code review 104610044: compiler: Convert array start index before bounds checking.

compiler: Convert array start index before bounds checking.

Fixes https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61308

[cmang, 2014-07-08 20:22:17]

Hello iant@golang.org (cc: gofrontend-dev@googlegroups.com),

I'd like you to review this change to
https://code.google.com/p/gofrontend

[iant, 2014-07-08 20:57:17]

What kind of bug is this?  Is this a bug in which the compiler emits an error
messages and then crashes?  If so I don't think we need to do anything else.  If
it's some other sort of bug we might want to add a test case to the master
testsuite.

[cmang, 2014-07-08 21:07:41]

On 2014/07/08 20:57:17, iant wrote:
> What kind of bug is this?  Is this a bug in which the compiler emits an error
> messages and then crashes?  If so I don't think we need to do anything else. 
If
> it's some other sort of bug we might want to add a test case to the master
> testsuite.

Sorry, I added the bug it fixes later, but it's the ICE mentioned in
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61308 from gosmith.  But yes, the
compiler just emits an error and then crashes.

[iant, 2014-07-08 21:27:13]

LGTM

[iant, 2014-07-08 21:27:25]

*** Submitted as
https://code.google.com/p/gofrontend/source/detail?r=fa6e0c716dba ***

compiler: Convert array start index before bounds checking.

Fixes https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61308

R=iant
CC=gofrontend-dev
https://codereview.appspot.com/104610044

Committer: Ian Lance Taylor <iant@golang.org>

[iant, 2014-07-08 22:50:45]

After Dmitriy's comment on http://gcc.gnu.org/PR61308 I tried the test case.  It
does build without error using the gc compiler and now it builds without error
using gccgo.  So this is valid code that caused gccgo to crash.  I think we
should have a test case for this.