[tree-ssa] Avoid nondeterminism in tree-ssanames

[Andrew MacLeod]

On Mon, 2003-12-01 at 16:41, law@redhat.com wrote:
> In message <1070313985.32255.102.camel@p4>, Andrew MacLeod writes:
>  >I dont particularly like re-using SSA_NAMEs versions. Expecially in
>  >large programs Im debugging, I tend to grep for VAR_v in a.c.* listing
>  >files to see where uses appear and dissappear. I guess its not a huge
>  >thing to filter out, but I can see it being very confusing sometimes,
>  >especially if the new use is at all similar to what the old use was.
>  >
>  >RTL never recycles register numbers does it? I dont recall ever doing it
>  >on any other compiler I used either. Thats not to say there isn't some
>  >benefits from it :-)
> We recycle registers numbers at the start of each function.  We almost

well yeah, at the beginning of a function I would expect to start at
one, I meant within a function between passes.

> We do recycle insn #s to cut down on our array/bitmap sizes.  It's flag
> controlled so that you can turn it off for debugging purposes.


Yeah, except sometimes by changing your environment like that, the bug
goes away when you try to enable debugging information. aaaaaaaaaaagh! I
hate those ones :-)


Andrew