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Date: Thu, 13 Apr 2000 13:01:04 +0200
From: Gautier <gautier DOT demontmollin AT maths DOT unine DOT ch>
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Subject: Re: inefficiency of GCC output code & -O problem
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To: djgpp AT delorie DOT com
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"Alexei A. Frounze":
> > Well... but _compared_ to other processors the choice of registers is very poor.

> The most awful problem is insufficiency of RAM and stack. Intel C51
> microcontroller has 8 (one-byte) registers. That's enough. But it has only 128
> bytes of RAM... :)

I see... I meant usage of registers by the optimiser, and there are never too many
- an excerpt of a project compiled by DEC Ada for an AXP server:

...
STILBurg                        Machine Code Listing
01                              SOLVE_LR            
430709B0     18A0		CMPLT		R24, R7, R16
47F80408     18A4		MOV		R24, R8
F6000071     18A8		BNE		R16, L$24
43070528     18AC		SUBQ		R24, R7, R8
41010648     18B0		S8ADDQ	R8, Y, R8		; R8, R1, R8
40403002     18B4		ADDL	I, 1, I			; R2, 1, R2
63FF0000     18B8		TRAPB
85400000     18BC		LDG	F10, (R0)
85680000     18C0		LDG	F11, (R8)
404709B0     18C4		CMPLT	I, R7, R16			; R2, R7, R16
...

_that_'s a good set of registers!

> Pascal is enough for me. I'll probably program in Delphi (visual version of
> object pascal for Win32) for the 1st time. Then I'll try C++ for the same tasks.

Beware of developing too much code in a proprietary language like Delphi.
Prefer standards like C++ or Ada: you can use/test different compilers, re-use
code for other bindings/OSes/platforms.
(MHO)
______________________________________________________
Gautier  --  http://members.xoom.com/gdemont/gsoft.htm