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authorPeter Tyser <ptyser@xes-inc.com>2010-04-12 22:28:05 -0500
committerWolfgang Denk <wd@denx.de>2010-04-13 09:13:04 +0200
commit78acc472d9719316f22e002a009a998d9ceec29d (patch)
treeaa99461b3d693cf3691869abea485091860a66d0 /lib/div64.c
parentea0364f1bbfed1e3ea711147420875cf338fe77a (diff)
Rename lib_generic/ to lib/
Now that the other architecture-specific lib directories have been moved out of the top-level directory there's not much reason to have the '_generic' suffix on the common lib directory. Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
Diffstat (limited to 'lib/div64.c')
-rw-r--r--lib/div64.c52
1 files changed, 52 insertions, 0 deletions
diff --git a/lib/div64.c b/lib/div64.c
new file mode 100644
index 00000000000..d9951b597f9
--- /dev/null
+++ b/lib/div64.c
@@ -0,0 +1,52 @@
+/*
+ * 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/ppc/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;
+}