91 lines
3.9 KiB
C
Executable File
91 lines
3.9 KiB
C
Executable File
/* MDH WCET BENCHMARK SUITE. */
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/* 2012/09/28, Jan Gustafsson <jan.gustafsson@mdh.se>
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* Changes:
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* - This program redefines the C standard function sqrt. Therefore, this function has been renamed to sqrtfcn.
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* - qrt.c:79:15: warning: explicitly assigning a variable of type 'float' to itself: fixed
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*/
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/*************************************************************************/
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/* */
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/* SNU-RT Benchmark Suite for Worst Case Timing Analysis */
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/* ===================================================== */
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/* Collected and Modified by S.-S. Lim */
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/* sslim@archi.snu.ac.kr */
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/* Real-Time Research Group */
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/* Seoul National University */
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/* */
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/* */
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/* < Features > - restrictions for our experimental environment */
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/* */
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/* 1. Completely structured. */
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/* - There are no unconditional jumps. */
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/* - There are no exit from loop bodies. */
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/* (There are no 'break' or 'return' in loop bodies) */
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/* 2. No 'switch' statements. */
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/* 3. No 'do..while' statements. */
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/* 4. Expressions are restricted. */
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/* - There are no multiple expressions joined by 'or', */
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/* 'and' operations. */
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/* 5. No library calls. */
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/* - All the functions needed are implemented in the */
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/* source file. */
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/* */
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/* */
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/*************************************************************************/
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/* */
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/* FILE: sqrt.c */
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/* SOURCE : Public Domain Code */
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/* */
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/* DESCRIPTION : */
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/* */
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/* Square root function implemented by Taylor series. */
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/* */
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/* REMARK : */
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/* */
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/* EXECUTION TIME : */
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/* */
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/* */
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/*************************************************************************/
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float fabs(float x)
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{
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if (x < 0)
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return -x;
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else
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return x;
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}
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float sqrtfcn(float val)
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{
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float x = val/10;
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float dx;
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double diff;
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double min_tol = 0.00001;
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int i, flag;
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flag = 0;
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if (val == 0 )
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x = 0;
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else {
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for (i=1;i<20;i++)
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{
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if (!flag) {
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dx = (val - (x*x)) / (2.0 * x);
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x = x + dx;
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diff = val - (x*x);
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if (fabs(diff) <= min_tol)
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flag = 1;
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}
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else {} /* JG */
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/* x =x; */
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}
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}
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return (x);
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}
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