* bignum.c (rb_big_lshift, rb_big_rshift): separated functions

to get rid of infinite recursion.  fixed calculation in edge
  cases.  [ruby-dev:31244]

* numeric.c (rb_fix_lshift, rb_fix_rshift): ditto.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@12814 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,11 @@
+Thu Jul 19 14:38:45 2007  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* bignum.c (rb_big_lshift, rb_big_rshift): separated functions
+	  to get rid of infinite recursion.  fixed calculation in edge
+	  cases.  [ruby-dev:31244]
+
+	* numeric.c (rb_fix_lshift, rb_fix_rshift): ditto.
+
 Wed Jul 18 16:57:41 2007  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* bignum.c (rb_big_pow): refine overflow check.  [ruby-dev:31242]

bignum.c

@@ -1529,7 +1529,17 @@ bdigbitsize(BDIGIT x)
     return size;
 }
 
-static VALUE rb_big_rshift(VALUE,VALUE);
+static VALUE big_lshift(VALUE, unsigned int);
+static VALUE big_rshift(VALUE, unsigned int);
+
+static VALUE big_shift(VALUE x, int n)
+{
+    if (n < 0)
+	return big_lshift(x, (unsigned int)n);
+    else if (n > 0)
+	return big_rshift(x, (unsigned int)n);
+    return x;
+}
 
 /*
  *  call-seq:
@@ -1558,7 +1568,7 @@ rb_big_quo(VALUE x, VALUE y)
 	ex = (RBIGNUM(bigtrunc(x))->len - 1) * BITSPERDIG;
 	ex += bdigbitsize(BDIGITS(x)[RBIGNUM(x)->len - 1]);
 	ex -= 2 * DBL_BIGDIG * BITSPERDIG;
-	if (ex) x = rb_big_rshift(x, INT2FIX(ex));
+	if (ex) x = big_shift(x, ex);
 
 	switch (TYPE(y)) {
 	  case T_FIXNUM:
@@ -1567,7 +1577,7 @@ rb_big_quo(VALUE x, VALUE y)
 	    ey = (RBIGNUM(bigtrunc(y))->len - 1) * BITSPERDIG;
 	    ey += bdigbitsize(BDIGITS(y)[RBIGNUM(y)->len - 1]);
 	    ey -= DBL_BIGDIG * BITSPERDIG;
-	    if (ey) y = rb_big_rshift(y, INT2FIX(ey));
+	    if (ey) y = big_shift(y, ey);
 	  bignum:
 	    bigdivrem(x, y, &z, 0);
 	    return rb_float_new(ldexp(big2dbl(z), ex - ey));
@@ -1872,6 +1882,16 @@ rb_big_xor(VALUE xx, VALUE yy)
     return bignorm(z);
 }
 
+static VALUE
+check_shiftdown(VALUE y, VALUE x)
+{
+    if (!RBIGNUM(x)->len) return INT2FIX(0);
+    if (RBIGNUM(y)->len > SIZEOF_LONG / SIZEOF_BDIGITS) {
+	return RBIGNUM(x)->sign ? INT2FIX(0) : INT2FIX(-1);
+    }
+    return Qnil;
+}
+
 /*
  * call-seq:
  *     big << numeric   =>  integer
@@ -1881,16 +1901,44 @@ rb_big_xor(VALUE xx, VALUE yy)
 
 VALUE
 rb_big_lshift(VALUE x, VALUE y)
+{
+    int shift, neg = 0;
+
+    for (;;) {
+	if (FIXNUM_P(y)) {
+	    shift = FIX2INT(y);
+	    if (shift < 0) {
+		neg = 1;
+		shift = -shift;
+	    }
+	    break;
+	}
+	else if (TYPE(y) == T_BIGNUM) {
+	    if (!RBIGNUM(y)->sign) {
+		VALUE t = check_shiftdown(y, x);
+		if (!NIL_P(t)) return t;
+		neg = 1;
+	    }
+	    shift = big2ulong(y, "long", Qtrue);
+	    break;
+	}
+	y = rb_to_int(y);
+    }
+
+    if (neg) return big_rshift(x, shift);
+    return big_lshift(x, shift);
+}
+
+static VALUE
+big_lshift(VALUE x, unsigned int shift)
 {
     BDIGIT *xds, *zds;
-    int shift = NUM2INT(y);
     int s1 = shift/BITSPERDIG;
     int s2 = shift%BITSPERDIG;
     VALUE z;
     BDIGIT_DBL num = 0;
     long len, i;
 
-    if (shift < 0) return rb_big_rshift(x, INT2FIX(-shift));
     len = RBIGNUM(x)->len;
     z = bignew(len+s1+1, RBIGNUM(x)->sign);
     zds = BDIGITS(z);
@@ -1914,11 +1962,43 @@ rb_big_lshift(VALUE x, VALUE y)
  * Shifts big right _numeric_ positions (left if _numeric_ is negative).
  */
 
-static VALUE
+VALUE
 rb_big_rshift(VALUE x, VALUE y)
+{
+    int shift;
+    int neg = 0;
+
+    for (;;) {
+	if (FIXNUM_P(y)) {
+	    shift = FIX2INT(y);
+	    if (shift < 0) {
+		neg = 1;
+		shift = -shift;
+	    }
+	    break;
+	}
+	else if (TYPE(y) == T_BIGNUM) {
+	    if (RBIGNUM(y)->sign) {
+		VALUE t = check_shiftdown(y, x);
+		if (!NIL_P(t)) return t;
+	    }
+	    else {
+		neg = 1;
+	    }
+	    shift = big2ulong(y, "long", Qtrue);
+	    break;
+	}
+	y = rb_to_int(y);
+    }
+
+    if (neg) return big_lshift(x, shift);
+    return big_rshift(x, shift);
+}
+
+static VALUE
+big_rshift(VALUE x, unsigned int shift)
 {
     BDIGIT *xds, *zds;
-    int shift = NUM2INT(y);
     long s1 = shift/BITSPERDIG;
     long s2 = shift%BITSPERDIG;
     VALUE z;
@@ -1926,8 +2006,6 @@ rb_big_rshift(VALUE x, VALUE y)
     long i, j;
     volatile VALUE save_x;
 
-    if (shift < 0) return rb_big_lshift(x, INT2FIX(-shift));
-
     if (s1 > RBIGNUM(x)->len) {
 	if (RBIGNUM(x)->sign)
 	    return INT2FIX(0);

include/ruby/intern.h

@@ -114,6 +114,7 @@ VALUE rb_big_and(VALUE, VALUE);
 VALUE rb_big_or(VALUE, VALUE);
 VALUE rb_big_xor(VALUE, VALUE);
 VALUE rb_big_lshift(VALUE, VALUE);
+VALUE rb_big_rshift(VALUE, VALUE);
 /* class.c */
 VALUE rb_class_boot(VALUE);
 VALUE rb_class_new(VALUE);

numeric.c

@@ -2591,7 +2591,8 @@ fix_xor(VALUE x, VALUE y)
     return LONG2NUM(val);
 }
 
-static VALUE fix_rshift(VALUE, VALUE);
+static VALUE fix_lshift(long, unsigned long);
+static VALUE fix_rshift(long, unsigned long);
 
 /*
  * call-seq:
@@ -2601,17 +2602,25 @@ static VALUE fix_rshift(VALUE, VALUE);
  */
 
 static VALUE
-fix_lshift(VALUE x, VALUE y)
+rb_fix_lshift(VALUE x, VALUE y)
 {
     long val, width;
 
     val = NUM2LONG(x);
-    width = NUM2LONG(y);
+    if (!FIXNUM_P(y))
+	return rb_big_lshift(rb_int2big(val), y);
+    width = FIX2LONG(y);
     if (width < 0)
-	return fix_rshift(x, LONG2FIX(-width));
+	return fix_rshift(val, (unsigned long)-width);
+    return fix_lshift(val, width);
+}
+
+static VALUE
+fix_lshift(long val, unsigned long width)
+{
     if (width > (sizeof(VALUE)*CHAR_BIT-1)
 	|| ((unsigned long)val)>>(sizeof(VALUE)*CHAR_BIT-1-width) > 0) {
-	return rb_big_lshift(rb_int2big(val), y);
+	return rb_big_lshift(rb_int2big(val), ULONG2NUM(width));
     }
     val = val << width;
     return LONG2NUM(val);
@@ -2625,15 +2634,23 @@ fix_lshift(VALUE x, VALUE y)
  */
 
 static VALUE
-fix_rshift(VALUE x, VALUE y)
+rb_fix_rshift(VALUE x, VALUE y)
 {
     long i, val;
 
-    i = NUM2LONG(y);
-    if (i < 0)
-	return fix_lshift(x, LONG2FIX(-i));
-    if (i == 0) return x;
     val = FIX2LONG(x);
+    if (!FIXNUM_P(y))
+	return rb_big_rshift(rb_int2big(val), y);
+    i = FIX2LONG(y);
+    if (i == 0) return x;
+    if (i < 0)
+	return fix_lshift(val, (unsigned long)-i);
+    return fix_rshift(val, i);
+}
+
+static VALUE
+fix_rshift(long val, unsigned long i)
+{
     if (i >= sizeof(long)*CHAR_BIT-1) {
 	if (val < 0) return INT2FIX(-1);
 	return INT2FIX(0);
@@ -2885,8 +2902,6 @@ int_downto(VALUE from, VALUE to)
 static VALUE
 int_dotimes(VALUE num)
 {
-    VALUE val;
-
     RETURN_ENUMERATOR(num, 0, 0);
 
     if (FIXNUM_P(num)) {
@@ -3105,8 +3120,8 @@ Init_Numeric(void)
     rb_define_method(rb_cFixnum, "^", fix_xor, 1);
     rb_define_method(rb_cFixnum, "[]", fix_aref, 1);
 
-    rb_define_method(rb_cFixnum, "<<", fix_lshift, 1);
+    rb_define_method(rb_cFixnum, "<<", rb_fix_lshift, 1);
-    rb_define_method(rb_cFixnum, ">>", fix_rshift, 1);
+    rb_define_method(rb_cFixnum, ">>", rb_fix_rshift, 1);
 
     rb_define_method(rb_cFixnum, "to_f", fix_to_f, 0);
     rb_define_method(rb_cFixnum, "size", fix_size, 0);

test/ruby/test_integer.rb

@@ -93,6 +93,14 @@ class TestInteger < Test::Unit::TestCase
 
   #VS.map! {|v| 0x4000000000000000.coerce(v)[0] }
 
+  BDSIZE = 0x4000000000000000.coerce(0)[0].size
+  def self.bdsize(x)
+    ((x + 1) / 8 + BDSIZE) / BDSIZE * BDSIZE
+  end
+  def bdsize(x)
+    self.class.bdsize(x)
+  end
+
   def test_aref
     VS.each {|a|
       100.times {|i|
@@ -233,6 +241,11 @@ class TestInteger < Test::Unit::TestCase
         end
       }
     }
+    assert_equal(0, 1 << -0x40000000)
+    assert_equal(0, 1 << -0x40000001)
+    assert_equal(0, 1 << -0x80000000)
+    assert_equal(0, 1 << -0x80000001)
+    # assert_equal(bdsize(0x80000000), (1 << 0x80000000).size)
   end
 
   def test_rshift
@@ -248,6 +261,12 @@ class TestInteger < Test::Unit::TestCase
         end
       }
     }
+    # assert_equal(bdsize(0x40000001), (1 >> -0x40000001).size)
+    assert((1 >> 0x80000000).zero?)
+    assert((1 >> 0xffffffff).zero?)
+    assert((1 >> 0x100000000).zero?)
+    # assert_equal((1 << 0x40000000), (1 >> -0x40000000))
+    # assert_equal((1 << 0x40000001), (1 >> -0x40000001))
   end
 
   def test_succ

version.h

@@ -1,7 +1,7 @@
 #define RUBY_VERSION "1.9.0"
-#define RUBY_RELEASE_DATE "2007-07-18"
+#define RUBY_RELEASE_DATE "2007-07-19"
 #define RUBY_VERSION_CODE 190
-#define RUBY_RELEASE_CODE 20070718
+#define RUBY_RELEASE_CODE 20070719
 #define RUBY_PATCHLEVEL 0
 
 #define RUBY_VERSION_MAJOR 1
@@ -9,7 +9,7 @@
 #define RUBY_VERSION_TEENY 0
 #define RUBY_RELEASE_YEAR 2007
 #define RUBY_RELEASE_MONTH 7
-#define RUBY_RELEASE_DAY 18
+#define RUBY_RELEASE_DAY 19
 
 #ifdef RUBY_EXTERN
 RUBY_EXTERN const char ruby_version[];