зеркало из https://github.com/github/ruby.git
* bignum.c (big_shift3): New function.
big_lshift and big_rshift are merged. (big_shift2): New function. (big_lshift): Use big_shift3. (big_rshift): Ditto. (check_shiftdown): Removed. (rb_big_lshift): Use big_shift2 and big_shift3. (rb_big_rshift): Ditto. (big_lshift): Removed. (big_rshift): Ditto. git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41942 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
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13
ChangeLog
13
ChangeLog
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@ -1,3 +1,16 @@
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Sat Jul 13 22:58:16 2013 Tanaka Akira <akr@fsij.org>
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* bignum.c (big_shift3): New function.
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big_lshift and big_rshift are merged.
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(big_shift2): New function.
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(big_lshift): Use big_shift3.
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(big_rshift): Ditto.
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(check_shiftdown): Removed.
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(rb_big_lshift): Use big_shift2 and big_shift3.
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(rb_big_rshift): Ditto.
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(big_lshift): Removed.
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(big_rshift): Ditto.
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Sat Jul 13 15:51:38 2013 Tanaka Akira <akr@fsij.org>
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* bignum.c (bary_small_lshift): Use size_t instead of long.
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215
bignum.c
215
bignum.c
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@ -445,6 +445,7 @@ bary_small_lshift(BDIGIT *zds, BDIGIT *xds, size_t n, int shift)
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{
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size_t i;
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BDIGIT_DBL num = 0;
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assert(0 <= shift && shift < BITSPERDIG);
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for (i=0; i<n; i++) {
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num = num | (BDIGIT_DBL)*xds++ << shift;
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@ -459,6 +460,9 @@ bary_small_rshift(BDIGIT *zds, BDIGIT *xds, size_t n, int shift, int sign_bit)
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{
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BDIGIT_DBL num = 0;
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BDIGIT x;
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assert(0 <= shift && shift < BITSPERDIG);
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if (sign_bit) {
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num = (~(BDIGIT_DBL)0) << BITSPERDIG;
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}
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@ -3187,6 +3191,104 @@ rb_str2inum(VALUE str, int base)
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return rb_str_to_inum(str, base, base==0);
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}
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static VALUE
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big_shift3(VALUE x, int lshift_p, size_t shift_numdigits, int shift_numbits)
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{
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BDIGIT *xds, *zds;
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long s1;
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int s2;
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VALUE z;
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long xn;
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if (LONG_MAX < shift_numdigits) {
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rb_raise(rb_eArgError, "too big number");
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}
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s1 = shift_numdigits;
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s2 = shift_numbits;
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if (lshift_p) {
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xn = RBIGNUM_LEN(x);
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z = bignew(xn+s1+1, RBIGNUM_SIGN(x));
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zds = BDIGITS(z);
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MEMZERO(zds, BDIGIT, s1);
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xds = BDIGITS(x);
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zds[xn+s1] = bary_small_lshift(zds+s1, xds, xn, s2);
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}
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else {
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long zn;
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BDIGIT hibitsx;
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if (s1 >= RBIGNUM_LEN(x)) {
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if (RBIGNUM_POSITIVE_P(x) ||
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bary_zero_p(BDIGITS(x), RBIGNUM_LEN(x)))
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return INT2FIX(0);
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else
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return INT2FIX(-1);
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}
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hibitsx = abs2twocomp(&x, &xn);
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xds = BDIGITS(x);
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if (xn <= s1) {
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return hibitsx ? INT2FIX(-1) : INT2FIX(0);
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}
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zn = xn - s1;
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z = bignew(zn, 0);
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zds = BDIGITS(z);
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bary_small_rshift(zds, xds+s1, zn, s2, hibitsx != 0);
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twocomp2abs_bang(z, hibitsx != 0);
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}
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RB_GC_GUARD(x);
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return z;
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}
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static VALUE
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big_shift2(VALUE x, int lshift_p, VALUE y)
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{
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int sign;
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size_t lens[2];
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size_t shift_numdigits;
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int shift_numbits;
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assert(POW2_P(CHAR_BIT));
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assert(POW2_P(BITSPERDIG));
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if (BIGZEROP(x))
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return INT2FIX(0);
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sign = rb_integer_pack(y, lens, numberof(lens), sizeof(size_t), 0,
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INTEGER_PACK_LSWORD_FIRST|INTEGER_PACK_NATIVE_BYTE_ORDER);
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if (sign < 0) {
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lshift_p = !lshift_p;
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sign = -sign;
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}
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if (lshift_p) {
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if (1 < sign || CHAR_BIT <= lens[1])
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rb_raise(rb_eRangeError, "shift width too big");
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}
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else {
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if (1 < sign || CHAR_BIT <= lens[1])
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return RBIGNUM_POSITIVE_P(x) ? INT2FIX(0) : INT2FIX(-1);
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}
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shift_numbits = lens[0] & (BITSPERDIG-1);
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shift_numdigits = (lens[0] >> bitsize(BITSPERDIG-1)) |
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(lens[1] << (CHAR_BIT*SIZEOF_SIZE_T - bitsize(BITSPERDIG-1)));
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return big_shift3(x, lshift_p, shift_numdigits, shift_numbits);
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}
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static VALUE
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big_lshift(VALUE x, unsigned long shift)
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{
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long s1 = shift/BITSPERDIG;
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int s2 = (int)(shift%BITSPERDIG);
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return big_shift3(x, 1, s1, s2);
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}
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static VALUE
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big_rshift(VALUE x, unsigned long shift)
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{
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long s1 = shift/BITSPERDIG;
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int s2 = (int)(shift%BITSPERDIG);
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return big_shift3(x, 0, s1, s2);
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}
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static inline int
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ones(register unsigned long x)
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{
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@ -4516,8 +4618,6 @@ big_split3(VALUE v, long n, volatile VALUE* p0, volatile VALUE* p1, volatile VAL
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*p2 = bigtrunc(v2);
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}
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static VALUE big_lshift(VALUE, unsigned long);
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static VALUE big_rshift(VALUE, unsigned long);
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static VALUE bigdivrem(VALUE, VALUE, volatile VALUE*, volatile VALUE*);
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static VALUE
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@ -5682,16 +5782,6 @@ rb_big_xor(VALUE x, VALUE y)
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return bignorm(z);
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}
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static VALUE
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check_shiftdown(VALUE y, VALUE x)
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{
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if (!RBIGNUM_LEN(x)) return INT2FIX(0);
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if (BIGSIZE(y) > SIZEOF_LONG) {
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return RBIGNUM_SIGN(x) ? INT2FIX(0) : INT2FIX(-1);
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}
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return Qnil;
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}
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/*
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* call-seq:
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* big << numeric -> integer
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@ -5702,56 +5792,33 @@ check_shiftdown(VALUE y, VALUE x)
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VALUE
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rb_big_lshift(VALUE x, VALUE y)
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{
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unsigned long shift;
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int neg = 0;
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int lshift_p;
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size_t shift_numdigits;
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int shift_numbits;
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for (;;) {
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if (FIXNUM_P(y)) {
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long l = FIX2LONG(y);
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unsigned long shift;
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if (0 <= l) {
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lshift_p = 1;
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shift = l;
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}
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else {
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neg = 1;
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lshift_p = 0;
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shift = 1+(unsigned long)(-(l+1));
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}
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break;
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shift_numbits = shift & (BITSPERDIG-1);
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shift_numdigits = shift >> bitsize(BITSPERDIG-1);
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return bignorm(big_shift3(x, lshift_p, shift_numdigits, shift_numbits));
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}
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else if (RB_TYPE_P(y, T_BIGNUM)) {
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if (!RBIGNUM_SIGN(y)) {
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VALUE t = check_shiftdown(y, x);
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if (!NIL_P(t)) return t;
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neg = 1;
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}
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shift = big2ulong(y, "long");
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break;
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return bignorm(big_shift2(x, 1, y));
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}
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y = rb_to_int(y);
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}
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x = neg ? big_rshift(x, shift) : big_lshift(x, shift);
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return bignorm(x);
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}
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static VALUE
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big_lshift(VALUE x, unsigned long shift)
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{
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BDIGIT *xds, *zds;
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long s1 = shift/BITSPERDIG;
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int s2 = (int)(shift%BITSPERDIG);
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VALUE z;
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long len, i;
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len = RBIGNUM_LEN(x);
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z = bignew(len+s1+1, RBIGNUM_SIGN(x));
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zds = BDIGITS(z);
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for (i=0; i<s1; i++) {
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*zds++ = 0;
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}
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xds = BDIGITS(x);
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zds[len] = bary_small_lshift(zds, xds, len, s2);
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return z;
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}
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/*
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* call-seq:
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@ -5763,69 +5830,31 @@ big_lshift(VALUE x, unsigned long shift)
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VALUE
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rb_big_rshift(VALUE x, VALUE y)
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{
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unsigned long shift;
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int neg = 0;
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int lshift_p;
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size_t shift_numdigits;
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int shift_numbits;
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for (;;) {
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if (FIXNUM_P(y)) {
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long l = FIX2LONG(y);
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unsigned long shift;
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if (0 <= l) {
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lshift_p = 0;
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shift = l;
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}
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else {
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neg = 1;
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lshift_p = 1;
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shift = 1+(unsigned long)(-(l+1));
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}
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break;
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shift_numbits = shift & (BITSPERDIG-1);
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shift_numdigits = shift >> bitsize(BITSPERDIG-1);
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return bignorm(big_shift3(x, lshift_p, shift_numdigits, shift_numbits));
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}
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else if (RB_TYPE_P(y, T_BIGNUM)) {
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if (RBIGNUM_SIGN(y)) {
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VALUE t = check_shiftdown(y, x);
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if (!NIL_P(t)) return t;
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}
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else {
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neg = 1;
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}
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shift = big2ulong(y, "long");
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break;
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return bignorm(big_shift2(x, 0, y));
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}
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y = rb_to_int(y);
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}
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x = neg ? big_lshift(x, shift) : big_rshift(x, shift);
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return bignorm(x);
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}
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static VALUE
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big_rshift(VALUE x, unsigned long shift)
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{
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BDIGIT *xds, *zds;
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long s1 = shift/BITSPERDIG;
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int s2 = (int)(shift%BITSPERDIG);
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VALUE z;
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long j;
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long xl;
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BDIGIT hibitsx;
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if (s1 > RBIGNUM_LEN(x)) {
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if (RBIGNUM_POSITIVE_P(x) || bary_zero_p(BDIGITS(x), RBIGNUM_LEN(x)))
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return INT2FIX(0);
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else
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return INT2FIX(-1);
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}
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hibitsx = abs2twocomp(&x, &xl);
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xds = BDIGITS(x);
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j = xl - s1;
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if (j <= 0) {
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if (!hibitsx) return INT2FIX(0);
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else return INT2FIX(-1);
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}
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z = bignew(j, 0);
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zds = BDIGITS(z);
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bary_small_rshift(zds, xds+s1, j, s2, hibitsx != 0);
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twocomp2abs_bang(z, hibitsx != 0);
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RB_GC_GUARD(x);
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return z;
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}
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/*
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@ -533,6 +533,11 @@ class TestBignum < Test::Unit::TestCase
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assert_equal(-1, -(2**31) >> 32)
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end
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def test_shift_bigshift
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big = 2**300
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assert_equal(2**65538 / (2**65537), 2**65538 >> big.coerce(65537).first)
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end
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def test_aref
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assert_equal(0, (2**32)[0])
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assert_equal(0, (2**32)[2**32])
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