ruby/util.h: DECIMAL_SIZE_OF_BITS

* include/ruby/util.h (DECIMAL_SIZE_OF_BITS): a preprocessor
  constant macro to approximate decimal representation size of n-bits
  integer.
* iseq.c (register_label): use DECIMAL_SIZE_OF_BITS for better
  approximation.
* ext/bigdecimal/bigdecimal.c (BigMath_s_log): ditto.
* common.mk (iseq.o), ext/bigdecimal/depend (bigdecimal.o): add
  dependency to ruby/util.h for DECIMAL_SIZE_OF_BITS.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@44562 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 2 insertions, 1 deletions

diff --git a/iseq.c b/iseq.c
index a829089ea4..befa0364dc 100644
--- a/iseq.c
+++ b/iseq.c
@@ -10,6 +10,7 @@
 **********************************************************************/
 
 #include "ruby/ruby.h"
+#include "ruby/util.h"
 #include "internal.h"
 #include "eval_intern.h"
 
@@ -1612,7 +1613,7 @@ static VALUE
 register_label(struct st_table *table, unsigned long idx)
 {
     VALUE sym;
-    char buff[8 + (sizeof(idx) * CHAR_BIT * 32 / 100)];
+    char buff[7 + DECIMAL_SIZE_OF_BITS(sizeof(idx) * CHAR_BIT)];
 
     snprintf(buff, sizeof(buff), "label_%lu", idx);
     sym = ID2SYM(rb_intern(buff));