Re: [PATCH][0/n] Merge from match-and-simplify

[Richard Biener <rguenther at suse dot de>]

On Fri, 17 Oct 2014, Richard Biener wrote:

> On Fri, 17 Oct 2014, Ramana Radhakrishnan wrote:
> 
> > On Wed, Oct 15, 2014 at 5:29 PM, Kyrill Tkachov <kyrylo.tkachov@arm.com> wrote:
> > >
> > > On 15/10/14 14:00, Richard Biener wrote:
> > >>
> > >>
> > >> Any comments and reviews welcome (I don't think that
> > >> my maintainership covers enough to simply check this in
> > >> without approval).
> > >>
> > > Hi Richard,
> > >
> > > The match-and-simplify branch bootstrapped successfully on
> > > aarch64-none-linux-gnu FWIW.
> > >
> > 
> > What about regression tests ?
> 
> Note the branch isn't regression free on x86_64 either.  The branch
> does more than I want to merge to trunk (and it also retains all
> folding code I added patterns for).  I've gone farther there to
> explore whether it will end up working in the end and what kind
> of features the IL and the APIs need.
> 
> I've pasted testsuite results on x86_64 below for rev. 216324
> which is based on trunk rev. 216315 which unfortunately has
> lots of regressions on its own.
> 
> This is why I want to restrict the effect of the machinery to
> fold (), fold_stmt () and tree-ssa-forwprop.c for the moment
> and merge individual patterns (well, maybe in small groups)
> separately to allow for easy bi-section.
> 
> I suppose I should push the most visible change to trunk first,
> namely tree-ssa-forwprop.c folding all statements via fold_stmt
> after the merge.  I suspect this alone can have some odd effects
> like the sub + cmp fusing.  That would be sth like the patch
> attached below.

Just finished testing this (with -m32 on x86_64), showing regressions
in the testsuite like

FAIL: gcc.dg/tree-ssa/slsr-19.c scan-tree-dump-times optimized " \\\\* y" 
1
FAIL: gcc.dg/vect/bb-slp-27.c -flto -ffat-lto-objects  
scan-tree-dump-times slp2
 "basic block vectorized" 1
FAIL: gcc.dg/vect/bb-slp-27.c scan-tree-dump-times slp2 "basic block 
vectorized"
 1
FAIL: gcc.dg/vect/bb-slp-8b.c -flto -ffat-lto-objects  
scan-tree-dump-times slp2
 "basic block vectorized" 1
FAIL: gcc.dg/vect/bb-slp-8b.c scan-tree-dump-times slp2 "basic block 
vectorized"
 1
FAIL: gcc.dg/vect/slp-cond-3.c -flto -ffat-lto-objects  
scan-tree-dump-times vec
t "vectorizing stmts using SLP" 1
FAIL: gcc.dg/vect/slp-cond-3.c scan-tree-dump-times vect "vectorizing 
stmts usin
g SLP" 1

Bah.

I suppose I need to investigate this (simply folding a stmt shouldn't
cause any of the above... - with SLP it is probably operand
canonicalization, but not sure).

Richard.

> Richard.
> 
> Index: gcc/tree-ssa-forwprop.c
> ===================================================================
> --- gcc/tree-ssa-forwprop.c	(revision 216258)
> +++ gcc/tree-ssa-forwprop.c	(working copy)
> @@ -54,6 +54,8 @@ along with GCC; see the file COPYING3.
>  #include "tree-ssa-propagate.h"
>  #include "tree-ssa-dom.h"
>  #include "builtins.h"
> +#include "tree-cfgcleanup.h"
> +#include "tree-into-ssa.h"
>  
>  /* This pass propagates the RHS of assignment statements into use
>     sites of the LHS of the assignment.  It's basically a specialized
> @@ -3586,6 +3588,8 @@ simplify_mult (gimple_stmt_iterator *gsi
>  
>    return false;
>  }
> +
> +
>  /* Main entry point for the forward propagation and statement combine
>     optimizer.  */
>  
> @@ -3626,6 +3630,40 @@ pass_forwprop::execute (function *fun)
>  
>    cfg_changed = false;
>  
> +  /* Combine stmts with the stmts defining their operands.  Do that
> +     in an order that guarantees visiting SSA defs before SSA uses.  */
> +  int *postorder = XNEWVEC (int, n_basic_blocks_for_fn (fun));
> +  int postorder_num = inverted_post_order_compute (postorder);
> +  for (int i = 0; i < postorder_num; ++i)
> +    {
> +      bb = BASIC_BLOCK_FOR_FN (fun, postorder[i]);
> +      for (gimple_stmt_iterator gsi = gsi_start_bb (bb);
> +	   !gsi_end_p (gsi); gsi_next (&gsi))
> +	{
> +	  gimple stmt = gsi_stmt (gsi);
> +	  gimple orig_stmt = stmt;
> +
> +	  if (fold_stmt (&gsi))
> +	    {
> +	      stmt = gsi_stmt (gsi);
> +	      if (maybe_clean_or_replace_eh_stmt (orig_stmt, stmt)
> +		  && gimple_purge_dead_eh_edges (bb))
> +		cfg_changed = true;
> +	      update_stmt (stmt);
> +	    }
> +	}
> +    }
> +  free (postorder);
> +
> +  /* ???  Code below doesn't expect non-renamed VOPs and the above
> +     doesn't keep virtual operand form up-to-date.  */
> +  if (cfg_changed)
> +    {
> +      cleanup_tree_cfg ();
> +      cfg_changed = false;
> +    }
> +  update_ssa (TODO_update_ssa_only_virtuals);
> +
>    FOR_EACH_BB_FN (bb, fun)
>      {
>        gimple_stmt_iterator gsi;
> 

-- 
Richard Biener <rguenther@suse.de>
SUSE / SUSE Labs
SUSE LINUX Products GmbH - Nuernberg - AG Nuernberg - HRB 16746
GF: Jeff Hawn, Jennifer Guild, Felix Imend"orffer