* bignum.c (rb_big_divrem_normal): New function.

* internal.h (rb_big_divrem_normal): Declared.

* ext/-test-/bignum/div.c: New file.

* test/-ext-/bignum/test_div.rb: New file.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42834 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,13 @@
+Thu Sep  5 00:38:32 2013  Tanaka Akira  <akr@fsij.org>
+
+	* bignum.c (rb_big_divrem_normal): New function.
+
+	* internal.h (rb_big_divrem_normal): Declared.
+
+	* ext/-test-/bignum/div.c: New file.
+
+	* test/-ext-/bignum/test_div.rb: New file.
+
 Thu Sep  5 00:08:44 2013  Tanaka Akira  <akr@fsij.org>
 
 	* bignum.c (bigdivrem_normal): Removed.

bignum.c

@@ -2644,6 +2644,7 @@ bary_divmod_normal(BDIGIT *qds, size_t qn, BDIGIT *rds, size_t rn, const BDIGIT
     VALUE tmpz = 0;
     VALUE tmpyy = 0;
 
+    assert(yn < xn || (xn == yn && yds[yn - 1] <= xds[xn - 1]));
     assert(qds ? (xn - yn + 1) <= qn : 1);
     assert(rds ? yn <= rn : 1);
 
@@ -2696,6 +2697,37 @@ bary_divmod_normal(BDIGIT *qds, size_t qn, BDIGIT *rds, size_t rn, const BDIGIT
         ALLOCV_END(tmpz);
 }
 
+VALUE
+rb_big_divrem_normal(VALUE x, VALUE y)
+{
+    size_t xn = RBIGNUM_LEN(x), yn = RBIGNUM_LEN(y), qn, rn;
+    BDIGIT *xds = BDIGITS(x), *yds = BDIGITS(y), *qds, *rds;
+    VALUE q, r;
+
+    BARY_TRUNC(yds, yn);
+    if (yn == 0)
+        rb_num_zerodiv();
+    BARY_TRUNC(xds, xn);
+
+    if (xn < yn || (xn == yn && xds[xn - 1] < yds[yn - 1]))
+        return rb_assoc_new(LONG2FIX(0), x);
+
+    qn = xn + BIGDIVREM_EXTRA_WORDS;
+    q = bignew(qn, RBIGNUM_SIGN(x)==RBIGNUM_SIGN(y));
+    qds = BDIGITS(q);
+
+    rn = yn;
+    r = bignew(rn, RBIGNUM_SIGN(x));
+    rds = BDIGITS(r);
+
+    bary_divmod_normal(qds, qn, rds, rn, xds, xn, yds, yn);
+
+    bigtrunc(q);
+    bigtrunc(r);
+
+    return rb_assoc_new(q, r);
+}
+
 static void
 bary_divmod(BDIGIT *qds, size_t qn, BDIGIT *rds, size_t rn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn)
 {

ext/-test-/bignum/depend

@@ -2,5 +2,6 @@ $(OBJS): $(HDRS) $(ruby_headers)
 
 intpack.o: intpack.c $(top_srcdir)/internal.h
 mul.o: mul.c $(top_srcdir)/internal.h
+div.o: div.c $(top_srcdir)/internal.h
 big2str.o: big2str.c $(top_srcdir)/internal.h
 str2big.o: big2str.c $(top_srcdir)/internal.h

ext/-test-/bignum/div.c

@@ -0,0 +1,25 @@
+#include "ruby.h"
+#include "internal.h"
+
+static VALUE
+big(VALUE x)
+{
+    if (FIXNUM_P(x))
+        return rb_int2big(FIX2LONG(x));
+    if (RB_TYPE_P(x, T_BIGNUM))
+        return x;
+    rb_raise(rb_eTypeError, "can't convert %s to Bignum",
+            rb_obj_classname(x));
+}
+
+static VALUE
+divrem_normal(VALUE x, VALUE y)
+{
+    return rb_big_norm(rb_big_divrem_normal(big(x), big(y)));
+}
+
+void
+Init_div(VALUE klass)
+{
+    rb_define_method(rb_cInteger, "big_divrem_normal", divrem_normal, 1);
+}

internal.h

@@ -696,6 +696,7 @@ VALUE rb_big_mul_balance(VALUE x, VALUE y);
 VALUE rb_big_mul_karatsuba(VALUE x, VALUE y);
 VALUE rb_big_mul_toom3(VALUE x, VALUE y);
 VALUE rb_big_sq_fast(VALUE x);
+VALUE rb_big_divrem_normal(VALUE x, VALUE y);
 VALUE rb_big2str_poweroftwo(VALUE x, int base);
 VALUE rb_big2str_generic(VALUE x, int base);
 VALUE rb_str2big_poweroftwo(VALUE arg, int base, int badcheck);

test/-ext-/bignum/test_div.rb

@@ -0,0 +1,19 @@
+require 'test/unit'
+require "-test-/bignum"
+
+class TestBignum < Test::Unit::TestCase
+  class TestDiv < Test::Unit::TestCase
+
+    SIZEOF_BDIGITS = Bignum::SIZEOF_BDIGITS
+    BITSPERDIG = Bignum::BITSPERDIG
+    BDIGMAX = (1 << BITSPERDIG) - 1
+
+    def test_divrem_normal
+      x = (1 << (BITSPERDIG*2)) | (2 << BITSPERDIG) | 3
+      y = (1 << BITSPERDIG) | 1
+      q = (1 << BITSPERDIG) | 1
+      r = 2
+      assert_equal([q, r], x.big_divrem_normal(y))
+    end
+  end
+end