Controls the collection of hardware counter overflow profiling data. If you attempt to enable hardware counter overflow profiling on systems that do not support it, dbx returns a warning message and the command is ignored. The allowed values for option are:
on– Turns on hardware counter overflow profiling. The default action is to collect data for the cycles counter at the normal overflow value.
off– Turns off hardware counter overflow profiling.
list– Returns a list of available counters. See Hardware Counter Lists for a description of the list. If your system does not support hardware counter overflow profiling, dbx returns a warning message.
counter counter_definition... [, counter_definition ]– A counter definition can take one of the following forms, depending on whether the processor supports attributes for hardware counters.
[+] counter_name[/ register_number][,interval ]
[+]counter_name[~ attribute_1=value_1]...[~attribute_n =value_n][/ register_number][,interval ]
Selects the hardware counter name, and sets its overflow value to interval; optionally selects additional hardware counter names and sets their overflow values to the specified intervals. The overflow value can be one of the following.
on, or a null string– The default overflow value, which you can determine by typing collect with no arguments.
hi[gh]– The high-resolution value for the chosen counter, which is approximately ten times shorter than the default overflow value. The abbreviation h is also supported for compatibility with previous software releases.
lo[w]– The low-resolution value for the chosen counter, which is approximately ten times longer than the default overflow value.
interval– A specific overflow value, which must be a positive integer and can be in decimal or hexadecimal format.
If you specify more than one counter, they must use different registers. If they do not, a warning message is printed and the command is ignored.
If the hardware counter counts events that relate to memory access, you can prefix the counter name with a + sign to turn on searching for the true PC of the instruction that caused the counter overflow. If the search is successful, the PC and the effective address that was referenced are stored in the event data packet.
The Collector does not collect hardware counter overflow profiling data by default. If hardware-counter overflow profiling is enabled and a profile command has not been given, clock-based profiling is turned off.