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Amberelle Mason ac30ff9032 Initial import
Initial import of SunOS 4.1.1 and TME 0.8
2023-05-01 12:16:40 -04:00

131 lines
4.9 KiB
C

/* $Id: runlength.c,v 1.1 2010/02/07 14:07:25 fredette Exp $ */
/* libtme/runlength.c - run length: */
/*
* Copyright (c) 2010 Matt Fredette
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Matt Fredette.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <tme/common.h>
_TME_RCSID("$Id: runlength.c,v 1.1 2010/02/07 14:07:25 fredette Exp $");
/* includes: */
#include <tme/runlength.h>
#include <tme/misc.h>
/* this initializes runlength state: */
void
tme_runlength_init(struct tme_runlength *runlength)
{
unsigned long runlength_history_count;
tme_runlength_t runlength_value;
/* allocate the runlength history: */
runlength_history_count = runlength->tme_runlength_history_count;
assert (runlength_history_count > 0);
runlength->_tme_runlength_history = tme_new(tme_runlength_t, runlength_history_count);
/* set the initial runlength history sum: */
runlength_value = runlength->tme_runlength_value;
runlength->_tme_runlength_history_sum
= (((double) runlength_value)
* runlength->tme_runlength_history_count);
/* initialize the runlength history: */
do {
runlength->_tme_runlength_history[runlength_history_count - 1] = runlength_value;
} while (--runlength_history_count);
runlength->_tme_runlength_history_next = 0;
}
/* this sets the runlength cycles target: */
void
tme_runlength_target_cycles(struct tme_runlength *runlength,
union tme_value64 cycles_elapsed_target_value64)
{
double two_to_the_thirtysecond;
/* make 2^32: */
two_to_the_thirtysecond = 65536 * (double) 65536;
/* set the target number of cycles to elapse during a run: */
runlength->_tme_runlength_cycles_elapsed_target
= ((cycles_elapsed_target_value64.tme_value64_uint32_hi
* two_to_the_thirtysecond)
+ cycles_elapsed_target_value64.tme_value64_uint32_lo);
}
/* this updates the runlength: */
void
tme_runlength_update(struct tme_runlength *runlength)
{
double two_to_the_thirtysecond;
union tme_value64 cycles_elapsed;
tme_runlength_t runlength_value;
unsigned long runlength_history_next;
double runlength_history_sum;
/* make 2^32: */
two_to_the_thirtysecond = 65536 * (double) 65536;
/* get the number of cycles that elapsed during this run: */
cycles_elapsed = tme_misc_cycles();
(void) tme_value64_sub(&cycles_elapsed, &runlength->tme_runlength_cycles_start);
/* get a better length for this run: */
runlength_value
= (runlength->tme_runlength_value
* (runlength->_tme_runlength_cycles_elapsed_target
/ ((cycles_elapsed.tme_value64_uint32_hi
* two_to_the_thirtysecond)
+ cycles_elapsed.tme_value64_uint32_lo)));
if (__tme_predict_false(runlength_value == 0)) {
runlength_value += 1;
}
/* update the runlength history and sum: */
runlength_history_next = runlength->_tme_runlength_history_next;
runlength_history_sum
= ((runlength->_tme_runlength_history_sum
- runlength->_tme_runlength_history[runlength_history_next])
+ runlength_value);
runlength->_tme_runlength_history[runlength_history_next] = runlength_value;
runlength->_tme_runlength_history_sum = runlength_history_sum;
if (runlength_history_next == 0) {
runlength_history_next = runlength->tme_runlength_history_count;
}
runlength->_tme_runlength_history_next = runlength_history_next - 1;
/* update the runlength value: */
runlength->tme_runlength_value
= (runlength_history_sum
/ runlength->tme_runlength_history_count);
}