Re: [PATCH v4] rs6000: Rework ELFv2 support for -fpatchable-function-entry* [PR99888]

["Kewen.Lin" <linkw@linux.ibm.com>]

Hi Segher,

Thanks for the review comments!

on 2022/9/28 23:22, Segher Boessenkool wrote:
> Hi!
> 
> On Thu, Aug 25, 2022 at 01:50:28PM +0800, Kewen.Lin wrote:
>> --- a/gcc/config/rs6000/rs6000-internal.h
>> +++ b/gcc/config/rs6000/rs6000-internal.h
>> @@ -183,10 +183,15 @@ extern tree rs6000_fold_builtin (tree fndecl ATTRIBUTE_UNUSED,
>>  			         tree *args ATTRIBUTE_UNUSED,
>>  			         bool ignore ATTRIBUTE_UNUSED);
>>
>> +extern void rs6000_print_patchable_function_entry (FILE *,
>> +						   unsigned HOST_WIDE_INT,
>> +						   bool);
>> +
>>  extern bool rs6000_passes_float;
>>  extern bool rs6000_passes_long_double;
>>  extern bool rs6000_passes_vector;
>>  extern bool rs6000_returns_struct;
>>  extern bool cpu_builtin_p;
>>
>> +
>>  #endif
> 
> No new random empty lines please.
> 
>> +	     point would be 2, 6 and 14.  It's possible to support those
>> +	     other counts of nops by not making a local entry point, but
>> +	     we don't have clear user cases for them, so leave them
> 
> "use cases"
> 
>> --- a/gcc/doc/invoke.texi
>> +++ b/gcc/doc/invoke.texi
>> @@ -16717,9 +16717,13 @@ the area size or to remove it completely on a single function.
>>  If @code{N=0}, no pad location is recorded.
>>
>>  The NOP instructions are inserted at---and maybe before, depending on
>> -@var{M}---the function entry address, even before the prologue.
>> +@var{M}---the function entry address, even before the prologue.  On
>> +PowerPC with the ELFv2 ABI, for one function with dual entry points,
>> +the local entry point is taken as the function entry for generation.
> 
> I think "the local entry point is this function entry address" is a bit
> clearer.
> 
>> -The maximum value of @var{N} and @var{M} is 65535.
>> +The maximum value of @var{N} and @var{M} is 65535.  On PowerPC with the
>> +ELFv2 ABI, for one function with dual entry points, the supported values
>> +for @var{M} are 0, 2, 6 and 14.
> 
> "for a function"
> 
> Okay for trunk with those trivial chnges.  Thanks!
> 

Updated as all above comments, re-tested and committed in r13-2984.  Thanks!


BR,
Kewen