* bignum.c (rb_big2ulong): the old logic seems to try to avoid

  calculating `-(long)(num-1)-1` if `num` is not LONG_MIN. (Note that
  `-LONG_MIN` may be larger than LONG_MAX) But C compilers can
  optimize it into single NEG instruction.
  Therefore those two conditions can be single if-body.

* bignum.c (rb_big2long): ditto.

* bignum.c (rb_big2ull): ditto.

* bignum.c (rb_big2ll): ditto.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@55528 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

2 files changed, 22 insertions, 16 deletions

diff --git a/ChangeLog b/ChangeLog
index a579b53459..4d69391762 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,17 @@
+Wed Jun 29 03:34:41 2016  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* bignum.c (rb_big2ulong): the old logic seems to try to avoid
+	  calculating `-(long)(num-1)-1` if `num` is not LONG_MIN. (Note that
+	  `-LONG_MIN` may be larger than LONG_MAX) But C compilers can
+	  optimize it into single NEG instruction.
+	  Therefore those two conditions can be single if-body.
+
+	* bignum.c (rb_big2long): ditto.
+
+	* bignum.c (rb_big2ull): ditto.
+
+	* bignum.c (rb_big2ll): ditto.
+
 Tue Jun 28 22:55:00 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* lib/pstore.rb (PStore::CHECKSUM_ALGO): extract the algorithm for
diff --git a/bignum.c b/bignum.c
index 767659d046..741fa2d21e 100644
--- a/bignum.c
+++ b/bignum.c
@@ -5079,10 +5079,8 @@ rb_big2ulong(VALUE x)
         return num;
     }
     else {
-        if (num <= LONG_MAX)
-            return -(long)num;
-        if (num == 1+(unsigned long)(-(LONG_MIN+1)))
-            return LONG_MIN;
+        if (num <= 1+(unsigned long)(-(LONG_MIN+1)))
+            return -(long)(num-1)-1;
     }
     rb_raise(rb_eRangeError, "bignum out of range of unsigned long");
 }
@@ -5097,10 +5095,8 @@ rb_big2long(VALUE x)
             return num;
     }
     else {
-        if (num <= LONG_MAX)
-            return -(long)num;
-        if (num == 1+(unsigned long)(-(LONG_MIN+1)))
-            return LONG_MIN;
+        if (num <= 1+(unsigned long)(-(LONG_MIN+1)))
+            return -(long)(num-1)-1;
     }
     rb_raise(rb_eRangeError, "bignum too big to convert into `long'");
 }
@@ -5139,10 +5135,8 @@ rb_big2ull(VALUE x)
         return num;
     }
     else {
-        if (num <= LLONG_MAX)
-            return -(LONG_LONG)num;
-        if (num == 1+(unsigned LONG_LONG)(-(LLONG_MIN+1)))
-            return LLONG_MIN;
+        if (num <= 1+(unsigned LONG_LONG)(-(LLONG_MIN+1)))
+            return -(LONG_LONG)(num-1)-1;
     }
     rb_raise(rb_eRangeError, "bignum out of range of unsigned long long");
 }
@@ -5157,10 +5151,8 @@ rb_big2ll(VALUE x)
             return num;
     }
     else {
-        if (num <= LLONG_MAX)
-            return -(LONG_LONG)num;
-        if (num == 1+(unsigned LONG_LONG)(-(LLONG_MIN+1)))
-            return LLONG_MIN;
+        if (num <= 1+(unsigned LONG_LONG)(-(LLONG_MIN+1)))
+            return -(LONG_LONG)(num-1)-1;
     }
     rb_raise(rb_eRangeError, "bignum too big to convert into `long long'");
 }