External format of integers (OTP-8540)

History.txt

@@ -1,3 +1,9 @@
+= 1.2.0 / 2010-10-02
+  * Minor Changes
+    * OTP-8540 (http://erlang.org/download/otp_src_R14B.readme):
+      "External format of integers changed to make full use of
+      all 32 bits of INTEGER_EXT"
+
 = 1.1.2 / 2010-02-08
   * Bug fixes
     * Fix bignum handling on 256 byte boundary

VERSION

@@ -1 +1 @@
-1.1.2
+1.2.0

ext/bert/c/decode.c

@@ -14,6 +14,8 @@
 #define ERL_STRING        107
 #define ERL_LIST          108
 #define ERL_BIN           109
+#define RB_MAX_FIXNUM     (1 << 30) - 1
+#define RB_MIN_FIXNUM     -(1 << 30)
 
 static VALUE mBERT;
 static VALUE cDecode;
@@ -287,7 +289,10 @@ VALUE read_int(unsigned char **pData) {
     value = (value - ((long long) 1 << 32));
   }
 
-  return INT2FIX(value);
+  if(value < RB_MIN_FIXNUM || value > RB_MAX_FIXNUM)
+       return INT2NUM(value);
+  else
+       return INT2FIX(value);
 }
 
 VALUE read_small_bignum(unsigned char **pData) {

lib/bert/decode.rb

@@ -113,7 +113,11 @@ def read_int
       value = read_4
       negative = (value >> 31)[0] == 1
       value = (value - (1 << 32)) if negative
-      value = Fixnum.induced_from(value)
+      if value < RB_MIN_FIXNUM or value > RB_MAX_FIXNUM
+           value = Bignum.induced_from(value)
+      else
+           value = Fixnum.induced_from(value)
+      end
     end
 
     def read_small_bignum

lib/bert/types.rb

@@ -15,7 +15,9 @@ module Types
     FUN = 117
     NEW_FUN = 112
     MAGIC = 131
-    MAX_INT = (1 << 27) -1
-    MIN_INT = -(1 << 27)
+    MAX_INT = (1 << 31) - 1
+    MIN_INT = -(1 << 31)
+    RB_MAX_FIXNUM = (1 << 30) - 1
+    RB_MIN_FIXNUM = -(1 << 30)
   end
 end