/********************************************************************** bignum.c - $Author$ created at: Fri Jun 10 00:48:55 JST 1994 Copyright (C) 1993-2007 Yukihiro Matsumoto **********************************************************************/ #include "ruby/ruby.h" #include "ruby/thread.h" #include "ruby/util.h" #include "internal.h" #ifdef HAVE_STRINGS_H #include #endif #include #include #include #ifdef HAVE_IEEEFP_H #include #endif #include VALUE rb_cBignum; static VALUE big_three = Qnil; #if defined __MINGW32__ #define USHORT _USHORT #endif #define BDIGITS(x) (RBIGNUM_DIGITS(x)) #define BITSPERDIG (SIZEOF_BDIGITS*CHAR_BIT) #define BIGRAD ((BDIGIT_DBL)1 << BITSPERDIG) #define BIGRAD_HALF ((BDIGIT)(BIGRAD >> 1)) #if SIZEOF_LONG >= SIZEOF_BDIGITS # define DIGSPERLONG (SIZEOF_LONG/SIZEOF_BDIGITS) #endif #if defined(HAVE_LONG_LONG) && SIZEOF_LONG_LONG >= SIZEOF_BDIGITS # define DIGSPERLL (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_LEN(x) == 0 || \ (BDIGITS(x)[0] == 0 && \ (RBIGNUM_LEN(x) == 1 || bigzero_p(x)))) #define BIGSIZE(x) (RBIGNUM_LEN(x) == 0 ? (size_t)0 : \ BDIGITS(x)[RBIGNUM_LEN(x)-1] ? \ (size_t)(RBIGNUM_LEN(x)*SIZEOF_BDIGITS - nlz(BDIGITS(x)[RBIGNUM_LEN(x)-1])/CHAR_BIT) : \ rb_absint_size(x, NULL)) #define BIGDIVREM_EXTRA_WORDS 2 #define roomof(n, m) ((int)(((n)+(m)-1) / (m))) #define bdigit_roomof(n) roomof(n, SIZEOF_BDIGITS) #define BARY_ARGS(ary) ary, numberof(ary) #define BARY_ADD(z, x, y) bary_add(BARY_ARGS(z), BARY_ARGS(x), BARY_ARGS(y)) #define BARY_SUB(z, x, y) bary_sub(BARY_ARGS(z), BARY_ARGS(x), BARY_ARGS(y)) #define BARY_MUL(z, x, y) bary_mul(BARY_ARGS(z), BARY_ARGS(x), BARY_ARGS(y)) #define BARY_DIVMOD(q, r, x, y) bary_divmod(BARY_ARGS(q), BARY_ARGS(r), BARY_ARGS(x), BARY_ARGS(y)) #define BARY_ZERO_P(x) bary_zero_p(BARY_ARGS(x)) static int nlz(BDIGIT x); static BDIGIT bary_small_lshift(BDIGIT *zds, BDIGIT *xds, long n, int shift); static void bary_small_rshift(BDIGIT *zds, BDIGIT *xds, long n, int shift, int sign_bit); static void bary_unpack(BDIGIT *bdigits, size_t num_bdigits, const void *words, size_t numwords, size_t wordsize, size_t nails, int flags); static void bary_mul(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds, size_t yl); static void bary_sub(BDIGIT *zds, size_t zn, BDIGIT *xds, size_t xn, BDIGIT *yds, size_t yn); static void bary_divmod(BDIGIT *qds, size_t nq, BDIGIT *rds, size_t nr, BDIGIT *xds, size_t nx, BDIGIT *yds, size_t ny); static void bary_add(BDIGIT *zds, size_t zn, BDIGIT *xds, size_t xn, BDIGIT *yds, size_t yn); static int bary_pack(int sign, BDIGIT *ds, size_t num_bdigits, void *words, size_t numwords, size_t wordsize, size_t nails, int flags); static BDIGIT bary_2comp(BDIGIT *ds, size_t n); #define BIGNUM_DEBUG 0 #if BIGNUM_DEBUG #define ON_DEBUG(x) do { x; } while (0) static void dump_bignum(VALUE x) { long i; printf("%c0x0", RBIGNUM_SIGN(x) ? '+' : '-'); for (i = RBIGNUM_LEN(x); i--; ) { printf("_%0*"PRIxBDIGIT, SIZEOF_BDIGITS*2, BDIGITS(x)[i]); } printf(", len=%lu", RBIGNUM_LEN(x)); puts(""); } static VALUE rb_big_dump(VALUE x) { dump_bignum(x); return x; } #else #define ON_DEBUG(x) #endif static int bary_zero_p(BDIGIT *xds, size_t nx) { if (nx == 0) return 1; do { if (xds[--nx]) return 0; } while (nx); return 1; } static int bigzero_p(VALUE x) { return bary_zero_p(BDIGITS(x), RBIGNUM_LEN(x)); } int rb_bigzero_p(VALUE x) { return BIGZEROP(x); } int rb_cmpint(VALUE val, VALUE a, VALUE b) { if (NIL_P(val)) { rb_cmperr(a, b); } if (FIXNUM_P(val)) { long l = FIX2LONG(val); if (l > 0) return 1; if (l < 0) return -1; return 0; } if (RB_TYPE_P(val, T_BIGNUM)) { if (BIGZEROP(val)) return 0; if (RBIGNUM_SIGN(val)) return 1; return -1; } if (RTEST(rb_funcall(val, '>', 1, INT2FIX(0)))) return 1; if (RTEST(rb_funcall(val, '<', 1, INT2FIX(0)))) return -1; return 0; } #define RBIGNUM_SET_LEN(b,l) \ ((RBASIC(b)->flags & RBIGNUM_EMBED_FLAG) ? \ (void)(RBASIC(b)->flags = \ (RBASIC(b)->flags & ~RBIGNUM_EMBED_LEN_MASK) | \ ((l) << RBIGNUM_EMBED_LEN_SHIFT)) : \ (void)(RBIGNUM(b)->as.heap.len = (l))) static void rb_big_realloc(VALUE big, long len) { BDIGIT *ds; if (RBASIC(big)->flags & RBIGNUM_EMBED_FLAG) { if (RBIGNUM_EMBED_LEN_MAX < len) { ds = ALLOC_N(BDIGIT, len); MEMCPY(ds, RBIGNUM(big)->as.ary, BDIGIT, RBIGNUM_EMBED_LEN_MAX); RBIGNUM(big)->as.heap.len = RBIGNUM_LEN(big); RBIGNUM(big)->as.heap.digits = ds; RBASIC(big)->flags &= ~RBIGNUM_EMBED_FLAG; } } else { if (len <= RBIGNUM_EMBED_LEN_MAX) { ds = RBIGNUM(big)->as.heap.digits; RBASIC(big)->flags |= RBIGNUM_EMBED_FLAG; RBIGNUM_SET_LEN(big, len); if (ds) { MEMCPY(RBIGNUM(big)->as.ary, ds, BDIGIT, len); xfree(ds); } } else { if (RBIGNUM_LEN(big) == 0) { RBIGNUM(big)->as.heap.digits = ALLOC_N(BDIGIT, len); } else { REALLOC_N(RBIGNUM(big)->as.heap.digits, BDIGIT, len); } } } } void rb_big_resize(VALUE big, long len) { rb_big_realloc(big, len); RBIGNUM_SET_LEN(big, len); } static VALUE bignew_1(VALUE klass, long len, int sign) { NEWOBJ_OF(big, struct RBignum, klass, T_BIGNUM | (RGENGC_WB_PROTECTED_BIGNUM ? FL_WB_PROTECTED : 0)); RBIGNUM_SET_SIGN(big, sign?1:0); if (len <= RBIGNUM_EMBED_LEN_MAX) { RBASIC(big)->flags |= RBIGNUM_EMBED_FLAG; RBIGNUM_SET_LEN(big, len); } else { RBIGNUM(big)->as.heap.digits = ALLOC_N(BDIGIT, len); RBIGNUM(big)->as.heap.len = len; } OBJ_FREEZE(big); return (VALUE)big; } #define bignew(len,sign) bignew_1(rb_cBignum,(len),(sign)) VALUE rb_big_new(long len, int sign) { return bignew(len, sign != 0); } VALUE rb_big_clone(VALUE x) { long len = RBIGNUM_LEN(x); VALUE z = bignew_1(CLASS_OF(x), len, RBIGNUM_SIGN(x)); MEMCPY(BDIGITS(z), BDIGITS(x), BDIGIT, len); return z; } static BDIGIT bary_2comp(BDIGIT *ds, size_t n) { size_t i = n; BDIGIT_DBL num; if (!n) return 1; while (i--) ds[i] = ~ds[i]; i = 0; num = 1; do { num += ds[i]; ds[i++] = BIGLO(num); num = BIGDN(num); } while (i < n); return (BDIGIT)num; } /* modify a bignum by 2's complement */ static void get2comp(VALUE x) { long i = RBIGNUM_LEN(x); 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_LEN(x)); if (num != 0) { rb_big_resize(x, RBIGNUM_LEN(x)+1); ds = BDIGITS(x); ds[RBIGNUM_LEN(x)-1] = 1; } } void rb_big_2comp(VALUE x) /* get 2's complement */ { get2comp(x); } static inline VALUE bigtrunc(VALUE x) { long len = RBIGNUM_LEN(x); BDIGIT *ds = BDIGITS(x); if (len == 0) return x; while (--len && !ds[len]); if (RBIGNUM_LEN(x) > len+1) { rb_big_resize(x, len+1); } return x; } static inline VALUE bigfixize(VALUE x) { long len = RBIGNUM_LEN(x); BDIGIT *ds = BDIGITS(x); if (len == 0) return INT2FIX(0); if (BIGSIZE(x) <= sizeof(long)) { long num = 0; #if SIZEOF_BDIGITS >= SIZEOF_LONG num = (long)ds[0]; #else while (len--) { num = (long)(BIGUP(num) + ds[len]); } #endif if (num >= 0) { if (RBIGNUM_SIGN(x)) { if (POSFIXABLE(num)) return LONG2FIX(num); } else { if (NEGFIXABLE(-num)) return LONG2FIX(-num); } } } return x; } static VALUE bignorm(VALUE x) { if (RB_TYPE_P(x, T_BIGNUM)) { x = bigfixize(x); if (!FIXNUM_P(x)) bigtrunc(x); } return x; } VALUE rb_big_norm(VALUE x) { return bignorm(x); } VALUE rb_uint2big(VALUE n) { long i; VALUE big = bignew(bdigit_roomof(SIZEOF_VALUE), 1); BDIGIT *digits = BDIGITS(big); #if SIZEOF_BDIGITS >= SIZEOF_VALUE digits[0] = n; #else i = 0; for (i = 0; i < bdigit_roomof(SIZEOF_VALUE); i++) { digits[i] = BIGLO(n); n = BIGDN(n); } #endif i = bdigit_roomof(SIZEOF_VALUE); while (--i && !digits[i]) ; RBIGNUM_SET_LEN(big, i+1); return big; } VALUE rb_int2big(SIGNED_VALUE n) { long neg = 0; VALUE u; VALUE big; if (n < 0) { u = 1 + (VALUE)(-(n + 1)); /* u = -n avoiding overflow */ neg = 1; } else { u = n; } big = rb_uint2big(u); if (neg) { RBIGNUM_SET_SIGN(big, 0); } return big; } VALUE rb_uint2inum(VALUE n) { if (POSFIXABLE(n)) return LONG2FIX(n); return rb_uint2big(n); } VALUE rb_int2inum(SIGNED_VALUE n) { if (FIXABLE(n)) return LONG2FIX(n); return rb_int2big(n); } #if 0 #if SIZEOF_LONG % SIZEOF_BDIGITS != 0 # error unexpected SIZEOF_LONG : SIZEOF_BDIGITS ratio #endif /* * buf is an array of long integers. * buf is ordered from least significant word to most significant word. * buf[0] is the least significant word and * buf[num_longs-1] is the most significant word. * This means words in buf is little endian. * However each word in buf is native endian. * (buf[i]&1) is the least significant bit and * (buf[i]&(1<<(SIZEOF_LONG*CHAR_BIT-1))) is the most significant bit * for each 0 <= i < num_longs. * So buf is little endian at whole on a little endian machine. * But buf is mixed endian on a big endian machine. * * The buf represents negative integers as two's complement. * So, the most significant bit of the most significant word, * (buf[num_longs-1]>>(SIZEOF_LONG*CHAR_BIT-1)), * is the sign bit: 1 means negative and 0 means zero or positive. * * If given size of buf (num_longs) is not enough to represent val, * higher words (including a sign bit) are ignored. */ void rb_big_pack(VALUE val, unsigned long *buf, long num_longs) { val = rb_to_int(val); if (num_longs == 0) return; if (FIXNUM_P(val)) { long i; long tmp = FIX2LONG(val); buf[0] = (unsigned long)tmp; tmp = tmp < 0 ? ~0L : 0; for (i = 1; i < num_longs; i++) buf[i] = (unsigned long)tmp; return; } else { long len = RBIGNUM_LEN(val); BDIGIT *ds = BDIGITS(val), *dend = ds + len; long i, j; for (i = 0; i < num_longs && ds < dend; i++) { unsigned long l = 0; for (j = 0; j < DIGSPERLONG && ds < dend; j++, ds++) { l |= ((unsigned long)*ds << (j * BITSPERDIG)); } buf[i] = l; } for (; i < num_longs; i++) buf[i] = 0; if (RBIGNUM_NEGATIVE_P(val)) { for (i = 0; i < num_longs; i++) { buf[i] = ~buf[i]; } for (i = 0; i < num_longs; i++) { buf[i]++; if (buf[i] != 0) return; } } } } /* See rb_big_pack comment for endianness and sign of buf. */ VALUE rb_big_unpack(unsigned long *buf, long num_longs) { while (2 <= num_longs) { if (buf[num_longs-1] == 0 && (long)buf[num_longs-2] >= 0) num_longs--; else if (buf[num_longs-1] == ~0UL && (long)buf[num_longs-2] < 0) num_longs--; else break; } if (num_longs == 0) return INT2FIX(0); else if (num_longs == 1) return LONG2NUM((long)buf[0]); else { VALUE big; BDIGIT *ds; long len = num_longs * DIGSPERLONG; long i; big = bignew(len, 1); ds = BDIGITS(big); for (i = 0; i < num_longs; i++) { unsigned long d = buf[i]; #if SIZEOF_LONG == SIZEOF_BDIGITS *ds++ = d; #else int j; for (j = 0; j < DIGSPERLONG; j++) { *ds++ = BIGLO(d); d = BIGDN(d); } #endif } if ((long)buf[num_longs-1] < 0) { get2comp(big); RBIGNUM_SET_SIGN(big, 0); } return bignorm(big); } } #endif void rb_big_pack(VALUE val, unsigned long *buf, long num_longs) { rb_integer_pack(val, buf, num_longs, sizeof(long), 0, INTEGER_PACK_LSWORD_FIRST|INTEGER_PACK_NATIVE_BYTE_ORDER| INTEGER_PACK_2COMP); } VALUE rb_big_unpack(unsigned long *buf, long num_longs) { return rb_integer_unpack(buf, num_longs, sizeof(long), 0, INTEGER_PACK_LSWORD_FIRST|INTEGER_PACK_NATIVE_BYTE_ORDER| INTEGER_PACK_2COMP); } /* number of bytes of abs(val). additionaly number of leading zeros can be returned. */ /* * Calculate the number of bytes to be required to represent * the absolute value of the integer given as _val_. * * [val] an integer. * [nlz_bits_ret] number of leading zero bits in the most significant byte is returned if not NULL. * * This function returns ((val_numbits * CHAR_BIT + CHAR_BIT - 1) / CHAR_BIT) * where val_numbits is the number of bits of abs(val). * This function should not overflow. * * If nlz_bits_ret is not NULL, * (return_value * CHAR_BIT - val_numbits) is stored in *nlz_bits_ret. * In this case, 0 <= *nlz_bits_ret < CHAR_BIT. * */ size_t rb_absint_size(VALUE val, int *nlz_bits_ret) { BDIGIT *dp; BDIGIT *de; BDIGIT fixbuf[bdigit_roomof(sizeof(long))]; int num_leading_zeros; val = rb_to_int(val); if (FIXNUM_P(val)) { long v = FIX2LONG(val); if (v < 0) { v = -v; } #if SIZEOF_BDIGITS >= SIZEOF_LONG fixbuf[0] = v; #else { int i; for (i = 0; i < numberof(fixbuf); i++) { fixbuf[i] = BIGLO(v); v = BIGDN(v); } } #endif dp = fixbuf; de = fixbuf + numberof(fixbuf); } else { dp = BDIGITS(val); de = dp + RBIGNUM_LEN(val); } while (dp < de && de[-1] == 0) de--; if (dp == de) { if (nlz_bits_ret) *nlz_bits_ret = 0; return 0; } num_leading_zeros = nlz(de[-1]); if (nlz_bits_ret) *nlz_bits_ret = num_leading_zeros % CHAR_BIT; return (de - dp) * SIZEOF_BDIGITS - num_leading_zeros / CHAR_BIT; } static size_t absint_numwords_small(size_t numbytes, int nlz_bits_in_msbyte, size_t word_numbits, size_t *nlz_bits_ret) { size_t val_numbits = numbytes * CHAR_BIT - nlz_bits_in_msbyte; size_t div = val_numbits / word_numbits; size_t mod = val_numbits % word_numbits; size_t numwords; size_t nlz_bits; numwords = mod == 0 ? div : div + 1; nlz_bits = mod == 0 ? 0 : word_numbits - mod; *nlz_bits_ret = nlz_bits; return numwords; } static size_t absint_numwords_generic(size_t numbytes, int nlz_bits_in_msbyte, size_t word_numbits, size_t *nlz_bits_ret) { BDIGIT numbytes_bary[bdigit_roomof(sizeof(numbytes))]; BDIGIT char_bit[1] = { CHAR_BIT }; BDIGIT val_numbits_bary[bdigit_roomof(sizeof(numbytes) + 1)]; BDIGIT nlz_bits_in_msbyte_bary[1] = { nlz_bits_in_msbyte }; BDIGIT word_numbits_bary[bdigit_roomof(sizeof(word_numbits))]; BDIGIT div_bary[numberof(val_numbits_bary) + BIGDIVREM_EXTRA_WORDS]; BDIGIT mod_bary[numberof(word_numbits_bary)]; BDIGIT one[1] = { 1 }; size_t nlz_bits; size_t mod; int sign; size_t numwords; /* * val_numbits = numbytes * CHAR_BIT - nlz_bits_in_msbyte * div, mod = val_numbits.divmod(word_numbits) * numwords = mod == 0 ? div : div + 1 * nlz_bits = mod == 0 ? 0 : word_numbits - mod */ bary_unpack(BARY_ARGS(numbytes_bary), &numbytes, 1, sizeof(numbytes), 0, INTEGER_PACK_NATIVE_BYTE_ORDER); BARY_MUL(val_numbits_bary, numbytes_bary, char_bit); if (nlz_bits_in_msbyte) BARY_SUB(val_numbits_bary, val_numbits_bary, nlz_bits_in_msbyte_bary); bary_unpack(BARY_ARGS(word_numbits_bary), &word_numbits, 1, sizeof(word_numbits), 0, INTEGER_PACK_NATIVE_BYTE_ORDER); BARY_DIVMOD(div_bary, mod_bary, val_numbits_bary, word_numbits_bary); if (BARY_ZERO_P(mod_bary)) { nlz_bits = 0; } else { BARY_ADD(div_bary, div_bary, one); bary_pack(+1, BARY_ARGS(mod_bary), &mod, 1, sizeof(mod), 0, INTEGER_PACK_NATIVE_BYTE_ORDER); nlz_bits = word_numbits - mod; } sign = bary_pack(+1, BARY_ARGS(div_bary), &numwords, 1, sizeof(numwords), 0, INTEGER_PACK_NATIVE_BYTE_ORDER); if (sign == 2) return (size_t)-1; *nlz_bits_ret = nlz_bits; return numwords; } /* * Calculate the number of words to be required to represent * the absolute value of the integer given as _val_. * * [val] an integer. * [word_numbits] number of bits in a word. * [nlz_bits_ret] number of leading zero bits in the most significant word is returned if not NULL. * * This function returns ((val_numbits * CHAR_BIT + word_numbits - 1) / word_numbits) * where val_numbits is the number of bits of abs(val). * * This function can overflow. * When overflow occur, (size_t)-1 is returned. * * If nlz_bits_ret is not NULL and overflow is not occur, * (return_value * word_numbits - val_numbits) is stored in *nlz_bits_ret. * In this case, 0 <= *nlz_bits_ret < word_numbits. * */ size_t rb_absint_numwords(VALUE val, size_t word_numbits, size_t *nlz_bits_ret) { size_t numbytes; int nlz_bits_in_msbyte; size_t numwords; size_t nlz_bits; if (word_numbits == 0) return (size_t)-1; numbytes = rb_absint_size(val, &nlz_bits_in_msbyte); if (numbytes <= SIZE_MAX / CHAR_BIT) { numwords = absint_numwords_small(numbytes, nlz_bits_in_msbyte, word_numbits, &nlz_bits); #ifdef DEBUG_INTEGER_PACK { size_t numwords0, nlz_bits0; numwords0 = absint_numwords_generic(numbytes, nlz_bits_in_msbyte, word_numbits, &nlz_bits0); assert(numwords0 == numwords); assert(nlz_bits0 == nlz_bits); } #endif } else { numwords = absint_numwords_generic(numbytes, nlz_bits_in_msbyte, word_numbits, &nlz_bits); } if (numwords == (size_t)-1) return numwords; if (nlz_bits_ret) *nlz_bits_ret = nlz_bits; return numwords; } int rb_absint_singlebit_p(VALUE val) { BDIGIT *dp; BDIGIT *de; BDIGIT fixbuf[bdigit_roomof(sizeof(long))]; BDIGIT d; val = rb_to_int(val); if (FIXNUM_P(val)) { long v = FIX2LONG(val); if (v < 0) { v = -v; } #if SIZEOF_BDIGITS >= SIZEOF_LONG fixbuf[0] = v; #else { int i; for (i = 0; i < numberof(fixbuf); i++) { fixbuf[i] = BIGLO(v); v = BIGDN(v); } } #endif dp = fixbuf; de = fixbuf + numberof(fixbuf); } else { dp = BDIGITS(val); de = dp + RBIGNUM_LEN(val); } while (dp < de && de[-1] == 0) de--; while (dp < de && dp[0] == 0) dp++; if (dp == de) /* no bit set. */ return 0; if (dp != de-1) /* two non-zero words. two bits set, at least. */ return 0; d = *dp; d = d & (d - 1); /* Clear the least significant bit set */ return d == 0; } #define INTEGER_PACK_WORDORDER_MASK \ (INTEGER_PACK_MSWORD_FIRST | \ INTEGER_PACK_LSWORD_FIRST) #define INTEGER_PACK_BYTEORDER_MASK \ (INTEGER_PACK_MSBYTE_FIRST | \ INTEGER_PACK_LSBYTE_FIRST | \ INTEGER_PACK_NATIVE_BYTE_ORDER) static void validate_integer_pack_format(size_t numwords, size_t wordsize, size_t nails, int flags, int supported_flags) { int wordorder_bits = flags & INTEGER_PACK_WORDORDER_MASK; int byteorder_bits = flags & INTEGER_PACK_BYTEORDER_MASK; if (flags & ~supported_flags) { rb_raise(rb_eArgError, "unsupported flags specified"); } if (wordorder_bits == 0) { if (1 < numwords) rb_raise(rb_eArgError, "word order not specified"); } else if (wordorder_bits != INTEGER_PACK_MSWORD_FIRST && wordorder_bits != INTEGER_PACK_LSWORD_FIRST) rb_raise(rb_eArgError, "unexpected word order"); if (byteorder_bits == 0) { rb_raise(rb_eArgError, "byte order not specified"); } else if (byteorder_bits != INTEGER_PACK_MSBYTE_FIRST && byteorder_bits != INTEGER_PACK_LSBYTE_FIRST && byteorder_bits != INTEGER_PACK_NATIVE_BYTE_ORDER) rb_raise(rb_eArgError, "unexpected byte order"); if (wordsize == 0) rb_raise(rb_eArgError, "invalid wordsize: %"PRI_SIZE_PREFIX"u", wordsize); if (SSIZE_MAX < wordsize) rb_raise(rb_eArgError, "too big wordsize: %"PRI_SIZE_PREFIX"u", wordsize); if (wordsize <= nails / CHAR_BIT) rb_raise(rb_eArgError, "too big nails: %"PRI_SIZE_PREFIX"u", nails); if (SIZE_MAX / wordsize < numwords) rb_raise(rb_eArgError, "too big numwords * wordsize: %"PRI_SIZE_PREFIX"u * %"PRI_SIZE_PREFIX"u", numwords, wordsize); } static void integer_pack_loop_setup( size_t numwords, size_t wordsize, size_t nails, int flags, size_t *word_num_fullbytes_ret, int *word_num_partialbits_ret, size_t *word_start_ret, ssize_t *word_step_ret, size_t *word_last_ret, size_t *byte_start_ret, int *byte_step_ret) { int wordorder_bits = flags & INTEGER_PACK_WORDORDER_MASK; int byteorder_bits = flags & INTEGER_PACK_BYTEORDER_MASK; size_t word_num_fullbytes; int word_num_partialbits; size_t word_start; ssize_t word_step; size_t word_last; size_t byte_start; int byte_step; word_num_partialbits = CHAR_BIT - (int)(nails % CHAR_BIT); if (word_num_partialbits == CHAR_BIT) word_num_partialbits = 0; word_num_fullbytes = wordsize - (nails / CHAR_BIT); if (word_num_partialbits != 0) { word_num_fullbytes--; } if (wordorder_bits == INTEGER_PACK_MSWORD_FIRST) { word_start = wordsize*(numwords-1); word_step = -(ssize_t)wordsize; word_last = 0; } else { word_start = 0; word_step = wordsize; word_last = wordsize*(numwords-1); } if (byteorder_bits == INTEGER_PACK_NATIVE_BYTE_ORDER) { #ifdef WORDS_BIGENDIAN byteorder_bits = INTEGER_PACK_MSBYTE_FIRST; #else byteorder_bits = INTEGER_PACK_LSBYTE_FIRST; #endif } if (byteorder_bits == INTEGER_PACK_MSBYTE_FIRST) { byte_start = wordsize-1; byte_step = -1; } else { byte_start = 0; byte_step = 1; } *word_num_partialbits_ret = word_num_partialbits; *word_num_fullbytes_ret = word_num_fullbytes; *word_start_ret = word_start; *word_step_ret = word_step; *word_last_ret = word_last; *byte_start_ret = byte_start; *byte_step_ret = byte_step; } static inline void integer_pack_fill_dd(BDIGIT **dpp, BDIGIT **dep, BDIGIT_DBL *ddp, int *numbits_in_dd_p) { if (*dpp < *dep && BITSPERDIG <= (int)sizeof(*ddp) * CHAR_BIT - *numbits_in_dd_p) { *ddp |= (BDIGIT_DBL)(*(*dpp)++) << *numbits_in_dd_p; *numbits_in_dd_p += BITSPERDIG; } else if (*dpp == *dep) { /* higher bits are infinity zeros */ *numbits_in_dd_p = (int)sizeof(*ddp) * CHAR_BIT; } } static inline BDIGIT_DBL integer_pack_take_lowbits(int n, BDIGIT_DBL *ddp, int *numbits_in_dd_p) { BDIGIT_DBL ret; ret = (*ddp) & (((BDIGIT_DBL)1 << n) - 1); *ddp >>= n; *numbits_in_dd_p -= n; return ret; } static int bary_pack(int sign, BDIGIT *ds, size_t num_bdigits, void *words, size_t numwords, size_t wordsize, size_t nails, int flags) { BDIGIT *dp, *de; unsigned char *buf, *bufend; dp = ds; de = ds + num_bdigits; validate_integer_pack_format(numwords, wordsize, nails, flags, INTEGER_PACK_MSWORD_FIRST| INTEGER_PACK_LSWORD_FIRST| INTEGER_PACK_MSBYTE_FIRST| INTEGER_PACK_LSBYTE_FIRST| INTEGER_PACK_NATIVE_BYTE_ORDER| INTEGER_PACK_2COMP); while (dp < de && de[-1] == 0) de--; if (dp == de) { sign = 0; } buf = words; bufend = buf + numwords * wordsize; if (buf == bufend) { /* overflow if non-zero*/ if (!(flags & INTEGER_PACK_2COMP) || 0 <= sign) sign *= 2; else { if (de - dp == 1 && dp[0] == 1) sign = -1; /* val == -1 == -2**(numwords*(wordsize*CHAR_BIT-nails)) */ else sign = -2; /* val < -1 == -2**(numwords*(wordsize*CHAR_BIT-nails)) */ } } else if (dp == de) { memset(buf, '\0', bufend - buf); } else if (dp < de && buf < bufend) { int word_num_partialbits; size_t word_num_fullbytes; ssize_t word_step; size_t byte_start; int byte_step; size_t word_start, word_last; unsigned char *wordp, *last_wordp; BDIGIT_DBL dd; int numbits_in_dd; integer_pack_loop_setup(numwords, wordsize, nails, flags, &word_num_fullbytes, &word_num_partialbits, &word_start, &word_step, &word_last, &byte_start, &byte_step); wordp = buf + word_start; last_wordp = buf + word_last; dd = 0; numbits_in_dd = 0; #define FILL_DD \ integer_pack_fill_dd(&dp, &de, &dd, &numbits_in_dd) #define TAKE_LOWBITS(n) \ integer_pack_take_lowbits(n, &dd, &numbits_in_dd) while (1) { size_t index_in_word = 0; unsigned char *bytep = wordp + byte_start; while (index_in_word < word_num_fullbytes) { FILL_DD; *bytep = TAKE_LOWBITS(CHAR_BIT); bytep += byte_step; index_in_word++; } if (word_num_partialbits) { FILL_DD; *bytep = TAKE_LOWBITS(word_num_partialbits); bytep += byte_step; index_in_word++; } while (index_in_word < wordsize) { *bytep = 0; bytep += byte_step; index_in_word++; } if (wordp == last_wordp) break; wordp += word_step; } FILL_DD; /* overflow tests */ if (dp != de || 1 < dd) { /* 2**(numwords*(wordsize*CHAR_BIT-nails)+1) <= abs(val) */ sign *= 2; } else if (dd == 1) { /* 2**(numwords*(wordsize*CHAR_BIT-nails)) <= abs(val) < 2**(numwords*(wordsize*CHAR_BIT-nails)+1) */ if (!(flags & INTEGER_PACK_2COMP) || 0 <= sign) sign *= 2; else { /* overflow_2comp && sign == -1 */ /* test lower bits are all zero. */ dp = ds; while (dp < de && *dp == 0) dp++; if (de - dp == 1 && /* only one non-zero word. */ (*dp & (*dp-1)) == 0) /* *dp contains only one bit set. */ sign = -1; /* val == -2**(numwords*(wordsize*CHAR_BIT-nails)) */ else sign = -2; /* val < -2**(numwords*(wordsize*CHAR_BIT-nails)) */ } } } if ((flags & INTEGER_PACK_2COMP) && (sign < 0 && numwords != 0)) { unsigned char *buf; int word_num_partialbits; size_t word_num_fullbytes; ssize_t word_step; size_t byte_start; int byte_step; size_t word_start, word_last; unsigned char *wordp, *last_wordp; unsigned int partialbits_mask; int carry; integer_pack_loop_setup(numwords, wordsize, nails, flags, &word_num_fullbytes, &word_num_partialbits, &word_start, &word_step, &word_last, &byte_start, &byte_step); partialbits_mask = (1 << word_num_partialbits) - 1; buf = words; wordp = buf + word_start; last_wordp = buf + word_last; carry = 1; while (1) { size_t index_in_word = 0; unsigned char *bytep = wordp + byte_start; while (index_in_word < word_num_fullbytes) { carry += (unsigned char)~*bytep; *bytep = (unsigned char)carry; carry >>= CHAR_BIT; bytep += byte_step; index_in_word++; } if (word_num_partialbits) { carry += (*bytep & partialbits_mask) ^ partialbits_mask; *bytep = carry & partialbits_mask; carry >>= word_num_partialbits; bytep += byte_step; index_in_word++; } if (wordp == last_wordp) break; wordp += word_step; } } return sign; #undef FILL_DD #undef TAKE_LOWBITS } /* * Export an integer into a buffer. * * This function fills the buffer specified by _words_ and _numwords_ as * val in the format specified by _wordsize_, _nails_ and _flags_. * * [val] Fixnum, Bignum or another integer like object which has to_int method. * [words] buffer to export abs(val). * [numwords] the size of given buffer as number of words. * [wordsize] the size of word as number of bytes. * [nails] number of padding bits in a word. * Most significant nails bits of each word are filled by zero. * [flags] bitwise or of constants which name starts "INTEGER_PACK_". * * flags: * [INTEGER_PACK_MSWORD_FIRST] Store the most significant word as the first word. * [INTEGER_PACK_LSWORD_FIRST] Store the least significant word as the first word. * [INTEGER_PACK_MSBYTE_FIRST] Store the most significant byte in a word as the first byte in the word. * [INTEGER_PACK_LSBYTE_FIRST] Store the least significant byte in a word as the first byte in the word. * [INTEGER_PACK_NATIVE_BYTE_ORDER] INTEGER_PACK_MSBYTE_FIRST or INTEGER_PACK_LSBYTE_FIRST corresponding to the host's endian. * [INTEGER_PACK_2COMP] Use 2's complement representation. * [INTEGER_PACK_LITTLE_ENDIAN] Same as INTEGER_PACK_LSWORD_FIRST|INTEGER_PACK_LSBYTE_FIRST * [INTEGER_PACK_BIG_ENDIAN] Same as INTEGER_PACK_MSWORD_FIRST|INTEGER_PACK_MSBYTE_FIRST * * This function fills the buffer specified by _words_ * as abs(val) if INTEGER_PACK_2COMP is not specified in _flags_. * If INTEGER_PACK_2COMP is specified, 2's complement representation of val is * filled in the buffer. * * This function returns the signedness and overflow condition. * The overflow condition depends on INTEGER_PACK_2COMP. * * INTEGER_PACK_2COMP is not specified: * -2 : negative overflow. val <= -2**(numwords*(wordsize*CHAR_BIT-nails)) * -1 : negative without overflow. -2**(numwords*(wordsize*CHAR_BIT-nails)) < val < 0 * 0 : zero. val == 0 * 1 : positive without overflow. 0 < val < 2**(numwords*(wordsize*CHAR_BIT-nails)) * 2 : positive overflow. 2**(numwords*(wordsize*CHAR_BIT-nails)) <= val * * INTEGER_PACK_2COMP is specified: * -2 : negative overflow. val < -2**(numwords*(wordsize*CHAR_BIT-nails)) * -1 : negative without overflow. -2**(numwords*(wordsize*CHAR_BIT-nails)) <= val < 0 * 0 : zero. val == 0 * 1 : positive without overflow. 0 < val < 2**(numwords*(wordsize*CHAR_BIT-nails)) * 2 : positive overflow. 2**(numwords*(wordsize*CHAR_BIT-nails)) <= val * * The value, -2**(numwords*(wordsize*CHAR_BIT-nails)), is representable * in 2's complement representation but not representable in absolute value. * So -1 is returned for the value if INTEGER_PACK_2COMP is specified * but returns -2 if INTEGER_PACK_2COMP is not specified. * * The least significant words are filled in the buffer when overflow occur. */ int rb_integer_pack(VALUE val, void *words, size_t numwords, size_t wordsize, size_t nails, int flags) { int sign; BDIGIT *ds; size_t num_bdigits; BDIGIT fixbuf[bdigit_roomof(sizeof(long))]; RB_GC_GUARD(val) = rb_to_int(val); if (FIXNUM_P(val)) { long v = FIX2LONG(val); if (v < 0) { sign = -1; v = -v; } else { sign = 1; } #if SIZEOF_BDIGITS >= SIZEOF_LONG fixbuf[0] = v; #else { int i; for (i = 0; i < numberof(fixbuf); i++) { fixbuf[i] = BIGLO(v); v = BIGDN(v); } } #endif ds = fixbuf; num_bdigits = numberof(fixbuf); } else { sign = RBIGNUM_POSITIVE_P(val) ? 1 : -1; ds = BDIGITS(val); num_bdigits = RBIGNUM_LEN(val); } return bary_pack(sign, ds, num_bdigits, words, numwords, wordsize, nails, flags); } static size_t integer_unpack_num_bdigits_small(size_t numwords, size_t wordsize, size_t nails, int *nlp_bits_ret) { /* nlp_bits stands for number of leading padding bits */ size_t num_bits = (wordsize * CHAR_BIT - nails) * numwords; size_t num_bdigits = (num_bits + BITSPERDIG - 1) / BITSPERDIG; *nlp_bits_ret = (int)(num_bdigits * BITSPERDIG - num_bits); return num_bdigits; } static size_t integer_unpack_num_bdigits_generic(size_t numwords, size_t wordsize, size_t nails, int *nlp_bits_ret) { /* BITSPERDIG = SIZEOF_BDIGITS * CHAR_BIT */ /* num_bits = (wordsize * CHAR_BIT - nails) * numwords */ /* num_bdigits = (num_bits + BITSPERDIG - 1) / BITSPERDIG */ /* num_bits = CHAR_BIT * (wordsize * numwords) - nails * numwords = CHAR_BIT * num_bytes1 - nails * numwords */ size_t num_bytes1 = wordsize * numwords; /* q1 * CHAR_BIT + r1 = numwords */ size_t q1 = numwords / CHAR_BIT; size_t r1 = numwords % CHAR_BIT; /* num_bits = CHAR_BIT * num_bytes1 - nails * (q1 * CHAR_BIT + r1) = CHAR_BIT * num_bytes2 - nails * r1 */ size_t num_bytes2 = num_bytes1 - nails * q1; /* q2 * CHAR_BIT + r2 = nails */ size_t q2 = nails / CHAR_BIT; size_t r2 = nails % CHAR_BIT; /* num_bits = CHAR_BIT * num_bytes2 - (q2 * CHAR_BIT + r2) * r1 = CHAR_BIT * num_bytes3 - r1 * r2 */ size_t num_bytes3 = num_bytes2 - q2 * r1; /* q3 * BITSPERDIG + r3 = num_bytes3 */ size_t q3 = num_bytes3 / BITSPERDIG; size_t r3 = num_bytes3 % BITSPERDIG; /* num_bits = CHAR_BIT * (q3 * BITSPERDIG + r3) - r1 * r2 = BITSPERDIG * num_digits1 + CHAR_BIT * r3 - r1 * r2 */ size_t num_digits1 = CHAR_BIT * q3; /* * if CHAR_BIT * r3 >= r1 * r2 * CHAR_BIT * r3 - r1 * r2 = CHAR_BIT * BITSPERDIG - (CHAR_BIT * BITSPERDIG - (CHAR_BIT * r3 - r1 * r2)) * q4 * BITSPERDIG + r4 = CHAR_BIT * BITSPERDIG - (CHAR_BIT * r3 - r1 * r2) * num_bits = BITSPERDIG * num_digits1 + CHAR_BIT * BITSPERDIG - (q4 * BITSPERDIG + r4) = BITSPERDIG * num_digits2 - r4 * else * q4 * BITSPERDIG + r4 = -(CHAR_BIT * r3 - r1 * r2) * num_bits = BITSPERDIG * num_digits1 - (q4 * BITSPERDIG + r4) = BITSPERDIG * num_digits2 - r4 * end */ if (CHAR_BIT * r3 >= r1 * r2) { size_t tmp1 = CHAR_BIT * BITSPERDIG - (CHAR_BIT * r3 - r1 * r2); size_t q4 = tmp1 / BITSPERDIG; int r4 = (int)(tmp1 % BITSPERDIG); size_t num_digits2 = num_digits1 + CHAR_BIT - q4; *nlp_bits_ret = r4; return num_digits2; } else { size_t tmp1 = r1 * r2 - CHAR_BIT * r3; size_t q4 = tmp1 / BITSPERDIG; int r4 = (int)(tmp1 % BITSPERDIG); size_t num_digits2 = num_digits1 - q4; *nlp_bits_ret = r4; return num_digits2; } } static size_t integer_unpack_num_bdigits(size_t numwords, size_t wordsize, size_t nails, int *nlp_bits_ret) { size_t num_bdigits; if (numwords <= (SIZE_MAX - (BITSPERDIG-1)) / CHAR_BIT / wordsize) { num_bdigits = integer_unpack_num_bdigits_small(numwords, wordsize, nails, nlp_bits_ret); #ifdef DEBUG_INTEGER_PACK { int nlp_bits1; size_t num_bdigits1 = integer_unpack_num_bdigits_generic(numwords, wordsize, nails, &nlp_bits1); assert(num_bdigits == num_bdigits1); assert(*nlp_bits_ret == nlp_bits1); } #endif } else { num_bdigits = integer_unpack_num_bdigits_generic(numwords, wordsize, nails, nlp_bits_ret); } return num_bdigits; } static inline void integer_unpack_push_bits(int data, int numbits, BDIGIT_DBL *ddp, int *numbits_in_dd_p, BDIGIT **dpp) { (*ddp) |= ((BDIGIT_DBL)data) << (*numbits_in_dd_p); *numbits_in_dd_p += numbits; while (BITSPERDIG <= *numbits_in_dd_p) { *(*dpp)++ = BIGLO(*ddp); *ddp = BIGDN(*ddp); *numbits_in_dd_p -= BITSPERDIG; } } static int bary_unpack_internal(BDIGIT *bdigits, size_t num_bdigits, const void *words, size_t numwords, size_t wordsize, size_t nails, int flags, int nlp_bits) { int sign; if (num_bdigits != 0) { const unsigned char *buf = words; BDIGIT *dp; BDIGIT *de; int word_num_partialbits; size_t word_num_fullbytes; ssize_t word_step; size_t byte_start; int byte_step; size_t word_start, word_last; const unsigned char *wordp, *last_wordp; BDIGIT_DBL dd; int numbits_in_dd; dp = bdigits; de = dp + num_bdigits; integer_pack_loop_setup(numwords, wordsize, nails, flags, &word_num_fullbytes, &word_num_partialbits, &word_start, &word_step, &word_last, &byte_start, &byte_step); wordp = buf + word_start; last_wordp = buf + word_last; dd = 0; numbits_in_dd = 0; #define PUSH_BITS(data, numbits) \ integer_unpack_push_bits(data, numbits, &dd, &numbits_in_dd, &dp) while (1) { size_t index_in_word = 0; const unsigned char *bytep = wordp + byte_start; while (index_in_word < word_num_fullbytes) { PUSH_BITS(*bytep, CHAR_BIT); bytep += byte_step; index_in_word++; } if (word_num_partialbits) { PUSH_BITS(*bytep & ((1 << word_num_partialbits) - 1), word_num_partialbits); bytep += byte_step; index_in_word++; } if (wordp == last_wordp) break; wordp += word_step; } if (dd) *dp++ = (BDIGIT)dd; assert(dp <= de); while (dp < de) *dp++ = 0; #undef PUSH_BITS } if (!(flags & INTEGER_PACK_2COMP)) { sign = (flags & INTEGER_PACK_NEGATIVE) ? -1 : 1; } else { if (nlp_bits) { if ((flags & INTEGER_PACK_NEGATIVE) || (bdigits[num_bdigits-1] >> (BITSPERDIG - nlp_bits - 1))) { bdigits[num_bdigits-1] |= (~(BDIGIT)0) << (BITSPERDIG - nlp_bits); sign = -1; } else { sign = 1; } } else { if (flags & INTEGER_PACK_NEGATIVE) { sign = bary_zero_p(bdigits, num_bdigits) ? -2 : -1; } else { if (num_bdigits != 0 && (bdigits[num_bdigits-1] >> (BITSPERDIG - 1))) sign = -1; else sign = 1; } } if (sign == -1 && num_bdigits != 0) { bary_2comp(bdigits, num_bdigits); } } return sign; } static void bary_unpack(BDIGIT *bdigits, size_t num_bdigits, const void *words, size_t numwords, size_t wordsize, size_t nails, int flags) { size_t num_bdigits0; int nlp_bits; int sign; validate_integer_pack_format(numwords, wordsize, nails, flags, INTEGER_PACK_MSWORD_FIRST| INTEGER_PACK_LSWORD_FIRST| INTEGER_PACK_MSBYTE_FIRST| INTEGER_PACK_LSBYTE_FIRST| INTEGER_PACK_NATIVE_BYTE_ORDER| INTEGER_PACK_2COMP| INTEGER_PACK_FORCE_BIGNUM| INTEGER_PACK_NEGATIVE); num_bdigits0 = integer_unpack_num_bdigits(numwords, wordsize, nails, &nlp_bits); assert(num_bdigits0 <= num_bdigits); sign = bary_unpack_internal(bdigits, num_bdigits0, words, numwords, wordsize, nails, flags, nlp_bits); if (num_bdigits0 < num_bdigits) { MEMZERO(bdigits + num_bdigits0, BDIGIT, num_bdigits - num_bdigits0); if (sign == -2) { bdigits[num_bdigits0] = 1; } } } /* * Import an integer into a buffer. * * [words] buffer to import. * [numwords] the size of given buffer as number of words. * [wordsize] the size of word as number of bytes. * [nails] number of padding bits in a word. * Most significant nails bits of each word are ignored. * [flags] bitwise or of constants which name starts "INTEGER_PACK_". * * flags: * [INTEGER_PACK_MSWORD_FIRST] Interpret the first word as the most significant word. * [INTEGER_PACK_LSWORD_FIRST] Interpret the first word as the least significant word. * [INTEGER_PACK_MSBYTE_FIRST] Interpret the first byte in a word as the most significant byte in the word. * [INTEGER_PACK_LSBYTE_FIRST] Interpret the first byte in a word as the least significant byte in the word. * [INTEGER_PACK_NATIVE_BYTE_ORDER] INTEGER_PACK_MSBYTE_FIRST or INTEGER_PACK_LSBYTE_FIRST corresponding to the host's endian. * [INTEGER_PACK_2COMP] Use 2's complement representation. * [INTEGER_PACK_LITTLE_ENDIAN] Same as INTEGER_PACK_LSWORD_FIRST|INTEGER_PACK_LSBYTE_FIRST * [INTEGER_PACK_BIG_ENDIAN] Same as INTEGER_PACK_MSWORD_FIRST|INTEGER_PACK_MSBYTE_FIRST * [INTEGER_PACK_FORCE_BIGNUM] the result will be a Bignum * even if it is representable as a Fixnum. * [INTEGER_PACK_NEGATIVE] Returns non-positive value. * (Returns non-negative value if not specified.) * * This function returns the imported integer as Fixnum or Bignum. * * The range of the result value depends on INTEGER_PACK_2COMP and INTEGER_PACK_NEGATIVE. * * INTEGER_PACK_2COMP is not set: * 0 <= val < 2**(numwords*(wordsize*CHAR_BIT-nails)) if !INTEGER_PACK_NEGATIVE * -2**(numwords*(wordsize*CHAR_BIT-nails)) < val <= 0 if INTEGER_PACK_NEGATIVE * * INTEGER_PACK_2COMP is set: * -2**(numwords*(wordsize*CHAR_BIT-nails)-1) <= val <= 2**(numwords*(wordsize*CHAR_BIT-nails)-1)-1 if !INTEGER_PACK_NEGATIVE * -2**(numwords*(wordsize*CHAR_BIT-nails)) <= val <= -1 if INTEGER_PACK_NEGATIVE * * INTEGER_PACK_2COMP without INTEGER_PACK_NEGATIVE means sign extension. * INTEGER_PACK_2COMP with INTEGER_PACK_NEGATIVE mean assuming the higher bits are 1. * * Note that this function returns 0 when numwords is zero and * INTEGER_PACK_2COMP is set but INTEGER_PACK_NEGATIVE is not set. */ VALUE rb_integer_unpack(const void *words, size_t numwords, size_t wordsize, size_t nails, int flags) { VALUE val; size_t num_bdigits; int sign; int nlp_bits; BDIGIT *ds; validate_integer_pack_format(numwords, wordsize, nails, flags, INTEGER_PACK_MSWORD_FIRST| INTEGER_PACK_LSWORD_FIRST| INTEGER_PACK_MSBYTE_FIRST| INTEGER_PACK_LSBYTE_FIRST| INTEGER_PACK_NATIVE_BYTE_ORDER| INTEGER_PACK_2COMP| INTEGER_PACK_FORCE_BIGNUM| INTEGER_PACK_NEGATIVE); num_bdigits = integer_unpack_num_bdigits(numwords, wordsize, nails, &nlp_bits); if (LONG_MAX-1 < num_bdigits) rb_raise(rb_eArgError, "too big to unpack as an integer"); val = bignew((long)num_bdigits, 0); ds = BDIGITS(val); sign = bary_unpack_internal(ds, num_bdigits, words, numwords, wordsize, nails, flags, nlp_bits); if (sign == -2) { rb_big_resize(val, (long)num_bdigits+1); BDIGITS(val)[num_bdigits] = 1; } if ((flags & INTEGER_PACK_FORCE_BIGNUM) && sign != 0 && bary_zero_p(BDIGITS(val), RBIGNUM_LEN(val))) sign = 0; RBIGNUM_SET_SIGN(val, 0 <= sign); if (flags & INTEGER_PACK_FORCE_BIGNUM) return bigtrunc(val); return bignorm(val); } #define QUAD_SIZE 8 #if SIZEOF_LONG_LONG == QUAD_SIZE && SIZEOF_BDIGITS*2 == SIZEOF_LONG_LONG void rb_quad_pack(char *buf, VALUE val) { LONG_LONG q; val = rb_to_int(val); if (FIXNUM_P(val)) { q = FIX2LONG(val); } else { long len = RBIGNUM_LEN(val); BDIGIT *ds; if (len > SIZEOF_LONG_LONG/SIZEOF_BDIGITS) { len = SIZEOF_LONG_LONG/SIZEOF_BDIGITS; } ds = BDIGITS(val); q = 0; while (len--) { q = BIGUP(q); q += ds[len]; } if (!RBIGNUM_SIGN(val)) q = -q; } memcpy(buf, (char*)&q, SIZEOF_LONG_LONG); } VALUE rb_quad_unpack(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_SET_LEN(big, i+1); if (neg) { RBIGNUM_SET_SIGN(big, 0); } return bignorm(big); } #else static int quad_buf_complement(char *buf, size_t len) { size_t i; for (i = 0; i < len; i++) buf[i] = ~buf[i]; for (i = 0; i < len; i++) { buf[i]++; if (buf[i] != 0) return 0; } return 1; } void rb_quad_pack(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_LEN(val) * SIZEOF_BDIGITS; if (len > QUAD_SIZE) { len = QUAD_SIZE; } memcpy(buf, (char*)BDIGITS(val), len); if (RBIGNUM_NEGATIVE_P(val)) { quad_buf_complement(buf, QUAD_SIZE); } } #define BNEG(b) (RSHIFT(((BDIGIT*)(b))[QUAD_SIZE/SIZEOF_BDIGITS-1],BITSPERDIG-1) != 0) VALUE rb_quad_unpack(const char *buf, int sign) { VALUE big = bignew(QUAD_SIZE/SIZEOF_BDIGITS, 1); memcpy((char*)BDIGITS(big), buf, QUAD_SIZE); if (sign && BNEG(buf)) { char *tmp = (char*)BDIGITS(big); RBIGNUM_SET_SIGN(big, 0); quad_buf_complement(tmp, QUAD_SIZE); } return bignorm(big); } #endif VALUE rb_cstr_to_inum(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; #undef ISDIGIT #define ISDIGIT(c) ('0' <= (c) && (c) <= '9') #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); } while (ISSPACE(*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, "invalid radix %d", base); } if (base <= 32) { len = 5; } else { len = 6; } break; } if (*str == '0') { /* squeeze preceding 0s */ int us = 0; while ((c = *++str) == '0' || c == '_') { if (c == '_') { if (++us >= 2) break; } else us = 0; } if (!(c = *str) || ISSPACE(c)) --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 ((size_t)len <= (sizeof(long)*CHAR_BIT)) { unsigned long val = STRTOUL(str, &end, base); if (str < end && *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_SET_SIGN(big, 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 (nondigit) { if (badcheck) goto bad; break; } nondigit = (char) c; continue; } else if ((c = conv_digit(c)) < 0) { break; } if (c >= base) break; nondigit = 0; i = 0; num = c; for (;;) { while (i> 1) & MASK_55; x = ((x >> 2) & MASK_33) + (x & MASK_33); x = ((x >> 4) + x) & MASK_0f; x += (x >> 8); x += (x >> 16); # if SIZEOF_LONG == 8 x += (x >> 32); # endif return (int)(x & 0x7f); # undef MASK_0f # undef MASK_33 # undef MASK_55 #endif } static inline unsigned long next_pow2(register unsigned long x) { x |= x >> 1; x |= x >> 2; x |= x >> 4; x |= x >> 8; x |= x >> 16; #if SIZEOF_LONG == 8 x |= x >> 32; #endif return x + 1; } static inline int floor_log2(register unsigned long x) { x |= x >> 1; x |= x >> 2; x |= x >> 4; x |= x >> 8; x |= x >> 16; #if SIZEOF_LONG == 8 x |= x >> 32; #endif return (int)ones(x) - 1; } static inline int ceil_log2(register unsigned long x) { return floor_log2(x) + !POW2_P(x); } #define LOG2_KARATSUBA_DIGITS 7 #define KARATSUBA_DIGITS (1L< KARATSUBA_DIGITS"); m = ceil_log2(n1); if (m1) *m1 = 1 << m; i = m - LOG2_KARATSUBA_DIGITS; if (i >= MAX_BIG2STR_TABLE_ENTRIES) i = MAX_BIG2STR_TABLE_ENTRIES - 1; t = power_cache_get_power0(base, i); j = KARATSUBA_DIGITS*(1 << i); while (n1 > j) { t = bigsqr(t); j *= 2; } return t; } /* big2str_muraken_find_n1 * * Let a natural number x is given by: * x = 2^0 * x_0 + 2^1 * x_1 + ... + 2^(B*n_0 - 1) * x_{B*n_0 - 1}, * where B is BITSPERDIG (i.e. BDIGITS*CHAR_BIT) and n_0 is * RBIGNUM_LEN(x). * * Now, we assume n_1 = min_n \{ n | 2^(B*n_0/2) <= b_1^(n_1) \}, so * it is realized that 2^(B*n_0) <= {b_1}^{2*n_1}, where b_1 is a * given radix number. And then, we have n_1 <= (B*n_0) / * (2*log_2(b_1)), therefore n_1 is given by ceil((B*n_0) / * (2*log_2(b_1))). */ static long big2str_find_n1(VALUE x, int base) { static const double log_2[] = { 1.0, 1.58496250072116, 2.0, 2.32192809488736, 2.58496250072116, 2.8073549220576, 3.0, 3.16992500144231, 3.32192809488736, 3.4594316186373, 3.58496250072116, 3.70043971814109, 3.8073549220576, 3.90689059560852, 4.0, 4.08746284125034, 4.16992500144231, 4.24792751344359, 4.32192809488736, 4.39231742277876, 4.4594316186373, 4.52356195605701, 4.58496250072116, 4.64385618977472, 4.70043971814109, 4.75488750216347, 4.8073549220576, 4.85798099512757, 4.90689059560852, 4.95419631038688, 5.0, 5.04439411935845, 5.08746284125034, 5.12928301694497, 5.16992500144231 }; long bits; if (base < 2 || 36 < base) rb_bug("invalid radix %d", base); if (FIXNUM_P(x)) { bits = (SIZEOF_LONG*CHAR_BIT - 1)/2 + 1; } else if (BIGZEROP(x)) { return 0; } else if (RBIGNUM_LEN(x) >= LONG_MAX/BITSPERDIG) { rb_raise(rb_eRangeError, "bignum too big to convert into `string'"); } else { bits = BITSPERDIG*RBIGNUM_LEN(x); } /* @shyouhei note: vvvvvvvvvvvvv this cast is suspicious. But I believe it is OK, because if that cast loses data, this x value is too big, and should have raised RangeError. */ return (long)ceil(((double)bits)/log_2[base - 2]); } static long big2str_orig(VALUE x, int base, char* ptr, long len, BDIGIT hbase, int hbase_numdigits, int trim) { long i = RBIGNUM_LEN(x), j = len; BDIGIT* ds = BDIGITS(x); while (i && j > 0) { long k = i; BDIGIT_DBL num = 0; while (k--) { /* x / hbase */ num = BIGUP(num) + ds[k]; ds[k] = (BDIGIT)(num / hbase); num %= hbase; } if (trim && ds[i-1] == 0) i--; k = hbase_numdigits; while (k--) { ptr[--j] = ruby_digitmap[num % base]; num /= base; if (j <= 0) break; if (trim && i == 0 && num == 0) break; } } if (trim) { while (j < len && ptr[j] == '0') j++; MEMMOVE(ptr, ptr + j, char, len - j); len -= j; } return len; } static long big2str_karatsuba(VALUE x, int base, char* ptr, long n1, long len, BDIGIT hbase, int hbase_numdigits, int trim) { long lh, ll, m1; VALUE b, q, r; if (BIGZEROP(x)) { if (trim) return 0; else { memset(ptr, '0', len); return len; } } if (n1 <= KARATSUBA_DIGITS) { return big2str_orig(x, base, ptr, len, hbase, hbase_numdigits, trim); } b = power_cache_get_power(base, n1, &m1); bigdivmod(x, b, &q, &r); rb_obj_hide(q); rb_obj_hide(r); lh = big2str_karatsuba(q, base, ptr, (len - m1)/2, len - m1, hbase, hbase_numdigits, trim); rb_big_resize(q, 0); ll = big2str_karatsuba(r, base, ptr + lh, m1/2, m1, hbase, hbase_numdigits, !lh && trim); rb_big_resize(r, 0); return lh + ll; } static void calc_hbase(int base, BDIGIT *hbase_p, int *hbase_numdigits_p) { BDIGIT hbase; int hbase_numdigits; hbase = base; hbase_numdigits = 1; while (hbase <= (~(BDIGIT)0) / base) { hbase *= base; hbase_numdigits++; } *hbase_p = hbase; *hbase_numdigits_p = hbase_numdigits; } static VALUE big2str_base_powerof2(VALUE x, size_t len, int base, int trim) { int word_numbits = ffs(base) - 1; size_t numwords; VALUE result; char *ptr; numwords = trim ? rb_absint_numwords(x, word_numbits, NULL) : len; if (RBIGNUM_NEGATIVE_P(x) || !trim) { if (LONG_MAX-1 < numwords) rb_raise(rb_eArgError, "too big number"); result = rb_usascii_str_new(0, 1+numwords); ptr = RSTRING_PTR(result); *ptr++ = RBIGNUM_POSITIVE_P(x) ? '+' : '-'; } else { if (LONG_MAX < numwords) rb_raise(rb_eArgError, "too big number"); result = rb_usascii_str_new(0, numwords); ptr = RSTRING_PTR(result); } rb_integer_pack(x, ptr, numwords, 1, CHAR_BIT-word_numbits, INTEGER_PACK_BIG_ENDIAN); while (0 < numwords) { *ptr = ruby_digitmap[*(unsigned char *)ptr]; ptr++; numwords--; } return result; } VALUE rb_big2str0(VALUE x, int base, int trim) { int off; VALUE ss, xx; long n1, n2, len; BDIGIT hbase; int hbase_numdigits; char* ptr; if (FIXNUM_P(x)) { return rb_fix2str(x, base); } if (BIGZEROP(x)) { return rb_usascii_str_new2("0"); } if (base < 2 || 36 < base) rb_raise(rb_eArgError, "invalid radix %d", base); n2 = big2str_find_n1(x, base); if (base & (base - 1) == 0) { /* base == 2 || base == 4 || base == 8 || base == 16 || base == 32 */ return big2str_base_powerof2(x, (size_t)n2, base, trim); } n1 = (n2 + 1) / 2; ss = rb_usascii_str_new(0, n2 + 1); /* plus one for sign */ ptr = RSTRING_PTR(ss); ptr[0] = RBIGNUM_SIGN(x) ? '+' : '-'; calc_hbase(base, &hbase, &hbase_numdigits); off = !(trim && RBIGNUM_SIGN(x)); /* erase plus sign if trim */ xx = rb_big_clone(x); RBIGNUM_SET_SIGN(xx, 1); if (n1 <= KARATSUBA_DIGITS) { len = off + big2str_orig(xx, base, ptr + off, n2, hbase, hbase_numdigits, trim); } else { len = off + big2str_karatsuba(xx, base, ptr + off, n1, n2, hbase, hbase_numdigits, trim); } rb_big_resize(xx, 0); ptr[len] = '\0'; rb_str_resize(ss, len); return ss; } VALUE rb_big2str(VALUE x, int base) { return rb_big2str0(x, base, 1); } /* * call-seq: * big.to_s(base=10) -> string * * Returns a string containing the representation of big radix * base (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(int argc, VALUE *argv, VALUE x) { int base; if (argc == 0) base = 10; else { VALUE b; rb_scan_args(argc, argv, "01", &b); base = NUM2INT(b); } return rb_big2str(x, base); } static unsigned long big2ulong(VALUE x, const char *type, int check) { long len = RBIGNUM_LEN(x); BDIGIT_DBL num; BDIGIT *ds; if (BIGSIZE(x) > sizeof(long)) { if (check) rb_raise(rb_eRangeError, "bignum too big to convert into `%s'", type); len = bdigit_roomof(sizeof(long)); } ds = BDIGITS(x); num = 0; while (len--) { num = BIGUP(num); num += ds[len]; } return (unsigned long)num; } VALUE rb_big2ulong_pack(VALUE x) { unsigned long num = big2ulong(x, "unsigned long", FALSE); if (!RBIGNUM_SIGN(x)) { return (VALUE)(-(SIGNED_VALUE)num); } return num; } VALUE rb_big2ulong(VALUE x) { unsigned long num = big2ulong(x, "unsigned long", TRUE); if (RBIGNUM_POSITIVE_P(x)) { return num; } else { if (num <= LONG_MAX) return -(long)num; if (num == 1+(unsigned long)(-(LONG_MIN+1))) return LONG_MIN; } rb_raise(rb_eRangeError, "bignum out of range of unsigned long"); } SIGNED_VALUE rb_big2long(VALUE x) { unsigned long num = big2ulong(x, "long", TRUE); if (RBIGNUM_POSITIVE_P(x)) { if (num <= LONG_MAX) return num; } else { if (num <= LONG_MAX) return -(long)num; if (num == 1+(unsigned long)(-(LONG_MIN+1))) return LONG_MIN; } rb_raise(rb_eRangeError, "bignum too big to convert into `long'"); } #if HAVE_LONG_LONG static unsigned LONG_LONG big2ull(VALUE x, const char *type) { long len = RBIGNUM_LEN(x); 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(VALUE x) { unsigned LONG_LONG num = big2ull(x, "unsigned long long"); if (RBIGNUM_POSITIVE_P(x)) { return num; } else { if (num <= LLONG_MAX) return -(LONG_LONG)num; if (num == 1+(unsigned LONG_LONG)(-(LLONG_MIN+1))) return LLONG_MIN; } rb_raise(rb_eRangeError, "bignum out of range of unsigned long long"); } LONG_LONG rb_big2ll(VALUE x) { unsigned LONG_LONG num = big2ull(x, "long long"); if (RBIGNUM_POSITIVE_P(x)) { if (num <= LLONG_MAX) return num; } else { if (num <= LLONG_MAX) return -(LONG_LONG)num; if (num == 1+(unsigned LONG_LONG)(-(LLONG_MIN+1))) return LLONG_MIN; } rb_raise(rb_eRangeError, "bignum too big to convert into `long long'"); } #endif /* HAVE_LONG_LONG */ static VALUE dbl2big(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(double d) { return bignorm(dbl2big(d)); } static int nlz(BDIGIT x) { BDIGIT y; int n = BITSPERDIG; #if BITSPERDIG > 64 y = x >> 64; if (y) {n -= 64; x = y;} #endif #if BITSPERDIG > 32 y = x >> 32; if (y) {n -= 32; x = y;} #endif #if BITSPERDIG > 16 y = x >> 16; if (y) {n -= 16; x = y;} #endif y = x >> 8; if (y) {n -= 8; x = y;} y = x >> 4; if (y) {n -= 4; x = y;} y = x >> 2; if (y) {n -= 2; x = y;} y = x >> 1; if (y) {return n - 2;} return (int)(n - x); } static double big2dbl(VALUE x) { double d = 0.0; long i = (bigtrunc(x), RBIGNUM_LEN(x)), lo = 0, bits; BDIGIT *ds = BDIGITS(x), dl; if (i) { bits = i * BITSPERDIG - nlz(ds[i-1]); if (bits > DBL_MANT_DIG+DBL_MAX_EXP) { d = HUGE_VAL; } else { if (bits > DBL_MANT_DIG+1) lo = (bits -= DBL_MANT_DIG+1) / BITSPERDIG; else bits = 0; while (--i > lo) { d = ds[i] + BIGRAD*d; } dl = ds[i]; if (bits && (dl & (1UL << (bits %= BITSPERDIG)))) { int carry = (dl & ~(~(BDIGIT)0 << bits)) != 0; if (!carry) { while (i-- > 0) { carry = ds[i] != 0; if (carry) break; } } if (carry) { dl &= (BDIGIT)~0 << bits; dl += (BDIGIT)1 << bits; if (!dl) d += 1; } } d = dl + BIGRAD*d; if (lo) { if (lo > INT_MAX / BITSPERDIG) d = HUGE_VAL; else if (lo < INT_MIN / BITSPERDIG) d = 0.0; else d = ldexp(d, (int)(lo * BITSPERDIG)); } } } if (!RBIGNUM_SIGN(x)) d = -d; return d; } double rb_big2dbl(VALUE x) { double d = big2dbl(x); if (isinf(d)) { rb_warning("Bignum out of Float range"); if (d < 0.0) d = -HUGE_VAL; else d = HUGE_VAL; } return d; } /* * call-seq: * big.to_f -> float * * Converts big to a Float. If big doesn't * fit in a Float, the result is infinity. * */ static VALUE rb_big_to_f(VALUE x) { return DBL2NUM(rb_big2dbl(x)); } VALUE rb_integer_float_cmp(VALUE x, VALUE y) { double yd = RFLOAT_VALUE(y); double yi, yf; VALUE rel; if (isnan(yd)) return Qnil; if (isinf(yd)) { if (yd > 0.0) return INT2FIX(-1); else return INT2FIX(1); } yf = modf(yd, &yi); if (FIXNUM_P(x)) { #if SIZEOF_LONG * CHAR_BIT < DBL_MANT_DIG /* assume FLT_RADIX == 2 */ double xd = (double)FIX2LONG(x); if (xd < yd) return INT2FIX(-1); if (xd > yd) return INT2FIX(1); return INT2FIX(0); #else long xl, yl; if (yi < FIXNUM_MIN) return INT2FIX(1); if (FIXNUM_MAX+1 <= yi) return INT2FIX(-1); xl = FIX2LONG(x); yl = (long)yi; if (xl < yl) return INT2FIX(-1); if (xl > yl) return INT2FIX(1); if (yf < 0.0) return INT2FIX(1); if (0.0 < yf) return INT2FIX(-1); return INT2FIX(0); #endif } y = rb_dbl2big(yi); rel = rb_big_cmp(x, y); if (yf == 0.0 || rel != INT2FIX(0)) return rel; if (yf < 0.0) return INT2FIX(1); return INT2FIX(-1); } VALUE rb_integer_float_eq(VALUE x, VALUE y) { double yd = RFLOAT_VALUE(y); double yi, yf; if (isnan(yd) || isinf(yd)) return Qfalse; yf = modf(yd, &yi); if (yf != 0) return Qfalse; if (FIXNUM_P(x)) { #if SIZEOF_LONG * CHAR_BIT < DBL_MANT_DIG /* assume FLT_RADIX == 2 */ double xd = (double)FIX2LONG(x); if (xd != yd) return Qfalse; return Qtrue; #else long xl, yl; if (yi < LONG_MIN || LONG_MAX < yi) return Qfalse; xl = FIX2LONG(x); yl = (long)yi; if (xl != yl) return Qfalse; return Qtrue; #endif } y = rb_dbl2big(yi); return rb_big_eq(x, y); } /* * call-seq: * big <=> numeric -> -1, 0, +1 or nil * * Comparison---Returns -1, 0, or +1 depending on whether +big+ is * less than, equal to, or greater than +numeric+. This is the * basis for the tests in Comparable. * * +nil+ is returned if the two values are incomparable. * */ VALUE rb_big_cmp(VALUE x, VALUE y) { long xlen = RBIGNUM_LEN(x); BDIGIT *xds, *yds; switch (TYPE(y)) { case T_FIXNUM: y = rb_int2big(FIX2LONG(y)); break; case T_BIGNUM: break; case T_FLOAT: return rb_integer_float_cmp(x, y); default: return rb_num_coerce_cmp(x, y, rb_intern("<=>")); } if (RBIGNUM_SIGN(x) > RBIGNUM_SIGN(y)) return INT2FIX(1); if (RBIGNUM_SIGN(x) < RBIGNUM_SIGN(y)) return INT2FIX(-1); if (xlen < RBIGNUM_LEN(y)) return (RBIGNUM_SIGN(x)) ? INT2FIX(-1) : INT2FIX(1); if (xlen > RBIGNUM_LEN(y)) return (RBIGNUM_SIGN(x)) ? INT2FIX(1) : INT2FIX(-1); xds = BDIGITS(x); yds = BDIGITS(y); while (xlen-- && (xds[xlen]==yds[xlen])); if (-1 == xlen) return INT2FIX(0); return (xds[xlen] > yds[xlen]) ? (RBIGNUM_SIGN(x) ? INT2FIX(1) : INT2FIX(-1)) : (RBIGNUM_SIGN(x) ? INT2FIX(-1) : INT2FIX(1)); } enum big_op_t { big_op_gt, big_op_ge, big_op_lt, big_op_le }; static VALUE big_op(VALUE x, VALUE y, enum big_op_t op) { VALUE rel; int n; switch (TYPE(y)) { case T_FIXNUM: case T_BIGNUM: rel = rb_big_cmp(x, y); break; case T_FLOAT: rel = rb_integer_float_cmp(x, y); break; default: { ID id = 0; switch (op) { case big_op_gt: id = '>'; break; case big_op_ge: id = rb_intern(">="); break; case big_op_lt: id = '<'; break; case big_op_le: id = rb_intern("<="); break; } return rb_num_coerce_relop(x, y, id); } } if (NIL_P(rel)) return Qfalse; n = FIX2INT(rel); switch (op) { case big_op_gt: return n > 0 ? Qtrue : Qfalse; case big_op_ge: return n >= 0 ? Qtrue : Qfalse; case big_op_lt: return n < 0 ? Qtrue : Qfalse; case big_op_le: return n <= 0 ? Qtrue : Qfalse; } return Qundef; } /* * call-seq: * big > real -> true or false * * Returns true if the value of big is * greater than that of real. */ static VALUE big_gt(VALUE x, VALUE y) { return big_op(x, y, big_op_gt); } /* * call-seq: * big >= real -> true or false * * Returns true if the value of big is * greater than or equal to that of real. */ static VALUE big_ge(VALUE x, VALUE y) { return big_op(x, y, big_op_ge); } /* * call-seq: * big < real -> true or false * * Returns true if the value of big is * less than that of real. */ static VALUE big_lt(VALUE x, VALUE y) { return big_op(x, y, big_op_lt); } /* * call-seq: * big <= real -> true or false * * Returns true if the value of big is * less than or equal to that of real. */ static VALUE big_le(VALUE x, VALUE y) { return big_op(x, y, big_op_le); } /* * call-seq: * big == obj -> true or false * * Returns true only if obj has the same value * as big. Contrast this with Bignum#eql?, which * requires obj to be a Bignum. * * 68719476736 == 68719476736.0 #=> true */ VALUE rb_big_eq(VALUE x, VALUE y) { switch (TYPE(y)) { case T_FIXNUM: if (bignorm(x) == y) return Qtrue; y = rb_int2big(FIX2LONG(y)); break; case T_BIGNUM: break; case T_FLOAT: return rb_integer_float_eq(x, y); default: return rb_equal(y, x); } if (RBIGNUM_SIGN(x) != RBIGNUM_SIGN(y)) return Qfalse; if (RBIGNUM_LEN(x) != RBIGNUM_LEN(y)) return Qfalse; if (MEMCMP(BDIGITS(x),BDIGITS(y),BDIGIT,RBIGNUM_LEN(y)) != 0) return Qfalse; return Qtrue; } /* * call-seq: * big.eql?(obj) -> true or false * * Returns true only if obj is a * Bignum with the same value as big. Contrast this * with Bignum#==, which performs type conversions. * * 68719476736.eql?(68719476736.0) #=> false */ VALUE rb_big_eql(VALUE x, VALUE y) { if (!RB_TYPE_P(y, T_BIGNUM)) return Qfalse; if (RBIGNUM_SIGN(x) != RBIGNUM_SIGN(y)) return Qfalse; if (RBIGNUM_LEN(x) != RBIGNUM_LEN(y)) return Qfalse; if (MEMCMP(BDIGITS(x),BDIGITS(y),BDIGIT,RBIGNUM_LEN(y)) != 0) return Qfalse; return Qtrue; } /* * call-seq: * -big -> integer * * Unary minus (returns an integer whose value is 0-big) */ VALUE rb_big_uminus(VALUE x) { VALUE z = rb_big_clone(x); RBIGNUM_SET_SIGN(z, !RBIGNUM_SIGN(x)); 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(VALUE x) { VALUE z = rb_big_clone(x); BDIGIT *ds; long i; if (!RBIGNUM_SIGN(x)) get2comp(z); ds = BDIGITS(z); i = RBIGNUM_LEN(x); if (!i) return INT2FIX(~(SIGNED_VALUE)0); while (i--) { ds[i] = ~ds[i]; } RBIGNUM_SET_SIGN(z, !RBIGNUM_SIGN(z)); if (RBIGNUM_SIGN(x)) get2comp(z); return bignorm(z); } static void bigsub_core(BDIGIT *xds, long xn, BDIGIT *yds, long yn, BDIGIT *zds, long zn) { BDIGIT_DBL_SIGNED num; long i; for (i = 0, num = 0; i < yn; i++) { num += (BDIGIT_DBL_SIGNED)xds[i] - yds[i]; zds[i] = BIGLO(num); num = BIGDN(num); } while (num && i < xn) { num += xds[i]; zds[i++] = BIGLO(num); num = BIGDN(num); } if (xds == zds && xn == zn) return; while (i < xn) { zds[i] = xds[i]; i++; } assert(i <= zn); while (i < zn) { zds[i++] = 0; } } static void bary_sub(BDIGIT *zds, size_t zn, BDIGIT *xds, size_t xn, BDIGIT *yds, size_t yn) { assert(yn <= xn); assert(xn <= zn); bigsub_core(xds, xn, yds, yn, zds, zn); } static VALUE bigsub(VALUE x, VALUE y) { VALUE z = 0; long i = RBIGNUM_LEN(x); BDIGIT *xds, *yds; /* if x is smaller than y, swap */ if (RBIGNUM_LEN(x) < RBIGNUM_LEN(y)) { z = x; x = y; y = z; /* swap x y */ } else if (RBIGNUM_LEN(x) == RBIGNUM_LEN(y)) { xds = BDIGITS(x); yds = BDIGITS(y); while (i > 0) { i--; if (xds[i] > yds[i]) { break; } if (xds[i] < yds[i]) { z = x; x = y; y = z; /* swap x y */ break; } } } z = bignew(RBIGNUM_LEN(x), z==0); bigsub_core(BDIGITS(x), RBIGNUM_LEN(x), BDIGITS(y), RBIGNUM_LEN(y), BDIGITS(z), RBIGNUM_LEN(z)); return z; } static VALUE bigadd_int(VALUE x, long y); static VALUE bigsub_int(VALUE x, long y0) { VALUE z; BDIGIT *xds, *zds; long xn; BDIGIT_DBL_SIGNED num; long i, y; y = y0; xds = BDIGITS(x); xn = RBIGNUM_LEN(x); z = bignew(xn, RBIGNUM_SIGN(x)); zds = BDIGITS(z); #if SIZEOF_BDIGITS >= SIZEOF_LONG num = (BDIGIT_DBL_SIGNED)xds[0] - y; if (xn == 1 && num < 0) { RBIGNUM_SET_SIGN(z, !RBIGNUM_SIGN(x)); zds[0] = (BDIGIT)-num; RB_GC_GUARD(x); return bignorm(z); } zds[0] = BIGLO(num); num = BIGDN(num); i = 1; #else num = 0; for (i=0; i<(int)(sizeof(y)/SIZEOF_BDIGITS); i++) { num += (BDIGIT_DBL_SIGNED)xds[i] - BIGLO(y); zds[i] = BIGLO(num); num = BIGDN(num); y = BIGDN(y); } #endif while (num && i < xn) { num += xds[i]; zds[i++] = BIGLO(num); num = BIGDN(num); } while (i < xn) { zds[i] = xds[i]; i++; } if (num < 0) { z = bigsub(x, rb_int2big(y0)); } RB_GC_GUARD(x); return bignorm(z); } static VALUE bigadd_int(VALUE x, long y) { VALUE z; BDIGIT *xds, *zds; long xn, zn; BDIGIT_DBL num; long i; xds = BDIGITS(x); xn = RBIGNUM_LEN(x); if (xn < 2) { zn = 3; } else { zn = xn + 1; } z = bignew(zn, RBIGNUM_SIGN(x)); zds = BDIGITS(z); #if SIZEOF_BDIGITS >= SIZEOF_LONG num = (BDIGIT_DBL)xds[0] + y; zds[0] = BIGLO(num); num = BIGDN(num); i = 1; #else num = 0; for (i=0; i<(int)(sizeof(y)/SIZEOF_BDIGITS); i++) { num += (BDIGIT_DBL)xds[i] + BIGLO(y); zds[i] = BIGLO(num); num = BIGDN(num); y = BIGDN(y); } #endif while (num && i < xn) { num += xds[i]; zds[i++] = BIGLO(num); num = BIGDN(num); } if (num) zds[i++] = (BDIGIT)num; else while (i < xn) { zds[i] = xds[i]; i++; } assert(i <= zn); while (i < zn) { zds[i++] = 0; } RB_GC_GUARD(x); return bignorm(z); } static void bigadd_core(BDIGIT *xds, long xn, BDIGIT *yds, long yn, BDIGIT *zds, long zn) { BDIGIT_DBL num = 0; long i; if (xn > yn) { BDIGIT *tds; tds = xds; xds = yds; yds = tds; i = xn; xn = yn; yn = i; } i = 0; while (i < xn) { num += (BDIGIT_DBL)xds[i] + yds[i]; zds[i++] = BIGLO(num); num = BIGDN(num); } while (num && i < yn) { num += yds[i]; zds[i++] = BIGLO(num); num = BIGDN(num); } while (i < yn) { zds[i] = yds[i]; i++; } if (num) zds[i++] = (BDIGIT)num; assert(i <= zn); while (i < zn) { zds[i++] = 0; } } static void bary_add(BDIGIT *zds, size_t zn, BDIGIT *xds, size_t xn, BDIGIT *yds, size_t yn) { bigadd_core(xds, xn, yds, yn, zds, zn); } static VALUE bigadd(VALUE x, VALUE y, int sign) { VALUE z; long len; sign = (sign == RBIGNUM_SIGN(y)); if (RBIGNUM_SIGN(x) != sign) { if (sign) return bigsub(y, x); return bigsub(x, y); } if (RBIGNUM_LEN(x) > RBIGNUM_LEN(y)) { len = RBIGNUM_LEN(x) + 1; } else { len = RBIGNUM_LEN(y) + 1; } z = bignew(len, sign); bigadd_core(BDIGITS(x), RBIGNUM_LEN(x), BDIGITS(y), RBIGNUM_LEN(y), BDIGITS(z), RBIGNUM_LEN(z)); return z; } /* * call-seq: * big + other -> Numeric * * Adds big and other, returning the result. */ VALUE rb_big_plus(VALUE x, VALUE y) { long n; switch (TYPE(y)) { case T_FIXNUM: n = FIX2LONG(y); if ((n > 0) != RBIGNUM_SIGN(x)) { if (n < 0) { n = -n; } return bigsub_int(x, n); } if (n < 0) { n = -n; } return bigadd_int(x, n); case T_BIGNUM: return bignorm(bigadd(x, y, 1)); case T_FLOAT: return DBL2NUM(rb_big2dbl(x) + RFLOAT_VALUE(y)); default: return rb_num_coerce_bin(x, y, '+'); } } /* * call-seq: * big - other -> Numeric * * Subtracts other from big, returning the result. */ VALUE rb_big_minus(VALUE x, VALUE y) { long n; switch (TYPE(y)) { case T_FIXNUM: n = FIX2LONG(y); if ((n > 0) != RBIGNUM_SIGN(x)) { if (n < 0) { n = -n; } return bigadd_int(x, n); } if (n < 0) { n = -n; } return bigsub_int(x, n); case T_BIGNUM: return bignorm(bigadd(x, y, 0)); case T_FLOAT: return DBL2NUM(rb_big2dbl(x) - RFLOAT_VALUE(y)); default: return rb_num_coerce_bin(x, y, '-'); } } static long big_real_len(VALUE x) { long i = RBIGNUM_LEN(x); BDIGIT *xds = BDIGITS(x); while (--i && !xds[i]); return i + 1; } static void bary_mul_single(BDIGIT *zds, size_t zl, BDIGIT x, BDIGIT y) { BDIGIT_DBL n; assert(2 <= zl); n = (BDIGIT_DBL)x * y; zds[0] = BIGLO(n); zds[1] = (BDIGIT)BIGDN(n); } static VALUE bigmul1_single(VALUE x, VALUE y) { VALUE z = bignew(2, RBIGNUM_SIGN(x)==RBIGNUM_SIGN(y)); BDIGIT *xds, *yds, *zds; xds = BDIGITS(x); yds = BDIGITS(y); zds = BDIGITS(z); bary_mul_single(zds, 2, xds[0], yds[0]); return z; } static void bary_mul_normal(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds, size_t yl) { size_t i; size_t j = zl; BDIGIT_DBL n = 0; assert(xl + yl <= zl); while (j--) zds[j] = 0; for (i = 0; i < xl; i++) { BDIGIT_DBL dd; dd = xds[i]; if (dd == 0) continue; n = 0; for (j = 0; j < yl; j++) { BDIGIT_DBL ee = n + (BDIGIT_DBL)dd * yds[j]; n = zds[i + j] + ee; if (ee) zds[i + j] = BIGLO(n); n = BIGDN(n); } if (n) { zds[i + j] = (BDIGIT)n; } } } static VALUE bigmul1_normal(VALUE x, VALUE y) { size_t xl = RBIGNUM_LEN(x), yl = RBIGNUM_LEN(y), zl = xl + yl; VALUE z = bignew(zl, RBIGNUM_SIGN(x)==RBIGNUM_SIGN(y)); BDIGIT *xds, *yds, *zds; xds = BDIGITS(x); yds = BDIGITS(y); zds = BDIGITS(z); bary_mul_normal(zds, zl, xds, xl, yds, yl); rb_thread_check_ints(); return z; } static void bary_mul(BDIGIT *zds, size_t zl, BDIGIT *xds, size_t xl, BDIGIT *yds, size_t yl) { size_t l; if (xl == 1 && yl == 1) { l = 2; bary_mul_single(zds, zl, xds[0], yds[0]); } else { l = xl + yl; bary_mul_normal(zds, zl, xds, xl, yds, yl); } MEMZERO(zds + l, BDIGIT, zl - l); } static VALUE bigmul0(VALUE x, VALUE y); /* balancing multiplication by slicing larger argument */ static VALUE bigmul1_balance(VALUE x, VALUE y) { VALUE z, t1, t2; long i, xn, yn, r, n; BDIGIT *yds, *zds, *t1ds; xn = RBIGNUM_LEN(x); yn = RBIGNUM_LEN(y); assert(2 * xn <= yn || 3 * xn <= 2*(yn+2)); z = bignew(xn + yn, RBIGNUM_SIGN(x)==RBIGNUM_SIGN(y)); t1 = bignew(xn, 1); yds = BDIGITS(y); zds = BDIGITS(z); t1ds = BDIGITS(t1); for (i = 0; i < xn + yn; i++) zds[i] = 0; n = 0; while (yn > 0) { r = xn > yn ? yn : xn; MEMCPY(t1ds, yds + n, BDIGIT, r); RBIGNUM_SET_LEN(t1, r); t2 = bigmul0(x, t1); bigadd_core(zds + n, RBIGNUM_LEN(z) - n, BDIGITS(t2), big_real_len(t2), zds + n, RBIGNUM_LEN(z) - n); yn -= r; n += r; } return z; } /* split a bignum into high and low bignums */ static void big_split(VALUE v, long n, volatile VALUE *ph, volatile VALUE *pl) { long hn = 0, ln = RBIGNUM_LEN(v); VALUE h, l; BDIGIT *vds = BDIGITS(v); if (ln > n) { hn = ln - n; ln = n; } if (!hn) { h = rb_uint2big(0); } else { while (--hn && !vds[hn + ln]); h = bignew(hn += 2, 1); MEMCPY(BDIGITS(h), vds + ln, BDIGIT, hn - 1); BDIGITS(h)[hn - 1] = 0; /* margin for carry */ } while (--ln && !vds[ln]); l = bignew(ln += 2, 1); MEMCPY(BDIGITS(l), vds, BDIGIT, ln - 1); BDIGITS(l)[ln - 1] = 0; /* margin for carry */ *pl = l; *ph = h; } /* multiplication by karatsuba method */ static VALUE bigmul1_karatsuba(VALUE x, VALUE y) { long i, n, xn, yn, t1n, t2n; VALUE xh, xl, yh, yl, z, t1, t2, t3; BDIGIT *zds; xn = RBIGNUM_LEN(x); yn = RBIGNUM_LEN(y); n = yn / 2; big_split(x, n, &xh, &xl); if (x == y) { yh = xh; yl = xl; } else big_split(y, n, &yh, &yl); /* x = xh * b + xl * y = yh * b + yl * * Karatsuba method: * x * y = z2 * b^2 + z1 * b + z0 * where * z2 = xh * yh * z0 = xl * yl * z1 = (xh + xl) * (yh + yl) - z2 - z0 * * ref: http://en.wikipedia.org/wiki/Karatsuba_algorithm */ /* allocate a result bignum */ z = bignew(xn + yn, RBIGNUM_SIGN(x)==RBIGNUM_SIGN(y)); zds = BDIGITS(z); /* t1 <- xh * yh */ t1 = bigmul0(xh, yh); t1n = big_real_len(t1); /* copy t1 into high bytes of the result (z2) */ MEMCPY(zds + 2 * n, BDIGITS(t1), BDIGIT, t1n); for (i = 2 * n + t1n; i < xn + yn; i++) zds[i] = 0; if (!BIGZEROP(xl) && !BIGZEROP(yl)) { /* t2 <- xl * yl */ t2 = bigmul0(xl, yl); t2n = big_real_len(t2); /* copy t2 into low bytes of the result (z0) */ MEMCPY(zds, BDIGITS(t2), BDIGIT, t2n); for (i = t2n; i < 2 * n; i++) zds[i] = 0; } else { t2 = Qundef; t2n = 0; /* copy 0 into low bytes of the result (z0) */ for (i = 0; i < 2 * n; i++) zds[i] = 0; } /* xh <- xh + xl */ if (RBIGNUM_LEN(xl) > RBIGNUM_LEN(xh)) { t3 = xl; xl = xh; xh = t3; } /* xh has a margin for carry */ bigadd_core(BDIGITS(xh), RBIGNUM_LEN(xh), BDIGITS(xl), RBIGNUM_LEN(xl), BDIGITS(xh), RBIGNUM_LEN(xh)); /* yh <- yh + yl */ if (x != y) { if (RBIGNUM_LEN(yl) > RBIGNUM_LEN(yh)) { t3 = yl; yl = yh; yh = t3; } /* yh has a margin for carry */ bigadd_core(BDIGITS(yh), RBIGNUM_LEN(yh), BDIGITS(yl), RBIGNUM_LEN(yl), BDIGITS(yh), RBIGNUM_LEN(yh)); } else yh = xh; /* t3 <- xh * yh */ t3 = bigmul0(xh, yh); i = xn + yn - n; /* subtract t1 from t3 */ bigsub_core(BDIGITS(t3), big_real_len(t3), BDIGITS(t1), t1n, BDIGITS(t3), big_real_len(t3)); /* subtract t2 from t3; t3 is now the middle term of the product */ if (t2 != Qundef) bigsub_core(BDIGITS(t3), big_real_len(t3), BDIGITS(t2), t2n, BDIGITS(t3), big_real_len(t3)); /* add t3 to middle bytes of the result (z1) */ bigadd_core(zds + n, i, BDIGITS(t3), big_real_len(t3), zds + n, i); return z; } static void biglsh_bang(BDIGIT *xds, long xn, unsigned long shift) { long const s1 = shift/BITSPERDIG; int const s2 = (int)(shift%BITSPERDIG); 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 = xds[xn]<>s3; num = xds[xn]< 0); *zds = num; for (i = s1; i > 0; --i) *zds-- = 0; } static void bigrsh_bang(BDIGIT* xds, long xn, unsigned long shift) { long s1 = shift/BITSPERDIG; int s2 = (int)(shift%BITSPERDIG); int s3 = BITSPERDIG - s2; int i; BDIGIT num; BDIGIT* zds; if (s1 >= xn) { MEMZERO(xds, BDIGIT, xn); return; } i = 0; zds = xds + s1; num = *zds++>>s2; do { xds[i++] = (BDIGIT)(*zds<>s2; } while (i < xn - s1 - 1); xds[i] = num; MEMZERO(xds + xn - s1, BDIGIT, s1); } static void big_split3(VALUE v, long n, volatile VALUE* p0, volatile VALUE* p1, volatile VALUE* p2) { VALUE v0, v12, v1, v2; big_split(v, n, &v12, &v0); big_split(v12, n, &v2, &v1); *p0 = bigtrunc(v0); *p1 = bigtrunc(v1); *p2 = bigtrunc(v2); } static VALUE big_lshift(VALUE, unsigned long); static VALUE big_rshift(VALUE, unsigned long); static VALUE bigdivrem(VALUE, VALUE, volatile VALUE*, volatile VALUE*); static VALUE bigmul1_toom3(VALUE x, VALUE y) { long n, xn, yn, zn; VALUE x0, x1, x2, y0, y1, y2; VALUE u0, u1, u2, u3, u4, v1, v2, v3; VALUE z0, z1, z2, z3, z4, z, t; BDIGIT* zds; xn = RBIGNUM_LEN(x); yn = RBIGNUM_LEN(y); assert(xn <= yn); /* assume y >= x */ n = (yn + 2) / 3; big_split3(x, n, &x0, &x1, &x2); if (x == y) { y0 = x0; y1 = x1; y2 = x2; } else big_split3(y, n, &y0, &y1, &y2); /* * ref. http://en.wikipedia.org/wiki/Toom%E2%80%93Cook_multiplication * * x(b) = x0 * b^0 + x1 * b^1 + x2 * b^2 * y(b) = y0 * b^0 + y1 * b^1 + y2 * b^2 * * z(b) = x(b) * y(b) * z(b) = z0 * b^0 + z1 * b^1 + z2 * b^2 + z3 * b^3 + z4 * b^4 * where: * z0 = x0 * y0 * z1 = x0 * y1 + x1 * y0 * z2 = x0 * y2 + x1 * y1 + x2 * y0 * z3 = x1 * y2 + x2 * y1 * z4 = x2 * y2 * * Toom3 method (a.k.a. Toom-Cook method): * (Step1) calculating 5 points z(b0), z(b1), z(b2), z(b3), z(b4), * where: * b0 = 0, b1 = 1, b2 = -1, b3 = -2, b4 = inf, * z(0) = x(0) * y(0) = x0 * y0 * z(1) = x(1) * y(1) = (x0 + x1 + x2) * (y0 + y1 + y2) * z(-1) = x(-1) * y(-1) = (x0 - x1 + x2) * (y0 - y1 + y2) * z(-2) = x(-2) * y(-2) = (x0 - 2 * (x1 - 2 * x2)) * (y0 - 2 * (y1 - 2 * y2)) * z(inf) = x(inf) * y(inf) = x2 * y2 * * (Step2) interpolating z0, z1, z2, z3, z4, and z5. * * (Step3) Substituting base value into b of the polynomial z(b), */ /* * [Step1] calculating 5 points z(b0), z(b1), z(b2), z(b3), z(b4) */ /* u1 <- x0 + x2 */ u1 = bigtrunc(bigadd(x0, x2, 1)); /* x(-1) : u2 <- u1 - x1 = x0 - x1 + x2 */ u2 = bigtrunc(bigsub(u1, x1)); /* x(1) : u1 <- u1 + x1 = x0 + x1 + x2 */ u1 = bigtrunc(bigadd(u1, x1, 1)); /* x(-2) : u3 <- 2 * (u2 + x2) - x0 = x0 - 2 * (x1 - 2 * x2) */ u3 = bigadd(u2, x2, 1); if (BDIGITS(u3)[RBIGNUM_LEN(u3)-1] & BIGRAD_HALF) { rb_big_resize(u3, RBIGNUM_LEN(u3) + 1); BDIGITS(u3)[RBIGNUM_LEN(u3)-1] = 0; } biglsh_bang(BDIGITS(u3), RBIGNUM_LEN(u3), 1); u3 = bigtrunc(bigadd(bigtrunc(u3), x0, 0)); if (x == y) { v1 = u1; v2 = u2; v3 = u3; } else { /* v1 <- y0 + y2 */ v1 = bigtrunc(bigadd(y0, y2, 1)); /* y(-1) : v2 <- v1 - y1 = y0 - y1 + y2 */ v2 = bigtrunc(bigsub(v1, y1)); /* y(1) : v1 <- v1 + y1 = y0 + y1 + y2 */ v1 = bigtrunc(bigadd(v1, y1, 1)); /* y(-2) : v3 <- 2 * (v2 + y2) - y0 = y0 - 2 * (y1 - 2 * y2) */ v3 = bigadd(v2, y2, 1); if (BDIGITS(v3)[RBIGNUM_LEN(v3)-1] & BIGRAD_HALF) { rb_big_resize(v3, RBIGNUM_LEN(v3) + 1); BDIGITS(v3)[RBIGNUM_LEN(v3)-1] = 0; } biglsh_bang(BDIGITS(v3), RBIGNUM_LEN(v3), 1); v3 = bigtrunc(bigadd(bigtrunc(v3), y0, 0)); } /* z(0) : u0 <- x0 * y0 */ u0 = bigtrunc(bigmul0(x0, y0)); /* z(1) : u1 <- u1 * v1 */ u1 = bigtrunc(bigmul0(u1, v1)); /* z(-1) : u2 <- u2 * v2 */ u2 = bigtrunc(bigmul0(u2, v2)); /* z(-2) : u3 <- u3 * v3 */ u3 = bigtrunc(bigmul0(u3, v3)); /* z(inf) : u4 <- x2 * y2 */ u4 = bigtrunc(bigmul0(x2, y2)); /* for GC */ v1 = v2 = v3 = Qnil; /* * [Step2] interpolating z0, z1, z2, z3, z4, and z5. */ /* z0 <- z(0) == u0 */ z0 = u0; /* z4 <- z(inf) == u4 */ z4 = u4; /* z3 <- (z(-2) - z(1)) / 3 == (u3 - u1) / 3 */ z3 = bigadd(u3, u1, 0); bigdivrem(z3, big_three, &z3, NULL); /* TODO: optimize */ bigtrunc(z3); /* z1 <- (z(1) - z(-1)) / 2 == (u1 - u2) / 2 */ z1 = bigtrunc(bigadd(u1, u2, 0)); bigrsh_bang(BDIGITS(z1), RBIGNUM_LEN(z1), 1); /* z2 <- z(-1) - z(0) == u2 - u0 */ z2 = bigtrunc(bigadd(u2, u0, 0)); /* z3 <- (z2 - z3) / 2 + 2 * z(inf) == (z2 - z3) / 2 + 2 * u4 */ z3 = bigtrunc(bigadd(z2, z3, 0)); bigrsh_bang(BDIGITS(z3), RBIGNUM_LEN(z3), 1); t = big_lshift(u4, 1); /* TODO: combining with next addition */ z3 = bigtrunc(bigadd(z3, t, 1)); /* z2 <- z2 + z1 - z(inf) == z2 + z1 - u4 */ z2 = bigtrunc(bigadd(z2, z1, 1)); z2 = bigtrunc(bigadd(z2, u4, 0)); /* z1 <- z1 - z3 */ z1 = bigtrunc(bigadd(z1, z3, 0)); /* * [Step3] Substituting base value into b of the polynomial z(b), */ zn = 6*n + 1; z = bignew(zn, RBIGNUM_SIGN(x)==RBIGNUM_SIGN(y)); zds = BDIGITS(z); MEMCPY(zds, BDIGITS(z0), BDIGIT, RBIGNUM_LEN(z0)); MEMZERO(zds + RBIGNUM_LEN(z0), BDIGIT, zn - RBIGNUM_LEN(z0)); bigadd_core(zds + n, zn - n, BDIGITS(z1), big_real_len(z1), zds + n, zn - n); bigadd_core(zds + 2*n, zn - 2*n, BDIGITS(z2), big_real_len(z2), zds + 2*n, zn - 2*n); bigadd_core(zds + 3*n, zn - 3*n, BDIGITS(z3), big_real_len(z3), zds + 3*n, zn - 3*n); bigadd_core(zds + 4*n, zn - 4*n, BDIGITS(z4), big_real_len(z4), zds + 4*n, zn - 4*n); z = bignorm(z); return bignorm(z); } /* efficient squaring (2 times faster than normal multiplication) * ref: Handbook of Applied Cryptography, Algorithm 14.16 * http://www.cacr.math.uwaterloo.ca/hac/about/chap14.pdf */ static VALUE bigsqr_fast(VALUE x) { long len = RBIGNUM_LEN(x), i, j; VALUE z = bignew(2 * len + 1, 1); BDIGIT *xds = BDIGITS(x), *zds = BDIGITS(z); BDIGIT_DBL c, v, w; for (i = 2 * len + 1; i--; ) zds[i] = 0; for (i = 0; i < len; i++) { v = (BDIGIT_DBL)xds[i]; if (!v) continue; c = (BDIGIT_DBL)zds[i + i] + v * v; zds[i + i] = BIGLO(c); c = BIGDN(c); v *= 2; for (j = i + 1; j < len; j++) { w = (BDIGIT_DBL)xds[j]; c += (BDIGIT_DBL)zds[i + j] + BIGLO(v) * w; zds[i + j] = BIGLO(c); c = BIGDN(c); if (BIGDN(v)) c += w; } if (c) { c += (BDIGIT_DBL)zds[i + len]; zds[i + len] = BIGLO(c); c = BIGDN(c); } if (c) zds[i + len + 1] += (BDIGIT)c; } return z; } #define KARATSUBA_MUL_DIGITS 70 #define TOOM3_MUL_DIGITS 150 /* determine whether a bignum is sparse or not by random sampling */ static inline VALUE big_sparse_p(VALUE x) { long c = 0, n = RBIGNUM_LEN(x); if ( BDIGITS(x)[rb_genrand_ulong_limited(n / 2) + n / 4]) c++; if (c <= 1 && BDIGITS(x)[rb_genrand_ulong_limited(n / 2) + n / 4]) c++; if (c <= 1 && BDIGITS(x)[rb_genrand_ulong_limited(n / 2) + n / 4]) c++; return (c <= 1) ? Qtrue : Qfalse; } static VALUE bigmul0(VALUE x, VALUE y) { long xn, yn; xn = RBIGNUM_LEN(x); yn = RBIGNUM_LEN(y); /* make sure that y is longer than x */ if (xn > yn) { VALUE t; long tn; t = x; x = y; y = t; tn = xn; xn = yn; yn = tn; } assert(xn <= yn); /* normal multiplication when x is small */ if (xn < KARATSUBA_MUL_DIGITS) { normal: if (x == y) return bigsqr_fast(x); if (xn == 1 && yn == 1) return bigmul1_single(x, y); return bigmul1_normal(x, y); } /* normal multiplication when x or y is a sparse bignum */ if (big_sparse_p(x)) goto normal; if (big_sparse_p(y)) return bigmul1_normal(y, x); /* balance multiplication by slicing y when x is much smaller than y */ if (2 * xn <= yn) return bigmul1_balance(x, y); if (xn < TOOM3_MUL_DIGITS) { /* multiplication by karatsuba method */ return bigmul1_karatsuba(x, y); } else if (3*xn <= 2*(yn + 2)) return bigmul1_balance(x, y); return bigmul1_toom3(x, y); } /* * call-seq: * big * other -> Numeric * * Multiplies big and other, returning the result. */ VALUE rb_big_mul(VALUE x, VALUE y) { switch (TYPE(y)) { case T_FIXNUM: y = rb_int2big(FIX2LONG(y)); break; case T_BIGNUM: break; case T_FLOAT: return DBL2NUM(rb_big2dbl(x) * RFLOAT_VALUE(y)); default: return rb_num_coerce_bin(x, y, '*'); } return bignorm(bigmul0(x, y)); } struct big_div_struct { long nx, ny, j, nyzero; BDIGIT *yds, *zds; volatile VALUE stop; }; static void * bigdivrem1(void *ptr) { struct big_div_struct *bds = (struct big_div_struct*)ptr; long ny = bds->ny; long i, j; BDIGIT *yds = bds->yds, *zds = bds->zds; BDIGIT_DBL t2; BDIGIT_DBL_SIGNED num; BDIGIT q; j = bds->j; do { if (bds->stop) { bds->j = j; return 0; } if (zds[j] == yds[ny-1]) q = (BDIGIT)BIGRAD-1; else q = (BDIGIT)((BIGUP(zds[j]) + zds[j-1])/yds[ny-1]); if (q) { i = bds->nyzero; 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); return 0; } static void rb_big_stop(void *ptr) { struct big_div_struct *bds = ptr; bds->stop = Qtrue; } static inline int bigdivrem_num_extra_words(long nx, long ny) { int ret = nx==ny ? 2 : 1; assert(ret <= BIGDIVREM_EXTRA_WORDS); return ret; } static BDIGIT bigdivrem_single(BDIGIT *qds, BDIGIT *xds, long nx, BDIGIT y) { long i; BDIGIT_DBL t2; t2 = 0; i = nx; while (i--) { t2 = BIGUP(t2) + xds[i]; qds[i] = (BDIGIT)(t2 / y); t2 %= y; } return (BDIGIT)t2; } static void bigdivrem_normal(BDIGIT *zds, long nz, BDIGIT *xds, long nx, BDIGIT *yds, long ny, int needs_mod) { struct big_div_struct bds; BDIGIT q; int shift; q = yds[ny-1]; shift = nlz(q); if (shift) { bary_small_lshift(yds, yds, ny, shift); zds[nx] = bary_small_lshift(zds, xds, nx, shift); } else { MEMCPY(zds, xds, BDIGIT, nx); zds[nx] = 0; } if (nx+1 < nz) zds[nx+1] = 0; bds.nx = nx; bds.ny = ny; bds.zds = zds; bds.yds = yds; bds.stop = Qfalse; bds.j = nz - 1; for (bds.nyzero = 0; !yds[bds.nyzero]; bds.nyzero++); if (nx > 10000 || ny > 10000) { retry: bds.stop = Qfalse; rb_thread_call_without_gvl(bigdivrem1, &bds, rb_big_stop, &bds); if (bds.stop == Qtrue) { /* execute trap handler, but exception was not raised. */ goto retry; } } else { bigdivrem1(&bds); } if (needs_mod && shift) { bary_small_rshift(zds, zds, ny, shift, 0); } } static void bary_divmod(BDIGIT *qds, size_t nq, BDIGIT *rds, size_t nr, BDIGIT *xds, size_t nx, BDIGIT *yds, size_t ny) { assert(nx <= nq); assert(ny <= nr); while (0 < ny && !yds[ny-1]) ny--; if (ny == 0) rb_num_zerodiv(); while (0 < nx && !xds[nx-1]) nx--; if (nx == 0) { MEMZERO(qds, BDIGIT, nq); MEMZERO(rds, BDIGIT, nr); return; } if (ny == 1) { MEMCPY(qds, xds, BDIGIT, nx); MEMZERO(qds+nx, BDIGIT, nq-nx); rds[0] = bigdivrem_single(qds, xds, nx, yds[0]); MEMZERO(rds+1, BDIGIT, nr-1); } else { int extra_words; long j; long nz; BDIGIT *zds; VALUE tmpz = 0; BDIGIT *tds; extra_words = bigdivrem_num_extra_words(nx, ny); nz = nx + extra_words; if (nx + extra_words <= nq) zds = qds; else zds = ALLOCV_N(BDIGIT, tmpz, nx + extra_words); MEMCPY(zds, xds, BDIGIT, nx); MEMZERO(zds+nx, BDIGIT, nz-nx); if ((yds[ny-1] >> (BITSPERDIG-1)) & 1) { /* bigdivrem_normal will not modify y. * So use yds directly. */ tds = yds; } else { /* bigdivrem_normal will modify y. * So use rds as a temporary buffer. */ MEMCPY(rds, yds, BDIGIT, ny); tds = rds; } bigdivrem_normal(zds, nz, xds, nx, tds, ny, 1); /* copy remainder */ MEMCPY(rds, zds, BDIGIT, ny); MEMZERO(rds+ny, BDIGIT, nr-ny); /* move quotient */ j = nz - ny; MEMMOVE(qds, zds+ny, BDIGIT, j); MEMZERO(qds+j, BDIGIT, nq-j); if (tmpz) ALLOCV_END(tmpz); } } static VALUE bigdivrem(VALUE x, VALUE y, volatile VALUE *divp, volatile VALUE *modp) { long nx = RBIGNUM_LEN(x), ny = RBIGNUM_LEN(y), nz; long j; VALUE z, zz; VALUE tmpy = 0, tmpz = 0; BDIGIT *xds, *yds, *zds, *tds; BDIGIT dd; yds = BDIGITS(y); while (0 < ny && !yds[ny-1]) ny--; if (ny == 0) rb_num_zerodiv(); xds = BDIGITS(x); while (0 < nx && !xds[nx-1]) nx--; if (nx < ny || (nx == ny && xds[nx - 1] < yds[ny - 1])) { if (divp) *divp = rb_int2big(0); if (modp) *modp = x; return Qnil; } if (ny == 1) { dd = yds[0]; z = bignew(nx, RBIGNUM_SIGN(x)==RBIGNUM_SIGN(y)); zds = BDIGITS(z); dd = bigdivrem_single(zds, xds, nx, dd); if (modp) { *modp = rb_uint2big((VALUE)dd); RBIGNUM_SET_SIGN(*modp, RBIGNUM_SIGN(x)); } if (divp) *divp = z; return Qnil; } if (((yds[ny-1] >> (BITSPERDIG-1)) & 1) == 0) { /* Make yds modifiable. */ tds = ALLOCV_N(BDIGIT, tmpy, ny); MEMCPY(tds, yds, BDIGIT, ny); yds = tds; } nz = nx + bigdivrem_num_extra_words(nx, ny); zds = ALLOCV_N(BDIGIT, tmpz, nz); bigdivrem_normal(zds, nz, xds, nx, yds, ny, modp != NULL); if (divp) { /* move quotient down in z */ j = nz - ny; while (0 < j && !zds[j-1+ny]) j--; *divp = zz = bignew(j, RBIGNUM_SIGN(x)==RBIGNUM_SIGN(y)); MEMCPY(BDIGITS(zz), zds+ny, BDIGIT, j); } if (modp) { /* normalize remainder */ while (ny > 0 && !zds[ny-1]) --ny; *modp = zz = bignew(ny, RBIGNUM_SIGN(x)); MEMCPY(BDIGITS(zz), zds, BDIGIT, ny); } if (tmpy) ALLOCV_END(tmpy); if (tmpz) ALLOCV_END(tmpz); return Qnil; } static void bigdivmod(VALUE x, VALUE y, volatile VALUE *divp, volatile VALUE *modp) { VALUE mod; bigdivrem(x, y, divp, &mod); if (RBIGNUM_SIGN(x) != RBIGNUM_SIGN(y) && !BIGZEROP(mod)) { if (divp) *divp = bigadd(*divp, rb_int2big(1), 0); if (modp) *modp = bigadd(mod, y, 1); } else if (modp) { *modp = mod; } } static VALUE rb_big_divide(VALUE x, VALUE y, ID op) { VALUE z; switch (TYPE(y)) { case T_FIXNUM: y = rb_int2big(FIX2LONG(y)); break; case T_BIGNUM: break; case T_FLOAT: { if (op == '/') { return DBL2NUM(rb_big2dbl(x) / RFLOAT_VALUE(y)); } else { double dy = RFLOAT_VALUE(y); if (dy == 0.0) rb_num_zerodiv(); return rb_dbl2big(rb_big2dbl(x) / dy); } } default: return rb_num_coerce_bin(x, y, op); } bigdivmod(x, y, &z, 0); return bignorm(z); } /* * call-seq: * big / other -> Numeric * * Performs division: the class of the resulting object depends on * the class of numeric and on the magnitude of the * result. */ VALUE rb_big_div(VALUE x, VALUE y) { return rb_big_divide(x, y, '/'); } /* * call-seq: * big.div(other) -> integer * * Performs integer division: returns integer value. */ VALUE rb_big_idiv(VALUE x, VALUE y) { return rb_big_divide(x, y, rb_intern("div")); } /* * call-seq: * big % other -> Numeric * big.modulo(other) -> Numeric * * Returns big modulo other. See Numeric.divmod for more * information. */ VALUE rb_big_modulo(VALUE x, VALUE 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 big by numeric. * * -1234567890987654321.remainder(13731) #=> -6966 * -1234567890987654321.remainder(13731.24) #=> -9906.22531493148 */ static VALUE rb_big_remainder(VALUE x, VALUE 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, rb_intern("remainder")); } bigdivrem(x, y, 0, &z); return bignorm(z); } /* * call-seq: * big.divmod(numeric) -> array * * See Numeric#divmod. * */ VALUE rb_big_divmod(VALUE x, VALUE 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, rb_intern("divmod")); } bigdivmod(x, y, &div, &mod); return rb_assoc_new(bignorm(div), bignorm(mod)); } static VALUE big_shift(VALUE x, long n) { if (n < 0) return big_lshift(x, (unsigned long)-n); else if (n > 0) return big_rshift(x, (unsigned long)n); return x; } static VALUE big_fdiv(VALUE x, VALUE y) { #define DBL_BIGDIG ((DBL_MANT_DIG + BITSPERDIG) / BITSPERDIG) VALUE z; long l, ex, ey; int i; bigtrunc(x); l = RBIGNUM_LEN(x); ex = l * BITSPERDIG - nlz(BDIGITS(x)[l-1]); ex -= 2 * DBL_BIGDIG * BITSPERDIG; if (ex) x = big_shift(x, ex); switch (TYPE(y)) { case T_FIXNUM: y = rb_int2big(FIX2LONG(y)); case T_BIGNUM: bigtrunc(y); l = RBIGNUM_LEN(y); ey = l * BITSPERDIG - nlz(BDIGITS(y)[l-1]); ey -= DBL_BIGDIG * BITSPERDIG; if (ey) y = big_shift(y, ey); break; case T_FLOAT: y = dbl2big(ldexp(frexp(RFLOAT_VALUE(y), &i), DBL_MANT_DIG)); ey = i - DBL_MANT_DIG; break; default: rb_bug("big_fdiv"); } bigdivrem(x, y, &z, 0); l = ex - ey; #if SIZEOF_LONG > SIZEOF_INT { /* Visual C++ can't be here */ if (l > INT_MAX) return DBL2NUM(INFINITY); if (l < INT_MIN) return DBL2NUM(0.0); } #endif return DBL2NUM(ldexp(big2dbl(z), (int)l)); } /* * call-seq: * big.fdiv(numeric) -> float * * Returns the floating point result of dividing big by * numeric. * * -1234567890987654321.fdiv(13731) #=> -89910996357705.5 * -1234567890987654321.fdiv(13731.24) #=> -89909424858035.7 * */ VALUE rb_big_fdiv(VALUE x, VALUE y) { double dx, dy; dx = big2dbl(x); switch (TYPE(y)) { case T_FIXNUM: dy = (double)FIX2LONG(y); if (isinf(dx)) return big_fdiv(x, y); break; case T_BIGNUM: dy = rb_big2dbl(y); if (isinf(dx) || isinf(dy)) return big_fdiv(x, y); break; case T_FLOAT: dy = RFLOAT_VALUE(y); if (isnan(dy)) return y; if (isinf(dx)) return big_fdiv(x, y); break; default: return rb_num_coerce_bin(x, y, rb_intern("fdiv")); } return DBL2NUM(dx / dy); } static VALUE bigsqr(VALUE x) { return bigtrunc(bigmul0(x, x)); } /* * 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(VALUE x, VALUE y) { double d; SIGNED_VALUE yy; if (y == INT2FIX(0)) return INT2FIX(1); switch (TYPE(y)) { case T_FLOAT: d = RFLOAT_VALUE(y); if ((!RBIGNUM_SIGN(x) && !BIGZEROP(x)) && d != round(d)) return rb_funcall(rb_complex_raw1(x), rb_intern("**"), 1, y); 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) return rb_funcall(rb_rational_raw1(x), rb_intern("**"), 1, y); else { VALUE z = 0; SIGNED_VALUE mask; const long xlen = RBIGNUM_LEN(x); const long xbits = BITSPERDIG*xlen - nlz(RBIGNUM_DIGITS(x)[xlen-1]); const long BIGLEN_LIMIT = 32*1024*1024; if ((xbits > BIGLEN_LIMIT) || (xbits * yy > BIGLEN_LIMIT)) { rb_warn("in a**b, b may be too big"); d = (double)yy; break; } for (mask = FIXNUM_MAX + 1; mask; mask >>= 1) { if (z) z = bigsqr(z); if (yy & mask) { z = z ? bigtrunc(bigmul0(z, x)) : x; } } return bignorm(z); } /* NOTREACHED */ break; default: return rb_num_coerce_bin(x, y, rb_intern("**")); } return DBL2NUM(pow(rb_big2dbl(x), d)); } static VALUE bigand_int(VALUE x, long y) { VALUE z; BDIGIT *xds, *zds; long xn, zn; long i; char sign; if (y == 0) return INT2FIX(0); sign = (y > 0); xds = BDIGITS(x); zn = xn = RBIGNUM_LEN(x); #if SIZEOF_BDIGITS >= SIZEOF_LONG if (sign) { y &= xds[0]; return LONG2NUM(y); } #endif z = bignew(zn, RBIGNUM_SIGN(x) || sign); zds = BDIGITS(z); #if SIZEOF_BDIGITS >= SIZEOF_LONG i = 1; zds[0] = xds[0] & y; #else { BDIGIT_DBL num = y; for (i=0; i<(int)(sizeof(y)/SIZEOF_BDIGITS); i++) { zds[i] = xds[i] & BIGLO(num); num = BIGDN(num); } } #endif while (i < xn) { zds[i] = sign?0:xds[i]; i++; } if (!RBIGNUM_SIGN(z)) get2comp(z); return bignorm(z); } /* * call-seq: * big & numeric -> integer * * Performs bitwise +and+ between _big_ and _numeric_. */ VALUE rb_big_and(VALUE xx, VALUE yy) { volatile VALUE x, y, z; BDIGIT *ds1, *ds2, *zds; long i, l1, l2; char sign; if (!FIXNUM_P(yy) && !RB_TYPE_P(yy, T_BIGNUM)) { return rb_num_coerce_bit(xx, yy, '&'); } x = xx; y = yy; if (!RBIGNUM_SIGN(x)) { x = rb_big_clone(x); get2comp(x); } if (FIXNUM_P(y)) { return bigand_int(x, FIX2LONG(y)); } if (!RBIGNUM_SIGN(y)) { y = rb_big_clone(y); get2comp(y); } if (RBIGNUM_LEN(x) > RBIGNUM_LEN(y)) { l1 = RBIGNUM_LEN(y); l2 = RBIGNUM_LEN(x); ds1 = BDIGITS(y); ds2 = BDIGITS(x); sign = RBIGNUM_SIGN(y); } else { l1 = RBIGNUM_LEN(x); l2 = RBIGNUM_LEN(y); ds1 = BDIGITS(x); ds2 = BDIGITS(y); sign = RBIGNUM_SIGN(x); } z = bignew(l2, RBIGNUM_SIGN(x) || RBIGNUM_SIGN(y)); zds = BDIGITS(z); for (i=0; i= 0); xds = BDIGITS(x); zn = xn = RBIGNUM_LEN(x); z = bignew(zn, RBIGNUM_SIGN(x) && sign); zds = BDIGITS(z); #if SIZEOF_BDIGITS >= SIZEOF_LONG i = 1; zds[0] = xds[0] | y; #else { BDIGIT_DBL num = y; for (i=0; i<(int)(sizeof(y)/SIZEOF_BDIGITS); i++) { zds[i] = xds[i] | BIGLO(num); num = BIGDN(num); } } #endif while (i < xn) { zds[i] = sign?xds[i]:(BDIGIT)(BIGRAD-1); i++; } if (!RBIGNUM_SIGN(z)) get2comp(z); return bignorm(z); } /* * call-seq: * big | numeric -> integer * * Performs bitwise +or+ between _big_ and _numeric_. */ VALUE rb_big_or(VALUE xx, VALUE yy) { volatile VALUE x, y, z; BDIGIT *ds1, *ds2, *zds; long i, l1, l2; char sign; if (!FIXNUM_P(yy) && !RB_TYPE_P(yy, T_BIGNUM)) { return rb_num_coerce_bit(xx, yy, '|'); } x = xx; y = yy; if (!RBIGNUM_SIGN(x)) { x = rb_big_clone(x); get2comp(x); } if (FIXNUM_P(y)) { return bigor_int(x, FIX2LONG(y)); } if (!RBIGNUM_SIGN(y)) { y = rb_big_clone(y); get2comp(y); } if (RBIGNUM_LEN(x) > RBIGNUM_LEN(y)) { l1 = RBIGNUM_LEN(y); l2 = RBIGNUM_LEN(x); ds1 = BDIGITS(y); ds2 = BDIGITS(x); sign = RBIGNUM_SIGN(y); } else { l1 = RBIGNUM_LEN(x); l2 = RBIGNUM_LEN(y); ds1 = BDIGITS(x); ds2 = BDIGITS(y); sign = RBIGNUM_SIGN(x); } z = bignew(l2, RBIGNUM_SIGN(x) && RBIGNUM_SIGN(y)); zds = BDIGITS(z); for (i=0; i= 0) ? 1 : 0; xds = BDIGITS(x); zn = xn = RBIGNUM_LEN(x); z = bignew(zn, !(RBIGNUM_SIGN(x) ^ sign)); zds = BDIGITS(z); #if SIZEOF_BDIGITS >= SIZEOF_LONG i = 1; zds[0] = xds[0] ^ y; #else { BDIGIT_DBL num = y; for (i=0; i<(int)(sizeof(y)/SIZEOF_BDIGITS); i++) { zds[i] = xds[i] ^ BIGLO(num); num = BIGDN(num); } } #endif while (i < xn) { zds[i] = sign?xds[i]:~xds[i]; i++; } if (!RBIGNUM_SIGN(z)) get2comp(z); return bignorm(z); } /* * call-seq: * big ^ numeric -> integer * * Performs bitwise +exclusive or+ between _big_ and _numeric_. */ VALUE rb_big_xor(VALUE xx, VALUE yy) { volatile VALUE x, y; VALUE z; BDIGIT *ds1, *ds2, *zds; long i, l1, l2; char sign; if (!FIXNUM_P(yy) && !RB_TYPE_P(yy, T_BIGNUM)) { return rb_num_coerce_bit(xx, yy, '^'); } x = xx; y = yy; if (!RBIGNUM_SIGN(x)) { x = rb_big_clone(x); get2comp(x); } if (FIXNUM_P(y)) { return bigxor_int(x, FIX2LONG(y)); } if (!RBIGNUM_SIGN(y)) { y = rb_big_clone(y); get2comp(y); } if (RBIGNUM_LEN(x) > RBIGNUM_LEN(y)) { l1 = RBIGNUM_LEN(y); l2 = RBIGNUM_LEN(x); ds1 = BDIGITS(y); ds2 = BDIGITS(x); sign = RBIGNUM_SIGN(y); } else { l1 = RBIGNUM_LEN(x); l2 = RBIGNUM_LEN(y); ds1 = BDIGITS(x); ds2 = BDIGITS(y); sign = RBIGNUM_SIGN(x); } z = bignew(l2, !(RBIGNUM_SIGN(x) ^ RBIGNUM_SIGN(y))); zds = BDIGITS(z); for (i=0; i SIZEOF_LONG) { return RBIGNUM_SIGN(x) ? 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(VALUE x, VALUE y) { unsigned long shift; int neg = 0; for (;;) { if (FIXNUM_P(y)) { long l = FIX2LONG(y); if (0 <= l) { shift = l; } else { neg = 1; shift = 1+(unsigned long)(-(l+1)); } break; } else if (RB_TYPE_P(y, T_BIGNUM)) { if (!RBIGNUM_SIGN(y)) { VALUE t = check_shiftdown(y, x); if (!NIL_P(t)) return t; neg = 1; } shift = big2ulong(y, "long", TRUE); break; } y = rb_to_int(y); } x = neg ? big_rshift(x, shift) : big_lshift(x, shift); return bignorm(x); } static BDIGIT bary_small_lshift(BDIGIT *zds, BDIGIT *xds, long n, int shift) { long i; BDIGIT_DBL num = 0; for (i=0; i> numeric -> integer * * Shifts big right _numeric_ positions (left if _numeric_ is negative). */ VALUE rb_big_rshift(VALUE x, VALUE y) { unsigned long shift; int neg = 0; for (;;) { if (FIXNUM_P(y)) { long l = FIX2LONG(y); if (0 <= l) { shift = l; } else { neg = 1; shift = 1+(unsigned long)(-(l+1)); } break; } else if (RB_TYPE_P(y, T_BIGNUM)) { if (RBIGNUM_SIGN(y)) { VALUE t = check_shiftdown(y, x); if (!NIL_P(t)) return t; } else { neg = 1; } shift = big2ulong(y, "long", TRUE); break; } y = rb_to_int(y); } x = neg ? big_lshift(x, shift) : big_rshift(x, shift); return bignorm(x); } static void bary_small_rshift(BDIGIT *zds, BDIGIT *xds, long n, int shift, int sign_bit) { BDIGIT_DBL num = 0; BDIGIT x; if (sign_bit) { num = (~(BDIGIT_DBL)0) << BITSPERDIG; } while (n--) { num = (num | xds[n]) >> shift; x = xds[n]; zds[n] = BIGLO(num); num = BIGUP(x); } } static VALUE big_rshift(VALUE x, unsigned long shift) { BDIGIT *xds, *zds; long s1 = shift/BITSPERDIG; int s2 = (int)(shift%BITSPERDIG); VALUE z; long i, j; volatile VALUE save_x; if (s1 > RBIGNUM_LEN(x)) { if (RBIGNUM_SIGN(x)) return INT2FIX(0); else return INT2FIX(-1); } if (!RBIGNUM_SIGN(x)) { x = rb_big_clone(x); get2comp(x); } save_x = x; xds = BDIGITS(x); i = RBIGNUM_LEN(x); j = i - s1; if (j == 0) { if (RBIGNUM_SIGN(x)) return INT2FIX(0); else return INT2FIX(-1); } z = bignew(j, RBIGNUM_SIGN(x)); zds = BDIGITS(z); bary_small_rshift(zds, xds+s1, j, s2, !RBIGNUM_SIGN(x)); if (!RBIGNUM_SIGN(x)) { get2comp(z); } RB_GC_GUARD(save_x); return z; } /* * call-seq: * big[n] -> 0, 1 * * Bit Reference---Returns the nth bit in the (assumed) binary * representation of big, where big[0] is the least * significant bit. * * a = 9**15 * 50.downto(0) do |n| * print a[n] * end * * produces: * * 000101110110100000111000011110010100111100010111001 * */ static VALUE rb_big_aref(VALUE x, VALUE y) { BDIGIT *xds; BDIGIT_DBL num; unsigned long shift; long i, s1, s2; if (RB_TYPE_P(y, T_BIGNUM)) { if (!RBIGNUM_SIGN(y)) return INT2FIX(0); bigtrunc(y); if (BIGSIZE(y) > sizeof(long)) { out_of_range: return RBIGNUM_SIGN(x) ? INT2FIX(0) : INT2FIX(1); } shift = big2ulong(y, "long", FALSE); } else { i = NUM2LONG(y); if (i < 0) return INT2FIX(0); shift = i; } s1 = shift/BITSPERDIG; s2 = shift%BITSPERDIG; if (s1 >= RBIGNUM_LEN(x)) goto out_of_range; if (!RBIGNUM_SIGN(x)) { xds = BDIGITS(x); i = 0; num = 1; while (num += BIGLO(~xds[i]), ++i <= s1) { num = BIGDN(num); } } else { num = BDIGITS(x)[s1]; } if (num & ((BDIGIT_DBL)1< fixnum * * Compute a hash based on the value of _big_. */ static VALUE rb_big_hash(VALUE x) { st_index_t hash; hash = rb_memhash(BDIGITS(x), sizeof(BDIGIT)*RBIGNUM_LEN(x)) ^ RBIGNUM_SIGN(x); return INT2FIX(hash); } /* * MISSING: documentation */ static VALUE rb_big_coerce(VALUE x, VALUE y) { if (FIXNUM_P(y)) { y = rb_int2big(FIX2LONG(y)); } else if (!RB_TYPE_P(y, T_BIGNUM)) { rb_raise(rb_eTypeError, "can't coerce %s to Bignum", rb_obj_classname(y)); } return rb_assoc_new(y, x); } /* * call-seq: * big.abs -> aBignum * big.magnitude -> aBignum * * Returns the absolute value of big. * * -1234567890987654321.abs #=> 1234567890987654321 */ static VALUE rb_big_abs(VALUE x) { if (!RBIGNUM_SIGN(x)) { x = rb_big_clone(x); RBIGNUM_SET_SIGN(x, 1); } return x; } /* * call-seq: * big.size -> integer * * Returns the number of bytes in the machine representation of * big. * * (256**10 - 1).size #=> 12 * (256**20 - 1).size #=> 20 * (256**40 - 1).size #=> 40 */ static VALUE rb_big_size(VALUE big) { return LONG2FIX(RBIGNUM_LEN(big)*SIZEOF_BDIGITS); } /* * call-seq: * big.odd? -> true or false * * Returns true if big is an odd number. */ static VALUE rb_big_odd_p(VALUE num) { if (BDIGITS(num)[0] & 1) { return Qtrue; } return Qfalse; } /* * call-seq: * big.even? -> true or false * * Returns true if big is an even number. */ static VALUE rb_big_even_p(VALUE num) { if (BDIGITS(num)[0] & 1) { return Qfalse; } return Qtrue; } /* * 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 [], 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(void) { rb_cBignum = rb_define_class("Bignum", rb_cInteger); rb_define_method(rb_cBignum, "to_s", rb_big_to_s, -1); rb_define_alias(rb_cBignum, "inspect", "to_s"); 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_idiv, 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, "fdiv", rb_big_fdiv, 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, ">", big_gt, 1); rb_define_method(rb_cBignum, ">=", big_ge, 1); rb_define_method(rb_cBignum, "<", big_lt, 1); rb_define_method(rb_cBignum, "<=", big_le, 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, "magnitude", rb_big_abs, 0); rb_define_method(rb_cBignum, "size", rb_big_size, 0); rb_define_method(rb_cBignum, "odd?", rb_big_odd_p, 0); rb_define_method(rb_cBignum, "even?", rb_big_even_p, 0); power_cache_init(); big_three = rb_uint2big(3); rb_gc_register_mark_object(big_three); }