Re: mem sharing fix [Re: Your flow.c change on 4/8]

[Jeffrey A Law <law at cygnus dot com>]

  In message <200004151129.MAA05279@cam-mail2.cambridge.arm.com>you write:
  > Applied.  I didn't supply an analysis and rationale last time.  Here it is 
  > now ...
  > 
  > Since addressof is shared across multiple rtx, replacing it can also 
  > replace any instances in the parameter list.  If these shared instances 
  > then get manipulated (for example, by turning them into pre/post incs), 
  > then this can confuse later passes that need to refer back to the original 
  > parameters (for example debugging information dumpers).  So we also need 
  > to re-unshare the parameter list.
  > 
  > Having added that to the list of things to unshare, it now seems simpler 
  > (and certainly safer) to re-unshare everything by making 
  > unshare_all_rtl_again call unshare_all_rtl after clearing the used marks.
  > 
  > 
  > Finally, here's a testcase (from cp/calls.c)
[ ... ]
Even though this is derived from GCC itself, it's a nice simple test, so I 
added it to the testsuite.

Thanks for taking the time to produce a simple test for this bug.
jeff