Benchmark Operations

Compounds
struct	bench
Typedefs
typedef bench	bench_t
Functions
void	bench_init (bench_t *b)
void	bench_start (bench_t *b)
void	bench_stop (bench_t *b)
void	bench_report (bench_t *b, const char *msg,...)
void	bench_empty (bench_t *b)

Detailed Description

The benchmark functions are designed to benchmark some piece of code in a precise and deterministic manner. Interrupts are masked during the benchmark. The benchmark uses the free running counter that exists in 68HC11 and 68HC12 (see get_timer_counter ). The implementation assumes that the free running counter can overflow only once during a benchmark. This imposes a restrictions on the benchmarked operation: they must be fast enough to not exceed 65536 times the update of the free running counter. For example on a 68HC11 @ 8Mhz they should not exceed 32ms.

The benchmark data is recorded in the bench_t data type. It must be initialized using bench_init. For example:

       bench_t b;

       bench_init (&b);
   

Then, the piece of code that must be benchmarked is enclosed by calls to bench_start and bench_stop as follows:

       bench_start (&b);
       ...
       bench_stop (&b);
       bench_report (&b, "Operation");
   

The bench_report function must be called to compute the time and print the result.

Function Documentation

void bench_empty (  bench_t *    b )

Benchmark overhead computation. This function computes the overhead of the benchmark operations bench_start and bench_stop. Parameters: b  pointer to benchmark record object See also: bench_init

void bench_init (  bench_t *    b )

Initialize the benchmark object. This function must be called to initialize the benchmark object. It locks the interrupts and computes the benchmark correction that will be applied to the results. The benchmark correction is based on the benchmark operations overhead computed using bench_empty. Parameters: b  pointer to benchmark record object See also: bench_start, bench_stop, bench_empty

void bench_report (  bench_t *    b, const char *    msg, ...    )

Report benchmark results. This function computes the time spent between the bench_start and bench_stop calls. It then reports the result. Parameters: b  pointer to benchmark record object msg  format description string See also: bench_start, bench_stop

__inline__ void bench_start (  bench_t *    b )

Start the benchmark. This function starts the benchmark operation by recording the precise time at which the measure begins. Parameters: b  pointer to benchmark record object See also: bench_stop, bench_init Definition at line 117 of file benchs.h. References bench::b_start.

__inline__ void bench_stop (  bench_t *    b )

Stop the benchmark. This function finishes the benchmark operation by recording the precise time at which the measure stops. Parameters: b  pointer to benchmark record object See also: bench_start, bench_init Definition at line 133 of file benchs.h. References bench::b_stop.