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Star Forth Test Suite

Current version: 1.0

Version	Pass/Fail	Test	Expected Results
1.0 260313	PASS	signed > `-3 0 > .`	`0`
1.0 260313	PASS	: ; `: TEST 42 . ;`	`42`
1.0 260313	PASS	IF/THEN `: SIGN DUP 0 > IF 43 EMIT THEN . ;` `5 SIGN` `-3 SIGN` 0 SIGN	`+5` `-3` `0`
1.0 260313	PASS	DO/LOOP/I `: TENS 10 0 DO I . LOOP ;` `TENS`	`0 1 2 3 4 5 6 7 8 9`
1.0 260313	PASS	BEGIN/UNTIL `: COUNT3 3 BEGIN DUP . 1 - DUP 0 = UNTIL DROP ;` `COUNT3`	`3 2 1`
1.0 260313	PASS	BEGIN/WHILE `: COUNTDOWN BEGIN DUP WHILE DUP . 1 - REPEAT DROP ;` `5 COUNTDOWN` `0 COUNTDOWN`	`5 4 3 2 1` `0`
1.0 260313	PASS	`HERE .`	`$030800`
1.0 260313	PASS	`HEX $030800 @ .`	`0`
1.0 260313	PASS	`$030800 C@ .`	`0`
1.0 260313	PASS	`42 HERE ! HERE @ .`	`42`
1.0 260313	PASS	`: GREET .“ Hello, World!” CR ;` `GREET`	`Hello, world!`
1.0 260313	PASS	`: FIZZBUZZ 21 1 DO I 15 MOD 0 = IF .“ FizzBuzz” ELSE I 3 MOD 0 = IF .“ Fizz” ELSE I 5 MOD 0 = IF .“ Buzz” ELSE I . THEN THEN THEN CR LOOP ;`	not shown (but it works)
1.0 260313	PASS	`: SIMPLE 500000 0 DO LOOP ;` `SIMPLE`	~6 seconds (170,000 w/s) at 4MHz
1.0 260313	PASS	`: BENCH 500000 0 DO I DUP * DROP LOOP ;` `BENCH`	22 seconds (140,000 w/s) at 4Mhz

Benchmarking

The SIMPLE and BENCH tests indicate SD/FORTH is:

75x faster than BASIC (1,800 lines/sec) × ~5 ops/line ≈ 9,000 ops/sec)
5x to 7x faster than a real C64 running DurexForth (~25,000 words/sec)
Comparable to a 4 MHz Z80 running Forth850 or an 8MHz Z80B running CamelForth.

However, this is an upper end. The following MUL and DIV heavy benchmarks operate a bit slower. Here's a summary of the followinf programs:

Benchmark	Words/Sec.	Notes
Bare Loop	170,000	Only dispatch overhead
DUP * DROP	136,000	Multiply, Stack Ops
FizzBench	97,000	3x MOD, branches
Mixed +-*/	90,000	Division, Heavy Stack
Mixed no DIV	100,000	Same as above minus the DIV
Mixed ADD only	120,000	Same as above but no MUL too.

The estimate is that 70% overhead is dispatch; the system wants to run at over 150,000 words/sec, but gets constrained down to 90-100k words/sec on MUL and DIV heavy code. This is not unusual, and is infact a great sign; this is a very fast FORTH all things considered.

FIZZBENCH

    : FIZZBENCH 0 10000 0
        DO I 15 MOD 0 = IF 1 + ELSE
            I 3 MOD 0 = IF 1 + ELSE
                I 5 MOD 0 = IF 1 + THEN
                THEN
            THEN 
        LOOP
    ;
    : FB10 10 0 DO FIZZBENCH LOOP . ." hits" CR ;
    FB10

This executes in 18.5 seconds, indicating 97,000 words/sec.

BENCH-ARITH

    : ARITH ( n -- n )
      DUP 42 +
      DUP 7 -
      DUP 3 *
      DUP 2 /
      DROP DROP DROP DROP ;

    : BENCH-ARITH ( -- )
      ." Arithmetic benchmark" CR
      100000 0 DO
        I ARITH DROP
      LOOP
      ." Done" CR ;

    BENCH-ARITH

Same without DIV:

    : ARITH3 ( n -- n )
      DUP 42 +
      DUP 7 -
      DUP 3 *
      DROP DROP DROP ;

    : BENCH3 ( -- )
      ." Add/Sub/Mul benchmark" CR
      100000 0 DO
        I ARITH3 DROP
      LOOP
      ." Done" CR ;

    BENCH3

Appledog

Table of Contents

Star Forth Test Suite

Benchmarking

FIZZBENCH

BENCH-ARITH