[fpc-devel] Wrong debug info when using clang backend

[Michael Van Canneyt]

On Wed, 13 Dec 2023, Jonas Maebe via fpc-devel wrote:

> On 09/12/2023 13:35, Adriaan van Os via fpc-devel wrote:
>> Jonas Maebe via fpc-devel wrote:
>>> So if/when we would get FPC equivalents of such directives, I could 
>>> translate those to LLVM IR as well.
>> 
>> Then I suggest the following (and I can prepare a patch to the code and 
>> docs if it were to be accepted)
>> 
>> $vectorize ON}
>> {$vectorize OFF}
>> {$vectorize WIDTH=VALUE}
>> {$vectorize TYPE=FIXED}
>> {$vectorize TYPE=SCALABLE}
>> {$vectorize PREDICATE=ON}
>> {$vectorize PREDICATE=OFF}
>> 
>> For a description, see 
>> <https://llvm.org/docs/Vectorizers.html#command-line-flags>. And
>> 
>> {$unroll ON}
>> {$unroll OFF}
>> {$unroll FULL}
>> {$unroll COUNT=VALUE}
>> 
>> For a description, see 
>> 
> <https://clang.llvm.org/docs/LanguageExtensions.html#extensions-for-loop-hint-optimizations>.
>
> I'd rather not introduce directives that are specific to clang, and 
> especially none only apply to the next loop. We don't have a single 
> directive yet that works like this.
>
> Maybe attributes would be more appropriate, although I don't think 
> Delphi (or FPC) currently supports attributes for statements.

Please don't:
Attributes are designed for runtime consumption. I'm heavily opposed to
start using them to influence the code generation. The compiler should
remain ignorant of their meaning and use.

Maybe a single {$PRAGMA XYZ} directive can be introduced to control this
kind of stuff, with a fixed list of XYZ. 
Backends can intepret the XYZ pragmas as they see fit.

Michael.