[patch] passes.c: Run CSE only once after GCSE instead of twice or more.

[Geoffrey Keating]

Kazu Hirata <kazu@cs.umass.edu> writes:

> OK, I just tried POOMA.  Six out of 28 assembly files differ.
> 
> One of them has trivial register allocation difference.  That is, some
> registers are shuffled.

I'd suggest that after looking at three or four large programs and
discovering no meaningful changes, I think that's enough evidence to
take these passes out...

> The other five have hash difference that I cannot disable even with
> -fno-random-seed.

That doesn't do what you think it does.  It does not make the seed
predictable.  It says "Ignore the seed I provided earlier, make one up
yourself."

> -	.long	_GLOBAL__I_DiskLayout.cmpl.ii_8D2A3925_5109C10D
> +	.long	_GLOBAL__I_DiskLayout.cmpl.ii_8D2A3925_107B918A