The GET_MODE_NUNITS patch made vect_grouped_store_supported and
vect_grouped_load_supported check for a constant number of elements,
so vect_permute_store_chain and vect_permute_load_chain can assert
for that. This patch adds commentary to that effect; the actual
asserts will be added by a later, more mechanical, patch.
The patch also reorganises the function so that the asserts
are linked specifically to code that builds permute vectors
element-by-element. This allows a later patch to add support
for some variable-length permutes.
2017-10-23 Richard Sandiford <richard.sandif...@linaro.org>
Alan Hayward <alan.hayw...@arm.com>
David Sherwood <david.sherw...@arm.com>
gcc/
* tree-vect-data-refs.c (vect_permute_store_chain): Reorganize
so that both the length == 3 and length != 3 cases set up their
own permute vectors. Add comments explaining why we know the
number of elements is constant.
(vect_permute_load_chain): Likewise.
Index: gcc/tree-vect-data-refs.c
===================================================================
--- gcc/tree-vect-data-refs.c 2017-10-23 17:25:48.623491897 +0100
+++ gcc/tree-vect-data-refs.c 2017-10-23 17:25:50.361429427 +0100
@@ -4734,11 +4734,7 @@ vect_permute_store_chain (vec<tree> dr_c
tree perm_mask_low, perm_mask_high;
tree data_ref;
tree perm3_mask_low, perm3_mask_high;
- unsigned int i, n, log_length = exact_log2 (length);
- unsigned int j, nelt = TYPE_VECTOR_SUBPARTS (vectype);
-
- auto_vec_perm_indices sel (nelt);
- sel.quick_grow (nelt);
+ unsigned int i, j, n, log_length = exact_log2 (length);
result_chain->quick_grow (length);
memcpy (result_chain->address (), dr_chain.address (),
@@ -4746,8 +4742,12 @@ vect_permute_store_chain (vec<tree> dr_c
if (length == 3)
{
+ /* vect_grouped_store_supported ensures that this is constant. */
+ unsigned int nelt = TYPE_VECTOR_SUBPARTS (vectype);
unsigned int j0 = 0, j1 = 0, j2 = 0;
+ auto_vec_perm_indices sel (nelt);
+ sel.quick_grow (nelt);
for (j = 0; j < 3; j++)
{
int nelt0 = ((3 - j) * nelt) % 3;
@@ -4806,6 +4806,10 @@ vect_permute_store_chain (vec<tree> dr_c
/* If length is not equal to 3 then only power of 2 is supported. */
gcc_assert (pow2p_hwi (length));
+ /* vect_grouped_store_supported ensures that this is constant. */
+ unsigned int nelt = TYPE_VECTOR_SUBPARTS (vectype);
+ auto_vec_perm_indices sel (nelt);
+ sel.quick_grow (nelt);
for (i = 0, n = nelt / 2; i < n; i++)
{
sel[i * 2] = i;
@@ -5321,10 +5325,6 @@ vect_permute_load_chain (vec<tree> dr_ch
gimple *perm_stmt;
tree vectype = STMT_VINFO_VECTYPE (vinfo_for_stmt (stmt));
unsigned int i, j, log_length = exact_log2 (length);
- unsigned nelt = TYPE_VECTOR_SUBPARTS (vectype);
-
- auto_vec_perm_indices sel (nelt);
- sel.quick_grow (nelt);
result_chain->quick_grow (length);
memcpy (result_chain->address (), dr_chain.address (),
@@ -5332,8 +5332,12 @@ vect_permute_load_chain (vec<tree> dr_ch
if (length == 3)
{
+ /* vect_grouped_load_supported ensures that this is constant. */
+ unsigned nelt = TYPE_VECTOR_SUBPARTS (vectype);
unsigned int k;
+ auto_vec_perm_indices sel (nelt);
+ sel.quick_grow (nelt);
for (k = 0; k < 3; k++)
{
for (i = 0; i < nelt; i++)
@@ -5379,6 +5383,10 @@ vect_permute_load_chain (vec<tree> dr_ch
/* If length is not equal to 3 then only power of 2 is supported. */
gcc_assert (pow2p_hwi (length));
+ /* vect_grouped_load_supported ensures that this is constant. */
+ unsigned nelt = TYPE_VECTOR_SUBPARTS (vectype);
+ auto_vec_perm_indices sel (nelt);
+ sel.quick_grow (nelt);
for (i = 0; i < nelt; ++i)
sel[i] = i * 2;
perm_mask_even = vect_gen_perm_mask_checked (vectype, sel);
