Location of "dg-final" directives? (was Re: [PATCH][GCC] Algorithmic optimization in match and simplify)

[Marek Polacek]

On Tue, Sep 01, 2015 at 12:50:27PM -0400, David Malcolm wrote:
> I can't comment on the patch itself, but I noticed that in the testsuite
> addition, you've gathered all the "dg-final" clauses at the end.
> 
> I think that this is consistent with existing practice in gcc, but
> AFAIK, the dg-final clauses can appear anywhere in the file.
> 
> Would it make test cases more readable if we put the dg-final clauses
> next to the code that they relate to?  Or, at least after the function
> that they relate to?
> 
> For example:
> 
>   unsigned short
>   foo (unsigned short a)
>   {
>     a ^= 0x4002;
>     a >>= 1;
>     a |= 0x8000; /* Simplify to ((a >> 1) ^ 0xa001).  */
>     return a;
>   }
>   /* { dg-final { scan-tree-dump "\\^ 40961" "forwprop1" } } */
> 
>   unsigned short
>   bar (unsigned short a)
>   {
>       /* snip */ /* Simplify to ((a << 1) | 0x8005).  */
>   }
>   /* { dg-final { scan-tree-dump "\\| 32773" "forwprop1" } } */
> 
>   ... etc ...
> 
> I think this may be more readable than the "group them all at the end of
> the file approach", especially with testcases with many files and
> dg-final directives.

Yeah, it's probably somewhat more readable.  Same for dg-output.  E.g. some
ubsan tests already use dg-outputs after functions they relate to.

	Marek