[Bug bootstrap/34255] scope-blocks-on-a-diet patch diverges -g from non-g output code

[rguenth at gcc dot gnu dot org]

------- Comment #2 from rguenth at gcc dot gnu dot org  2007-11-28 12:15 -------
The two patches reduce the boostrap-debug failures that re-appear with
reverting
the part that fixes

> http://gcc.gnu.org/ml/gcc-patches/2007-07/msg01745.html regresses the property
> that code output with -g must be the same as that without -g.  make
> bootstrap-debug demonstrates that several files miscompare after this patch,
> and don't if the patch is reversed.

to

./lcm.o differs
./cfghooks.o differs
./postreload.o differs
./cfgloopmanip.o differs

from several dozen miscompares.  My bet is that this is because we process
the unexpanded_vars list in non-UID order at expansion time.  I'm testing
a patch that sorts them after UID before expanding (we could also keep
a bitmap now with the first patch, but that would be more work now).


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34255