diff options
-rw-r--r-- | ChangeLog | 5 | ||||
-rw-r--r-- | bignum.c | 47 |
2 files changed, 32 insertions, 20 deletions
@@ -1,3 +1,8 @@ +Tue Jul 9 01:47:16 2013 Tanaka Akira <akr@fsij.org> + + * bignum.c (biglsh_bang): Don't shift a BDIGIT with BITSPERDIG bits. + (bigrsh_bang): Ditto. + Tue Jul 9 01:17:57 2013 Tanaka Akira <akr@fsij.org> * bignum.c (bigrsh_bang): Fix bignum digits overrun. @@ -4417,22 +4417,25 @@ biglsh_bang(BDIGIT *xds, long xn, unsigned long shift) int const s3 = BITSPERDIG-s2; BDIGIT* zds; BDIGIT num; - long i; if (s1 >= xn) { MEMZERO(xds, BDIGIT, xn); return; } - zds = xds + xn - 1; - xn -= s1 + 1; - num = BIGLO(xds[xn]<<s2); - while (0 < xn) { - *zds-- = num | xds[--xn]>>s3; - num = BIGLO(xds[xn]<<s2); + if (s2 == 0) { + MEMMOVE(xds + s1, xds, BDIGIT, xn - s1); + } + else { + zds = xds + xn - 1; + xn -= s1 + 1; + num = BIGLO(xds[xn]<<s2); + while (0 < xn) { + *zds-- = num | xds[--xn]>>s3; + num = BIGLO(xds[xn]<<s2); + } + assert(xds <= zds); + *zds = num; } - assert(xds <= zds); - *zds = num; - for (i = s1; i > 0; --i) - *zds-- = 0; + MEMZERO(xds, BDIGIT, s1); } static void @@ -4448,16 +4451,20 @@ bigrsh_bang(BDIGIT* xds, long xn, unsigned long shift) MEMZERO(xds, BDIGIT, xn); return; } - - i = 0; - zds = xds + s1; - num = *zds++>>s2; - while (i < xn - s1 - 1) { - xds[i++] = BIGLO(*zds<<s3) | num; - num = *zds++>>s2; + if (s2 == 0) { + MEMMOVE(xds, xds + s1, BDIGIT, xn - s1); + } + else { + i = 0; + zds = xds + s1; + num = *zds++>>s2; + while (i < xn - s1 - 1) { + xds[i++] = BIGLO(*zds<<s3) | num; + num = *zds++>>s2; + } + assert(i < xn); + xds[i] = num; } - assert(i < xn); - xds[i] = num; MEMZERO(xds + xn - s1, BDIGIT, s1); } |