MSX Programming Languages Showdown

Interesting, but some more test cases would be useful.

About the shortened loops: you could use accurate emulators and just emulate at full speed to get the actual numbers (If you don't trust the emulator, first do a comparison run of course.)

How about a comparison with R800 mode as well? (Although I guess that none of the compilers can generate R800 optimized code, if applicable at all for the test case.)

My Pascal is a bit rusty but if I'm correct the test ported to C should be this

#include 
#include 

void main (void) {
	unsigned int i,j,s;
	s = 0;
	for (i=0;i<10000;i++)
	  for(j=0;j<100;j++)
	    s++;
	printf("%d",s);
}

The COM compiled with the Hitech C cross compiler (v 7.8p2) has an execution time of 6 secs on plain msx1.This is the corresponding ASM

	global	small_model
;stdlib.h: 122: extern int atexit(void (*)(void));
;stdlib.h: 126: extern void qsort(void *, size_t, size_t, int (*)(const void *, const void *));
;stdlib.h: 127: extern void * bsearch(const void *, void *, size_t, size_t, int(*)(const void *, const void *));
	global	_main
	signat	_main,24
	psect	text,class=CODE
	global	_printf
	signat	_printf,26
	file	"C:\HT-Z80\BIN\TEST.C"
	line	4
_main:
	push	ix
	ld	ix,0
	add	ix,sp
	push	bc
	push	iy
;TEST.C: 5: unsigned int i,j,s;
; _s allocated to bc
	line	6
	ld	bc,0
;TEST.C: 7: for (i=0;i<10000;i++)
	line	7
	ld	(ix+-2),c
	ld	(ix+-1),c
	line	8
l8:
;TEST.C: 8: for(j=0;j<100;j++)
; _j allocated to iy
	ld	iy,0
	line	9
l11:
;TEST.C: 9: s++;
	inc	bc
	line	8
	inc	iy
	ld	de,064h
	push	iy
	pop	hl
	or	a
	sbc	hl,de
	jp	c,l11
	line	7
	inc	(ix+-2)
	jp	nz,u11
	inc	(ix+-1)
u11:
	ld	de,02710h
	ld	l,(ix+-2)
	ld	h,(ix+-1)
	or	a
	sbc	hl,de
	jp	c,l8
;TEST.C: 10: printf("%d",s);
	line	10
	push	bc
	ld	hl,u19
	push	hl
	call	_printf
	pop	bc
	pop	bc
;TEST.C: 11: }
	line	11
	pop	iy
	ld	sp,ix
	pop	ix
	ret	
	psect	strings,class=CODE
u19:
	defb	37,100,0
	psect		text
	end

ops! I did a mistake in computing the times.
The COM from the Hitech Crosscompiler needs 32 secs on plain z80, not 6 secs

I'm happy to see the topic sparked some discussion And the test case, indeed, is a trivial one, but at least it tells a thing or two. Loops are so fundamental that if they are slow, probably everything else is, too. Need to try the Hisoft cross-compiler when I get the chance. SDCC isn't that bad after all: if you look at the code it seems to do silly things at times, but the overhead isn't that heavy compared to many other compilers tested here. There's a lot of good top-level optimization going on even if the Z80 code generator is quite lame.

Well, I didn't mean this experiment as any conclusive test – just a fun one-afternoon test run of different compilers. At least it made me quite happy about my choice of SDCC+inline Was considering z88dk at some point, but according to this it's a no go. In real applications the differences would, of course, be smaller especially if they're I/O bound.