Hi All,
This finishes wiring that didn't fit in any of the other patches.
Essentially just adding related changes so peeling for early break works.
Bootstrapped Regtested on aarch64-none-linux-gnu and no issues.
Ok for master?
Thanks,
Tamar
gcc/ChangeLog:
* tree-vect-loop-manip.cc (vect_set_loop_condition_normal,
vect_do_peeling): Support early breaks.
* tree-vect-loop.cc (vect_need_peeling_or_partial_vectors_p): Likewise.
* tree-vectorizer.cc (pass_vectorize::execute): Check all exits.
--- inline copy of patch --
diff --git a/gcc/tree-vect-loop-manip.cc b/gcc/tree-vect-loop-manip.cc
index
eef2bb50c1505f5cf802d5d80300affc2cbe69f6..9c1405d79fd8fe8689007df3b7605b7a3d3ecdd7
100644
--- a/gcc/tree-vect-loop-manip.cc
+++ b/gcc/tree-vect-loop-manip.cc
@@ -1187,7 +1187,7 @@ vect_set_loop_condition_partial_vectors_avx512 (class
loop *loop,
loop handles exactly VF scalars per iteration. */
static gcond *
-vect_set_loop_condition_normal (loop_vec_info /* loop_vinfo */, edge exit_edge,
+vect_set_loop_condition_normal (loop_vec_info loop_vinfo, edge exit_edge,
class loop *loop, tree niters, tree step,
tree final_iv, bool niters_maybe_zero,
gimple_stmt_iterator loop_cond_gsi)
@@ -1296,7 +1296,8 @@ vect_set_loop_condition_normal (loop_vec_info /*
loop_vinfo */, edge exit_edge,
gsi_insert_before (&loop_cond_gsi, cond_stmt, GSI_SAME_STMT);
/* Record the number of latch iterations. */
- if (limit == niters)
+ if (limit == niters
+ || LOOP_VINFO_EARLY_BREAKS (loop_vinfo))
/* Case A: the loop iterates NITERS times. Subtract one to get the
latch count. */
loop->nb_iterations = fold_build2 (MINUS_EXPR, niters_type, niters,
@@ -3242,6 +3243,16 @@ vect_do_peeling (loop_vec_info loop_vinfo, tree niters,
tree nitersm1,
bound_epilog += vf - 1;
if (LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo))
bound_epilog += 1;
+
+ /* For early breaks the scalar loop needs to execute at most VF times
+ to find the element that caused the break. */
+ if (LOOP_VINFO_EARLY_BREAKS (loop_vinfo))
+ {
+ bound_epilog = vf;
+ /* Force a scalar epilogue as we can't vectorize the index finding. */
+ vect_epilogues = false;
+ }
+
bool epilog_peeling = maybe_ne (bound_epilog, 0U);
poly_uint64 bound_scalar = bound_epilog;
@@ -3376,14 +3387,23 @@ vect_do_peeling (loop_vec_info loop_vinfo, tree niters,
tree nitersm1,
bound_prolog + bound_epilog)
: (!LOOP_REQUIRES_VERSIONING (loop_vinfo)
|| vect_epilogues));
+
+ /* We only support early break vectorization on known bounds at this time.
+ This means that if the vector loop can't be entered then we won't generate
+ it at all. So for now force skip_vector off because the additional
control
+ flow messes with the BB exits and we've already analyzed them. */
+ skip_vector = skip_vector && !LOOP_VINFO_EARLY_BREAKS (loop_vinfo);
+
/* Epilog loop must be executed if the number of iterations for epilog
loop is known at compile time, otherwise we need to add a check at
the end of vector loop and skip to the end of epilog loop. */
bool skip_epilog = (prolog_peeling < 0
|| !LOOP_VINFO_NITERS_KNOWN_P (loop_vinfo)
|| !vf.is_constant ());
- /* PEELING_FOR_GAPS is special because epilog loop must be executed. */
- if (LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo))
+ /* PEELING_FOR_GAPS and peeling for early breaks are special because epilog
+ loop must be executed. */
+ if (LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo)
+ || LOOP_VINFO_EARLY_BREAKS (loop_vinfo))
skip_epilog = false;
class loop *scalar_loop = LOOP_VINFO_SCALAR_LOOP (loop_vinfo);
diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc
index
55d6aee3d29151e6b528f6fdde15c693e5bdd847..51a054c5b035ac80dfbbf3b5ba2f6da82fda91f6
100644
--- a/gcc/tree-vect-loop.cc
+++ b/gcc/tree-vect-loop.cc
@@ -1236,6 +1236,14 @@ vect_need_peeling_or_partial_vectors_p (loop_vec_info
loop_vinfo)
th = LOOP_VINFO_COST_MODEL_THRESHOLD (LOOP_VINFO_ORIG_LOOP_INFO
(loop_vinfo));
+ /* When we have multiple exits and VF is unknown, we must require partial
+ vectors because the loop bounds is not a minimum but a maximum. That is
to
+ say we cannot unpredicate the main loop unless we peel or use partial
+ vectors in the epilogue. */
+ if (LOOP_VINFO_EARLY_BREAKS (loop_vinfo)
+ && !LOOP_VINFO_VECT_FACTOR (loop_vinfo).is_constant ())
+ return true;
+
if (LOOP_VINFO_NITERS_KNOWN_P (loop_vinfo)
&& LOOP_VINFO_PEELING_FOR_ALIGNMENT (loop_vinfo) >= 0)
{
@@ -3149,7 +3157,8 @@ start_over:
/* If an epilogue loop is required make sure we can create one. */
if (LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo)
- || LOOP_VINFO_PEELING_FOR_NITER (loop_vinfo))
+ || LOOP_VINFO_PEELING_FOR_NITER (loop_vinfo)
+ || LOOP_VINFO_EARLY_BREAKS (loop_vinfo))
{
if (dump_enabled_p ())
dump_printf_loc (MSG_NOTE, vect_location, "epilog loop required\n");
diff --git a/gcc/tree-vectorizer.cc b/gcc/tree-vectorizer.cc
index
d97e2b54c25ac60378935392aa7b73476efed74b..8b495fc7ca137109fc0097c77837233c660e032a
100644
--- a/gcc/tree-vectorizer.cc
+++ b/gcc/tree-vectorizer.cc
@@ -1381,7 +1381,9 @@ pass_vectorize::execute (function *fun)
predicates that need to be shared for optimal predicate usage.
However reassoc will re-order them and prevent CSE from working
as it should. CSE only the loop body, not the entry. */
- bitmap_set_bit (exit_bbs, single_exit (loop)->dest->index);
+ auto_vec<edge> exits = get_loop_exit_edges (loop);
+ for (edge exit : exits)
+ bitmap_set_bit (exit_bbs, exit->dest->index);
edge entry = EDGE_PRED (loop_preheader_edge (loop)->src, 0);
do_rpo_vn (fun, entry, exit_bbs);
--
diff --git a/gcc/tree-vect-loop-manip.cc b/gcc/tree-vect-loop-manip.cc
index
eef2bb50c1505f5cf802d5d80300affc2cbe69f6..9c1405d79fd8fe8689007df3b7605b7a3d3ecdd7
100644
--- a/gcc/tree-vect-loop-manip.cc
+++ b/gcc/tree-vect-loop-manip.cc
@@ -1187,7 +1187,7 @@ vect_set_loop_condition_partial_vectors_avx512 (class
loop *loop,
loop handles exactly VF scalars per iteration. */
static gcond *
-vect_set_loop_condition_normal (loop_vec_info /* loop_vinfo */, edge exit_edge,
+vect_set_loop_condition_normal (loop_vec_info loop_vinfo, edge exit_edge,
class loop *loop, tree niters, tree step,
tree final_iv, bool niters_maybe_zero,
gimple_stmt_iterator loop_cond_gsi)
@@ -1296,7 +1296,8 @@ vect_set_loop_condition_normal (loop_vec_info /*
loop_vinfo */, edge exit_edge,
gsi_insert_before (&loop_cond_gsi, cond_stmt, GSI_SAME_STMT);
/* Record the number of latch iterations. */
- if (limit == niters)
+ if (limit == niters
+ || LOOP_VINFO_EARLY_BREAKS (loop_vinfo))
/* Case A: the loop iterates NITERS times. Subtract one to get the
latch count. */
loop->nb_iterations = fold_build2 (MINUS_EXPR, niters_type, niters,
@@ -3242,6 +3243,16 @@ vect_do_peeling (loop_vec_info loop_vinfo, tree niters,
tree nitersm1,
bound_epilog += vf - 1;
if (LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo))
bound_epilog += 1;
+
+ /* For early breaks the scalar loop needs to execute at most VF times
+ to find the element that caused the break. */
+ if (LOOP_VINFO_EARLY_BREAKS (loop_vinfo))
+ {
+ bound_epilog = vf;
+ /* Force a scalar epilogue as we can't vectorize the index finding. */
+ vect_epilogues = false;
+ }
+
bool epilog_peeling = maybe_ne (bound_epilog, 0U);
poly_uint64 bound_scalar = bound_epilog;
@@ -3376,14 +3387,23 @@ vect_do_peeling (loop_vec_info loop_vinfo, tree niters,
tree nitersm1,
bound_prolog + bound_epilog)
: (!LOOP_REQUIRES_VERSIONING (loop_vinfo)
|| vect_epilogues));
+
+ /* We only support early break vectorization on known bounds at this time.
+ This means that if the vector loop can't be entered then we won't generate
+ it at all. So for now force skip_vector off because the additional
control
+ flow messes with the BB exits and we've already analyzed them. */
+ skip_vector = skip_vector && !LOOP_VINFO_EARLY_BREAKS (loop_vinfo);
+
/* Epilog loop must be executed if the number of iterations for epilog
loop is known at compile time, otherwise we need to add a check at
the end of vector loop and skip to the end of epilog loop. */
bool skip_epilog = (prolog_peeling < 0
|| !LOOP_VINFO_NITERS_KNOWN_P (loop_vinfo)
|| !vf.is_constant ());
- /* PEELING_FOR_GAPS is special because epilog loop must be executed. */
- if (LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo))
+ /* PEELING_FOR_GAPS and peeling for early breaks are special because epilog
+ loop must be executed. */
+ if (LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo)
+ || LOOP_VINFO_EARLY_BREAKS (loop_vinfo))
skip_epilog = false;
class loop *scalar_loop = LOOP_VINFO_SCALAR_LOOP (loop_vinfo);
diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc
index
55d6aee3d29151e6b528f6fdde15c693e5bdd847..51a054c5b035ac80dfbbf3b5ba2f6da82fda91f6
100644
--- a/gcc/tree-vect-loop.cc
+++ b/gcc/tree-vect-loop.cc
@@ -1236,6 +1236,14 @@ vect_need_peeling_or_partial_vectors_p (loop_vec_info
loop_vinfo)
th = LOOP_VINFO_COST_MODEL_THRESHOLD (LOOP_VINFO_ORIG_LOOP_INFO
(loop_vinfo));
+ /* When we have multiple exits and VF is unknown, we must require partial
+ vectors because the loop bounds is not a minimum but a maximum. That is
to
+ say we cannot unpredicate the main loop unless we peel or use partial
+ vectors in the epilogue. */
+ if (LOOP_VINFO_EARLY_BREAKS (loop_vinfo)
+ && !LOOP_VINFO_VECT_FACTOR (loop_vinfo).is_constant ())
+ return true;
+
if (LOOP_VINFO_NITERS_KNOWN_P (loop_vinfo)
&& LOOP_VINFO_PEELING_FOR_ALIGNMENT (loop_vinfo) >= 0)
{
@@ -3149,7 +3157,8 @@ start_over:
/* If an epilogue loop is required make sure we can create one. */
if (LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo)
- || LOOP_VINFO_PEELING_FOR_NITER (loop_vinfo))
+ || LOOP_VINFO_PEELING_FOR_NITER (loop_vinfo)
+ || LOOP_VINFO_EARLY_BREAKS (loop_vinfo))
{
if (dump_enabled_p ())
dump_printf_loc (MSG_NOTE, vect_location, "epilog loop required\n");
diff --git a/gcc/tree-vectorizer.cc b/gcc/tree-vectorizer.cc
index
d97e2b54c25ac60378935392aa7b73476efed74b..8b495fc7ca137109fc0097c77837233c660e032a
100644
--- a/gcc/tree-vectorizer.cc
+++ b/gcc/tree-vectorizer.cc
@@ -1381,7 +1381,9 @@ pass_vectorize::execute (function *fun)
predicates that need to be shared for optimal predicate usage.
However reassoc will re-order them and prevent CSE from working
as it should. CSE only the loop body, not the entry. */
- bitmap_set_bit (exit_bbs, single_exit (loop)->dest->index);
+ auto_vec<edge> exits = get_loop_exit_edges (loop);
+ for (edge exit : exits)
+ bitmap_set_bit (exit_bbs, exit->dest->index);
edge entry = EDGE_PRED (loop_preheader_edge (loop)->src, 0);
do_rpo_vn (fun, entry, exit_bbs);
