#50080 [Com]: 1 bit short of an 8 byte integer

ID: 50080 Comment by: aidevelopment at gmail dot com Reported By: aidevelopment at gmail dot com Status: Open Bug Type: Variables related Operating System: Linux 2.6.15-26-server PHP Version: 5.2.11 New Comment: I understand what you are saying. However, the handling is very difficult to understand. As you can see, adding 1 simply has no effect past positive 0 (1000000000000000000000000000000000000000000000000000000000000000). I have not been able to determine yet exactly what happens when you explicitly assign a variable to a value "too large". Is there no way to have PHP utilize 64 bit values (uint64)? Previous Comments: ------------------------------------------------------------------------ [2009-11-04 17:17:58] sjoerd@php.net In a 64 bit integer, 1 bit indicates the sign and 63 bits are left for the number. Thus the range is from -2^63 to 2^63, giving 2^64 numbers. ------------------------------------------------------------------------ [2009-11-04 16:14:21] aidevelopment at gmail dot com Description: ------------ Despite having PHP_INT_MAX set to 8 bytes, It is impossible to have an int greater than 1000000000000000000000000000000000000000000000000000000000000000. 8 Byte, or 64 bit maximum should be 1111111111111111111111111111111111111111111111111111111111111111. In my included example, it is clear that when attempting to increase the value above(by adding 1), simply nothing happens. Attempting to assign a variable to a number greater than the above number produces unpredictable results. Reproduce code: --------------- <?php echo "Int Size = ".PHP_INT_SIZE." bytes.<br>"; $status = 0x7FFFFFFFFFFFFFFF; for($i=0;$i<=4;$i++) { printf ("status = '%b'<br>", $status); $status++; } ?> Expected result: ---------------- Int Size = 8 bytes. status = '111111111111111111111111111111111111111111111111111111111111111' status = '1000000000000000000000000000000000000000000000000000000000000000' status = '1000000000000000000000000000000000000000000000000000000000000001' status = '1000000000000000000000000000000000000000000000000000000000000010' status = '1000000000000000000000000000000000000000000000000000000000000011' Actual result: -------------- Int Size = 8 bytes. status = '111111111111111111111111111111111111111111111111111111111111111' status = '1000000000000000000000000000000000000000000000000000000000000000' status = '1000000000000000000000000000000000000000000000000000000000000000' status = '1000000000000000000000000000000000000000000000000000000000000000' status = '1000000000000000000000000000000000000000000000000000000000000000' ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=50080&edit=1