Re: Move value numbering routines and add VALUE_HANDLE code

[Daniel Berlin <dberlin at dberlin dot org>]

On Jun 23, 2004, at 6:39 AM, Diego Novillo wrote:

> This is mostly mechanical.  It adds a new VALUE_HANDLE tree code that 
> is
> generated and consumed internally by GVN-PRE.  This ought to reduce
> memory consumption somewhat (not tested, though) because we won't use
> VAR_DECLs as value handles anymore.
>
> The patch also moves all the value numbering routines to tree-vn.c.  I
> also have changes to make value numbering incorporate virtual operands,
> but that is still unstable, so I'm flushing the stable bits out to 
> avoid
> lugging around a huge patch.
>
> Finally, the patch uncovered a subtle bug in tree-optimize.c.  The 
> calls
> to init_tree_ssa() and delete_tree_ssa() were sometimes not paired.
> When not optimizing, we would call delete_tree_ssa() but not
> init_tree_ssa().  Since we are now removing the value numbering hash
> table in delete_tree_ssa(), we were ICEing at -O0.
>
> Bootstrapped and tested x86 and x86-64 with no regressions.  Dan and
> Steven, could you folks take a look and make sure I haven't broken
> anything subtle?  There should be no behavioural change in PRE.
It looks fine to me.  I'll give it a try on my local PRE tests (which 
are unfortunately too large to put in the testsuite) and make sure 
nothing subtle broke.  Shouldn't be more than an hour or two