Re: patch for 930513-1 on Darwin

[Dale Johannesen <dalej at apple dot com>]

On Thursday, May 31, 2001, at 06:03  PM, Dale Johannesen wrote:
> On Thursday, May 31, 2001, at 05:52  PM, Richard Henderson wrote:
>> On Thu, May 31, 2001 at 04:59:37PM -0700, dalej@apple.com wrote:
>>> On Darwin, the required syntax for a function name is different
>>> when you call it and when you pass its address, so the inliner
>>> needs to change things to compensate.
>>
>> Err... no it doesn't.  You can get into the same issue without
>> inlining if you CSE a function address into a call pattern.
>
> Hmm, for some reason the function address doesn't seem to get put into 
> the call in this case, but you're right, obviously it should.   I'll 
> check it out.

This turns out to be interesting.  With -static, a function address is 
pushed forward into a call in a case like this:
    int (*p) = foo;
   (*p)();
It is combine, not cse, that does this, and it does so because combine 
has hardwired code that knows that (lo_sum (high foo) foo)==(foo).

The usual case on Darwin, however, is pic, and there is no analogous 
code in combine for pic trees, so the substitution does not take place.  
Do you think it might be a good idea to add such code?  Pic trees are 
different on different targets, of course, so it would have to be a 
macro.  (I can also imagine that this substitution might not be a good 
idea with pic on some targets.)