[Bug tree-optimization/60174] [4.9 regression] ICE on ACATS cc3305a

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60174

--- Comment #12 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Eric Botcazou from comment #11)
> Reproducible on x86{-64}/Linux with the following procedure:
> 
>  - copy $srcdir/gcc/testsuite/ada/acats/support/repbody.ada to $buildir
>  - gnatchop repbody.ada
>  - copy $srcdir/gcc/testsuite/ada/acats/support/repspec.ada to $buildir
>  - gnatchop repspec.ada
>  - copy $builddir/gcc/ada/rts/system.ads to $buildir
>  - edit system.ads and change ZCX_By_Default to False
>  - compile

Unfortunately that's always telling me

error: "gnat1drv.adb" must be recompiled ("system.ads" has been modified)
error: "s-stalib.adb" must be recompiled ("system.ads" has been modified)
error: "a-except.adb" must be recompiled ("system.ads" has been modified)
...

(recurring problem when I try to re-build gnat1 or all-gcc in my
dev-tree after svn up)

I wonder if this is a missing dependency.

> eric@polaris:~/build/gcc/native> gcc/xgcc -Bgcc -S cc3305a.adb -O2
> 
> Unable to coalesce ssa_names 34 and 399 which are marked as MUST COALESCE.
> i_34(ab) and  i_399(ab)
> +===========================GNAT BUG DETECTED==============================+
> | 4.9.0 20140213 (experimental) [trunk revision 207749] (x86_64-suse-linux)
> GCC error:|
> | SSA corruption                                                           |
> | Error detected around cc3305a.adb:35:1                                   |
> | Please submit a bug report; see http://gcc.gnu.org/bugs.html.            |
> | Use a subject line meaningful to you and us to track the bug.            |
> | Include the entire contents of this bug box in the report.               |
> | Include the exact gcc or gnatmake command that you entered.              |
> | Also include sources listed below in gnatchop format                     |
> | (concatenated together with no headers between files).                   |
> +==========================================================================+