PROGRAM TEST4 * * -- LAPACK test routine (version 3.1) -- * Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. * November 2006 * * .. Parameters .. INTEGER NMAX, ITS PARAMETER ( NMAX = 100, ITS = 5000 ) * .. * .. Local Scalars .. INTEGER I, J REAL ALPHA, AVG, T1, T2, TNOSEC * .. * .. Local Arrays .. REAL X( NMAX ), Y( NMAX ) * .. * .. External Functions .. REAL SECOND EXTERNAL SECOND * .. * .. Intrinsic Functions .. INTRINSIC REAL * .. * .. Executable Statements .. * * * Initialize X and Y * DO 10 I = 1, NMAX X( I ) = REAL( 1 ) / REAL( I ) Y( I ) = REAL( NMAX-I ) / REAL( NMAX ) 10 CONTINUE ALPHA = 0.315 * * Time 1,000,000 SAXPY operations * T1 = SECOND( ) DO 30 J = 1, ITS DO 20 I = 1, NMAX Y( I ) = Y( I ) + ALPHA*X( I ) 20 CONTINUE ALPHA = -ALPHA 30 CONTINUE T2 = SECOND( ) WRITE( 6, 9999 )T2 - T1 IF( T2-T1.GT.0.0 ) THEN WRITE( 6, 9998 )1.0 / ( T2-T1 ) ELSE WRITE( 6, 9994 ) END IF TNOSEC = T2 - T1 * * Time 1,000,000 SAXPY operations with SECOND in the outer loop * T1 = SECOND( ) DO 50 J = 1, ITS DO 40 I = 1, NMAX Y( I ) = Y( I ) + ALPHA*X( I ) 40 CONTINUE ALPHA = -ALPHA T2 = SECOND( ) 50 CONTINUE * * Compute the time used in milliseconds used by an average call * to SECOND. * WRITE( 6, 9997 )T2 - T1 AVG = ( ( T2-T1 ) - TNOSEC ) * 1000./REAL( ITS ) WRITE( 6, 9996 )AVG * * Compute the equivalent number of floating point operations used * by an average call to SECOND. * IF( TNOSEC.GT.0.0 ) $ WRITE( 6, 9995 )1000.*AVG / TNOSEC * 9999 FORMAT( ' Time for 1,000,000 SAXPY ops = ', G10.3, ' seconds' ) 9998 FORMAT( ' SAXPY performance rate = ', G10.3, ' mflops ' ) 9997 FORMAT( ' Including SECOND, time = ', G10.3, ' seconds' ) 9996 FORMAT( ' Average time for SECOND = ', G10.3, $ ' milliseconds' ) 9995 FORMAT( ' Equivalent floating point ops = ', G10.3, ' ops' ) 9994 FORMAT( ' *** Error: Time for operations was zero' ) CALL MYSUB(NMAX,X,Y) END SUBROUTINE MYSUB(N,X,Y) INTEGER N REAL X(N), Y(N) RETURN END