From: Andrew Haley <aph@redhat.com>
To: kenner@vlsi1.ultra.nyu.edu (Richard Kenner)
Cc: gcc-patches@gcc.gnu.org, java@gcc.gnu.org
Subject: Re: Patch to allow Ada to work with tree-ssa
Date: Tue, 22 Jun 2004 20:27:00 -0000 [thread overview]
Message-ID: <16600.32689.283297.508488@cuddles.cambridge.redhat.com> (raw)
In-Reply-To: <10406221818.AA08344@vlsi1.ultra.nyu.edu>
Richard Kenner writes:
> > I somebody could point out what tree transformation is going wrong, I'll
> > be glad to fix it.
>
> It seems that something has changed the depth-first, left-to-right
> parsing of expressions. Have you any idea what might have caused this?
>
> "parsing"? Did you mean gimplifying?
Yes.
> Indeed a number of things I did might have had the effect of
> changing the order in which subtrees are gimplified. Since I
> didn't think that anything depended on that, I didn't pay that much
> attention to the issue. If there are places that do depend on
> that, can you identify them so that comments can be placed in
> gimplify.c saying what's order-dependent.
Java assumes that all expressions are fully evaluated in strict
left-to-right order.
For example, in Java "a += a++ + a" is well-defined.
> The changes would mostly relate to the order of gimplification of MODIFY_EXPR
> and certain compound values, I'd guess.
>
> Can you give an example of an expression that's handled differently?
Ranjit Mathew has reported that this breaks:
public class err6 {
public static void main(String[] args) {
int[] x = { 10, 11, 12, 1, 14 };
int[] y = { 1, 2, 3, 4, 5, 6 };
if ( x[(x=y)[2]] == 1 ) {
System.out.println("OK");
} else {
System.out.println("NG:[1]-->[" +x[(x=y)[2]]+ "]");
}
}
}
The rule we're checking is that each dimension expression is fully
evaluated before any part of any dimension expression to its right.
So, this
x[(x=y)[2]]
is gimplified as
x1 = x
x = y
tmp = x1[2]
x1[tmp]
I'll provide a more detailed diagnosis tomorrow. It's quite possible,
of course, that you've revealed a bug in the Java gimplification code.
Andrew.
next prev parent reply other threads:[~2004-06-22 18:59 UTC|newest]
Thread overview: 77+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-06-22 19:05 Richard Kenner
2004-06-22 20:10 ` Joseph S. Myers
2004-06-22 20:27 ` Andrew Haley [this message]
-- strict thread matches above, loose matches on Subject: below --
2004-07-29 19:02 Richard Kenner
2004-07-29 18:43 Richard Kenner
2004-07-29 17:12 Richard Kenner
2004-07-29 17:13 ` Diego Novillo
2004-07-29 17:57 ` Richard Henderson
2004-06-25 15:28 Richard Kenner
2004-06-28 15:09 ` Paolo Bonzini
2004-06-24 15:58 Richard Kenner
2004-06-24 16:04 ` Nathan Sidwell
2004-06-25 14:43 ` Joseph S. Myers
2004-06-23 5:54 Richard Kenner
2004-06-23 2:32 Richard Kenner
2004-06-23 4:54 ` Bryce McKinlay
2004-06-23 0:16 Richard Kenner
2004-06-22 23:05 Richard Kenner
2004-06-23 11:42 ` Nathan Sidwell
2004-06-22 22:18 Richard Kenner
2004-06-23 1:07 ` Richard Henderson
2004-06-22 21:30 Richard Kenner
2004-06-22 22:04 ` Paul Brook
2004-06-22 21:27 Richard Kenner
2004-06-22 21:29 ` Mark Mitchell
2004-06-22 21:10 Richard Kenner
2004-06-22 21:12 ` Mark Mitchell
2004-06-22 22:16 ` Daniel Berlin
2004-06-22 21:07 Richard Kenner
2004-06-22 21:12 ` Bryce McKinlay
2004-06-22 21:05 Richard Kenner
2004-06-22 21:01 Richard Kenner
2004-06-22 20:54 Richard Kenner
2004-06-22 21:06 ` Paul Brook
2004-06-22 21:37 ` Richard Henderson
2004-06-22 20:44 Richard Kenner
2004-06-22 21:03 ` Mark Mitchell
2004-06-23 20:58 ` Geoffrey Keating
2004-06-22 20:40 Richard Kenner
2004-06-22 22:02 ` Nathan Sidwell
2004-06-22 22:27 ` Joseph S. Myers
2004-06-22 20:23 Richard Kenner
2004-06-22 20:37 ` Joseph S. Myers
2004-06-23 20:47 ` Geoffrey Keating
2004-06-24 14:59 ` Joseph S. Myers
2004-06-24 16:26 ` Richard Earnshaw
2004-06-24 19:57 ` Laurent GUERBY
2004-06-24 20:06 ` Diego Novillo
2004-06-24 20:24 ` Andrew Pinski
2004-06-24 22:35 ` Laurent GUERBY
2004-06-24 21:33 ` Laurent GUERBY
2004-06-24 21:01 ` Joseph S. Myers
2004-06-25 14:51 ` Richard Earnshaw
2004-06-22 20:22 Richard Kenner
2004-06-22 20:30 ` Mark Mitchell
[not found] <10406221359.AA05860@vlsi1.ultra.nyu.edu>
2004-06-22 18:47 ` Richard Henderson
2004-06-22 18:33 Richard Kenner
2004-06-22 18:19 Richard Kenner
2004-06-22 18:36 ` Nathan Sidwell
2004-06-22 18:37 ` Nathan Sidwell
2004-06-22 18:45 ` Mark Mitchell
2004-06-22 17:05 Richard Kenner
2004-06-22 17:21 ` Andrew Haley
2004-06-22 19:01 ` Richard Henderson
2004-06-22 16:34 Richard Kenner
2004-06-22 16:33 Richard Kenner
2004-06-22 17:46 ` Mark Mitchell
2004-06-22 18:17 ` Joseph S. Myers
2004-06-22 18:52 ` Richard Henderson
2004-06-22 19:37 ` Zack Weinberg
2004-06-22 7:05 Richard Kenner
2004-06-22 7:29 ` Mark Mitchell
2004-06-22 9:14 ` Andrew Pinski
2004-06-22 14:16 ` Andrew Haley
2004-06-22 11:00 ` Richard Henderson
2004-06-22 13:52 ` Ranjit Mathew
2004-07-29 17:02 ` Diego Novillo
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