79 lines
1.6 KiB
C
79 lines
1.6 KiB
C
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#include <stdlib.h>
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#include <stdio.h>
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#include "sar.h"
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/*extern int _asm_krecipasm (int);*/
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int reciptable[2048], fpuasm;
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void init (void)
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{
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int i;
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for(i=0;i<2048;i++) reciptable[i] = i;/* divscale30(2048L,i+2048);*/
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}
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static int krecipasm(int i1)
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{
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int retval;
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__asm__ __volatile__ ("
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call _asm_krecipasm
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" : "=a" (retval) : "a" (i1)
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: "cc", "ebx", "ecx", "memory");
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return(retval);
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} // krecipasm
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static int ansi_c_krecip (int x)
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{
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float xf;
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int z;
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int not;
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if (x & 0x80000000) /* If the highest bit is set... */
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not = 0x0FFFFFFFF;
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else
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not = 0;
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xf = (float)x;/* convert the int to a float */
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/* Pretend the float is an int so we can extract bits */
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x = *((int*)(&xf));
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z = x;
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x = x & 0x007FF000;/* Mask out: 11 << 13 */
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x = x >> 10; /* Divide x by 1024 */
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/* X now contains: 13 high order bits of the mantissa, followed by two 0 bits */
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/* Now we perform an elaborate extraction
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of the exponent from the floating point
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numer? WTF is the subtraction for? */
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z = z - 0x03F800000;/* Subtract (127<<23) */
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z = z >> 23;
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/* z now contains the exponent divided by two? */
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x = shift_algebraic_right(reciptable[(x>>2)], z) ^ not;
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return x;
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}
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static int mykrecipasm(int i1)
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{
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int retval;
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retval = ansi_c_krecip(i1);
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return retval;
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}
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int main (int argc, char** argv)
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{
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int u;
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init();
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printf("sizeof(long) = %u, sizeof(int) = %u\n",
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sizeof(long int), sizeof(int));
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u = 0;
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while(scanf("%d", &u) >= 1){
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printf("Original: %d \tMine: %d\n",
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krecipasm(u),mykrecipasm(u));
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u = 0;
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}
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return 0;
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}
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