+
+/* for inc/ctype.h */
+unsigned char _ctype[] = {
+_C,_C,_C,_C,_C,_C,_C,_C, /* 0-7 */
+_C,_C|_S,_C|_S,_C|_S,_C|_S,_C|_S,_C,_C, /* 8-15 */
+_C,_C,_C,_C,_C,_C,_C,_C, /* 16-23 */
+_C,_C,_C,_C,_C,_C,_C,_C, /* 24-31 */
+_S|_SP,_P,_P,_P,_P,_P,_P,_P, /* 32-39 */
+_P,_P,_P,_P,_P,_P,_P,_P, /* 40-47 */
+_D,_D,_D,_D,_D,_D,_D,_D, /* 48-55 */
+_D,_D,_P,_P,_P,_P,_P,_P, /* 56-63 */
+_P,_U|_X,_U|_X,_U|_X,_U|_X,_U|_X,_U|_X,_U, /* 64-71 */
+_U,_U,_U,_U,_U,_U,_U,_U, /* 72-79 */
+_U,_U,_U,_U,_U,_U,_U,_U, /* 80-87 */
+_U,_U,_U,_P,_P,_P,_P,_P, /* 88-95 */
+_P,_L|_X,_L|_X,_L|_X,_L|_X,_L|_X,_L|_X,_L, /* 96-103 */
+_L,_L,_L,_L,_L,_L,_L,_L, /* 104-111 */
+_L,_L,_L,_L,_L,_L,_L,_L, /* 112-119 */
+_L,_L,_L,_P,_P,_P,_P,_C, /* 120-127 */
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 128-143 */
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 144-159 */
+_S|_SP,_P,_P,_P,_P,_P,_P,_P,_P,_P,_P,_P,_P,_P,_P,_P, /* 160-175 */
+_P,_P,_P,_P,_P,_P,_P,_P,_P,_P,_P,_P,_P,_P,_P,_P, /* 176-191 */
+_U,_U,_U,_U,_U,_U,_U,_U,_U,_U,_U,_U,_U,_U,_U,_U, /* 192-207 */
+_U,_U,_U,_U,_U,_U,_U,_P,_U,_U,_U,_U,_U,_U,_U,_L, /* 208-223 */
+_L,_L,_L,_L,_L,_L,_L,_L,_L,_L,_L,_L,_L,_L,_L,_L, /* 224-239 */
+_L,_L,_L,_L,_L,_L,_L,_P,_L,_L,_L,_L,_L,_L,_L,_L}; /* 240-255 */
+
+
+unsigned long str_to_quad(unsigned char *s)
+{
+ unsigned long quad = 0;
+ do {
+ quad <<= 8;
+ quad |= simple_strtol(s, (char **)&s, 10);
+ }
+ while ( *s++ == '.' );
+ return quad;
+}
+
+
+unsigned char *quad_to_str(unsigned long q, unsigned char *s)
+{
+ sprintf(s, "%ld.%ld.%ld.%ld",
+ (q>>24)&255, (q>>16)&255, (q>>8)&255, (q>>0)&255);
+ return s;
+}
+
+
+/* a couple of 64 bit operations ported from freebsd */
+
+/*-
+ * Copyright (c) 1992, 1993
+ * The Regents of the University of California. All rights reserved.
+ *
+ * This software was developed by the Computer Systems Engineering group
+ * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
+ * contributed to Berkeley.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * 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 <asm/types.h>
+
+
+/*
+ * Depending on the desired operation, we view a `long long' (aka quad_t) in
+ * one or more of the following formats.
+ */
+union uu {
+ s64 q; /* as a (signed) quad */
+ s64 uq; /* as an unsigned quad */
+ long sl[2]; /* as two signed longs */
+ unsigned long 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
+
+/*
+ * Total number of bits in a quad_t and in the pieces that make it up.
+ * These are used for shifting, and also below for halfword extraction
+ * and assembly.
+ */
+#define CHAR_BIT 8 /* number of bits in a char */
+#define QUAD_BITS (sizeof(s64) * CHAR_BIT)
+#define LONG_BITS (sizeof(long) * CHAR_BIT)
+#define HALF_BITS (sizeof(long) * CHAR_BIT / 2)
+
+/*
+ * Extract high and low shortwords from longword, and move low shortword of
+ * longword to upper half of long, i.e., produce the upper longword of
+ * ((quad_t)(x) << (number_of_bits_in_long/2)). (`x' must actually be u_long.)
+ *
+ * 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(long)*CHAR_BIT/2).
+ */
+#define HHALF(x) ((x) >> HALF_BITS)
+#define LHALF(x) ((x) & ((1 << HALF_BITS) - 1))
+#define LHUP(x) ((x) << HALF_BITS)
+
+/*
+ * Multiprecision divide. This algorithm is from Knuth vol. 2 (2nd ed),
+ * section 4.3.1, pp. 257--259.
+ */
+#define B (1 << HALF_BITS) /* digit base */
+
+/* Combine two `digits' to make a single two-digit number. */
+#define COMBINE(a, b) (((u_long)(a) << HALF_BITS) | (b))
+
+/* select a type for digits in base B: use unsigned short if they fit */
+#if ULONG_MAX == 0xffffffff && USHRT_MAX >= 0xffff
+typedef unsigned short digit;
+#else
+typedef u_long digit;
+#endif
+
+/*
+ * Shift p[0]..p[len] left `sh' bits, ignoring any bits that
+ * `fall out' the left (there never will be any such anyway).
+ * We may assume len >= 0. NOTE THAT THIS WRITES len+1 DIGITS.
+ */
+static void
+shl(register digit *p, register int len, register int sh)
+{
+ register int i;
+
+ for (i = 0; i < len; i++)
+ p[i] = LHALF(p[i] << sh) | (p[i + 1] >> (HALF_BITS - sh));
+ p[i] = LHALF(p[i] << sh);
+}
+
+/*
+ * __qdivrem(u, v, rem) returns u/v and, optionally, sets *rem to u%v.
+ *
+ * We do this in base 2-sup-HALF_BITS, so that all intermediate products
+ * fit within u_long. As a consequence, the maximum length dividend and
+ * divisor are 4 `digits' in this base (they are shorter if they have
+ * leading zeros).
+ */
+u64
+__qdivrem(uq, vq, arq)
+ u64 uq, vq, *arq;
+{
+ union uu tmp;
+ digit *u, *v, *q;
+ register digit v1, v2;
+ u_long qhat, rhat, t;
+ int m, n, d, j, i;
+ digit uspace[5], vspace[5], qspace[5];
+
+ /*
+ * Take care of special cases: divide by zero, and u < v.
+ */
+ if (vq == 0) {
+ /* divide by zero. */
+ static volatile const unsigned int zero = 0;
+
+ tmp.ul[H] = tmp.ul[L] = 1 / zero;
+ if (arq)
+ *arq = uq;
+ return (tmp.q);
+ }
+ if (uq < vq) {
+ if (arq)
+ *arq = uq;
+ return (0);
+ }
+ u = &uspace[0];
+ v = &vspace[0];
+ q = &qspace[0];
+
+ /*
+ * Break dividend and divisor into digits in base B, then
+ * count leading zeros to determine m and n. When done, we
+ * will have:
+ * u = (u[1]u[2]...u[m+n]) sub B
+ * v = (v[1]v[2]...v[n]) sub B
+ * v[1] != 0
+ * 1 < n <= 4 (if n = 1, we use a different division algorithm)
+ * m >= 0 (otherwise u < v, which we already checked)
+ * m + n = 4
+ * and thus
+ * m = 4 - n <= 2
+ */
+ tmp.uq = uq;
+ u[0] = 0;
+ u[1] = HHALF(tmp.ul[H]);
+ u[2] = LHALF(tmp.ul[H]);
+ u[3] = HHALF(tmp.ul[L]);
+ u[4] = LHALF(tmp.ul[L]);
+ tmp.uq = vq;
+ v[1] = HHALF(tmp.ul[H]);
+ v[2] = LHALF(tmp.ul[H]);
+ v[3] = HHALF(tmp.ul[L]);
+ v[4] = LHALF(tmp.ul[L]);
+ for (n = 4; v[1] == 0; v++) {
+ if (--n == 1) {
+ u_long rbj; /* r*B+u[j] (not root boy jim) */
+ digit q1, q2, q3, q4;
+
+ /*
+ * Change of plan, per exercise 16.
+ * r = 0;
+ * for j = 1..4:
+ * q[j] = floor((r*B + u[j]) / v),
+ * r = (r*B + u[j]) % v;
+ * We unroll this completely here.
+ */
+ t = v[2]; /* nonzero, by definition */
+ q1 = u[1] / t;
+ rbj = COMBINE(u[1] % t, u[2]);
+ q2 = rbj / t;
+ rbj = COMBINE(rbj % t, u[3]);
+ q3 = rbj / t;
+ rbj = COMBINE(rbj % t, u[4]);
+ q4 = rbj / t;
+ if (arq)
+ *arq = rbj % t;
+ tmp.ul[H] = COMBINE(q1, q2);
+ tmp.ul[L] = COMBINE(q3, q4);
+ return (tmp.q);
+ }
+ }
+
+ /*
+ * By adjusting q once we determine m, we can guarantee that
+ * there is a complete four-digit quotient at &qspace[1] when
+ * we finally stop.
+ */
+ for (m = 4 - n; u[1] == 0; u++)
+ m--;
+ for (i = 4 - m; --i >= 0;)
+ q[i] = 0;
+ q += 4 - m;
+
+ /*
+ * Here we run Program D, translated from MIX to C and acquiring
+ * a few minor changes.
+ *
+ * D1: choose multiplier 1 << d to ensure v[1] >= B/2.
+ */
+ d = 0;
+ for (t = v[1]; t < B / 2; t <<= 1)
+ d++;
+ if (d > 0) {
+ shl(&u[0], m + n, d); /* u <<= d */
+ shl(&v[1], n - 1, d); /* v <<= d */
+ }
+ /*
+ * D2: j = 0.
+ */
+ j = 0;
+ v1 = v[1]; /* for D3 -- note that v[1..n] are constant */
+ v2 = v[2]; /* for D3 */
+ do {
+ register digit uj0, uj1, uj2;
+
+ /*
+ * D3: Calculate qhat (\^q, in TeX notation).
+ * Let qhat = min((u[j]*B + u[j+1])/v[1], B-1), and
+ * let rhat = (u[j]*B + u[j+1]) mod v[1].
+ * While rhat < B and v[2]*qhat > rhat*B+u[j+2],
+ * decrement qhat and increase rhat correspondingly.
+ * Note that if rhat >= B, v[2]*qhat < rhat*B.
+ */
+ uj0 = u[j + 0]; /* for D3 only -- note that u[j+...] change */
+ uj1 = u[j + 1]; /* for D3 only */
+ uj2 = u[j + 2]; /* for D3 only */
+ if (uj0 == v1) {
+ qhat = B;
+ rhat = uj1;
+ goto qhat_too_big;
+ } else {
+ u_long nn = COMBINE(uj0, uj1);
+ qhat = nn / v1;
+ rhat = nn % v1;
+ }
+ while (v2 * qhat > COMBINE(rhat, uj2)) {
+ qhat_too_big:
+ qhat--;
+ if ((rhat += v1) >= B)
+ break;
+ }
+ /*
+ * D4: Multiply and subtract.
+ * The variable `t' holds any borrows across the loop.
+ * We split this up so that we do not require v[0] = 0,
+ * and to eliminate a final special case.
+ */
+ for (t = 0, i = n; i > 0; i--) {
+ t = u[i + j] - v[i] * qhat - t;
+ u[i + j] = LHALF(t);
+ t = (B - HHALF(t)) & (B - 1);
+ }
+ t = u[j] - t;
+ u[j] = LHALF(t);
+ /*
+ * D5: test remainder.
+ * There is a borrow if and only if HHALF(t) is nonzero;
+ * in that (rare) case, qhat was too large (by exactly 1).
+ * Fix it by adding v[1..n] to u[j..j+n].
+ */
+ if (HHALF(t)) {
+ qhat--;
+ for (t = 0, i = n; i > 0; i--) { /* D6: add back. */
+ t += u[i + j] + v[i];
+ u[i + j] = LHALF(t);
+ t = HHALF(t);
+ }
+ u[j] = LHALF(u[j] + t);
+ }
+ q[j] = qhat;
+ } while (++j <= m); /* D7: loop on j. */
+
+ /*
+ * If caller wants the remainder, we have to calculate it as
+ * u[m..m+n] >> d (this is at most n digits and thus fits in
+ * u[m+1..m+n], but we may need more source digits).
+ */
+ if (arq) {
+ if (d) {
+ for (i = m + n; i > m; --i)
+ u[i] = (u[i] >> d) |
+ LHALF(u[i - 1] << (HALF_BITS - d));
+ u[i] = 0;
+ }
+ tmp.ul[H] = COMBINE(uspace[1], uspace[2]);
+ tmp.ul[L] = COMBINE(uspace[3], uspace[4]);
+ *arq = tmp.q;
+ }
+
+ tmp.ul[H] = COMBINE(qspace[1], qspace[2]);
+ tmp.ul[L] = COMBINE(qspace[3], qspace[4]);
+ return (tmp.q);
+}
+
+
+/*
+ * Divide two signed quads.
+ * ??? if -1/2 should produce -1 on this machine, this code is wrong
+ */
+s64
+__divdi3(s64 a, s64 b)
+{
+ u64 ua, ub, uq;
+ int neg;
+
+ if (a < 0)
+ ua = -(u64)a, neg = 1;
+ else
+ ua = a, neg = 0;
+ if (b < 0)
+ ub = -(u64)b, neg ^= 1;
+ else
+ ub = b;
+ uq = __qdivrem(ua, ub, (u64 *)0);
+ return (neg ? -uq : uq);
+}
+
+/*
+ * Divide two unsigned quads.
+ */
+u64
+__udivdi3(a, b)
+ u64 a, b;
+{
+
+ return (__qdivrem(a, b, (u64 *)0));
+}