compare before macro?

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l4m2

Joined: 15 Jan 2015
Posts: 674

l4m2 05 Aug 2016, 16:32

Code:

if version < 201109 {
  macro xchg op1, op2 \{
    push op1 op2
    pop  op1 op2
  \}
}

05 Aug 2016, 16:32

revolution
When all else fails, read the source

Joined: 24 Aug 2004
Posts: 20299
Location: In your JS exploiting you and your system

revolution 05 Aug 2016, 16:38

Are you trying to conditionally define a macro? For that you can only use other preprocessor commands (rept, match, etc.). "if" is processed during assembly time so it won't work there.

05 Aug 2016, 16:38

l4m2

Joined: 15 Jan 2015
Posts: 674

l4m2 05 Aug 2016, 16:59

I put the topic in Compiler Internals because I mainly mean to have a compare-if on the 1st step, not focus on macro.
I also know that if won't fit, only in order to find a way.

05 Aug 2016, 16:59

revolution
When all else fails, read the source

Joined: 24 Aug 2004
Posts: 20299
Location: In your JS exploiting you and your system

revolution 05 Aug 2016, 17:51

You can use match for preprocessor conditionals.

05 Aug 2016, 17:51

l4m2

Joined: 15 Jan 2015
Posts: 674

l4m2 06 Aug 2016, 03:02

revolution wrote:

You can use match for preprocessor conditionals.

I already know that. I just hadn't known how to actually do it.
I found that

Code:

rept 1 t:a-b{ match -u, t \{ ... \} }

matches when a-b<0 or to say a<b, but it still seems unreadable?

Last edited by l4m2 on 06 Aug 2016, 03:10; edited 1 time in total

06 Aug 2016, 03:02

revolution
When all else fails, read the source

Joined: 24 Aug 2004
Posts: 20299
Location: In your JS exploiting you and your system

revolution 06 Aug 2016, 03:09

l4m2 wrote:

revolution wrote:
You can use match for preprocessor conditionals.

I already know that. I just hadn't known how to actually do it.

If you had stated that in the first post then we could have helped you better. We are not mind readers (or at least I am not) so it is difficult to know what you want when you only post 5 lines of code with no explanation.

l4m2 wrote:

I found that
Code:
rept 1 t:a-b{ match -u, t \{ ... \} }    
matches when a-b<0 or to say a-b, but it still seems unreadable?

Perhaps a way to make it more understandable is to put comments in the code the explain what it is intended to do. Wink

Perhaps the most useful, and most ignored, part of assembly code is the semi-colon character used to introduce comments. Razz

06 Aug 2016, 03:09

l4m2

Joined: 15 Jan 2015
Posts: 674

l4m2 21 Aug 2016, 01:29

revolution wrote:

Perhaps a way to make it more understandable is to put comments in the code the explain what it is intended to do.

Perhaps the most useful, and most ignored, part of assembly code is the semi-colon character used to introduce comments.

Comments should be the last way to make understandable code. Try macroing it

21 Aug 2016, 01:29

shutdownall

Joined: 02 Apr 2010
Posts: 517
Location: Munich

shutdownall 21 Aug 2016, 23:08

l4m2 wrote:

Comments should be the last way to make understandable code. Try macroing it

Comments make it easier to understand the code for other but also for yourself.
Whenever you tried to understand own code written years ago you would make the experience that comments are absolutely helpful and appreciated. Even just for yourself. The time you save in sparing comments you will invest double or triple or even more in finding bugs in your code later. Wink

21 Aug 2016, 23:08

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