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authorH. Nikolaus Schaller <hns@goldelico.com>2012-03-26 20:55:28 +0200
committerH. Nikolaus Schaller <hns@goldelico.com>2012-03-26 20:55:28 +0200
commit92988a21ad4c4c9504295ccb580c9f806134471b (patch)
tree5effc9f14170112450de05c67dafbe8d5034d595 /u-boot/lib/div64.c
parentca2b506783b676c95762c54ea24dcfdaae1947c9 (diff)
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added boot script files to repository
Diffstat (limited to 'u-boot/lib/div64.c')
-rw-r--r--u-boot/lib/div64.c52
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diff --git a/u-boot/lib/div64.c b/u-boot/lib/div64.c
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+/*
+ * Copyright (C) 2003 Bernardo Innocenti <bernie@develer.com>
+ *
+ * Based on former do_div() implementation from asm-parisc/div64.h:
+ * Copyright (C) 1999 Hewlett-Packard Co
+ * Copyright (C) 1999 David Mosberger-Tang <davidm@hpl.hp.com>
+ *
+ *
+ * Generic C version of 64bit/32bit division and modulo, with
+ * 64bit result and 32bit remainder.
+ *
+ * The fast case for (n>>32 == 0) is handled inline by do_div().
+ *
+ * Code generated for this function might be very inefficient
+ * for some CPUs. __div64_32() can be overridden by linking arch-specific
+ * assembly versions such as arch/powerpc/lib/div64.S and arch/sh/lib/div64.S.
+ */
+
+#include <linux/types.h>
+
+uint32_t __div64_32(uint64_t *n, uint32_t base)
+{
+ uint64_t rem = *n;
+ uint64_t b = base;
+ uint64_t res, d = 1;
+ uint32_t high = rem >> 32;
+
+ /* Reduce the thing a bit first */
+ res = 0;
+ if (high >= base) {
+ high /= base;
+ res = (uint64_t) high << 32;
+ rem -= (uint64_t) (high*base) << 32;
+ }
+
+ while ((int64_t)b > 0 && b < rem) {
+ b = b+b;
+ d = d+d;
+ }
+
+ do {
+ if (rem >= b) {
+ rem -= b;
+ res += d;
+ }
+ b >>= 1;
+ d >>= 1;
+ } while (d);
+
+ *n = res;
+ return rem;
+}