Inserting raw data in inline asm

[Frits van Bommel]

BCS wrote:
> Leopold Walkling wrote:
>> Jarrett Billingsley schrieb:
>>> "Leopold Walkling" <leopold_walkling at web.de> wrote in message 
>>> news:enjsji$kjj$1 at digitaldaemon.com...
>>>> What are those "pseudo-ops" in inline asm like db, dw, dd, dl, df... 
>>>> for?
>>>
>>> Doesn't your topic answer your question?
>>>
>>> I guess they're for inserting static data without using D syntax..
>>>
>> I found out what it does, but for what reason should I insert a raw 
>> float into the machine code?
> 
> for doing something like this in ASM;
> 
> float a, b;
> 
> a = b * 7.35235532;
> 
> or maybe
> 
> float[] arr;
> 
> arr[] = [cast(flost)####, ####, ####, ####];

I think you'll find you'd put the floats into instructions that move 
them to the coprocessor (or whatever, never used floats from asm). But 
I'm pretty sure you wouldn't want to just paste the raw binary 
representation of a float into a spot where the cpu will expect a new 
instruction to start. That sounds like a recipe for disaster...

I guess those pseudo-ops are not very useful in an inline assembler. 
Though I suppose you could jump over them and use them as values in 
memory from other instructions[1].
Or you could use them to generate opcodes for (new) instructions that 
the compiler doesn't (yet) know about :)...


[1]: which is probably as good as useless, since you typically can't 
modify the code section, which is where they'd be stored...