diff options
Diffstat (limited to 'rational.c')
| -rw-r--r-- | rational.c | 55 |
1 files changed, 54 insertions, 1 deletions
diff --git a/rational.c b/rational.c index ee0e1689e9..d70dfd41ab 100644 --- a/rational.c +++ b/rational.c @@ -17,10 +17,17 @@ #define NDEBUG #include <assert.h> +#if defined(HAVE_LIBGMP) && defined(HAVE_GMP_H) +#define USE_GMP +#include <gmp.h> +#endif + #define ZERO INT2FIX(0) #define ONE INT2FIX(1) #define TWO INT2FIX(2) +#define GMP_GCD_DIGITS 1 + VALUE rb_cRational; static ID id_abs, id_cmp, id_convert, id_eqeq_p, id_expt, id_fdiv, @@ -276,6 +283,32 @@ k_rational_p(VALUE x) #define k_exact_zero_p(x) (k_exact_p(x) && f_zero_p(x)) #define k_exact_one_p(x) (k_exact_p(x) && f_one_p(x)) +#ifdef USE_GMP +VALUE +rb_gcd_gmp(VALUE x, VALUE y) +{ + const size_t nails = (sizeof(BDIGIT)-SIZEOF_BDIGITS)*CHAR_BIT; + mpz_t mx, my, mz; + size_t count; + VALUE z; + long zn; + + mpz_init(mx); + mpz_init(my); + mpz_init(mz); + mpz_import(mx, RBIGNUM_LEN(x), -1, sizeof(BDIGIT), 0, nails, RBIGNUM_DIGITS(x)); + mpz_import(my, RBIGNUM_LEN(y), -1, sizeof(BDIGIT), 0, nails, RBIGNUM_DIGITS(y)); + + mpz_gcd(mz, mx, my); + + zn = (mpz_sizeinbase(mz, 16) + SIZEOF_BDIGITS*2 - 1) / (SIZEOF_BDIGITS*2); + z = rb_big_new(zn, 1); + mpz_export(RBIGNUM_DIGITS(z), &count, -1, sizeof(BDIGIT), 0, nails, mz); + + return rb_big_norm(z); +} +#endif + #ifndef NDEBUG #define f_gcd f_gcd_orig #endif @@ -302,7 +335,7 @@ i_gcd(long x, long y) } inline static VALUE -f_gcd(VALUE x, VALUE y) +f_gcd_normal(VALUE x, VALUE y) { VALUE z; @@ -333,6 +366,26 @@ f_gcd(VALUE x, VALUE y) /* NOTREACHED */ } +VALUE +rb_gcd_normal(VALUE x, VALUE y) +{ + return f_gcd_normal(x, y); +} + +inline static VALUE +f_gcd(VALUE x, VALUE y) +{ +#ifdef USE_GMP + if (TYPE(x) == T_BIGNUM && TYPE(y) == T_BIGNUM) { + long xn = RBIGNUM_LEN(x); + long yn = RBIGNUM_LEN(y); + if (GMP_GCD_DIGITS <= xn && GMP_GCD_DIGITS <= yn) + return rb_gcd_gmp(x, y); + } +#endif + return f_gcd_normal(x, y); +} + #ifndef NDEBUG #undef f_gcd |