Author: njn Date: 2007-10-17 23:29:08 +0100 (Wed, 17 Oct 2007) New Revision: 7015
Log: clarify a paragraph Modified: trunk/docs/xml/manual-core.xml Modified: trunk/docs/xml/manual-core.xml =================================================================== --- trunk/docs/xml/manual-core.xml 2007-10-17 11:04:21 UTC (rev 7014) +++ trunk/docs/xml/manual-core.xml 2007-10-17 22:29:08 UTC (rev 7015) @@ -105,18 +105,19 @@ already, if you intended to debug your program with GNU gdb, or some other debugger.</para> -<para>This paragraph applies only if you plan to use Memcheck: On rare -occasions, optimisation levels at <computeroutput>-O2</computeroutput> -and above have been observed to generate code which fools Memcheck into -wrongly reporting uninitialised value errors. We have looked in detail -into fixing this, and unfortunately the result is that doing so would -give a further significant slowdown in what is already a slow tool. So -the best solution is to turn off optimisation altogether. Since this -often makes things unmanagably slow, a reasonable compromise is to use +<para>If you are planning to use Memcheck: On rare +occasions, compiler optimisations (at <computeroutput>-O2</computeroutput> +and above, and sometimes <computeroutput>-O1</computeroutput>) have been +observed to generate code which fools Memcheck into wrongly reporting +uninitialised value errors, or missing uninitialised value errors. We have +looked in detail into fixing this, and unfortunately the result is that +doing so would give a further significant slowdown in what is already a slow +tool. So the best solution is to turn off optimisation altogether. Since +this often makes things unmanagably slow, a reasonable compromise is to use <computeroutput>-O</computeroutput>. This gets you the majority of the -benefits of higher optimisation levels whilst keeping relatively small -the chances of false complaints from Memcheck. All other tools (as far -as we know) are unaffected by optimisation level.</para> +benefits of higher optimisation levels whilst keeping relatively small the +chances of false positives or false negatives from Memcheck. All other +tools (as far as we know) are unaffected by optimisation level.</para> <para>Valgrind understands both the older "stabs" debugging format, used by gcc versions prior to 3.1, and the newer DWARF2 and DWARF3 formats ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Valgrind-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/valgrind-developers
