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author | Laurent Bercot <ska-skaware@skarnet.org> | 2014-09-18 18:55:44 +0000 |
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committer | Laurent Bercot <ska-skaware@skarnet.org> | 2014-09-18 18:55:44 +0000 |
commit | 3534b428629be185e096be99e3bd5fdfe32d5544 (patch) | |
tree | 210ef3198ed66bc7f7b7bf6a85e4579f455e5a36 /src/libbiguint/bu_gcd.c | |
download | skalibs-3534b428629be185e096be99e3bd5fdfe32d5544.tar.xz |
initial commit with rc for skalibs-2.0.0.0
Diffstat (limited to 'src/libbiguint/bu_gcd.c')
-rw-r--r-- | src/libbiguint/bu_gcd.c | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/src/libbiguint/bu_gcd.c b/src/libbiguint/bu_gcd.c new file mode 100644 index 0000000..d6c5791 --- /dev/null +++ b/src/libbiguint/bu_gcd.c @@ -0,0 +1,33 @@ +/* ISC license. */ + +#include <skalibs/uint32.h> +#include <skalibs/biguint.h> + +int bu_gcd (uint32 *r, unsigned int rn, uint32 const *a, unsigned int an, uint32 const *b, unsigned int bn) +{ + if (bu_cmp(a, an, b, bn) < 0) + { + register uint32 const *t = a ; + register unsigned int tn = an ; + a = b ; an = bn ; + b = t ; bn = tn ; + } + { + uint32 trash[an] ; + uint32 aa[an] ; + uint32 bb[an] ; + uint32 *aaa = aa, *bbb = bb ; + bu_copy_internal(aa, a, an) ; + bu_copy_internal(bb, b, bn) ; + bu_zero(bb+bn, an-bn) ; + + while (bu_len(bbb, an)) + { + register uint32 *ttt = aaa ; + bu_div_internal(aaa, an, bbb, an, trash, an) ; + aaa = bbb ; + bbb = ttt ; + } + return bu_copy(r, rn, aaa, an) ; + } +} |