🚀 go-pugleaf

I think I must have been asleep when I ran my earlier floating point 
benchmarks, because I took a more careful look at it and it turns out I
wrote my numbers down backwards.  Here are the correct numbers for 
primitive arithmetic operations.  These are in 200-hz clock tick units 
for 1000 repetitions of the operation, with no attempt made to account 
the overhead of the loop.  There was no significant difference between
IEEE single and double precision here.

           IEEE        FFP
    +       15          13
    -       15          23
    *       22          20
    /       58          19


Ali Ozer <ali@rocky.stanford.edu> recently sent me a floating point
benchmark program called the "Savage" benchmark, which primarily tests
the double-precision floating point math library.  I've tacked on his
original message to the end.  Here's my C version:

main ()
{   int i, iloop;
    double a;
    long start, end;

    start = gettime ();    
    a = 1.0;
    iloop = 2499;
    for (i=0; i<iloop; i++)
        a = tan(atan(exp(log(sqrt(a*a))))) + 1.0;
    end = gettime ();
    printf ("%e\n", (float)(a-2500.0));		/* error term */
    printf ("%ld\n", (long)(end - start));      /* elapsed time */
    }

And the results for Alcyon C V4.14:

IEEE (libm):  1.763e-7, 72.6 seconds
FFP  (libf):  2.269e+2, 7.4 seconds

So the FFP library is much faster, but loses on accuracy as it is only
single precision.

-Sandra (sandra@cs.utah.edu)

-----------------------------------

***************************************************************
*                     Savage Benchmark Results                *
*                           16 DEC 1986                       *
* Al Aburto/Lew Wolfgang/Larry Phillips/John Gilmore/Ali Ozer *
* Glenn Miller/Mike Howard/And Others........................ *
***************************************************************
123456789012345678901234567890123456789012345678901234567890123456789012345
System         CPU / FPP    CLOCK        LANGUAGE          TIME     ERROR 
		   	    (MHz)                           (Sec)  Abs(a-2500)
Turbo-Amiga  (68020/68881)  14.32   Absoft F77 V2.2B         0.39   2.7 E-12
Sun-3/160    (68020/68881)  16.67   Sun 3.0 F77              0.4    2.0 E-12
Turbo-Amiga  (68020/68881)  14.32   Lattice C/68881 Assem    0.46   9.2 E-13
HP 9000/320  (68020/68881)          Fortran 77               0.7    3.2 E-09
HP 9000/320  (68020/68881)          Pascal                   0.7    2.8 E-07
Amiga        (68020/68881)   7.16   Absoft F77 V2.2B         0.78   2.0 E-12
VAX-8600                            Fortran 77               0.9    1.8 E-08
Amiga        (68020/68881)   7.16   Lattice C/68881 Assem    0.92   5.9 E-12
HP 9000/320  (68020/68881)          C                        1.0    2.5 E-08
DEC 2060                                                     1.6    2.0 E-12
VAX-11/750                          Fortran 77               1.9    6.6 E-10
Masscomp     (68010/  FPP)                                   2.1    3.2 E-07
VAX-11/780                          UNIX 4.3BSD F77-O        2.7    1.8 E-12
Turbo-Amiga  (68020/68881)  14.32   MetaComCo ABasiC V1.0    3.2    2.3 E+01
DMS          ( 8086/ 8087)          Turbo Pascal             3.8    1.1 E-09
Zenith Z-248 (80286/80287)   8.00   MS Fortran77 V3.20       4.5    1.2 E-09
IBM PC-AT    (80286/80287)   6.00   ProFor F77               4.9    8.7 E-11
IBM PC-AT    (80286/80287)   6.00   MS Fortran77             7.2    1.2 E-09
IBM PC-AT    (80286/80287)   6.00   Turbo Pascal             7.4    1.2 E-09
IBM PC       ( 8088/ 8087)   4.77   Microsoft C              8.0    1.2 E-09
Amiga        (68020/68881)   7.16   Metacomco ABasiC V1.0    8.6    2.3 E+01
Turbo-Amiga  (68020/-----)  14.32   Metacomco ABasiC V1.0   13.3    2.7 E+02
Turbo-Amiga  (68020/-----)  14.32   ABasiC V1.0(Cache Off)  14.7    2.7 E+02
Sun-3/160    (68020/-----)  16.67   Sun 3.0 F77             21.5    3.1 E-07
Turbo-Amiga  (68020/-----)  14.32   Absoft F77 V2.2B        21.9    1.8 E-07
Amiga        (68020/-----)   7.16   Metacomco ABasiC V1.0   37.0    2.7 E+02
Amiga        (68000/-----)   7.16   Metacomco ABasiC V1.0   39.7    2.7 E+02
Amiga        (68020/-----)   7.16   ABasiC V1.0(Cache Off)  42.2    2.7 E+02
HP 9826      (68000/-----)   8.00   HP Basic V2.0           44.5    3.2 E-07
Turbo-Amiga  (68020/-----)  14.32   Lattice C V3.03         55.4    3.2 E-07
IBM PC-XT    ( 8088/ 8087)   4.77   Gauss                   58.0    1.2 E-09
Amiga        (68020/-----)   7.16   Absoft F77 V2.2B        59.7    1.8 E-07
HP Integral  (68000/-----)          Basic Interpreter       60.9    3.2 E-07
HP Integral  (68000/-----)          C                       63.0    3.2 E-07
Amiga        (68000/-----)   7.16   True Basic (Compiler)   65.2    3.0 E-03
Amiga        (68020/-----)   7.16   MS AmigaBASIC V1.0      67.0    3.2 E-07
Amiga        (68000/-----)   7.16   MS AmigaBASIC V1.0      73.0    3.2 E-07
Amiga        (68000/-----)   7.16   Absoft F77 V2.2B        77.2    1.8 E-07
HP Integral  (68000/-----)          Absoft F77             100.0    1.8 E-07
Amiga        (68020/-----)   7.16   Lattice C V3.03        139.0    3.2 E-07
Macintosh    (68000/-----)   7.83   MAC C                  221.0    (?)
Amiga        (68000/-----)   7.16   Lattice C V3.03        234.0    3.2 E-07
Macintosh    (68000/-----)   7.83   DeSmet C               244.0    (?)
Commodore 128( 8502/-----)   2.00   Basic Interpreter      256.0    9.0 E-04
Macintosh    (68000/-----)   7.83   Manx Aztec C           353.0    (?)
IBM PC-XT    ( 8088/-----)   4.77   BASICA                 895.0    3.0 E-08
Tandy PC-5                          Basic Interpreter      961.0    2.7 E-03
****************************************************************************
Notes:
	(1) The Savage Benchmark, by Bill Savage, first appeared in Dr. Dobb's
	    Journal, Sept 1983, page 120.
        (2) The Macintosh results are from Byte, The Small Systems Journal,
	    Aug 1986, page 254.  There appears to be a 'typo' in the
	    published accuracy results.  Exact result should be 2500.0  .
        (3) The Savage Benchmark requires use of IEEE double precision
	    to obtain a reasonably small error. The error is unacceptably 
	    large for IEEE single precision.  All the above results were
	    obtained with double precision except for the MetaComCo ABasiC
	    where double precision variables were used but the math functions
	    were calculated only to single precision.  As can be seen ABasiC
	    is fast but the error is too large for a meaningful result.



-----------------------------------

c Here is the Savage Benchmark Program:
c **************************************
c *           Fortran 77               *
c **************************************
	Program Savage
	implicit double precision (a-h,o-z)

	write(*,1000)

	a = 1.0
	iloop = 2499

	do 100 i=1,iloop
	 a = dtan(datan(dexp(dlog(dsqrt(a*a))))) + 1.0
 100     continue

       write(*,1010)
       write(*,1020) a
 1000  format(5x,'Start')
 1010  format(5x,'Stop ')
 1020  format(5x,'a = ',f22.15)
       stop
       end



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