HP Caliper 5.3 User Guide (5900-1558, February 2011)

B Descriptions of Measurement Reports
This appendix contains descriptions of reports produced for each HP Caliper measurement. It
shows example command lines you can use to produce the reports and describes the data available
with the measurements.
NOTE: The information provided in this appendix for each report description is a subset of the
information you receive when you use the --info option to append help to the end of text reports,
or when you use this command:
$ caliper info -r measurement
For more information (some of which you receive when you use the --info option or the caliper
info command), see “Controlling the Content of Reports” (p. 104). In particular, see these topics:
• “Function Details” (page 109)
• “Disassembly Listing” (page 109)
• “Source Position Correlation” (page 110)
• “Address Types Shown” (page 110)
• “Unnamed Functions” (page 111)
• “Unknown Functions” (page 111)
alat Measurement Report Description
With the alat measurement, produced by the alat measurement configuration file, HP Caliper
measures and reports advance load address table (ALAT) misses.
The ALAT keeps track of speculative (that is, advance) loads. An excessive number of ALAT compares
that result in a failed advance load (an ALAT miss) can seriously degrade performance. ALAT
misses might point to inefficient use of data speculation in assembly-level code or code generated
by a compiler or virtual machine.
A miss ratio higher than 10 percent suggests a problem with how the program uses data speculation.
The report shows two levels of information:
• Exact counts of ALAT metrics summed across the entire run of an application
• Sampled failed ALAT check instructions (chk.a or ld.c) that are associated with particular
locations in the measured application.
The report shows measured data by thread, load module, function, statement, and instruction.
Command-line options allow you to control the amount of data reported, how the data is sorted,
and the number of statements and instructions reported for each sampled program location.
To improve your results, try the following:
• When compiling from high-level code, change compiler options that affect data speculation.
• When writing assembly code, tune the source code in the hot spots shown in the report.
• When writing a compiler or a virtual machine, tune the code generator.
Example Command Line for Text Report
$ caliper alat -o reports/alat.txt ./wordplay thequickbrownfox
Example Command Line for CSV Report
$ caliper alat --csv csvout ./wordplay thequickbrownfox
168 Descriptions of Measurement Reports