I am currently testing the following patch to fix PR69378 (another
fallout of the PR69117 fix).
Bootstrap and regtest running on x86_64-unknown-linux-gnu.
Richard.
2016-01-20 Richard Biener <rguent...@suse.de>
PR tree-optimization/69378
* tree-ssa-sccvn.c (dominated_by_p_w_unex): New function.
(set_ssa_val_to): Use it for dominance checks taking into
account not executable edges.
Index: gcc/tree-ssa-sccvn.c
===================================================================
*** gcc/tree-ssa-sccvn.c (revision 232603)
--- gcc/tree-ssa-sccvn.c (working copy)
*************** print_scc (FILE *out, vec<tree> scc)
*** 2969,2974 ****
--- 2969,3055 ----
fprintf (out, "\n");
}
+ /* Return true if BB1 is dominated by BB2 taking into account edges
+ that are not executable. */
+
+ static bool
+ dominated_by_p_w_unex (basic_block bb1, basic_block bb2)
+ {
+ edge_iterator ei;
+ edge e;
+
+ if (dominated_by_p (CDI_DOMINATORS, bb1, bb2))
+ return true;
+
+ /* Before iterating we'd like to know if there exists a
+ (executable) path from bb2 to bb1 at all, if not we can
+ directly return false. For now simply iterate once. */
+
+ /* Iterate to the single executable bb1 predecessor. */
+ if (EDGE_COUNT (bb1->preds) > 1)
+ {
+ edge prede = NULL;
+ FOR_EACH_EDGE (e, ei, bb1->preds)
+ if (e->flags & EDGE_EXECUTABLE)
+ {
+ if (prede)
+ {
+ prede = NULL;
+ break;
+ }
+ prede = e;
+ }
+ if (prede)
+ {
+ bb1 = prede->src;
+
+ /* Re-do the dominance check with changed bb1. */
+ if (dominated_by_p (CDI_DOMINATORS, bb1, bb2))
+ return true;
+ }
+ }
+
+ /* Iterate to the single executable bb2 successor. */
+ edge succe = NULL;
+ FOR_EACH_EDGE (e, ei, bb2->succs)
+ if (e->flags & EDGE_EXECUTABLE)
+ {
+ if (succe)
+ {
+ succe = NULL;
+ break;
+ }
+ succe = e;
+ }
+ if (succe)
+ {
+ /* Verify the reached block is only reached through succe.
+ If there is only one edge we can spare us the dominator
+ check and iterate directly. */
+ if (EDGE_COUNT (succe->dest->preds) > 1)
+ {
+ FOR_EACH_EDGE (e, ei, succe->dest->preds)
+ if (e != succe
+ && (e->flags & EDGE_EXECUTABLE))
+ {
+ succe = NULL;
+ break;
+ }
+ }
+ if (succe)
+ {
+ bb2 = succe->dest;
+
+ /* Re-do the dominance check with changed bb2. */
+ if (dominated_by_p (CDI_DOMINATORS, bb1, bb2))
+ return true;
+ }
+ }
+
+ /* We could now iterate updating bb1 / bb2. */
+ return false;
+ }
+
/* Set the value number of FROM to TO, return true if it has changed
as a result. */
*************** set_ssa_val_to (tree from, tree to)
*** 3046,3060 ****
&& SSA_NAME_RANGE_INFO (to))
{
if (SSA_NAME_IS_DEFAULT_DEF (to)
! || dominated_by_p (CDI_DOMINATORS,
! gimple_bb (SSA_NAME_DEF_STMT (from)),
! gimple_bb (SSA_NAME_DEF_STMT (to))))
/* Keep the info from the dominator. */
;
else if (SSA_NAME_IS_DEFAULT_DEF (from)
! || dominated_by_p (CDI_DOMINATORS,
! gimple_bb (SSA_NAME_DEF_STMT (to)),
! gimple_bb (SSA_NAME_DEF_STMT (from))))
{
/* Save old info. */
if (! VN_INFO (to)->info.range_info)
--- 3127,3141 ----
&& SSA_NAME_RANGE_INFO (to))
{
if (SSA_NAME_IS_DEFAULT_DEF (to)
! || dominated_by_p_w_unex
! (gimple_bb (SSA_NAME_DEF_STMT (from)),
! gimple_bb (SSA_NAME_DEF_STMT (to))))
/* Keep the info from the dominator. */
;
else if (SSA_NAME_IS_DEFAULT_DEF (from)
! || dominated_by_p_w_unex
! (gimple_bb (SSA_NAME_DEF_STMT (to)),
! gimple_bb (SSA_NAME_DEF_STMT (from))))
{
/* Save old info. */
if (! VN_INFO (to)->info.range_info)
*************** set_ssa_val_to (tree from, tree to)
*** 3076,3090 ****
&& SSA_NAME_PTR_INFO (to))
{
if (SSA_NAME_IS_DEFAULT_DEF (to)
! || dominated_by_p (CDI_DOMINATORS,
! gimple_bb (SSA_NAME_DEF_STMT (from)),
! gimple_bb (SSA_NAME_DEF_STMT (to))))
/* Keep the info from the dominator. */
;
else if (SSA_NAME_IS_DEFAULT_DEF (from)
! || dominated_by_p (CDI_DOMINATORS,
! gimple_bb (SSA_NAME_DEF_STMT (to)),
! gimple_bb (SSA_NAME_DEF_STMT (from))))
{
/* Save old info. */
if (! VN_INFO (to)->info.ptr_info)
--- 3157,3171 ----
&& SSA_NAME_PTR_INFO (to))
{
if (SSA_NAME_IS_DEFAULT_DEF (to)
! || dominated_by_p_w_unex
! (gimple_bb (SSA_NAME_DEF_STMT (from)),
! gimple_bb (SSA_NAME_DEF_STMT (to))))
/* Keep the info from the dominator. */
;
else if (SSA_NAME_IS_DEFAULT_DEF (from)
! || dominated_by_p_w_unex
! (gimple_bb (SSA_NAME_DEF_STMT (to)),
! gimple_bb (SSA_NAME_DEF_STMT (from))))
{
/* Save old info. */
if (! VN_INFO (to)->info.ptr_info)
