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Date: Wed, 04 Feb 2009 16:28:16 +0000
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Subject: casting doubles to ints
From: ilewis@uk.ibm.com (Iain Lewis)

Hello all,

I wanted to suggest back porting the behaviour of the DVAL_TO_LVAL macro 
from zend_operators.h from 5.3 to 5.2, and wondered whether people 
thought this was a good idea or not?

The reason I want to do this is that while writing some tests, I noticed 
that the behaviour of casting a float to an int is a bit 
counter-intuitive on 64bit platforms for PHP 5.2. It looks as though 
this has been fixed in 5.3, and it would seem like a good idea to put 
this change back to 5.2 as well. From a personal point of view, it would 
mean I could write one test that would work on both 5.2 and 5.3, but it 
also seems like a sensible change, as the current behaviour is 
non-obvious. The change would cause some current tests to break, but I 
am happy to do the work to fix those up.

This is how a few expressions get evaluated at the moment. Changing the 
macro would make the 5.2 behaviour match 5.3

Expression			5.3 (RHEL5-64)       5.2 (RHEL5-64)

(int) (PHP_INT_MAX)		9223372036854775807  9223372036854775807
(int) (PHP_INT_MAX + 1)		9223372036854775807 -9223372036854775808
(int) (PHP_INT_MAX + 1000)	9223372036854775807 -9223372036854775808
(int) (PHP_INT_MAX + 10000)	9223372036854775807 -9223372036854765568

Does this seem like a good change?