Re: [committed] Minor cleanup/prep in DOM
On 9/30/22 18:07, H.J. Lu wrote:
On Fri, Sep 30, 2022 at 4:06 PM Jeff Law wrote:
It's a bit weird that free_dom_edge_info leaves a dangling pointer in
e->aux. Not sure what I was thinking.
There's two callers. One wipes e->aux immediately after the call, the
other attaches a newly created object immediately after the call. So we
can wipe e->aux within the call and simplify one of the two call sites.
This is preparatory work for a minor optimization where we want to
detect another class of edge equivalences in DOM (until something better
is available) and either attach them an existing edge_info structure or
create a new one if one doesn't currently exist for a given edge.
Bootstrapped and regression tested on x86_64. Installing on the trunk.
I got
[ ... ]
Pushed wrong version. Sorry about that. Fixed by attached patch which
just moves the test down to its proper position.
Jeff
commit aa360fbf68b11e54017e8fa5b1bdb87ce7c19188
Author: Jeff Law
Date: Fri Sep 30 20:46:04 2022 -0400
Install correct patch version.
gcc/
* tree-ssa-dom.cc (record_edge_info): Install correct version of
patch.
diff --git a/gcc/tree-ssa-dom.cc b/gcc/tree-ssa-dom.cc
index 8d8312ca350..e6b8dace5e9 100644
--- a/gcc/tree-ssa-dom.cc
+++ b/gcc/tree-ssa-dom.cc
@@ -684,11 +684,6 @@ record_edge_info (basic_block bb)
!gsi_end_p (gsi);
gsi_next ())
{
- /* If the other alternative is the same as the result,
-then this is a degenerate and can be ignored. */
- if (dst == PHI_ARG_DEF (phi, !alternative))
- continue;
-
/* Now get the EDGE_INFO class so we can append
it to our list. We want the successor edge
where the destination is not the source of
@@ -697,6 +692,11 @@ record_edge_info (basic_block bb)
tree src = PHI_ARG_DEF (phi, alternative);
tree dst = PHI_RESULT (phi);
+ /* If the other alternative is the same as the result,
+then this is a degenerate and can be ignored. */
+ if (dst == PHI_ARG_DEF (phi, !alternative))
+ continue;
+
if (EDGE_SUCC (bb, 0)->dest
!= EDGE_PRED (bb, !alternative)->src)
edge_info = (class edge_info *)EDGE_SUCC (bb, 0)->aux;
Re: [committed] Minor cleanup/prep in DOM
On Fri, Sep 30, 2022 at 4:06 PM Jeff Law wrote: > > > It's a bit weird that free_dom_edge_info leaves a dangling pointer in > e->aux. Not sure what I was thinking. > > > There's two callers. One wipes e->aux immediately after the call, the > other attaches a newly created object immediately after the call. So we > can wipe e->aux within the call and simplify one of the two call sites. > > This is preparatory work for a minor optimization where we want to > detect another class of edge equivalences in DOM (until something better > is available) and either attach them an existing edge_info structure or > create a new one if one doesn't currently exist for a given edge. > > Bootstrapped and regression tested on x86_64. Installing on the trunk. > I got /export/gnu/import/git/sources/gcc/gcc/tree-ssa-dom.cc: In function ‘void record_edge_info(basic_block)’: /export/gnu/import/git/sources/gcc/gcc/tree-ssa-dom.cc:689:27: error: ‘dst’ was not declared in this scope; did you mean ‘dse’? 689 | if (dst == PHI_ARG_DEF (phi, !alternative)) | ^~~ | dse In file included from /export/gnu/import/git/sources/gcc/gcc/gimple-ssa.h:24, from /export/gnu/import/git/sources/gcc/gcc/ssa.h:27, from /export/gnu/import/git/sources/gcc/gcc/tree-ssa-dom.cc:28: /export/gnu/import/git/sources/gcc/gcc/tree-ssa-dom.cc:689:47: error: ‘phi’ was not declared in this scope; did you mean ‘gphi’? 689 | if (dst == PHI_ARG_DEF (phi, !alternative)) | ^~~ /export/gnu/import/git/sources/gcc/gcc/tree-ssa-operands.h:82:54: note: in definition of macro ‘PHI_ARG_DEF’ 82 | #define PHI_ARG_DEF(PHI, I) gimple_phi_arg_def ((PHI), (I)) | ^~~ make: *** [Makefile:1146: tree-ssa-dom.o] Error 1 -- H.J.
[committed] Minor cleanup/prep in DOM
It's a bit weird that free_dom_edge_info leaves a dangling pointer in
e->aux. Not sure what I was thinking.
There's two callers. One wipes e->aux immediately after the call, the
other attaches a newly created object immediately after the call. So we
can wipe e->aux within the call and simplify one of the two call sites.
This is preparatory work for a minor optimization where we want to
detect another class of edge equivalences in DOM (until something better
is available) and either attach them an existing edge_info structure or
create a new one if one doesn't currently exist for a given edge.
Bootstrapped and regression tested on x86_64. Installing on the trunk.
Jeff
commit fbd95c027edcc169cc3b40806375fbabc08500e0
Author: Jeff Law
Date: Fri Sep 30 18:59:24 2022 -0400
Minor cleanup/prep in DOM
It's a bit weird that free_dom_edge_info leaves a dangling pointer in
e->aux.
Not sure what I was thinking.
There's two callers. One wipes e->aux immediately after the call, the other
attaches a newly created object immediately after the call. So we can wipe
e->aux within the call and simplify one of the two call sites.
This is preparatory work for a minor optimization where we want to detect
another class of edge equivalences in DOM (until something better is
available)
and either attach them an existing edge_info structure or create a new one
if
one doesn't currently exist for a given edge.
gcc/
* tree-ssa-dom.cc (free_dom_edge_info): Clear e->aux too.
(free_all_edge_infos): Do not clear e->aux here.
diff --git a/gcc/tree-ssa-dom.cc b/gcc/tree-ssa-dom.cc
index 84bef798f52..fa43dbe6c44 100644
--- a/gcc/tree-ssa-dom.cc
+++ b/gcc/tree-ssa-dom.cc
@@ -393,7 +393,8 @@ edge_info::record_simple_equiv (tree lhs, tree rhs)
simple_equivalences.safe_push (equiv_pair (lhs, rhs));
}
-/* Free the edge_info data attached to E, if it exists. */
+/* Free the edge_info data attached to E, if it exists and
+ clear e->aux. */
void
free_dom_edge_info (edge e)
@@ -402,6 +403,7 @@ free_dom_edge_info (edge e)
if (edge_info)
delete edge_info;
+ e->aux = NULL;
}
/* Free all EDGE_INFO structures associated with edges in the CFG.
@@ -420,10 +422,7 @@ free_all_edge_infos (void)
FOR_EACH_BB_FN (bb, cfun)
{
FOR_EACH_EDGE (e, ei, bb->preds)
-{
- free_dom_edge_info (e);
- e->aux = NULL;
- }
+ free_dom_edge_info (e);
}
}
