ClockCycleCounter.cpp Example File

multimedia/spectrum/3rdparty/fftreal/stopwatch/ClockCycleCounter.cpp
/***************************************************************************** ClockCycleCounter.cpp Copyright (c) 2003 Laurent de Soras --- Legal stuff --- This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA *Tab=3***********************************************************************/
#if defined (_MSC_VER) #pragma warning (1 : 4130) // "'operator' : logical operation on address of string constant" #pragma warning (1 : 4223) // "nonstandard extension used : non-lvalue array converted to pointer" #pragma warning (1 : 4705) // "statement has no effect" #pragma warning (1 : 4706) // "assignment within conditional expression" #pragma warning (4 : 4786) // "identifier was truncated to '255' characters in the debug information" #pragma warning (4 : 4800) // "forcing value to bool 'true' or 'false' (performance warning)" #pragma warning (4 : 4355) // "'this' : used in base member initializer list" #endif /*\\\ INCLUDE FILES \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*/ #include "ClockCycleCounter.h" #include <cassert> namespace stopwatch { /*\\\ PUBLIC \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*/ /* ============================================================================== Name: ctor Description: The first object constructed initialise global data. This first construction may be a bit slow. Throws: Nothing ============================================================================== */ ClockCycleCounter::ClockCycleCounter () : _start_time (0) , _state (0) , _best_score (-1) { if (! _init_flag) { // Should be executed in this order compute_clk_mul (); compute_measure_time_total (); compute_measure_time_lap (); // Restores object state _start_time = 0; _state = 0; _best_score = -1; _init_flag = true; } } /* ============================================================================== Name: get_time_total Description: Gives the time elapsed between the latest stop_lap() and start() calls. Returns: The duration, in clock cycles. Throws: Nothing ============================================================================== */ Int64 ClockCycleCounter::get_time_total () const { const Int64 duration = _state - _start_time; assert (duration >= 0); const Int64 t = max ( duration - _measure_time_total, static_cast <Int64> (0) ); return (t * _clk_mul); } /* ============================================================================== Name: get_time_best_lap Description: Gives the smallest time between two consecutive stop_lap() or between the stop_lap() and start(). The value is reset by a call to start(). Call this function only after a stop_lap(). The time is amputed from the duration of the stop_lap() call itself. Returns: The smallest duration, in clock cycles. Throws: Nothing ============================================================================== */ Int64 ClockCycleCounter::get_time_best_lap () const { assert (_best_score >= 0); const Int64 t1 = max ( _best_score - _measure_time_lap, static_cast <Int64> (0) ); const Int64 t = min (t1, get_time_total ()); return (t * _clk_mul); } /*\\\ PROTECTED \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*/ /*\\\ PRIVATE \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*/ #if defined (__MACOS__) static inline double stopwatch_ClockCycleCounter_get_time_s () { const Nanoseconds ns = AbsoluteToNanoseconds (UpTime ()); return (ns.hi * 4294967296e-9 + ns.lo * 1e-9); } #endif // __MACOS__ /* ============================================================================== Name: compute_clk_mul Description: This function, only for PowerPC/MacOS computers, computes the multiplier required to deduce clock cycles from the internal counter. Throws: Nothing ============================================================================== */ void ClockCycleCounter::compute_clk_mul () { assert (! _init_flag); #if defined (__MACOS__) long clk_speed_mhz = CurrentProcessorSpeed (); const Int64 clk_speed = static_cast <Int64> (clk_speed_mhz) * (1000L*1000L); const double start_time_s = stopwatch_ClockCycleCounter_get_time_s (); start (); const double duration = 0.01; // Seconds while (stopwatch_ClockCycleCounter_get_time_s () - start_time_s < duration) { continue; } const double stop_time_s = stopwatch_ClockCycleCounter_get_time_s (); stop (); const double diff_time_s = stop_time_s - start_time_s; const double nbr_cycles = diff_time_s * static_cast <double> (clk_speed); const Int64 diff_time_c = _state - _start_time; const double clk_mul = nbr_cycles / static_cast <double> (diff_time_c); _clk_mul = round_int (clk_mul); #endif // __MACOS__ } void ClockCycleCounter::compute_measure_time_total () { start (); spend_time (); Int64 best_result = 0x7FFFFFFFL; // Should be enough long nbr_tests = 100; for (long cnt = 0; cnt < nbr_tests; ++cnt) { start (); stop_lap (); const Int64 duration = _state - _start_time; best_result = min (best_result, duration); } _measure_time_total = best_result; } /* ============================================================================== Name: compute_measure_time_lap Description: Computes the duration of one stop_lap() call and store it. It will be used later to get the real duration of the measured operation (by substracting the measurement duration). Throws: Nothing ============================================================================== */ void ClockCycleCounter::compute_measure_time_lap () { start (); spend_time (); long nbr_tests = 10; for (long cnt = 0; cnt < nbr_tests; ++cnt) { stop_lap (); stop_lap (); stop_lap (); stop_lap (); } _measure_time_lap = _best_score; } void ClockCycleCounter::spend_time () { const Int64 nbr_clocks = 500; // Number of clock cycles to spend const Int64 start = read_clock_counter (); Int64 current; do { current = read_clock_counter (); } while ((current - start) * _clk_mul < nbr_clocks); } Int64 ClockCycleCounter::_measure_time_total = 0; Int64 ClockCycleCounter::_measure_time_lap = 0; int ClockCycleCounter::_clk_mul = 1; bool ClockCycleCounter::_init_flag = false; } // namespace stopwatch /*\\\ EOF \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*/

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