[php-maint] Bug#462980: php5-common: When running under AMD64 with X2 CPU round(17.775, 2) returns 17.77 - not under i486

Tony Mason-Sherwood tmason at thecomputerfarm.com
Mon Jan 28 18:16:20 UTC 2008

Package: php5-common
Version: 5.2.0-8+etch10
Severity: important

I am not sophisticated enough to know which module in php is doing this.  
It is generated by the round function.  We found it because we 
discovered rounding errors in processes we were doing using mysql to do 
calculations on a large number of records.  I was able to isolate the 
problem to the round function which does the same thing whether it is 
written round(17.775 * 100)/100 or round(17.775,2).  It returns 17.77 
as a result.  I know that there  are many other operations of this 
function that work correctly because of other calculations.  This 
problem occurs when running under linux-image-2.6.18-5-amd64.  
Under linux-image-2.6.18-5 it does fail to round not even when the 
processor is an amd athlon 64 X2.  We have tested it on several intel 
processor machines without finding the problem.  

-- System Information:
Debian Release: 4.0
  APT prefers stable
  APT policy: (500, 'stable')
Architecture: i386 (i686)
Shell:  /bin/sh linked to /bin/bash
Kernel: Linux 2.6.18-5-686
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)

Versions of packages php5-common depends on:
ii  sed                           4.1.5-1    The GNU sed stream editor

php5-common recommends no packages.

-- no debconf information

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