Re: Patch to fix gcc.c-torture/compile/20010102-1.c on IA64 HP-UX

[Peter Bergner <bergner@vnet.ibm.com>]

On Tue, 2008-09-16 at 13:14 -0600, Jeff Law wrote:
> You don't necessarily need to set REG_POINTER on hard registers, and in 
> general it's unwise.
> 
> What we do  is we set REG_POINTER on appropriate pseudos within the RTL 
> for the pseudo.  Then after register allocation/reloading, alter_reg 
> changes the REGNO field for the pseudo to turn it into a hard register.  
> Note this preserves the REG_POINTER flag so that you can test it after 
> reload. 
> 
> So you'll need to look into where that insn was created and ensure that 
> the appropriate pseudo has REG_POINTER set (r699)  Then verify that it 
> was carried forward through allocation/reloading.
> 
> REG_POINTER, when set, indicates the object is a pointer for its entire 
> lifetime -- thus setting it on hard registers is generally a bad idea 
> and it's only safe under certain circumstances on pseudos, particularly 
> in the presence of cross jumping.

So something similar to this untested patch to fix Steve's problem?
(This assumes ORIGINAL_REG (reg) == reg if reg is a psuedo.  Maybe it
isn't. :)

Peter

--- config/ia64/predicates.md	(revision 140251)
+++ config/ia64/predicates.md	(working copy)
@@ -585,6 +585,6 @@ (define_predicate "ar_pfs_reg_operand"
 (define_predicate "basereg_operand"
   (match_operand 0 "register_operand")
 {
-  return REG_P (op) && REG_POINTER (op);
+  return REG_P (op) && REG_POINTER (regno_reg_rtx[ORIGINAL_REGNO
(op)]);
 })