vect_recog_rotate_pattern had code to prevent operations
on invariants being vectorised unnecessarily:
if (dt == vect_external_def
&& TREE_CODE (oprnd1) == SSA_NAME
&& is_a <loop_vec_info> (vinfo))
{
struct loop *loop = as_a <loop_vec_info> (vinfo)->loop;
ext_def = loop_preheader_edge (loop);
if (!SSA_NAME_IS_DEFAULT_DEF (oprnd1))
{
basic_block bb = gimple_bb (SSA_NAME_DEF_STMT (oprnd1));
if (bb == NULL
|| !dominated_by_p (CDI_DOMINATORS, ext_def->dest, bb))
ext_def = NULL;
}
}
[..]
if (ext_def)
{
basic_block new_bb
= gsi_insert_on_edge_immediate (ext_def, def_stmt);
gcc_assert (!new_bb);
}
This patch reuses the same idea for casts of invariants created
during widening optimisations.
One hitch was that vect_loop_versioning asserted that the vector loop
preheader was still empty, although the cfg transformation it's doing
should be correct either way.
Tested on aarch64-linux-gnu and x86_64-linux-gnu. OK to install?
Richard
2018-06-20 Richard Sandiford <richard.sandif...@arm.com>
gcc/
* tree-vect-patterns.c (vect_get_external_def_edge): New function,
split out from...
(vect_recog_rotate_pattern): ...here.
(vect_convert_input): Try to insert casts of invariants in the
preheader.
* tree-vect-loop-manip.c (vect_loop_versioning): Don't require the
preheader to be empty.
gcc/testsuite/
* gcc.dg/vect/vect-widen-mult-extern-1.c: New test.
Index: gcc/tree-vect-patterns.c
===================================================================
--- gcc/tree-vect-patterns.c 2018-06-20 11:26:11.409264955 +0100
+++ gcc/tree-vect-patterns.c 2018-06-20 11:26:16.089223672 +0100
@@ -123,6 +123,30 @@ new_pattern_def_seq (stmt_vec_info stmt_
append_pattern_def_seq (stmt_info, stmt);
}
+/* The caller wants to perform new operations on vect_external variable
+ VAR, so that the result of the operations would also be vect_external.
+ Return the edge on which the operations can be performed, if one exists.
+ Return null if the operations should instead be treated as part of
+ the pattern that needs them. */
+
+static edge
+vect_get_external_def_edge (vec_info *vinfo, tree var)
+{
+ edge e = NULL;
+ if (loop_vec_info loop_vinfo = dyn_cast <loop_vec_info> (vinfo))
+ {
+ e = loop_preheader_edge (loop_vinfo->loop);
+ if (!SSA_NAME_IS_DEFAULT_DEF (var))
+ {
+ basic_block bb = gimple_bb (SSA_NAME_DEF_STMT (var));
+ if (bb == NULL
+ || !dominated_by_p (CDI_DOMINATORS, e->dest, bb))
+ e = NULL;
+ }
+ }
+ return e;
+}
+
/* Return true if the target supports a vector version of CODE,
where CODE is known to map to a direct optab. ITYPE specifies
the type of (some of) the scalar inputs and OTYPE specifies the
@@ -561,6 +585,16 @@ vect_convert_input (stmt_vec_info stmt_i
tree new_op = vect_recog_temp_ssa_var (type, NULL);
gassign *new_stmt = gimple_build_assign (new_op, NOP_EXPR, unprom->op);
+ /* If OP is an external value, see if we can insert the new statement
+ on an incoming edge. */
+ if (unprom->dt == vect_external_def)
+ if (edge e = vect_get_external_def_edge (stmt_info->vinfo, unprom->op))
+ {
+ basic_block new_bb = gsi_insert_on_edge_immediate (e, new_stmt);
+ gcc_assert (!new_bb);
+ return new_op;
+ }
+
/* As a (common) last resort, add the statement to the pattern itself. */
append_pattern_def_seq (stmt_info, new_stmt, vectype);
return new_op;
@@ -1760,19 +1794,8 @@ vect_recog_rotate_pattern (vec<gimple *>
*type_out = vectype;
if (dt == vect_external_def
- && TREE_CODE (oprnd1) == SSA_NAME
- && is_a <loop_vec_info> (vinfo))
- {
- struct loop *loop = as_a <loop_vec_info> (vinfo)->loop;
- ext_def = loop_preheader_edge (loop);
- if (!SSA_NAME_IS_DEFAULT_DEF (oprnd1))
- {
- basic_block bb = gimple_bb (SSA_NAME_DEF_STMT (oprnd1));
- if (bb == NULL
- || !dominated_by_p (CDI_DOMINATORS, ext_def->dest, bb))
- ext_def = NULL;
- }
- }
+ && TREE_CODE (oprnd1) == SSA_NAME)
+ ext_def = vect_get_external_def_edge (vinfo, oprnd1);
def = NULL_TREE;
scalar_int_mode mode = SCALAR_INT_TYPE_MODE (type);
Index: gcc/tree-vect-loop-manip.c
===================================================================
--- gcc/tree-vect-loop-manip.c 2018-06-20 08:59:51.294580064 +0100
+++ gcc/tree-vect-loop-manip.c 2018-06-20 11:26:16.089223672 +0100
@@ -3034,8 +3034,9 @@ vect_loop_versioning (loop_vec_info loop
while we need to move it above LOOP's preheader. */
e = loop_preheader_edge (loop);
scalar_e = loop_preheader_edge (scalar_loop);
- gcc_assert (empty_block_p (e->src)
- && single_pred_p (e->src));
+ /* The vector loop preheader might not be empty, since new
+ invariants could have been created while analyzing the loop. */
+ gcc_assert (single_pred_p (e->src));
gcc_assert (empty_block_p (scalar_e->src)
&& single_pred_p (scalar_e->src));
gcc_assert (single_pred_p (condition_bb));
Index: gcc/testsuite/gcc.dg/vect/vect-widen-mult-extern-1.c
===================================================================
--- /dev/null 2018-06-13 14:36:57.192460992 +0100
+++ gcc/testsuite/gcc.dg/vect/vect-widen-mult-extern-1.c 2018-06-20
11:26:16.089223672 +0100
@@ -0,0 +1,15 @@
+/* { dg-do compile } */
+
+#define N 1024
+
+void
+f (unsigned int *x1, unsigned int *x2, unsigned short *y, unsigned char z)
+{
+ unsigned short zu = z;
+ for (int i = 0; i < N; ++i)
+ {
+ unsigned short yi = y[i];
+ x1[i] = x1[i] > 10 ? yi * zu : x1[i] + 1;
+ x2[i] += 1;
+ }
+}
