Code Profiling Utilities Manual

HP Code Profiling Utilities Manual—542684-003
Glossary- 1
Glossary
basic block. A sequence of code that is entered only at the beginning and exited at the
end. Once code enters a block, it executes the entire block unless an exception is
raised within the block. Although the terms “basic block” and “block” are often used
interchangeably, “block” is more generic and usually refers to any block (or sequence)
of instructions.
code coverage. Information about which parts of the source code of a program file were
executed during runs of the program file.
code profiling. Creating a specially-instrumented object file containing information about
which functions and basic blocks in a program are executed, and how many times they
are executed. This information can used for two purposes: to perform profile-guided
optimization or to generate a code coverage report.
covered. Executed during a test run. A block is covered if it was entered in the course of a
test run.
DPI file. Dynamic profiling information file, default name pgopti.dpi. This file is produced by
profmrg from raw data file(s), existing DPI files, or both, and used as input to a
compiler or to codecov.
instrumented code. Code into which the compiler inserted additional instructions to provide
information about how the code behaved at runtime, such as which source lines were
executed.
Files produced by instrumented object code when it runs on the NonStop server are
moved to the workstation for use as input by profmrg. These files have default names
of the following form:
•
ZZPF* if the program was run in the Guardian environment
•
ZZPF* if the program was run in the OSS environment and the current directory is
a Guardian subvolume
•
*.dyn if the program was run in the OSS environment and the current directory is
an OSS directory.
partially covered. Partially executed during a test run. When multiple basic blocks have the
same source code location, with some blocks covered and others not, that location is
said to be partially covered.
profile-guided optimization. An optimization technique in which code profiling information
about a program is input to a compiler to generate more efficient object code.
SPI file. Static profiling information file, having the name pgospi in the Guardian
environment and pgopti.spi in the OSS and Windows environments. This file is
produced by compilations and used as input by codecov.