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-rw-r--r--bignum.c55
1 files changed, 55 insertions, 0 deletions
diff --git a/bignum.c b/bignum.c
index 7a6e1f29341..ecb338a7914 100644
--- a/bignum.c
+++ b/bignum.c
@@ -135,6 +135,8 @@ STATIC_ASSERT(sizeof_long_and_sizeof_bdigit, SIZEOF_BDIGITS % SIZEOF_LONG == 0);
#define KARATSUBA_MUL_DIGITS 70
#define TOOM3_MUL_DIGITS 150
+#define GMP_BIG2STR_DIGITS 20
+
typedef void (mulfunc_t)(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn, BDIGIT *wds, size_t wn);
static mulfunc_t bary_mul_toom3_start;
@@ -4466,6 +4468,50 @@ rb_big2str_generic(VALUE x, int base)
return big2str_generic(x, base, xds, xn);
}
+#ifdef USE_GMP
+VALUE
+big2str_gmp(int negative_p, int base, BDIGIT *xds, size_t xn)
+{
+ const size_t nails = (sizeof(BDIGIT)-SIZEOF_BDIGITS)*CHAR_BIT;
+ mpz_t x;
+ size_t size;
+ VALUE str;
+ char *p;
+
+ mpz_init(x);
+ mpz_import(x, xn, -1, sizeof(BDIGIT), 0, nails, xds);
+
+ size = mpz_sizeinbase(x, base);
+
+ if (negative_p) {
+ str = rb_usascii_str_new(0, size+1);
+ p = RSTRING_PTR(str);
+ *p++ = '-';
+ }
+ else {
+ str = rb_usascii_str_new(0, size);
+ p = RSTRING_PTR(str);
+ }
+ mpz_get_str(p, base, x);
+ mpz_clear(x);
+
+ if (RSTRING_PTR(str)[RSTRING_LEN(str)-1] == '\0') {
+ rb_str_set_len(str, RSTRING_LEN(str)-1);
+ }
+
+ return str;
+}
+
+VALUE
+rb_big2str_gmp(VALUE x, int base)
+{
+ VALUE str;
+ str = big2str_gmp(RBIGNUM_NEGATIVE_P(x), base, BDIGITS(x), RBIGNUM_LEN(x));
+ RB_GC_GUARD(x);
+ return str;
+}
+#endif
+
static VALUE
rb_big2str1(VALUE x, int base)
{
@@ -4496,6 +4542,15 @@ rb_big2str1(VALUE x, int base)
return big2str_base_poweroftwo(x, base);
}
+#ifdef USE_GMP
+ if (GMP_BIG2STR_DIGITS < xn) {
+ VALUE str;
+ str = big2str_gmp(RBIGNUM_NEGATIVE_P(x), base, xds, xn);
+ RB_GC_GUARD(x);
+ return str;
+ }
+#endif
+
return big2str_generic(x, base, xds, xn);
}