Sun Studio 12: C User's Guide

B.2.90 -xhwcprof

(SPARC) Enables compiler support for hardware counter-based profiling.

When -xhwcprof is enabled, the compiler generates information that helps tools associate profiled load and store instructions with the data-types and structure members (in conjunction with symbolic information produced with -gto which they refer. It associates profile data with the data space of the target, rather than the instruction space, and provides insight into behavior that is not easily obtained from only instruction profiling.

You can compile a specified set of object files with -xhwcprof. However, -xhwcprof is most useful when applied to all object files in the application. This will provide coverage to identify and correlate all memory references distributed in the application’s object files.

If you are compiling and linking in separate steps, use -xhwcprof at link time as well. Future extensions to -xhwcprof may require its use at link time. For a complete list of all compiler options that must be specified at both compile time and at link time, see Table A–2.

An instance of -xhwcprof=enable or -xhwcprof=disable overrides all previous instances of -xhwcprof in the same command line.

-xhwcprof is disabled by default. Specifying -xhwcprof without any arguments is the equivalent to -xhwcprof=enable.

-xhwcprof requires that optimization be turned on and that the debug data format be set to DWARF (-xdebugformat=dwarf).

The combination of -xhwcprof and -g increases compiler temporary file storage requirements by more than the sum of the increases due to -xhwcprof and -g specified alone.

The following command compiles example.c and specifies support for hardware counter profiling and symbolic analysis of data types and structure members using DWARF symbols:

example% cc -c -O -xhwcprof -g -xdebugformat=dwarf example.c

For more information on hardware counter-based profiling, see the Program Performance Analysis Tools manual.