The following patch deals with the testsuite fallout of the patch
forcing LOOP_VECTORIZED () versioning in GIMPLE if-conversion. We
no longer see the if-converted body when doing BB vectorization.
While the real fix would be to teach BB vectorization about
conditions (and thus if-conversion) itself a quick workaround to
restore previous behavior is to simply run BB vectorization
for if-converted loop bodies from inside the loop vectorizer itself.
That fixes the testcase and restores behavior for all
if-converted (but not also unrolled) loops.
Bootstrap & regtest in progress on x86_64-unknown-linux-gnu.
Richard.
2016-11-21 Richard Biener <rguent...@suse.de>
PR tree-optimization/78396
* tree-vectorizer.c (vectorize_loops): If an innermost loop didn't
vectorize try vectorizing an if-converted body using BB vectorization.
* gcc.dg/vect/bb-slp-cond-1.c: Adjust.
diff --git a/gcc/testsuite/gcc.dg/vect/bb-slp-cond-1.c
b/gcc/testsuite/gcc.dg/vect/bb-slp-cond-1.c
index 35811bd..ddad853 100644
--- a/gcc/testsuite/gcc.dg/vect/bb-slp-cond-1.c
+++ b/gcc/testsuite/gcc.dg/vect/bb-slp-cond-1.c
@@ -1,4 +1,5 @@
/* { dg-require-effective-target vect_condition } */
+/* { dg-additional-options "-fdump-tree-vect-details" } */
#include "tree-vect.h"
@@ -41,5 +42,10 @@ int main ()
return 0;
}
-/* { dg-final { scan-tree-dump-times "basic block vectorized" 1 "slp1" {
target vect_element_align } } } */
+/* Basic blocks of if-converted loops are vectorized from within the loop
+ vectorizer pass. In this case it is really a deficiency in loop
+ vectorization data dependence analysis that causes us to require
+ basic block vectorization in the first place. */
+
+/* { dg-final { scan-tree-dump-times "basic block vectorized" 1 "vect" {
target vect_element_align } } } */
diff --git a/gcc/tree-vectorizer.c b/gcc/tree-vectorizer.c
index 35d7a3e..b390664 100644
--- a/gcc/tree-vectorizer.c
+++ b/gcc/tree-vectorizer.c
@@ -540,6 +540,7 @@ vectorize_loops (void)
|| loop->force_vectorize)
{
loop_vec_info loop_vinfo, orig_loop_vinfo = NULL;
+ gimple *loop_vectorized_call = vect_loop_vectorized_call (loop);
vectorize_epilogue:
vect_location = find_loop_location (loop);
if (LOCATION_LOCUS (vect_location) != UNKNOWN_LOCATION
@@ -558,6 +559,33 @@ vectorize_epilogue:
if (loop_constraint_set_p (loop, LOOP_C_FINITE))
vect_free_loop_info_assumptions (loop);
+ /* If we applied if-conversion then try to vectorize the
+ BB of innermost loops.
+ ??? Ideally BB vectorization would learn to vectorize
+ control flow by applying if-conversion on-the-fly, the
+ following retains the if-converted loop body even when
+ only non-if-converted parts took part in BB vectorization. */
+ if (flag_tree_slp_vectorize != 0
+ && loop_vectorized_call
+ && ! loop->inner)
+ {
+ basic_block bb = loop->header;
+ for (gimple_stmt_iterator gsi = gsi_start_bb (bb);
+ !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ gimple *stmt = gsi_stmt (gsi);
+ gimple_set_uid (stmt, -1);
+ gimple_set_visited (stmt, false);
+ }
+ if (vect_slp_bb (bb))
+ {
+ dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, vect_location,
+ "basic block vectorized\n");
+ fold_loop_vectorized_call (loop_vectorized_call,
+ boolean_true_node);
+ ret |= TODO_cleanup_cfg;
+ }
+ }
continue;
}
@@ -575,7 +603,6 @@ vectorize_epilogue:
break;
}
- gimple *loop_vectorized_call = vect_loop_vectorized_call (loop);
if (loop_vectorized_call)
set_uid_loop_bbs (loop_vinfo, loop_vectorized_call);
if (LOCATION_LOCUS (vect_location) != UNKNOWN_LOCATION
