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Re: [RFC] Ignore TREE_CONSTANT_OVERFLOW in integer_zerop
- From: Roger Sayle <roger at eyesopen dot com>
- To: Eric Botcazou <ebotcazou at adacore dot com>
- Cc: gcc at gcc dot gnu dot org, <gcc-patches at gcc dot gnu dot org>
- Date: Sun, 2 Apr 2006 09:21:41 -0600 (MDT)
- Subject: Re: [RFC] Ignore TREE_CONSTANT_OVERFLOW in integer_zerop
On Sun, 2 Apr 2006, Eric Botcazou wrote:
> > 2006-04-01 Roger Sayle <roger@eyesopen.com>
> >
> > * tree.c (integer_zerop): Ignore TREE_CONSTANT_OVERFLOW.
> > [...]
> > (int_size_in_bytes): Likewise.
> > (host_integerp): Likewise.
>
> Is this an oversight?
Doh. Indeed. The last two lines of the ChangeLog should read
(int_size_in_bytes): Ignore TREE_OVERFLOW.
(host_integerp): Likewise.
As one aspect of the series I've been investigating is to unify these
two flags, I tend to think of them a synonymous. The only difference
in semantics is that the C/C++ front-ends uses both to track whether
a diagnostic has been emitted. It turns out that this conceptual
difference can be handled entirely in the C family front-ends, and
at the same time improve the diagnostic warnings that are emitted.
Indeed, a many of the uses of TREE_OVERFLOW or TREE_CONSTANT_OVERFLOW
currently test the wrong one, but the vast majority of writes are
to clear these flags to prevent them screwing things up.
Good catch. Thanks.
Roger
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