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From: Andrew Haley <aph@redhat.com>
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Date: Fri, 11 Jun 2004 20:44:00 -0000
To: Richard Henderson <rth@redhat.com>
Cc: gcc-patches@gcc.gnu.org
Subject: Re: New flag: TREE_THIS_NOTRAP
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Richard Henderson writes:
 > On Fri, Jun 11, 2004 at 05:41:31PM +0100, Andrew Haley wrote:
 > >       case INDIRECT_REF:
 > > +       {
 > > + 	tree t = TREE_OPERAND (expr, 0);
 > > + 	return (TREE_THIS_NOTRAP (t) == false);
 > 
 > So the NOTRAP bit is on the pointer and not the INDIRECT_REF?

It has to be doesn't it?  The trapping in

   *exp

is a property of exp, not a property of *.  If someone attaches
another INDIRECT_REF to exp, it will not be marked as NOTRAP.

I could mark *both* exp and its INDIRECT_REF as notrap, I
guess.

 > This seems likely to get lost during gimplification, unless
 > you're taking extra special care...

Andrew.