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Re: Fix PR 19643. [ Was Re: Speedup CSE by 5% ]
- From: Jeffrey A Law <law at redhat dot com>
- To: Ranjit Mathew <rmathew at gmail dot com>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Mon, 31 Jan 2005 17:54:12 -0700
- Subject: Re: Fix PR 19643. [ Was Re: Speedup CSE by 5% ]
- Organization: Red Hat, Inc
- References: <email@example.com> <Pine.LNX.firstname.lastname@example.org> <email@example.com>
- Reply-to: law at redhat dot com
On Sat, 2005-01-29 at 20:06 +0530, Ranjit Mathew wrote:
> Roger Sayle wrote:
> > Hi Jeff,
> >>This fixes PR 19643 in the obvious way.
> > Alas, not so "obvious" as this is clearly incorrect.
I'm clearly a moron.
> > I'm still investigating possible java front-end interactions and
> > whether gcj/bytecode requires the evaluation of "0 % 0" to throw
> > a java.lang.ArithmeticException.
> Indeed this causes a Jacks testsuite regression for GCJ.
> Specifically testcase 15.28-div0-2.
> Since "0 % 0" is undefined, it is not a compile-time constant
> expression and must be complained about.
> In fact, this is a regression even for C w.r.t. GCC 3.4.3:
> /tmp > cat x.c
> int foo(int x)
> case 0 % 0:
> return 1;
> return 2;
Yea. I added this to pr19723. I'm testing a fix for both problems.