Re: Switch ARM, SPARC and i386 to generic dummy frames (PC_IN_CALL_DUMMY)?

[Andrew Cagney <ac131313 at cygnus dot com>]

> On Sun, Apr 14, 2002 at 10:51:36AM -0400, Andrew Cagney wrote:
> 
>> Hello,
>> 
>> If I remember one of those unwritten ``grand plans'' correctly, the 
>> intent is to have all targets switched to ``generic dummy frames''.  True?
>> 
>> Among other things, generic dummy frames do not save/restore registers 
>> on the target stack (instead they are cached locally) and this should 
>> improve the overall performance of an inferior function call.
>> 
>> Anyway, the thing that prompts this is PC_IN_CALL_DUMMY(PC, SP, FP). 
>> There are several implementations.  Only two:
>> 
>> - generic: looks for the FP in the list of dummy frames
>> - stack: looks for PC in [FP..SP)
>> 
>> require the SP/FP parameters.  I've a patch to fix the first one (search 
>> for the PC).  If the ARM, SPARC and i386 can switch to generic dummy 
>> frames then those parameters can be eliminated and all calls simplified.
> 
> 
> Wait a second.  Switch to searching for the PC?  Does that work
> reliably if the PC being searched for is in more than one dummy frame?
> I guess it does for PC_IN_CALL_DUMMY (a predicate), but does anything
> else use the search code?

Sorry, you've lost me.  BTW, the line:
 >> - generic: looks for the FP in the list of dummy frames
isn't a typo.

Andrew