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author | Wolfgang Denk <wd@denx.de> | 2010-09-28 23:30:47 +0200 |
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committer | Wolfgang Denk <wd@denx.de> | 2010-09-28 23:30:47 +0200 |
commit | 2e6e1772c0e34871769be4aef79748fe3e47d953 (patch) | |
tree | 00e4e19d7bccd2a1cd5753854ff4c2b8a26bebb0 /lib/qsort.c | |
parent | 1e4e5ef0469050f014aee1204dae8a9ab6053e49 (diff) | |
parent | 3df61957938586c512c17e72d83551d190400981 (diff) | |
download | u-boot-2e6e1772c0e34871769be4aef79748fe3e47d953.tar.gz u-boot-2e6e1772c0e34871769be4aef79748fe3e47d953.tar.xz u-boot-2e6e1772c0e34871769be4aef79748fe3e47d953.zip |
Merge branch 'next' of /home/wd/git/u-boot/next
Conflicts:
include/ppc4xx.h
Signed-off-by: Wolfgang Denk <wd@denx.de>
Diffstat (limited to 'lib/qsort.c')
-rw-r--r-- | lib/qsort.c | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/lib/qsort.c b/lib/qsort.c new file mode 100644 index 0000000000..bb47319f8b --- /dev/null +++ b/lib/qsort.c @@ -0,0 +1,69 @@ +/* + * Code adapted from uClibc-0.9.30.3 + * + * It is therefore covered by the GNU LESSER GENERAL PUBLIC LICENSE + * Version 2.1, February 1999 + * + * Wolfgang Denk <wd@denx.de> + */ + +/* This code is derived from a public domain shell sort routine by + * Ray Gardner and found in Bob Stout's snippets collection. The + * original code is included below in an #if 0/#endif block. + * + * I modified it to avoid the possibility of overflow in the wgap + * calculation, as well as to reduce the generated code size with + * bcc and gcc. */ + +#include <linux/types.h> +#if 0 +#include <assert.h> +#else +#define assert(arg) +#endif + +void qsort(void *base, + size_t nel, + size_t width, + int (*comp)(const void *, const void *)) +{ + size_t wgap, i, j, k; + char tmp; + + if ((nel > 1) && (width > 0)) { + assert(nel <= ((size_t)(-1)) / width); /* check for overflow */ + wgap = 0; + do { + wgap = 3 * wgap + 1; + } while (wgap < (nel-1)/3); + /* From the above, we know that either wgap == 1 < nel or */ + /* ((wgap-1)/3 < (int) ((nel-1)/3) <= (nel-1)/3 ==> wgap < nel. */ + wgap *= width; /* So this can not overflow if wnel doesn't. */ + nel *= width; /* Convert nel to 'wnel' */ + do { + i = wgap; + do { + j = i; + do { + register char *a; + register char *b; + + j -= wgap; + a = j + ((char *)base); + b = a + wgap; + if ((*comp)(a, b) <= 0) { + break; + } + k = width; + do { + tmp = *a; + *a++ = *b; + *b++ = tmp; + } while (--k); + } while (j >= wgap); + i += width; + } while (i < nel); + wgap = (wgap - width)/3; + } while (wgap); + } +} |