123 lines
2.4 KiB
C
123 lines
2.4 KiB
C
/* BYTE magazine October 1982. Jerry Pournelle. */
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/* ported to C by David Lee */
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/* various bugs not found because dimensions are square fixed by David Lee */
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/* expected result: 4.65880E+05 */
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/* normal version runs in 13 seconds on the original PC and 8.9 seconds with the "f/fast" versions */
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#define LINT_ARGS
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#include <stdio.h>
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#define l 20 /* rows in A and resulting matrix C */
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#define m 20 /* columns in A and rows in B (must be identical) */
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#define n 20 /* columns in B and resulting matrix C */
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#define ftype float
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ftype Summ;
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ftype A[ l ] [ m ];
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ftype B[ m ] [ n ];
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ftype C[ l ] [ n ];
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void filla()
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{
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register int i, j;
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for ( i = 0; i < l; i++ )
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for ( j = 0; j < m; j++ )
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A[ i ][ j ] = i + j + 2;
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}
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void fillb()
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{
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register int i, j;
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for ( i = 0; i < m; i++ )
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for ( j = 0; j < n; j++ )
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B[ i ][ j ] = (ftype) ( ( i + j + 2 ) / ( j + 1 ) );
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}
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void fillc()
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{
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register int i, j;
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for ( i = 0; i < l; i++ )
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for ( j = 0; j < n; j++ )
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C[ i ][ j ] = 0;
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}
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void ffillc()
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{
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ftype * p = (ftype *) C;
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ftype * pend = ( (ftype *) C ) + ( l * n );
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while ( p < pend )
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*p++ = 0;
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}
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void matmult()
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{
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register int i, j, k;
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for ( i = 0; i < l; i++ )
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for ( j = 0; j < n; j++ )
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for ( k = 0; k < m; k++ )
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C[ i ][ j ] += A[ i ][ k ] * B[ k ][ j ];
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}
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void fmatmult()
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{
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static int i, j, k;
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static ftype * pC, * pA, * pAI, * pBJ, *pCI;
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for ( i = 0; i < l; i++ )
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{
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pAI = (ftype *) & ( A[ i ][ 0 ] );
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pCI = (ftype *) & ( C[ i ][ 0 ] );
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for ( j = 0; j < n; j++ )
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{
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pC = (ftype *) & pCI[ j ];
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pA = pAI;
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pBJ = & ( B[ 0 ][ j ] );
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for ( k = 0; k < m; k++ )
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{
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*pC += pA[ k ] * ( *pBJ );
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pBJ += m;
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}
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}
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}
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}
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void summit()
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{
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register int i, j;
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for ( i = 0; i < l; i++ )
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for ( j = 0; j < n; j++ )
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Summ += C[ i ][ j ];
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}
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void fsummit()
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{
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ftype * p = (ftype *) C;
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ftype * pend = ( (ftype *) C ) + ( l * n );
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while ( p < pend )
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Summ += *p++;
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}
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int main( argc, argv ) int argc; char * argv[];
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{
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Summ = 0;
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filla();
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fillb();
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ffillc();
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fmatmult();
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fsummit();
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printf( "summ is : %f\n", Summ );
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return 0;
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}
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