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43,50337/21/fqc.qlp
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00100 FQC - MEASUREMENT AND TRACING SYSTEM FOR SIMULA PROGRAMS
00200 ========================================================
00300
00400 If a SIMULA program has been developed which will be used very often,
00500 e.g. as a part in a regularly used production system, it is often
00600 profitable to spend some efforts optimizing the program.
00700
00800 A central and sometimes non-trivial problem in program optimization
00900 is to find the innermost loops of the program. Once the execution
01000 profile of a program is known it is usually easy to make it faster
01100 with a few changes such as modifications in processing algorithms or
01200 by using a small machine language subroutine.
01300
01400 DEC-10 SIMULA is delivered with a frequency measurement system which
01500 assists in spotting frequently executed parts of a SIMULA program.
01600 The system consists of two SIMULA programs, FQCRED and FQCLST.
01700
01800 The system is used as follows:
01900
02000 The program to be analyzed must have been tested well enough to run
02100 to normal completion. It is read by the program FQCRED which
02200 produces two modified versions of it, one of which is a compilable
02300 SIMULA program (.FQ1+.FQ2) and the other a listing later used to
02400 produce the frequency listing (.FQD). The modified compilable
02500 program is executed (.FQR) and produces, if normally terminated, a
02600 file of measured frequencies (.FQS). This file is merged with the
02700 listing output from FQCRED by the program FQCLST, which produces the
02800 final output (.FQL).
02900
03000 The user may also measure the execution time for different parts of
03100 his program by editing calls to a procedure Z_T(I) into his program.
03200 A call with I > 0 initiates a timing which is ended by a call with
03300 the corresponding negative I. The logic is as follows:
03700 +100>=I>0 T0[I]:= cptime;
03800 -100<=I<0 J:=-I; ACC[J]:= ACC[J]+(cptime-T0[J]);
03900 Calls to Z_T may be overlapping (even partly).
04000
04100 For example:
04200
04300 BEGIN
04400 ....
04500 Z_T(+1);------------+
04600 .... |
04700 Z_T(+2);---------+ |
04800 .... | |
04900 Z_T(+3);------+ | |
05000 .... | | |
05100 Z_T(-2);------)--+ |
05200 .... | |
05300 Z_T(-3);------+ |
05400 .... |
05500 Z_T(-1);------------+
05600 ....
05700 END
05800
05900 The resulting CPU-times will be presented at the end of the result
06000 file (.FQL). For reliable results, do not try to measure too small
06100 intervalls (depending on the precision of the timing). Note that only
06200 such measurements that yielded accumulated times > 0 will be printed.
06400
06500 The measured program should satisfy some restrictions:
06600
06700 i) The program must not contain the identifiers Z_Q, Z_T or Z__.
06800
06900 ii) The program should not use any files on DSK: named
07000 <program name>.FQ1 .FQ2 .FQR .FQD .FQS .FQL or .FQT.
07100
07200 iii) The program should terminate through its last END.
07300 I.e. not through call to Exit or through SIMDDT.
07400
07500 iv) The source code lines should preferably not contain
07600 any internal TABs (leading TABs are OK). If so, the
07700 produced frequency indicators (|) might be misplaced
07800 (within such a line). TABs may be removed with
07900 .COPY temp.sim=prog.sim(W).
08000
08100 Note that the frequency indicators will be positioned at the first
08200 position of the symbol counted. Its related number should be
08300 interpreted as the number of times this symbol has been PASSED during
08400 the execution. An indicated label (L:) will thus tell how many times
08500 control passed the label from left, excluding explicit jumps (GO TO
08600 L).
08700
08800 By adding the switch /T to the filespecification requested by FQCRED
08900 a trace file (.FQT) will be produced, containing the number of each
09000 executed (counted) statement. This may be useful when debugging
09100 Simulation programs or programs making use of resume/detach. If the
09200 program terminates with an error the file with logical name TRACE
09300 must be closed before leaving SIMDDT.
09400
09600 The result file (.FQL) will contain information about the number of
09700 the first traced statement on each source line. Consequetive numbers
09800 will be indicated as xx-yy in .FQT. Note that the file is created in
09900 APPEND mode adding new traces to the end of the file. The trace file
10000 will contain the first six characters of the traced symbol followed
10100 by its statement number.
10300
10400 Adding a number to the trace switch (/T:x) will trace
10500 the executed statements the first x times. Every statement
10600 number will be displayed (no xx-yy compacting). X must be >= 0,
10700 /T:0 is equivalent to /T.
10800
10900 The use of tracing will considerably increase the execution
11000 time of the modified program. Thus it is not recommended to
11100 use timing (Z_T) together with tracing. The tracing may be
11200 switched off by calling the procedure TRACEOFF. It may be
11300 activated again by calling TRACEON.
11400
11500
11600 If you want to include any of your external modules in the
11700 analysis, run the program SIMEXP prior to FQCRED.
11800
11900
12000 The following session illustrates the use of the system on the
12100 SIMULA program FLOPY.SIM.
12200
12300
12400 .run pub:fqcred
12500
12600 Welcome to FQCRED Version 3
12700
12800 Program:flopy
12900
13000 [FQCRED: CPU time: 0.88]
13100 Running modified program: SIMULA: FLOPY
13200 LINK: Loading
13300 [LNKXCT FLOPY Execution]
13400
13500 If you want to have the result at once type .CONTINUE
13600 To accumulate the frequencies just type: START
13700
13800 .con
13900
14000 Welcome to FQCLST Version 3
14100
14200 Result on file: DSK: FLOPY.FQL - Type CON to see them at once.
14300
14400 .con
14500
14600 Max --------------------- FQC Result ---------------------
14700
14800 BEGIN COMMENT FREQUENCY MEASUREMENT EXAMPLE;
14900 INTEGER u,k; TEXT t;
15000 z_t(+1);
15100 1 |1
15200 WHILE Draw(0.999,u) DO u:= u+2;
15300 1636 |1 |1636
15400 z_t(-1);
15500 1 |1
15600 z_t(+2);
15700 1 |1
15800 FOR u:= 1 STEP 1 UNTIL 5000 DO
15900 1 |1
16000 IF t = NOTEXT THEN k:=k+1;
16100 5000 |5000 |5000
16200 z_t(-2);
16300 1 |1
16400 z_t(+3);
16500 1 |1
16600 FOR u:= 1 STEP 1 UNTIL 5000 DO
16700 1 |1
16800 IF t == NOTEXT THEN k:=k+1;
16900 5000 |5000 |5000
17000 z_t(-3);
17100 1 |1
17200 z_t(+4);
17300 1 |1
17400 FOR u:= 1 STEP 1 UNTIL 5000 DO
17500 1 |1
17600 IF TRUE THEN k:=k+1;
17700 5000 |5000 |5000
17800 z_t(-4);
17900 1 |1
18000 END;
18100 1 |1
18200
18300 FQC results:
18400 Max frequency: 5000
18500 Sum frequency: 31649
18600 No. of executions: 1
18700
18800 CPU timing: Total 0.50 sec.
18900
19000 Call no. Time spent % of runtime
19100 1 0.047 9.46
19200 2 0.248 49.90
19300 3 0.095 19.11
19400 4 0.089 17.91
19500
19600
19700 .DIRECT flopy
19800
19900 FLOPY SIM 1 <057> 8-Aug-78 User program
20000 FLOPY FQ1 4 <057> 8-Aug-78 Modif. file part 1
20100 FLOPY FQ2 3 <057> 8-Aug-78 Modif. file part 2
20200 FLOPY FQD 1 <057> 8-Aug-78 Edited file with bars (|)
20300 FLOPY FQR 11 <057> 8-Aug-78 REL-file from FQ1+FQ2
20400 FLOPY FQS 1 <057> 8-Aug-78 Frequency + timing data (binary)
20500 FLOPY FQL 3 <057> 8-Aug-78 Result file (FQS+FQD)
20600
20700
20800 Cleaning up afterwards might be done with .DELETE *.FQ?
20900
21000 [End of FQC.HLP 78-08-16 MO]