Re: com php-src: Fix for failing tests. gcc 4.8.3 would optimize away the assigment.: ext/mysqlnd/mysqlnd_ps_codec.c

Hi, I'm also on holidays... I may take a look after January 12, but I think this must not make any problems. Thanks. Dmitry. On Jan 6, 2015 11:00 AM, "Keyur Govande" <kgovande@gmail.com> wrote: > > > On Sat, Dec 27, 2014 at 2:17 AM, Keyur Govande <kgovande@gmail.com> wrote: > >> >> >> On Fri, Dec 26, 2014 at 9:52 PM, Dmitry Stogov <dmitry@zend.com> wrote: >> >>> This patch increases the binary size on 2MB (20%) :( >>> >>> # without patch >>> >>> $ size sapi/cli/php >>> text data bss dec hex filename >>> 11243874 55868 134140 11433882 ae779a sapi/cli/php >>> >>> # with patch >>> >>> $ size sapi/cli/php >>> text data bss dec hex filename >>> 13398084 55888 134148 13588120 cf5698 sapi/cli/php >>> >>> It's probably better not to use dec32. >>> >> >> Ahh :( >> >> dec32 is 3 orders of magnitude faster than the alternative (convert float >> to a string via fcvt or gcvt, and then to double via strtod). >> >> That said though, I will make dec32 optional via a configure option >> defaulted to off and make the slow path the default. This will bring the >> Mysqli implementation in-line with what PDO-libmysqlclient does and fix the >> slight discrepancy in precision that arises due to that. >> >> dec32 is more precise, for example 3.141593 vs. 3.14159 with >> PDO-libmysqlclient when pi is stored in a Mysql 4 byte float column. >> >> I should have a pull request on Github in a day or two. >> > > Sorry for the delay, the holidays intruded on my plans. > > The pull request is up here: > https://github.com/php/php-src/pull/983 and > all tests pass on Windows and Linux (with gcc 4.8.3). I'll merge it in in a > few days if no concerns are raised. > > Thanks and Happy New Year! > Keyur. > > >> >>> Thanks. Dmitry. >>> >>> On Fri, Dec 26, 2014 at 11:36 PM, Keyur Govande <keyur@php.net> wrote: >>> >>>> Commit: aa192f57c9d867ab3d7be69c7f269cfd7a10d14f >>>> Author: Keyur Govande <keyur@php.net> Fri, 26 Dec 2014 >>>> 20:36:19 +0000 >>>> Parents: 80260bcfa667bf25c65264b129f08a35059436a0 >>>> Branches: PHP-5.5 PHP-5.6 master >>>> >>>> Link: >>>> >>>> http://git.php.net/?p=php-src.git;a=commitdiff;h=aa192f57c9d867ab3d7be69c7f269cfd7a10d14f >>>> >>>> Log: >>>> Fix for failing tests. gcc 4.8.3 would optimize away the assigment. >>>> >>>> Changed paths: >>>> M ext/mysqlnd/mysqlnd_ps_codec.c >>>> >>>> >>>> Diff: >>>> diff --git a/ext/mysqlnd/mysqlnd_ps_codec.c >>>> b/ext/mysqlnd/mysqlnd_ps_codec.c >>>> index d960912..a57ff5d 100644 >>>> --- a/ext/mysqlnd/mysqlnd_ps_codec.c >>>> +++ b/ext/mysqlnd/mysqlnd_ps_codec.c >>>> @@ -195,7 +195,8 @@ ps_fetch_float(zval * zv, const MYSQLND_FIELD * >>>> const field, unsigned int pack_l >>>> #ifdef HAVE_DECIMAL_FP_SUPPORT >>>> { >>>> typedef float dec32 __attribute__((mode(SD))); >>>> - dec32 d32val = fval; >>>> + /* volatile so the compiler will not optimize away the >>>> conversion */ >>>> + volatile dec32 d32val = fval; >>>> >>>> /* The following cast is guaranteed to do the right >>>> thing */ >>>> dval = (double) d32val; >>>> >>>> >>>> -- >>>> PHP CVS Mailing List (http://www.php.net/) >>>> To unsubscribe, visit: http://www.php.net/unsub.php >>>> >>>> >>> >> >