C51 will generate different code for the following function:
void timer1 (void) interrupt 3 { second; #pragma asm clr TF1 #pragma endasm }
Compiler v8.08 code (edited)
USING 0 timer1: ; #pragma asm clr TF1 ; #pragma endasm RETI
Compiler v8.17 code (edited)
USING 0 timer1: PUSH ACC PUSH B PUSH DPH PUSH DPL PUSH PSW MOV PSW,#00H PUSH AR0 ... PUSH AR7 USING 0 ; #pragma asm clr TF1 ; #pragma endasm POP AR7 ... POP AR0 POP PSW POP DPL POP DPH POP B POP ACC RETI
C51 v8.17 generates code to save and restore all registers, as soon as the (very simplified, nonsense) C function contains any assembly source, whereas C51 v8.08 does not. For a function containing equivalent C code only (TF=0), nothing would be saved with either version.
Is there a reason for the different code generated by v8.17 ? How could saving/restoring of the registes be avoided ?
Now, you'll argue that you don't use standard 'C' but in fact use Keil 'C' IN CONTEXT: 1) NOT Keil C" but "'51 C" 2) 'standard C has many 'features' that the '51 is inacabable of processing efficiently and such constructs should thus be avoided.
Your repeated implication that learning the 'C' programming language properly somehow makes one unable to write code that is suitable for use on an 8051 derivative is frankly laughable If you did not know C you would be at a loss using Keil C. I do not discuss 'learning' or 'knowing' but 'applying' I have never stated "that learning the 'C' programming language properly somehow makes one unable to write code", what I have stated and will restate is that "if you approach '51 programming with the attitude "I am using C so I do not need to be concerned with the archiotecture" your ability to make efficient code is not even that of a sardine
Erik
IN CONTEXT: 1) NOT Keil C" but "'51 C"
There is standard 'C' of which there are implementations, many of which include extensions to the standard. '51 C' is merely a figment of your imagination.
2) 'standard C has many 'features' that the '51 is inacabable of processing efficiently and such constructs should thus be avoided.
In your opinion, perhaps. Efficiency (by which I assume you mean speed and/or code size) is only relevant if it matters, otherwise clarity and maintainability should take precedence.
As you're so very fond of them, here's a car analogy:
You need to drive somewhere 100 miles away. You need to be there in 6 hours. Do you:
1) Drive at a sensible speed and get there in plenty of time. 2) Drive flat out and get there way too early.
If you did not know C you would be at a loss using Keil C. I do not discuss 'learning' or 'knowing' but 'applying'
You cannot 'apply' without first 'learning' and hopefully 'knowing'. I can only judge your state of knowledge by what you post on this forum, and I'm afraid your code snippets and queries along with your comments on the 'C' language betray a worrying lack of it.
I have never stated "that learning the 'C' programming language properly somehow makes one unable to write code",
Ah yes, the old 'Malund trick', snipping the important bit of the quote:
Your repeated implication that learning the 'C' programming language properly somehow makes one unable to write code that is suitable for use on an 8051 derivative
Which is, in fact, what you repeatedly imply. Don't you even have your own little nickname for people who know 'C' well?
what I have stated and will restate is that "if you approach '51 programming with the attitude "I am using C so I do not need to be concerned with the archiotecture" your ability to make efficient code is not even that of a sardine
Er, fascinating, but not what is being discussed. That's 'Malund trick 2', number three, if I recall, will be answering the question you would prefer to have been asked rather than the one you have been asked.
Woohoo.
Go Jack, go Jack, gooooooooooooo Jack!
Which is, in fact, what you repeatedly imply. Don't you even have your own little nickname for people who know 'C' well? Not that I know of, I would call them knowledgeable.
HOWEVER "if you approach '51 programming with the attitude "I am using C so I do not need to be concerned with the archiotecture" I call you a Cidiot
Well, that's a breakthrough. I'd have thought you'd aspire to be one of them, but there you go.