The new diagnostic reports can help you to identify opportunities to improve performance of code.
It is now possible to get information in XML format about some of the optimizations that the compiler was able to perform and also which optimization opportunities were missed. This information can be used to improve programmer productivity when tuning applications, especially high performance applications.
The information from the compiler is produced in XML 1.0 format. The report is defined by an XML schema and is easily consumable by tools that you can create to read and analyze the results. A stylesheet, xlstyle.xsl, is provided to render the report into a human readable format that can be read by anyone with a browser which supports XSLT.
In this release, there are four optimization categories in the report, one for inlining, one for loop transformations, one for data reorganizations, and one for profile-directed feedback information. The new -qlistfmt option and its associated suboptions generate the new XML 1.0 report.
For detailed information about this report and how to use it, see Using reports to diagnose optimization opportunities.
For detailed information about the profile-directed feedback, see Using profile-directed feedback.
For additional information about the listing files, see Compiler listings
To generate information about data prefetch insertion locations, use the optimization level of -qhot, or any other option that implies -qhot together with -qreport. This information appears in the LOOP TRANSFORMATION SECTION of the listing file.
A new suboption has been added to -qhot to add some more aggressive loop analysis. -qhot=level=2 together with -qsmp and -qreport add information about loop nests on which the aggressive loop analysis was performed to the LOOP TRANSFORMATION SECTION of the listing file. This information can also appear in the XML listing file created with the -qlistfmt option.
The entries in the following table describe new or changed compiler options and directives that give you control over compiler listings.
Information presented here is a brief overview. For detailed information about these and other performance-related compiler options, see Listings, messages and compiler information.
| Option/directive | Description |
|---|---|
| -qlistfmt | Generates a report in an XML 1.0 format containing information about optimizations performed by the compiler and missed optimization opportunities. The report contains information about inlining, loop transformations, data reorganization and profile-directed feedback. |
| -qreport | The listing now contains a PDF report section when used with -qpdf2. Another new section in the listing files is a DATA REORGANIZATION section when used with -qipa=level=2 or -O5. |
| -qskipsrc | Determines whether the source statements skipped by the compiler are shown in the SOURCE section of the listing file. |