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Diffstat (limited to 'ruby_1_8_6/bignum.c')
-rw-r--r-- | ruby_1_8_6/bignum.c | 2244 |
1 files changed, 2244 insertions, 0 deletions
diff --git a/ruby_1_8_6/bignum.c b/ruby_1_8_6/bignum.c new file mode 100644 index 0000000000..58e804091f --- /dev/null +++ b/ruby_1_8_6/bignum.c @@ -0,0 +1,2244 @@ +/********************************************************************** + + bignum.c - + + $Author$ + $Date$ + created at: Fri Jun 10 00:48:55 JST 1994 + + Copyright (C) 1993-2003 Yukihiro Matsumoto + +**********************************************************************/ + +#include "ruby.h" + +#include <math.h> +#include <ctype.h> +#ifdef HAVE_IEEEFP_H +#include <ieeefp.h> +#endif + +VALUE rb_cBignum; + +#if defined __MINGW32__ +#define USHORT _USHORT +#endif + +#define BDIGITS(x) ((BDIGIT*)RBIGNUM(x)->digits) +#define BITSPERDIG (SIZEOF_BDIGITS*CHAR_BIT) +#define BIGRAD ((BDIGIT_DBL)1 << BITSPERDIG) +#define DIGSPERLONG ((unsigned int)(SIZEOF_LONG/SIZEOF_BDIGITS)) +#if HAVE_LONG_LONG +# define DIGSPERLL ((unsigned int)(SIZEOF_LONG_LONG/SIZEOF_BDIGITS)) +#endif +#define BIGUP(x) ((BDIGIT_DBL)(x) << BITSPERDIG) +#define BIGDN(x) RSHIFT(x,BITSPERDIG) +#define BIGLO(x) ((BDIGIT)((x) & (BIGRAD-1))) +#define BDIGMAX ((BDIGIT)-1) + +#define BIGZEROP(x) (RBIGNUM(x)->len == 0 || (RBIGNUM(x)->len == 1 && BDIGITS(x)[0] == 0)) + +static VALUE +bignew_1(klass, len, sign) + VALUE klass; + long len; + int sign; +{ + NEWOBJ(big, struct RBignum); + OBJSETUP(big, klass, T_BIGNUM); + big->sign = sign?1:0; + big->len = len; + big->digits = ALLOC_N(BDIGIT, len); + + return (VALUE)big; +} + +#define bignew(len,sign) bignew_1(rb_cBignum,len,sign) + +VALUE +rb_big_clone(x) + VALUE x; +{ + VALUE z = bignew_1(CLASS_OF(x), RBIGNUM(x)->len, RBIGNUM(x)->sign); + + MEMCPY(BDIGITS(z), BDIGITS(x), BDIGIT, RBIGNUM(x)->len); + return z; +} + +/* modify a bignum by 2's complement */ +static void +get2comp(x) + VALUE x; +{ + long i = RBIGNUM(x)->len; + BDIGIT *ds = BDIGITS(x); + BDIGIT_DBL num; + + if (!i) return; + while (i--) ds[i] = ~ds[i]; + i = 0; num = 1; + do { + num += ds[i]; + ds[i++] = BIGLO(num); + num = BIGDN(num); + } while (i < RBIGNUM(x)->len); + if (num != 0) { + REALLOC_N(RBIGNUM(x)->digits, BDIGIT, ++RBIGNUM(x)->len); + ds = BDIGITS(x); + ds[RBIGNUM(x)->len-1] = RBIGNUM(x)->sign ? ~0 : 1; + } +} + +void +rb_big_2comp(x) /* get 2's complement */ + VALUE x; +{ + get2comp(x); +} + +static VALUE +bigtrunc(x) + VALUE x; +{ + long len = RBIGNUM(x)->len; + BDIGIT *ds = BDIGITS(x); + + while (--len && !ds[len]); + RBIGNUM(x)->len = ++len; + return x; +} + +static VALUE +bigfixize(VALUE x) +{ + long len = RBIGNUM(x)->len; + BDIGIT *ds = BDIGITS(x); + + if (len*SIZEOF_BDIGITS <= sizeof(VALUE)) { + long num = 0; + while (len--) { + num = BIGUP(num) + ds[len]; + } + if (num >= 0) { + if (RBIGNUM(x)->sign) { + if (POSFIXABLE(num)) return LONG2FIX(num); + } + else { + if (NEGFIXABLE(-(long)num)) return LONG2FIX(-(long)num); + } + } + } + return x; +} + +static VALUE +bignorm(VALUE x) +{ + if (!FIXNUM_P(x) && TYPE(x) == T_BIGNUM) { + x = bigfixize(bigtrunc(x)); + } + return x; +} + +VALUE +rb_big_norm(x) + VALUE x; +{ + return bignorm(x); +} + +VALUE +rb_uint2big(n) + unsigned long n; +{ + BDIGIT_DBL num = n; + long i = 0; + BDIGIT *digits; + VALUE big; + + big = bignew(DIGSPERLONG, 1); + digits = BDIGITS(big); + while (i < DIGSPERLONG) { + digits[i++] = BIGLO(num); + num = BIGDN(num); + } + + i = DIGSPERLONG; + while (--i && !digits[i]) ; + RBIGNUM(big)->len = i+1; + return big; +} + +VALUE +rb_int2big(n) + long n; +{ + long neg = 0; + VALUE big; + + if (n < 0) { + n = -n; + neg = 1; + } + big = rb_uint2big(n); + if (neg) { + RBIGNUM(big)->sign = 0; + } + return big; +} + +VALUE +rb_uint2inum(n) + unsigned long n; +{ + if (POSFIXABLE(n)) return LONG2FIX(n); + return rb_uint2big(n); +} + +VALUE +rb_int2inum(n) + long n; +{ + if (FIXABLE(n)) return LONG2FIX(n); + return rb_int2big(n); +} + +#ifdef HAVE_LONG_LONG + +void +rb_quad_pack(buf, val) + char *buf; + VALUE val; +{ + LONG_LONG q; + + val = rb_to_int(val); + if (FIXNUM_P(val)) { + q = FIX2LONG(val); + } + else { + long len = RBIGNUM(val)->len; + BDIGIT *ds; + + if (len > SIZEOF_LONG_LONG/SIZEOF_BDIGITS) + rb_raise(rb_eRangeError, "bignum too big to convert into `quad int'"); + ds = BDIGITS(val); + q = 0; + while (len--) { + q = BIGUP(q); + q += ds[len]; + } + if (!RBIGNUM(val)->sign) q = -q; + } + memcpy(buf, (char*)&q, SIZEOF_LONG_LONG); +} + +VALUE +rb_quad_unpack(buf, sign) + const char *buf; + int sign; +{ + unsigned LONG_LONG q; + long neg = 0; + long i; + BDIGIT *digits; + VALUE big; + + memcpy(&q, buf, SIZEOF_LONG_LONG); + if (sign) { + if (FIXABLE((LONG_LONG)q)) return LONG2FIX((LONG_LONG)q); + if ((LONG_LONG)q < 0) { + q = -(LONG_LONG)q; + neg = 1; + } + } + else { + if (POSFIXABLE(q)) return LONG2FIX(q); + } + + i = 0; + big = bignew(DIGSPERLL, 1); + digits = BDIGITS(big); + while (i < DIGSPERLL) { + digits[i++] = BIGLO(q); + q = BIGDN(q); + } + + i = DIGSPERLL; + while (i-- && !digits[i]) ; + RBIGNUM(big)->len = i+1; + + if (neg) { + RBIGNUM(big)->sign = 0; + } + return bignorm(big); +} + +#else + +#define QUAD_SIZE 8 + +void +rb_quad_pack(buf, val) + char *buf; + VALUE val; +{ + long len; + + memset(buf, 0, QUAD_SIZE); + val = rb_to_int(val); + if (FIXNUM_P(val)) { + val = rb_int2big(FIX2LONG(val)); + } + len = RBIGNUM(val)->len * SIZEOF_BDIGITS; + if (len > QUAD_SIZE) { + rb_raise(rb_eRangeError, "bignum too big to convert into `quad int'"); + } + memcpy(buf, (char*)BDIGITS(val), len); + if (!RBIGNUM(val)->sign) { + len = QUAD_SIZE; + while (len--) { + *buf = ~*buf; + buf++; + } + } +} + +#define BNEG(b) (RSHIFT(((BDIGIT*)b)[QUAD_SIZE/SIZEOF_BDIGITS-1],BITSPERDIG-1) != 0) + +VALUE +rb_quad_unpack(buf, sign) + const char *buf; + int sign; +{ + VALUE big = bignew(QUAD_SIZE/SIZEOF_BDIGITS, 1); + + memcpy((char*)BDIGITS(big), buf, QUAD_SIZE); + if (sign && BNEG(buf)) { + long len = QUAD_SIZE; + char *tmp = (char*)BDIGITS(big); + + RBIGNUM(big)->sign = 0; + while (len--) { + *tmp = ~*tmp; + tmp++; + } + } + + return bignorm(big); +} + +#endif + +VALUE +rb_cstr_to_inum(str, base, badcheck) + const char *str; + int base; + int badcheck; +{ + const char *s = str; + char *end; + char sign = 1, nondigit = 0; + int c; + BDIGIT_DBL num; + long len, blen = 1; + long i; + VALUE z; + BDIGIT *zds; + +#define conv_digit(c) \ + (!ISASCII(c) ? -1 : \ + isdigit(c) ? ((c) - '0') : \ + islower(c) ? ((c) - 'a' + 10) : \ + isupper(c) ? ((c) - 'A' + 10) : \ + -1) + + if (!str) { + if (badcheck) goto bad; + return INT2FIX(0); + } + if (badcheck) { + while (ISSPACE(*str)) str++; + } + else { + while (ISSPACE(*str) || *str == '_') str++; + } + + if (str[0] == '+') { + str++; + } + else if (str[0] == '-') { + str++; + sign = 0; + } + if (str[0] == '+' || str[0] == '-') { + if (badcheck) goto bad; + return INT2FIX(0); + } + if (base <= 0) { + if (str[0] == '0') { + switch (str[1]) { + case 'x': case 'X': + base = 16; + break; + case 'b': case 'B': + base = 2; + break; + case 'o': case 'O': + base = 8; + break; + case 'd': case 'D': + base = 10; + break; + default: + base = 8; + } + } + else if (base < -1) { + base = -base; + } + else { + base = 10; + } + } + switch (base) { + case 2: + len = 1; + if (str[0] == '0' && (str[1] == 'b'||str[1] == 'B')) { + str += 2; + } + break; + case 3: + len = 2; + break; + case 8: + if (str[0] == '0' && (str[1] == 'o'||str[1] == 'O')) { + str += 2; + } + case 4: case 5: case 6: case 7: + len = 3; + break; + case 10: + if (str[0] == '0' && (str[1] == 'd'||str[1] == 'D')) { + str += 2; + } + case 9: case 11: case 12: case 13: case 14: case 15: + len = 4; + break; + case 16: + len = 4; + if (str[0] == '0' && (str[1] == 'x'||str[1] == 'X')) { + str += 2; + } + break; + default: + if (base < 2 || 36 < base) { + rb_raise(rb_eArgError, "illegal radix %d", base); + } + if (base <= 32) { + len = 5; + } + else { + len = 6; + } + break; + } + if (*str == '0') { /* squeeze preceeding 0s */ + while (*++str == '0'); + if (!*str) --str; + } + c = *str; + c = conv_digit(c); + if (c < 0 || c >= base) { + if (badcheck) goto bad; + return INT2FIX(0); + } + len *= strlen(str)*sizeof(char); + + if (len <= (sizeof(VALUE)*CHAR_BIT)) { + unsigned long val = strtoul((char*)str, &end, base); + + if (*end == '_') goto bigparse; + if (badcheck) { + if (end == str) goto bad; /* no number */ + while (*end && ISSPACE(*end)) end++; + if (*end) goto bad; /* trailing garbage */ + } + + if (POSFIXABLE(val)) { + if (sign) return LONG2FIX(val); + else { + long result = -(long)val; + return LONG2FIX(result); + } + } + else { + VALUE big = rb_uint2big(val); + RBIGNUM(big)->sign = sign; + return bignorm(big); + } + } + bigparse: + len = (len/BITSPERDIG)+1; + if (badcheck && *str == '_') goto bad; + + z = bignew(len, sign); + zds = BDIGITS(z); + for (i=len;i--;) zds[i]=0; + while ((c = *str++) != 0) { + if (c == '_') { + if (badcheck) { + if (nondigit) goto bad; + nondigit = c; + } + continue; + } + else if ((c = conv_digit(c)) < 0) { + break; + } + if (c >= base) break; + nondigit = 0; + i = 0; + num = c; + for (;;) { + while (i<blen) { + num += (BDIGIT_DBL)zds[i]*base; + zds[i++] = BIGLO(num); + num = BIGDN(num); + } + if (num) { + blen++; + continue; + } + break; + } + } + if (badcheck) { + str--; + if (s+1 < str && str[-1] == '_') goto bad; + while (*str && ISSPACE(*str)) str++; + if (*str) { + bad: + rb_invalid_str(s, "Integer"); + } + } + + return bignorm(z); +} + +VALUE +rb_str_to_inum(str, base, badcheck) + VALUE str; + int base; + int badcheck; +{ + char *s; + long len; + + StringValue(str); + if (badcheck) { + s = StringValueCStr(str); + } + else { + s = RSTRING(str)->ptr; + } + if (s) { + len = RSTRING(str)->len; + if (s[len]) { /* no sentinel somehow */ + char *p = ALLOCA_N(char, len+1); + + MEMCPY(p, s, char, len); + p[len] = '\0'; + s = p; + } + } + return rb_cstr_to_inum(s, base, badcheck); +} + +#if HAVE_LONG_LONG + +VALUE +rb_ull2big(n) + unsigned LONG_LONG n; +{ + BDIGIT_DBL num = n; + long i = 0; + BDIGIT *digits; + VALUE big; + + big = bignew(DIGSPERLL, 1); + digits = BDIGITS(big); + while (i < DIGSPERLL) { + digits[i++] = BIGLO(num); + num = BIGDN(num); + } + + i = DIGSPERLL; + while (i-- && !digits[i]) ; + RBIGNUM(big)->len = i+1; + return big; +} + +VALUE +rb_ll2big(n) + LONG_LONG n; +{ + long neg = 0; + VALUE big; + + if (n < 0) { + n = -n; + neg = 1; + } + big = rb_ull2big(n); + if (neg) { + RBIGNUM(big)->sign = 0; + } + return big; +} + +VALUE +rb_ull2inum(n) + unsigned LONG_LONG n; +{ + if (POSFIXABLE(n)) return LONG2FIX(n); + return rb_ull2big(n); +} + +VALUE +rb_ll2inum(n) + LONG_LONG n; +{ + if (FIXABLE(n)) return LONG2FIX(n); + return rb_ll2big(n); +} + +#endif /* HAVE_LONG_LONG */ + +VALUE +rb_cstr2inum(str, base) + const char *str; + int base; +{ + return rb_cstr_to_inum(str, base, base==0); +} + +VALUE +rb_str2inum(str, base) + VALUE str; + int base; +{ + return rb_str_to_inum(str, base, base==0); +} + +const char ruby_digitmap[] = "0123456789abcdefghijklmnopqrstuvwxyz"; +VALUE +rb_big2str0(x, base, trim) + VALUE x; + int base; + int trim; +{ + volatile VALUE t; + BDIGIT *ds; + long i, j, hbase; + VALUE ss; + char *s; + + if (FIXNUM_P(x)) { + return rb_fix2str(x, base); + } + i = RBIGNUM(x)->len; + if (BIGZEROP(x)) { + return rb_str_new2("0"); + } + j = SIZEOF_BDIGITS*CHAR_BIT*i; + switch (base) { + case 2: break; + case 3: + j = j * 53L / 84 + 1; + break; + case 4: case 5: case 6: case 7: + j = (j + 1) / 2; + break; + case 8: case 9: + j = (j + 2) / 3; + break; + case 10: case 11: case 12: case 13: case 14: case 15: + j = j * 28L / 93 + 1; + break; + case 16: case 17: case 18: case 19: case 20: case 21: + case 22: case 23: case 24: case 25: case 26: case 27: + case 28: case 29: case 30: case 31: + j = (j + 3) / 4; + break; + case 32: case 33: case 34: case 35: case 36: + j = (j + 4) / 5; + break; + default: + rb_raise(rb_eArgError, "illegal radix %d", base); + break; + } + j++; /* space for sign */ + + hbase = base * base; +#if SIZEOF_BDIGITS > 2 + hbase *= hbase; +#endif + + t = rb_big_clone(x); + ds = BDIGITS(t); + ss = rb_str_new(0, j+1); + s = RSTRING(ss)->ptr; + + s[0] = RBIGNUM(x)->sign ? '+' : '-'; + while (i && j > 1) { + long k = i; + BDIGIT_DBL num = 0; + + while (k--) { + num = BIGUP(num) + ds[k]; + ds[k] = (BDIGIT)(num / hbase); + num %= hbase; + } + if (trim && ds[i-1] == 0) i--; + k = SIZEOF_BDIGITS; + while (k--) { + s[--j] = ruby_digitmap[num % base]; + num /= base; + if (!trim && j < 1) break; + if (trim && i == 0 && num == 0) break; + } + } + if (trim) {while (s[j] == '0') j++;} + i = RSTRING(ss)->len - j; + if (RBIGNUM(x)->sign) { + memmove(s, s+j, i); + RSTRING(ss)->len = i-1; + } + else { + memmove(s+1, s+j, i); + RSTRING(ss)->len = i; + } + s[RSTRING(ss)->len] = '\0'; + + return ss; +} + +VALUE +rb_big2str(VALUE x, int base) +{ + return rb_big2str0(x, base, Qtrue); +} + +/* + * call-seq: + * big.to_s(base=10) => string + * + * Returns a string containing the representation of <i>big</i> radix + * <i>base</i> (2 through 36). + * + * 12345654321.to_s #=> "12345654321" + * 12345654321.to_s(2) #=> "1011011111110110111011110000110001" + * 12345654321.to_s(8) #=> "133766736061" + * 12345654321.to_s(16) #=> "2dfdbbc31" + * 78546939656932.to_s(36) #=> "rubyrules" + */ + +static VALUE +rb_big_to_s(argc, argv, x) + int argc; + VALUE *argv; + VALUE x; +{ + VALUE b; + int base; + + rb_scan_args(argc, argv, "01", &b); + if (argc == 0) base = 10; + else base = NUM2INT(b); + return rb_big2str(x, base); +} + +static unsigned long +big2ulong(x, type) + VALUE x; + char *type; +{ + long len = RBIGNUM(x)->len; + BDIGIT_DBL num; + BDIGIT *ds; + + if (len > SIZEOF_LONG/SIZEOF_BDIGITS) + rb_raise(rb_eRangeError, "bignum too big to convert into `%s'", type); + ds = BDIGITS(x); + num = 0; + while (len--) { + num = BIGUP(num); + num += ds[len]; + } + return num; +} + +unsigned long +rb_big2ulong_pack(x) + VALUE x; +{ + unsigned long num = big2ulong(x, "unsigned long"); + if (!RBIGNUM(x)->sign) { + return -num; + } + return num; +} + +unsigned long +rb_big2ulong(x) + VALUE x; +{ + unsigned long num = big2ulong(x, "unsigned long"); + + if (!RBIGNUM(x)->sign) { + if ((long)num < 0) { + rb_raise(rb_eRangeError, "bignum out of range of unsigned long"); + } + return -num; + } + return num; +} + +long +rb_big2long(x) + VALUE x; +{ + unsigned long num = big2ulong(x, "long"); + + if ((long)num < 0 && (RBIGNUM(x)->sign || (long)num != LONG_MIN)) { + rb_raise(rb_eRangeError, "bignum too big to convert into `long'"); + } + if (!RBIGNUM(x)->sign) return -(long)num; + return num; +} + +#if HAVE_LONG_LONG + +static unsigned LONG_LONG +big2ull(x, type) + VALUE x; + char *type; +{ + long len = RBIGNUM(x)->len; + BDIGIT_DBL num; + BDIGIT *ds; + + if (len > SIZEOF_LONG_LONG/SIZEOF_BDIGITS) + rb_raise(rb_eRangeError, "bignum too big to convert into `%s'", type); + ds = BDIGITS(x); + num = 0; + while (len--) { + num = BIGUP(num); + num += ds[len]; + } + return num; +} + +unsigned LONG_LONG +rb_big2ull(x) + VALUE x; +{ + unsigned LONG_LONG num = big2ull(x, "unsigned long long"); + + if (!RBIGNUM(x)->sign) return -num; + return num; +} + +LONG_LONG +rb_big2ll(x) + VALUE x; +{ + unsigned LONG_LONG num = big2ull(x, "long long"); + + if ((LONG_LONG)num < 0 && (RBIGNUM(x)->sign + || (LONG_LONG)num != LLONG_MIN)) { + rb_raise(rb_eRangeError, "bignum too big to convert into `long long'"); + } + if (!RBIGNUM(x)->sign) return -(LONG_LONG)num; + return num; +} + +#endif /* HAVE_LONG_LONG */ + +static VALUE +dbl2big(d) + double d; +{ + long i = 0; + BDIGIT c; + BDIGIT *digits; + VALUE z; + double u = (d < 0)?-d:d; + + if (isinf(d)) { + rb_raise(rb_eFloatDomainError, d < 0 ? "-Infinity" : "Infinity"); + } + if (isnan(d)) { + rb_raise(rb_eFloatDomainError, "NaN"); + } + + while (!POSFIXABLE(u) || 0 != (long)u) { + u /= (double)(BIGRAD); + i++; + } + z = bignew(i, d>=0); + digits = BDIGITS(z); + while (i--) { + u *= BIGRAD; + c = (BDIGIT)u; + u -= c; + digits[i] = c; + } + + return z; +} + +VALUE +rb_dbl2big(d) + double d; +{ + return bignorm(dbl2big(d)); +} + +double +rb_big2dbl(x) + VALUE x; +{ + double d = 0.0; + long i = RBIGNUM(x)->len; + BDIGIT *ds = BDIGITS(x); + + while (i--) { + d = ds[i] + BIGRAD*d; + } + if (isinf(d)) { + rb_warn("Bignum out of Float range"); + d = HUGE_VAL; + } + if (!RBIGNUM(x)->sign) d = -d; + return d; +} + +/* + * call-seq: + * big.to_f -> float + * + * Converts <i>big</i> to a <code>Float</code>. If <i>big</i> doesn't + * fit in a <code>Float</code>, the result is infinity. + * + */ + +static VALUE +rb_big_to_f(x) + VALUE x; +{ + return rb_float_new(rb_big2dbl(x)); +} + +/* + * call-seq: + * big <=> numeric => -1, 0, +1 + * + * Comparison---Returns -1, 0, or +1 depending on whether <i>big</i> is + * less than, equal to, or greater than <i>numeric</i>. This is the + * basis for the tests in <code>Comparable</code>. + * + */ + +static VALUE +rb_big_cmp(x, y) + VALUE x, y; +{ + long xlen = RBIGNUM(x)->len; + + switch (TYPE(y)) { + case T_FIXNUM: + y = rb_int2big(FIX2LONG(y)); + break; + + case T_BIGNUM: + break; + + case T_FLOAT: + return rb_dbl_cmp(rb_big2dbl(x), RFLOAT(y)->value); + + default: + return rb_num_coerce_cmp(x, y); + } + + if (RBIGNUM(x)->sign > RBIGNUM(y)->sign) return INT2FIX(1); + if (RBIGNUM(x)->sign < RBIGNUM(y)->sign) return INT2FIX(-1); + if (xlen < RBIGNUM(y)->len) + return (RBIGNUM(x)->sign) ? INT2FIX(-1) : INT2FIX(1); + if (xlen > RBIGNUM(y)->len) + return (RBIGNUM(x)->sign) ? INT2FIX(1) : INT2FIX(-1); + + while(xlen-- && (BDIGITS(x)[xlen]==BDIGITS(y)[xlen])); + if (-1 == xlen) return INT2FIX(0); + return (BDIGITS(x)[xlen] > BDIGITS(y)[xlen]) ? + (RBIGNUM(x)->sign ? INT2FIX(1) : INT2FIX(-1)) : + (RBIGNUM(x)->sign ? INT2FIX(-1) : INT2FIX(1)); +} + +/* + * call-seq: + * big == obj => true or false + * + * Returns <code>true</code> only if <i>obj</i> has the same value + * as <i>big</i>. Contrast this with <code>Bignum#eql?</code>, which + * requires <i>obj</i> to be a <code>Bignum</code>. + * + * 68719476736 == 68719476736.0 #=> true + */ + +static VALUE +rb_big_eq(x, y) + VALUE x, y; +{ + switch (TYPE(y)) { + case T_FIXNUM: + y = rb_int2big(FIX2LONG(y)); + break; + case T_BIGNUM: + break; + case T_FLOAT: + { + volatile double a, b; + + a = RFLOAT(y)->value; + if (isnan(a)) return Qfalse; + b = rb_big2dbl(x); + return (a == b)?Qtrue:Qfalse; + } + default: + return rb_equal(y, x); + } + if (RBIGNUM(x)->sign != RBIGNUM(y)->sign) return Qfalse; + if (RBIGNUM(x)->len != RBIGNUM(y)->len) return Qfalse; + if (MEMCMP(BDIGITS(x),BDIGITS(y),BDIGIT,RBIGNUM(y)->len) != 0) return Qfalse; + return Qtrue; +} + +/* + * call-seq: + * big.eql?(obj) => true or false + * + * Returns <code>true</code> only if <i>obj</i> is a + * <code>Bignum</code> with the same value as <i>big</i>. Contrast this + * with <code>Bignum#==</code>, which performs type conversions. + * + * 68719476736.eql?(68719476736.0) #=> false + */ + +static VALUE +rb_big_eql(x, y) + VALUE x, y; +{ + if (TYPE(y) != T_BIGNUM) return Qfalse; + if (RBIGNUM(x)->sign != RBIGNUM(y)->sign) return Qfalse; + if (RBIGNUM(x)->len != RBIGNUM(y)->len) return Qfalse; + if (MEMCMP(BDIGITS(x),BDIGITS(y),BDIGIT,RBIGNUM(y)->len) != 0) return Qfalse; + return Qtrue; +} + +/* + * call-seq: + * -big => other_big + * + * Unary minus (returns a new Bignum whose value is 0-big) + */ + +static VALUE +rb_big_uminus(x) + VALUE x; +{ + VALUE z = rb_big_clone(x); + + RBIGNUM(z)->sign = !RBIGNUM(x)->sign; + + return bignorm(z); +} + +/* + * call-seq: + * ~big => integer + * + * Inverts the bits in big. As Bignums are conceptually infinite + * length, the result acts as if it had an infinite number of one + * bits to the left. In hex representations, this is displayed + * as two periods to the left of the digits. + * + * sprintf("%X", ~0x1122334455) #=> "..FEEDDCCBBAA" + */ + +static VALUE +rb_big_neg(x) + VALUE x; +{ + VALUE z = rb_big_clone(x); + long i; + BDIGIT *ds; + + if (!RBIGNUM(x)->sign) get2comp(z); + ds = BDIGITS(z); + i = RBIGNUM(x)->len; + if (!i) return INT2FIX(~0); + while (i--) ds[i] = ~ds[i]; + RBIGNUM(z)->sign = !RBIGNUM(z)->sign; + if (RBIGNUM(x)->sign) get2comp(z); + + return bignorm(z); +} + +static VALUE +bigsub(x, y) + VALUE x, y; +{ + VALUE z = 0; + BDIGIT *zds; + BDIGIT_DBL_SIGNED num; + long i = RBIGNUM(x)->len; + + /* if x is larger than y, swap */ + if (RBIGNUM(x)->len < RBIGNUM(y)->len) { + z = x; x = y; y = z; /* swap x y */ + } + else if (RBIGNUM(x)->len == RBIGNUM(y)->len) { + while (i > 0) { + i--; + if (BDIGITS(x)[i] > BDIGITS(y)[i]) { + break; + } + if (BDIGITS(x)[i] < BDIGITS(y)[i]) { + z = x; x = y; y = z; /* swap x y */ + break; + } + } + } + + z = bignew(RBIGNUM(x)->len, z==0); + zds = BDIGITS(z); + + for (i = 0, num = 0; i < RBIGNUM(y)->len; i++) { + num += (BDIGIT_DBL_SIGNED)BDIGITS(x)[i] - BDIGITS(y)[i]; + zds[i] = BIGLO(num); + num = BIGDN(num); + } + while (num && i < RBIGNUM(x)->len) { + num += BDIGITS(x)[i]; + zds[i++] = BIGLO(num); + num = BIGDN(num); + } + while (i < RBIGNUM(x)->len) { + zds[i] = BDIGITS(x)[i]; + i++; + } + + return z; +} + +static VALUE +bigadd(x, y, sign) + VALUE x, y; + int sign; +{ + VALUE z; + BDIGIT_DBL num; + long i, len; + + sign = (sign == RBIGNUM(y)->sign); + if (RBIGNUM(x)->sign != sign) { + if (sign) return bigsub(y, x); + return bigsub(x, y); + } + + if (RBIGNUM(x)->len > RBIGNUM(y)->len) { + len = RBIGNUM(x)->len + 1; + z = x; x = y; y = z; + } + else { + len = RBIGNUM(y)->len + 1; + } + z = bignew(len, sign); + + len = RBIGNUM(x)->len; + for (i = 0, num = 0; i < len; i++) { + num += (BDIGIT_DBL)BDIGITS(x)[i] + BDIGITS(y)[i]; + BDIGITS(z)[i] = BIGLO(num); + num = BIGDN(num); + } + len = RBIGNUM(y)->len; + while (num && i < len) { + num += BDIGITS(y)[i]; + BDIGITS(z)[i++] = BIGLO(num); + num = BIGDN(num); + } + while (i < len) { + BDIGITS(z)[i] = BDIGITS(y)[i]; + i++; + } + BDIGITS(z)[i] = (BDIGIT)num; + + return z; +} + +/* + * call-seq: + * big + other => Numeric + * + * Adds big and other, returning the result. + */ + +VALUE +rb_big_plus(x, y) + VALUE x, y; +{ + switch (TYPE(y)) { + case T_FIXNUM: + y = rb_int2big(FIX2LONG(y)); + /* fall through */ + case T_BIGNUM: + return bignorm(bigadd(x, y, 1)); + + case T_FLOAT: + return rb_float_new(rb_big2dbl(x) + RFLOAT(y)->value); + + default: + return rb_num_coerce_bin(x, y); + } +} + +/* + * call-seq: + * big - other => Numeric + * + * Subtracts other from big, returning the result. + */ + +VALUE +rb_big_minus(x, y) + VALUE x, y; +{ + switch (TYPE(y)) { + case T_FIXNUM: + y = rb_int2big(FIX2LONG(y)); + /* fall through */ + case T_BIGNUM: + return bignorm(bigadd(x, y, 0)); + + case T_FLOAT: + return rb_float_new(rb_big2dbl(x) - RFLOAT(y)->value); + + default: + return rb_num_coerce_bin(x, y); + } +} + +VALUE +rb_big_mul0(x, y) + VALUE x, y; +{ + long i, j; + BDIGIT_DBL n = 0; + VALUE z; + BDIGIT *zds; + + if (FIXNUM_P(x)) x = rb_int2big(FIX2LONG(x)); + switch (TYPE(y)) { + case T_FIXNUM: + y = rb_int2big(FIX2LONG(y)); + break; + + case T_BIGNUM: + break; + + case T_FLOAT: + return rb_float_new(rb_big2dbl(x) * RFLOAT(y)->value); + + default: + return rb_num_coerce_bin(x, y); + } + + j = RBIGNUM(x)->len + RBIGNUM(y)->len + 1; + z = bignew(j, RBIGNUM(x)->sign==RBIGNUM(y)->sign); + zds = BDIGITS(z); + while (j--) zds[j] = 0; + for (i = 0; i < RBIGNUM(x)->len; i++) { + BDIGIT_DBL dd = BDIGITS(x)[i]; + if (dd == 0) continue; + n = 0; + for (j = 0; j < RBIGNUM(y)->len; j++) { + BDIGIT_DBL ee = n + (BDIGIT_DBL)dd * BDIGITS(y)[j]; + n = zds[i + j] + ee; + if (ee) zds[i + j] = BIGLO(n); + n = BIGDN(n); + } + if (n) { + zds[i + j] = n; + } + } + + return z; +} + +/* + * call-seq: + * big * other => Numeric + * + * Multiplies big and other, returning the result. + */ + +VALUE +rb_big_mul(x, y) + VALUE x, y; +{ + return bignorm(rb_big_mul0(x, y)); +} + +static void +bigdivrem(x, y, divp, modp) + VALUE x, y; + VALUE *divp, *modp; +{ + long nx = RBIGNUM(x)->len, ny = RBIGNUM(y)->len; + long i, j; + VALUE yy, z; + BDIGIT *xds, *yds, *zds, *tds; + BDIGIT_DBL t2; + BDIGIT_DBL_SIGNED num; + BDIGIT dd, q; + + if (BIGZEROP(y)) rb_num_zerodiv(); + yds = BDIGITS(y); + if (nx < ny || (nx == ny && BDIGITS(x)[nx - 1] < BDIGITS(y)[ny - 1])) { + if (divp) *divp = rb_int2big(0); + if (modp) *modp = x; + return; + } + xds = BDIGITS(x); + if (ny == 1) { + dd = yds[0]; + z = rb_big_clone(x); + zds = BDIGITS(z); + t2 = 0; i = nx; + while (i--) { + t2 = BIGUP(t2) + zds[i]; + zds[i] = (BDIGIT)(t2 / dd); + t2 %= dd; + } + RBIGNUM(z)->sign = RBIGNUM(x)->sign==RBIGNUM(y)->sign; + if (modp) { + *modp = rb_uint2big((unsigned long)t2); + RBIGNUM(*modp)->sign = RBIGNUM(x)->sign; + } + if (divp) *divp = z; + return; + } + z = bignew(nx==ny?nx+2:nx+1, RBIGNUM(x)->sign==RBIGNUM(y)->sign); + zds = BDIGITS(z); + if (nx==ny) zds[nx+1] = 0; + while (!yds[ny-1]) ny--; + + dd = 0; + q = yds[ny-1]; + while ((q & (1<<(BITSPERDIG-1))) == 0) { + q <<= 1; + dd++; + } + if (dd) { + yy = rb_big_clone(y); + tds = BDIGITS(yy); + j = 0; + t2 = 0; + while (j<ny) { + t2 += (BDIGIT_DBL)yds[j]<<dd; + tds[j++] = BIGLO(t2); + t2 = BIGDN(t2); + } + yds = tds; + j = 0; + t2 = 0; + while (j<nx) { + t2 += (BDIGIT_DBL)xds[j]<<dd; + zds[j++] = BIGLO(t2); + t2 = BIGDN(t2); + } + zds[j] = (BDIGIT)t2; + } + else { + zds[nx] = 0; + j = nx; + while (j--) zds[j] = xds[j]; + } + + j = nx==ny?nx+1:nx; + do { + if (zds[j] == yds[ny-1]) q = BIGRAD-1; + else q = (BDIGIT)((BIGUP(zds[j]) + zds[j-1])/yds[ny-1]); + if (q) { + i = 0; num = 0; t2 = 0; + do { /* multiply and subtract */ + BDIGIT_DBL ee; + t2 += (BDIGIT_DBL)yds[i] * q; + ee = num - BIGLO(t2); + num = (BDIGIT_DBL)zds[j - ny + i] + ee; + if (ee) zds[j - ny + i] = BIGLO(num); + num = BIGDN(num); + t2 = BIGDN(t2); + } while (++i < ny); + num += zds[j - ny + i] - t2;/* borrow from high digit; don't update */ + while (num) { /* "add back" required */ + i = 0; num = 0; q--; + do { + BDIGIT_DBL ee = num + yds[i]; + num = (BDIGIT_DBL)zds[j - ny + i] + ee; + if (ee) zds[j - ny + i] = BIGLO(num); + num = BIGDN(num); + } while (++i < ny); + num--; + } + } + zds[j] = q; + } while (--j >= ny); + if (divp) { /* move quotient down in z */ + *divp = rb_big_clone(z); + zds = BDIGITS(*divp); + j = (nx==ny ? nx+2 : nx+1) - ny; + for (i = 0;i < j;i++) zds[i] = zds[i+ny]; + RBIGNUM(*divp)->len = i; + } + if (modp) { /* normalize remainder */ + *modp = rb_big_clone(z); + zds = BDIGITS(*modp); + while (--ny && !zds[ny]); ++ny; + if (dd) { + t2 = 0; i = ny; + while(i--) { + t2 = (t2 | zds[i]) >> dd; + q = zds[i]; + zds[i] = BIGLO(t2); + t2 = BIGUP(q); + } + } + RBIGNUM(*modp)->len = ny; + RBIGNUM(*modp)->sign = RBIGNUM(x)->sign; + } +} + +static void +bigdivmod(x, y, divp, modp) + VALUE x, y; + VALUE *divp, *modp; +{ + VALUE mod; + + bigdivrem(x, y, divp, &mod); + if (RBIGNUM(x)->sign != RBIGNUM(y)->sign && !BIGZEROP(mod)) { + if (divp) *divp = bigadd(*divp, rb_int2big(1), 0); + if (modp) *modp = bigadd(mod, y, 1); + } + else { + if (divp) *divp = *divp; + if (modp) *modp = mod; + } +} + +/* + * call-seq: + * big / other => Numeric + * big.div(other) => Numeric + * + * Divides big by other, returning the result. + */ + +static VALUE +rb_big_div(x, y) + VALUE x, y; +{ + VALUE z; + + switch (TYPE(y)) { + case T_FIXNUM: + y = rb_int2big(FIX2LONG(y)); + break; + + case T_BIGNUM: + break; + + case T_FLOAT: + return rb_float_new(rb_big2dbl(x) / RFLOAT(y)->value); + + default: + return rb_num_coerce_bin(x, y); + } + bigdivmod(x, y, &z, 0); + + return bignorm(z); +} + +/* + * call-seq: + * big % other => Numeric + * big.modulo(other) => Numeric + * + * Returns big modulo other. See Numeric.divmod for more + * information. + */ + +static VALUE +rb_big_modulo(x, y) + VALUE x, y; +{ + VALUE z; + + switch (TYPE(y)) { + case T_FIXNUM: + y = rb_int2big(FIX2LONG(y)); + break; + + case T_BIGNUM: + break; + + default: + return rb_num_coerce_bin(x, y); + } + bigdivmod(x, y, 0, &z); + + return bignorm(z); +} + +/* + * call-seq: + * big.remainder(numeric) => number + * + * Returns the remainder after dividing <i>big</i> by <i>numeric</i>. + * + * -1234567890987654321.remainder(13731) #=> -6966 + * -1234567890987654321.remainder(13731.24) #=> -9906.22531493148 + */ +static VALUE +rb_big_remainder(x, y) + VALUE x, y; +{ + VALUE z; + + switch (TYPE(y)) { + case T_FIXNUM: + y = rb_int2big(FIX2LONG(y)); + break; + + case T_BIGNUM: + break; + + default: + return rb_num_coerce_bin(x, y); + } + bigdivrem(x, y, 0, &z); + + return bignorm(z); +} + +static VALUE big_lshift _((VALUE, unsigned int)); +static VALUE big_rshift _((VALUE, unsigned int)); + +static VALUE big_shift(x, n) + VALUE x; + int n; +{ + if (n < 0) + return big_lshift(x, (unsigned int)n); + else if (n > 0) + return big_rshift(x, (unsigned int)n); + return x; +} + +/* + * call-seq: + * big.divmod(numeric) => array + * + * See <code>Numeric#divmod</code>. + * + */ +VALUE +rb_big_divmod(x, y) + VALUE x, y; +{ + VALUE div, mod; + + switch (TYPE(y)) { + case T_FIXNUM: + y = rb_int2big(FIX2LONG(y)); + break; + + case T_BIGNUM: + break; + + default: + return rb_num_coerce_bin(x, y); + } + bigdivmod(x, y, &div, &mod); + + return rb_assoc_new(bignorm(div), bignorm(mod)); +} + +/* + * call-seq: + * big.quo(numeric) -> float + * + * Returns the floating point result of dividing <i>big</i> by + * <i>numeric</i>. + * + * -1234567890987654321.quo(13731) #=> -89910996357705.5 + * -1234567890987654321.quo(13731.24) #=> -89909424858035.7 + * + */ + +static VALUE +rb_big_quo(x, y) + VALUE x, y; +{ + double dx = rb_big2dbl(x); + double dy; + + switch (TYPE(y)) { + case T_FIXNUM: + dy = (double)FIX2LONG(y); + break; + + case T_BIGNUM: + dy = rb_big2dbl(y); + break; + + case T_FLOAT: + dy = RFLOAT(y)->value; + break; + + default: + return rb_num_coerce_bin(x, y); + } + return rb_float_new(dx / dy); +} + +/* + * call-seq: + * big ** exponent #=> numeric + * + * Raises _big_ to the _exponent_ power (which may be an integer, float, + * or anything that will coerce to a number). The result may be + * a Fixnum, Bignum, or Float + * + * 123456789 ** 2 #=> 15241578750190521 + * 123456789 ** 1.2 #=> 5126464716.09932 + * 123456789 ** -2 #=> 6.5610001194102e-17 + */ + +VALUE +rb_big_pow(x, y) + VALUE x, y; +{ + double d; + long yy; + + if (y == INT2FIX(0)) return INT2FIX(1); + switch (TYPE(y)) { + case T_FLOAT: + d = RFLOAT(y)->value; + break; + + case T_BIGNUM: + rb_warn("in a**b, b may be too big"); + d = rb_big2dbl(y); + break; + + case T_FIXNUM: + yy = FIX2LONG(y); + if (yy > 0) { + VALUE z = x; + const long BIGLEN_LIMIT = 1024*1024 / SIZEOF_BDIGITS; + + if ((RBIGNUM(x)->len > BIGLEN_LIMIT) || + (RBIGNUM(x)->len > BIGLEN_LIMIT / yy)) { + rb_warn("in a**b, b may be too big"); + d = (double)yy; + break; + } + for (;;) { + yy -= 1; + if (yy == 0) break; + while (yy % 2 == 0) { + yy /= 2; + x = rb_big_mul0(x, x); + bigtrunc(x); + } + z = rb_big_mul0(z, x); + bigtrunc(z); + } + return bignorm(z); + } + d = (double)yy; + break; + + default: + return rb_num_coerce_bin(x, y); + } + return rb_float_new(pow(rb_big2dbl(x), d)); +} + +/* + * call-seq: + * big & numeric => integer + * + * Performs bitwise +and+ between _big_ and _numeric_. + */ + +VALUE +rb_big_and(xx, yy) + VALUE xx, yy; +{ + volatile VALUE x, y, z; + BDIGIT *ds1, *ds2, *zds; + long i, l1, l2; + char sign; + + x = xx; + y = rb_to_int(yy); + if (FIXNUM_P(y)) { + y = rb_int2big(FIX2LONG(y)); + } + if (!RBIGNUM(y)->sign) { + y = rb_big_clone(y); + get2comp(y); + } + if (!RBIGNUM(x)->sign) { + x = rb_big_clone(x); + get2comp(x); + } + if (RBIGNUM(x)->len > RBIGNUM(y)->len) { + l1 = RBIGNUM(y)->len; + l2 = RBIGNUM(x)->len; + ds1 = BDIGITS(y); + ds2 = BDIGITS(x); + sign = RBIGNUM(y)->sign; + } + else { + l1 = RBIGNUM(x)->len; + l2 = RBIGNUM(y)->len; + ds1 = BDIGITS(x); + ds2 = BDIGITS(y); + sign = RBIGNUM(x)->sign; + } + z = bignew(l2, RBIGNUM(x)->sign || RBIGNUM(y)->sign); + zds = BDIGITS(z); + + for (i=0; i<l1; i++) { + zds[i] = ds1[i] & ds2[i]; + } + for (; i<l2; i++) { + zds[i] = sign?0:ds2[i]; + } + if (!RBIGNUM(z)->sign) get2comp(z); + return bignorm(z); +} + +/* + * call-seq: + * big | numeric => integer + * + * Performs bitwise +or+ between _big_ and _numeric_. + */ + +VALUE +rb_big_or(xx, yy) + VALUE xx, yy; +{ + volatile VALUE x, y, z; + BDIGIT *ds1, *ds2, *zds; + long i, l1, l2; + char sign; + + x = xx; + y = rb_to_int(yy); + if (FIXNUM_P(y)) { + y = rb_int2big(FIX2LONG(y)); + } + if (!RBIGNUM(y)->sign) { + y = rb_big_clone(y); + get2comp(y); + } + if (!RBIGNUM(x)->sign) { + x = rb_big_clone(x); + get2comp(x); + } + if (RBIGNUM(x)->len > RBIGNUM(y)->len) { + l1 = RBIGNUM(y)->len; + l2 = RBIGNUM(x)->len; + ds1 = BDIGITS(y); + ds2 = BDIGITS(x); + sign = RBIGNUM(y)->sign; + } + else { + l1 = RBIGNUM(x)->len; + l2 = RBIGNUM(y)->len; + ds1 = BDIGITS(x); + ds2 = BDIGITS(y); + sign = RBIGNUM(x)->sign; + } + z = bignew(l2, RBIGNUM(x)->sign && RBIGNUM(y)->sign); + zds = BDIGITS(z); + + for (i=0; i<l1; i++) { + zds[i] = ds1[i] | ds2[i]; + } + for (; i<l2; i++) { + zds[i] = sign?ds2[i]:(BIGRAD-1); + } + if (!RBIGNUM(z)->sign) get2comp(z); + + return bignorm(z); +} + +/* + * call-seq: + * big ^ numeric => integer + * + * Performs bitwise +exclusive or+ between _big_ and _numeric_. + */ + +VALUE +rb_big_xor(xx, yy) + VALUE xx, yy; +{ + volatile VALUE x, y; + VALUE z; + BDIGIT *ds1, *ds2, *zds; + long i, l1, l2; + char sign; + + x = xx; + y = rb_to_int(yy); + if (FIXNUM_P(y)) { + y = rb_int2big(FIX2LONG(y)); + } + if (!RBIGNUM(y)->sign) { + y = rb_big_clone(y); + get2comp(y); + } + if (!RBIGNUM(x)->sign) { + x = rb_big_clone(x); + get2comp(x); + } + if (RBIGNUM(x)->len > RBIGNUM(y)->len) { + l1 = RBIGNUM(y)->len; + l2 = RBIGNUM(x)->len; + ds1 = BDIGITS(y); + ds2 = BDIGITS(x); + sign = RBIGNUM(y)->sign; + } + else { + l1 = RBIGNUM(x)->len; + l2 = RBIGNUM(y)->len; + ds1 = BDIGITS(x); + ds2 = BDIGITS(y); + sign = RBIGNUM(x)->sign; + } + RBIGNUM(x)->sign = RBIGNUM(x)->sign?1:0; + RBIGNUM(y)->sign = RBIGNUM(y)->sign?1:0; + z = bignew(l2, !(RBIGNUM(x)->sign ^ RBIGNUM(y)->sign)); + zds = BDIGITS(z); + + for (i=0; i<l1; i++) { + zds[i] = ds1[i] ^ ds2[i]; + } + for (; i<l2; i++) { + zds[i] = sign?ds2[i]:~ds2[i]; + } + if (!RBIGNUM(z)->sign) get2comp(z); + + return bignorm(z); +} + +static VALUE +check_shiftdown(VALUE y, VALUE x) +{ + if (!RBIGNUM(x)->len) return INT2FIX(0); + if (RBIGNUM(y)->len > SIZEOF_LONG / SIZEOF_BDIGITS) { + return RBIGNUM(x)->sign ? INT2FIX(0) : INT2FIX(-1); + } + return Qnil; +} + +/* + * call-seq: + * big << numeric => integer + * + * Shifts big left _numeric_ positions (right if _numeric_ is negative). + */ + +VALUE +rb_big_lshift(x, y) + VALUE x, y; +{ + int shift, neg = 0; + + for (;;) { + if (FIXNUM_P(y)) { + shift = FIX2INT(y); + if (shift < 0) { + neg = 1; + shift = -shift; + } + break; + } + else if (TYPE(y) == T_BIGNUM) { + if (!RBIGNUM(y)->sign) { + VALUE t = check_shiftdown(y, x); + if (!NIL_P(t)) return t; + neg = 1; + } + shift = big2ulong(y, "long", Qtrue); + break; + } + y = rb_to_int(y); + } + + if (neg) return big_rshift(x, shift); + return big_lshift(x, shift); +} + +static VALUE +big_lshift(x, shift) + VALUE x; + unsigned int shift; +{ + BDIGIT *xds, *zds; + int s1 = shift/BITSPERDIG; + int s2 = shift%BITSPERDIG; + VALUE z; + BDIGIT_DBL num = 0; + long len, i; + + len = RBIGNUM(x)->len; + z = bignew(len+s1+1, RBIGNUM(x)->sign); + zds = BDIGITS(z); + for (i=0; i<s1; i++) { + *zds++ = 0; + } + xds = BDIGITS(x); + for (i=0; i<len; i++) { + num = num | (BDIGIT_DBL)*xds++<<s2; + *zds++ = BIGLO(num); + num = BIGDN(num); + } + *zds = BIGLO(num); + return bignorm(z); +} + +/* + * call-seq: + * big >> numeric => integer + * + * Shifts big right _numeric_ positions (left if _numeric_ is negative). + */ + +VALUE +rb_big_rshift(x, y) + VALUE x, y; +{ + int shift; + int neg = 0; + + for (;;) { + if (FIXNUM_P(y)) { + shift = FIX2INT(y); + if (shift < 0) { + neg = 1; + shift = -shift; + } + break; + } + else if (TYPE(y) == T_BIGNUM) { + if (RBIGNUM(y)->sign) { + VALUE t = check_shiftdown(y, x); + if (!NIL_P(t)) return t; + } + else { + neg = 1; + } + shift = big2ulong(y, "long", Qtrue); + break; + } + y = rb_to_int(y); + } + + if (neg) return big_lshift(x, shift); + return big_rshift(x, shift); +} + +static VALUE +big_rshift(x, shift) + VALUE x; + unsigned int shift; +{ + BDIGIT *xds, *zds; + long s1 = shift/BITSPERDIG; + long s2 = shift%BITSPERDIG; + VALUE z; + BDIGIT_DBL num = 0; + long i, j; + volatile VALUE save_x; + + if (s1 > RBIGNUM(x)->len) { + if (RBIGNUM(x)->sign) + return INT2FIX(0); + else + return INT2FIX(-1); + } + if (!RBIGNUM(x)->sign) { + save_x = x = rb_big_clone(x); + get2comp(x); + } + xds = BDIGITS(x); + i = RBIGNUM(x)->len; j = i - s1; + if (j == 0) { + if (RBIGNUM(x)->sign) return INT2FIX(0); + else return INT2FIX(-1); + } + z = bignew(j, RBIGNUM(x)->sign); + if (!RBIGNUM(x)->sign) { + num = ((BDIGIT_DBL)~0) << BITSPERDIG; + } + zds = BDIGITS(z); + while (i--, j--) { + num = (num | xds[i]) >> s2; + zds[j] = BIGLO(num); + num = BIGUP(xds[i]); + } + if (!RBIGNUM(x)->sign) { + get2comp(z); + } + return bignorm(z); +} + +/* + * call-seq: + * big[n] -> 0, 1 + * + * Bit Reference---Returns the <em>n</em>th bit in the (assumed) binary + * representation of <i>big</i>, where <i>big</i>[0] is the least + * significant bit. + * + * a = 9**15 + * 50.downto(0) do |n| + * print a[n] + * end + * + * <em>produces:</em> + * + * 000101110110100000111000011110010100111100010111001 + * + */ + +static VALUE +rb_big_aref(x, y) + VALUE x, y; +{ + BDIGIT *xds; + BDIGIT_DBL num; + unsigned long shift; + long i, s1, s2; + + if (TYPE(y) == T_BIGNUM) { + if (!RBIGNUM(y)->sign) + return INT2FIX(0); + if (RBIGNUM(bigtrunc(y))->len > SIZEOF_LONG/SIZEOF_BDIGITS) { + out_of_range: + return RBIGNUM(x)->sign ? INT2FIX(0) : INT2FIX(1); + } + shift = big2ulong(y, "long", Qfalse); + } + else { + i = NUM2LONG(y); + if (i < 0) return INT2FIX(0); + shift = (VALUE)i; + } + s1 = shift/BITSPERDIG; + s2 = shift%BITSPERDIG; + + if (s1 >= RBIGNUM(x)->len) goto out_of_range; + if (!RBIGNUM(x)->sign) { + xds = BDIGITS(x); + i = 0; num = 1; + while (num += ~xds[i], ++i <= s1) { + num = BIGDN(num); + } + } + else { + num = BDIGITS(x)[s1]; + } + if (num & ((BDIGIT_DBL)1<<s2)) + return INT2FIX(1); + return INT2FIX(0); +} + +/* + * call-seq: + * big.hash => fixnum + * + * Compute a hash based on the value of _big_. + */ + +static VALUE +rb_big_hash(x) + VALUE x; +{ + long i, len, key; + BDIGIT *digits; + + key = 0; digits = BDIGITS(x); len = RBIGNUM(x)->len; + for (i=0; i<len; i++) { + key ^= *digits++; + } + return LONG2FIX(key); +} + +/* + * MISSING: documentation + */ + +static VALUE +rb_big_coerce(x, y) + VALUE x, y; +{ + if (FIXNUM_P(y)) { + return rb_assoc_new(rb_int2big(FIX2LONG(y)), x); + } + else if (TYPE(y) == T_BIGNUM) { + return rb_assoc_new(y, x); + } + else { + rb_raise(rb_eTypeError, "can't coerce %s to Bignum", + rb_obj_classname(y)); + } + /* not reached */ + return Qnil; +} + +/* + * call-seq: + * big.abs -> aBignum + * + * Returns the absolute value of <i>big</i>. + * + * -1234567890987654321.abs #=> 1234567890987654321 + */ + +static VALUE +rb_big_abs(x) + VALUE x; +{ + if (!RBIGNUM(x)->sign) { + x = rb_big_clone(x); + RBIGNUM(x)->sign = 1; + } + return x; +} + +VALUE +rb_big_rand(max, rand_buf) + VALUE max; + double *rand_buf; +{ + VALUE v; + long len = RBIGNUM(max)->len; + + if (BIGZEROP(max)) { + return rb_float_new(rand_buf[0]); + } + v = bignew(len,1); + len--; + BDIGITS(v)[len] = BDIGITS(max)[len] * rand_buf[len]; + while (len--) { + BDIGITS(v)[len] = ((BDIGIT)~0) * rand_buf[len]; + } + + return v; +} + +/* + * call-seq: + * big.size -> integer + * + * Returns the number of bytes in the machine representation of + * <i>big</i>. + * + * (256**10 - 1).size #=> 12 + * (256**20 - 1).size #=> 20 + * (256**40 - 1).size #=> 40 + */ + +static VALUE +rb_big_size(big) + VALUE big; +{ + return LONG2FIX(RBIGNUM(big)->len*SIZEOF_BDIGITS); +} + +/* + * Bignum objects hold integers outside the range of + * Fixnum. Bignum objects are created + * automatically when integer calculations would otherwise overflow a + * Fixnum. When a calculation involving + * Bignum objects returns a result that will fit in a + * Fixnum, the result is automatically converted. + * + * For the purposes of the bitwise operations and <code>[]</code>, a + * Bignum is treated as if it were an infinite-length + * bitstring with 2's complement representation. + * + * While Fixnum values are immediate, Bignum + * objects are not---assignment and parameter passing work with + * references to objects, not the objects themselves. + * + */ + +void +Init_Bignum() +{ + rb_cBignum = rb_define_class("Bignum", rb_cInteger); + + rb_define_method(rb_cBignum, "to_s", rb_big_to_s, -1); + rb_define_method(rb_cBignum, "coerce", rb_big_coerce, 1); + rb_define_method(rb_cBignum, "-@", rb_big_uminus, 0); + rb_define_method(rb_cBignum, "+", rb_big_plus, 1); + rb_define_method(rb_cBignum, "-", rb_big_minus, 1); + rb_define_method(rb_cBignum, "*", rb_big_mul, 1); + rb_define_method(rb_cBignum, "/", rb_big_div, 1); + rb_define_method(rb_cBignum, "%", rb_big_modulo, 1); + rb_define_method(rb_cBignum, "div", rb_big_div, 1); + rb_define_method(rb_cBignum, "divmod", rb_big_divmod, 1); + rb_define_method(rb_cBignum, "modulo", rb_big_modulo, 1); + rb_define_method(rb_cBignum, "remainder", rb_big_remainder, 1); + rb_define_method(rb_cBignum, "quo", rb_big_quo, 1); + rb_define_method(rb_cBignum, "**", rb_big_pow, 1); + rb_define_method(rb_cBignum, "&", rb_big_and, 1); + rb_define_method(rb_cBignum, "|", rb_big_or, 1); + rb_define_method(rb_cBignum, "^", rb_big_xor, 1); + rb_define_method(rb_cBignum, "~", rb_big_neg, 0); + rb_define_method(rb_cBignum, "<<", rb_big_lshift, 1); + rb_define_method(rb_cBignum, ">>", rb_big_rshift, 1); + rb_define_method(rb_cBignum, "[]", rb_big_aref, 1); + + rb_define_method(rb_cBignum, "<=>", rb_big_cmp, 1); + rb_define_method(rb_cBignum, "==", rb_big_eq, 1); + rb_define_method(rb_cBignum, "eql?", rb_big_eql, 1); + rb_define_method(rb_cBignum, "hash", rb_big_hash, 0); + rb_define_method(rb_cBignum, "to_f", rb_big_to_f, 0); + rb_define_method(rb_cBignum, "abs", rb_big_abs, 0); + rb_define_method(rb_cBignum, "size", rb_big_size, 0); +} |