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// @(#) $Revision: 4.14 $ $Source: /judy/src/apps/benchmark/timeit.h $
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// Timing and timers header file with example program.
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// You should compile with one of these defined:
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// JU_HPUX_PA # control register available (via asm()).
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// JU_HPUX_IPF # TBD, see below.
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// JU_LINUX_IA32 # control register available (via get_cycles()).
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// JU_LINUX_IPF # control register available (via get_cycles()).
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// JU_WIN_IA32 # uses clock().
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// Otherwise default (low-res) timing code using gettimeofday() results. This
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// mode is only accurate to usecs, and fuzzy due to syscall overhead.
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// Public macros; the *_HRTm() forms are much faster than the others:
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// TIMER_vars(T) - declare variables to use for timers
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// STARTTm(T) - start the timer with variable T
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// ENDTm(D,T) - compute usec from last STARTTm(T), save result in double D
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// START_HRTm(T) - high-res for short intervals (< 2^32[64] clock ticks) only
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// END_HRTm(D,T) - high-res for short intervals (< 2^32[64] clock ticks) only
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// __START_HRTm(T) - read high-res control register, save in T
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// __END_HRTm(T) - read high-res control register, save in T
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// __HRONLY(D,T) - use high-res clock only
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// Note: The __*_HRTm and __HRONLY macros are only available on platforms with
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// control registers for high-res clocks. On hpux_pa this is a 32-bit register
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// and gettimeofday() must be used to handle rollover; on linux_* this is a
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#include <sys/time.h> // Win32 uses a whole different paradigm.
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#include <unistd.h> // for getopt(), which Win32 lacks.
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extern double USecPerClock; // defined in timeit.c.
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// __HRONLY is used for multiple platforms, but only in cases where there is a
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// high-res clock and find_CPU_speed() is available from timeit.c:
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#define __HRONLY(D,T) \
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if (USecPerClock == 0.0) USecPerClock = find_CPU_speed(); \
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(D) = ((double) (__stop_##T - __start_##T)) * USecPerClock; \
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// ********************* HPUX PA ****************************
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// Define __START_HRTm and __END_HRTm only, and let later common code add
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// TBD: On hpux_pa or hpux_ipf 64-bit, is CR_IT a 64-bit register? If so, it's
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// unnecessary and wasteful to use gettimeofday() later to watch for rollover.
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// TBD: JU_HPUX_IPF does not recognize CR_IT ("Undeclared variable 'CR_IT'"),
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// so for now treat that platform as having no high-res clock and do not
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// included it in this section.
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#include <machine/reg.h>
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#include <sys/pstat.h>
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double find_CPU_speed(void);
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// Note: On hpux_*, at least older compilers, it is neither necessary nor even
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// allowed to mark the __start_* and __stop_* variables as volatile; the
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// compiler does not optimize out the code even without it:
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#define TIMER_vars(T) \
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register unsigned long __start_##T, __stop_##T; \
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struct timeval __TVBeg_##T, __TVEnd_##T
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#define __START_HRTm(T) _asm("MFCTL", CR_IT, __start_##T)
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#define __END_HRTm(T) _asm("MFCTL", CR_IT, __stop_##T )
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#endif // (JU_HPUX_PA)
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// ********************* LINUX IA32 **************************
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double find_CPU_speed(void);
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#define TIMER_vars(T) \
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register unsigned long __start_##T, __stop_##T; \
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struct timeval __TVBeg_##T, __TVEnd_##T
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#define __START_HRTm(T) rdtscl(__start_##T)
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#define __END_HRTm(T) rdtscl(__stop_##T)
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#endif // JU_LINUX_IA32
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// ********************* LINUX_IPF **************************
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// Define __START_HRTm and __END_HRTm, and also STARTTm and ENDTm in terms of
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// the former (no need for gettimeofday()).
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#include <asm/timex.h>
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double find_CPU_speed(void);
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// Using cycles_t rather than unsigned long [long] should be more portable;
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// and, it appears necessary to mark __start_* and __end_* as volatile so the
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// gcc compiler does not optimize out the register access:
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#define TIMER_vars(T) \
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register volatile cycles_t __start_##T, __stop_##T; \
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struct timeval __TVBeg_##T, __TVEnd_##T
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// This seems required for linux_ia32:
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// Older code (see 4.13) used rdtscl(), but this is not portable and does not
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// result in a 64-bit value, unlike get_cycles(), which apparently takes
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// advantage of a 64-bit control register on both IA32 and IPF => always
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// high-res timing with no rollover issues. Note, cycles_t is unsigned, so the
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// math works even in case of a rollover.
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#define __START_HRTm(T) __start_##T = get_cycles()
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#define __END_HRTm(T) __stop_##T = get_cycles()
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#define STARTTm(T) __START_HRTm(T)
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#define ENDTm(D,T) { __END_HRTm(T); __HRONLY(D,T); }
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#endif // JU_LINUX_IPF
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// ********************* WIN IA32 *****************************
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// WIN IA32 has no way to access the control register (?), so define STARTTm
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// and ENDTm directly using clock():
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#define TIMER_vars(T) struct timeval __TVBeg_##T, __TVEnd_##T
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#define STARTTm(T) __TVBeg_##T = clock()
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#define ENDTm(D,T) { __TVEnd_##T = clock(); \
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(D) = ((double) (__TVEnd_##T - __TVBeg_##T)); }
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#endif // JU_WIN_IA32
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// ********************* OTHER *****************************
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// Default to using the low-res, slow-access clock only.
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#define TIMER_vars(T) struct timeval __TVBeg_##T, __TVEnd_##T
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#define STARTTm(T) gettimeofday(&__TVBeg_##T, NULL)
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#define ENDTm(D,T) gettimeofday(&__TVEnd_##T, NULL); \
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(D) = (((double) __TVEnd_##T.tv_sec * ((double) 1E6)) \
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+ (double) __TVEnd_##T.tv_usec) \
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- (((double) __TVBeg_##T.tv_sec * ((double) 1E6)) \
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+ (double) __TVBeg_##T.tv_usec)
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#endif // ! TIMER_vars
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// COMMON CODE FOR SYSTEMS WITH HIGH-RES CLOCKS (CONTROL REGISTERS):
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// Platforms that define __START_HRTm but not STARTTm (presently only hpux_pa)
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// use gettimeofday() for the low-res clock and __START_HRTm/__END_HRTm for
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// the high-res clock. If the low-res clock did not "roll over", use the
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// high-res clock; see __HRONLY.
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// Note: Rollover is defined conservatively as 1E5 usec (= 1/10 sec). This
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// would require a 40 GHz 32-bit system to be violated.
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gettimeofday(&__TVBeg_##T, NULL); __START_HRTm(T); \
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__END_HRTm(T); gettimeofday(&__TVEnd_##T, NULL); \
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(D) = (((double) __TVEnd_##T.tv_sec * ((double) 1E6)) \
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+ (double) __TVEnd_##T.tv_usec) \
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- (((double) __TVBeg_##T.tv_sec * ((double) 1E6)) \
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+ (double) __TVBeg_##T.tv_usec); \
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if ((D) < 1E5) __HRONLY(D,T); \
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// Faster forms for heavy/frequent use in code loops where intervals are less
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// than 2^32[64] clock ticks:
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#define START_HRTm(T) __START_HRTm(T)
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#define END_HRTm(D,T) { __END_HRTm(T); __HRONLY(D,T); }
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#endif // __START_HRTm
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#endif // #ifndef _TIMEIT_H
added
removed
test/manual/timeit.h
