public inbox for gcc-cvs@sourceware.org
help / color / mirror / Atom feed
* [gcc r12-4706] Move negative stride bias out of dr_misalignment
@ 2021-10-26 10:30 Richard Biener
0 siblings, 0 replies; only message in thread
From: Richard Biener @ 2021-10-26 10:30 UTC (permalink / raw)
To: gcc-cvs
https://gcc.gnu.org/g:94f28340513753ba94ab483e93ce1d096842a5ad
commit r12-4706-g94f28340513753ba94ab483e93ce1d096842a5ad
Author: Richard Biener <rguenther@suse.de>
Date: Mon Oct 25 13:39:07 2021 +0200
Move negative stride bias out of dr_misalignment
This moves applying of a bias for negative stride accesses out of
dr_misalignment in favor of a more general optional offset argument.
The negative bias is now computed by get_load_store_type and applied
accordingly to determine the alignment support scheme. Likewise
the peeling/versioning code is adjusted albeit that still assumes
we'll end up with VMAT_CONTIGUOUS_DOWN or VMAT_CONTIGUOUS_REVERSE
but at least when not so (VMAT_STRIDED_SLP is one possibility) then
get_load_store_type will _not_ falsely report an aligned access but
instead an access with known misalignment.
This fixes PR96109.
2021-10-25 Richard Biener <rguenther@suse.de>
PR tree-optimization/96109
* tree-vectorizer.h (dr_misalignment): Add optional offset
parameter.
* tree-vect-data-refs.c (dr_misalignment): Likewise. Remove
offset applied for negative stride accesses.
(vect_enhance_data_refs_alignment): Compute negative stride
access offset and pass it to dr_misalignment.
* tree-vect-stmts.c (get_negative_load_store_type): Pass
negative offset to dr_misalignment.
(get_group_load_store_type): Likewise.
(get_load_store_type): Likewise.
(vectorizable_store): Remove asserts about alignment.
(vectorizable_load): Likewise.
Diff:
---
gcc/tree-vect-data-refs.c | 58 +++++++++++++++++++++++++++++++----------------
gcc/tree-vect-stmts.c | 20 ++++++----------
gcc/tree-vectorizer.h | 3 ++-
3 files changed, 48 insertions(+), 33 deletions(-)
diff --git a/gcc/tree-vect-data-refs.c b/gcc/tree-vect-data-refs.c
index 46360c50bd4..cda89ef9725 100644
--- a/gcc/tree-vect-data-refs.c
+++ b/gcc/tree-vect-data-refs.c
@@ -887,10 +887,11 @@ vect_slp_analyze_instance_dependence (vec_info *vinfo, slp_instance instance)
return res;
}
-/* Return the misalignment of DR_INFO accessed in VECTYPE. */
+/* Return the misalignment of DR_INFO accessed in VECTYPE with OFFSET
+ applied. */
int
-dr_misalignment (dr_vec_info *dr_info, tree vectype)
+dr_misalignment (dr_vec_info *dr_info, tree vectype, poly_int64 offset)
{
HOST_WIDE_INT diff = 0;
/* Alignment is only analyzed for the first element of a DR group,
@@ -919,13 +920,9 @@ dr_misalignment (dr_vec_info *dr_info, tree vectype)
targetm.vectorize.preferred_vector_alignment (vectype)))
return DR_MISALIGNMENT_UNKNOWN;
- /* If this is a backward running DR then first access in the larger
- vectype actually is N-1 elements before the address in the DR.
- Adjust misalign accordingly. */
- poly_int64 misalignment = misalign + diff;
- if (tree_int_cst_sgn (DR_STEP (dr_info->dr)) < 0)
- misalignment += ((TYPE_VECTOR_SUBPARTS (vectype) - 1)
- * -TREE_INT_CST_LOW (TYPE_SIZE_UNIT (TREE_TYPE (vectype))));
+ /* Apply the offset from the DR group start and the externally supplied
+ offset which can for example result from a negative stride access. */
+ poly_int64 misalignment = misalign + diff + offset;
/* vect_compute_data_ref_alignment will have ensured that target_alignment
is constant and otherwise set misalign to DR_MISALIGNMENT_UNKNOWN. */
@@ -1549,8 +1546,15 @@ vect_get_peeling_costs_all_drs (loop_vec_info loop_vinfo,
int misalignment;
unsigned HOST_WIDE_INT alignment;
+ bool negative = tree_int_cst_compare (DR_STEP (dr_info->dr),
+ size_zero_node) < 0;
+ poly_int64 off = 0;
+ if (negative)
+ off = ((TYPE_VECTOR_SUBPARTS (vectype) - 1)
+ * -TREE_INT_CST_LOW (TYPE_SIZE_UNIT (TREE_TYPE (vectype))));
+
if (npeel == 0)
- misalignment = dr_misalignment (dr_info, vectype);
+ misalignment = dr_misalignment (dr_info, vectype, off);
else if (dr_info == dr0_info
|| vect_dr_aligned_if_peeled_dr_is (dr_info, dr0_info))
misalignment = 0;
@@ -1560,7 +1564,7 @@ vect_get_peeling_costs_all_drs (loop_vec_info loop_vinfo,
misalignment = DR_MISALIGNMENT_UNKNOWN;
else
{
- misalignment = dr_misalignment (dr_info, vectype);
+ misalignment = dr_misalignment (dr_info, vectype, off);
misalignment += npeel * TREE_INT_CST_LOW (DR_STEP (dr_info->dr));
misalignment &= alignment - 1;
}
@@ -1960,8 +1964,11 @@ vect_enhance_data_refs_alignment (loop_vec_info loop_vinfo)
*/
unsigned int target_align =
DR_TARGET_ALIGNMENT (dr_info).to_constant ();
- unsigned int dr_size = vect_get_scalar_dr_size (dr_info);
- unsigned int mis = dr_misalignment (dr_info, vectype);
+ unsigned HOST_WIDE_INT dr_size = vect_get_scalar_dr_size (dr_info);
+ poly_int64 off = 0;
+ if (negative)
+ off = (TYPE_VECTOR_SUBPARTS (vectype) - 1) * -dr_size;
+ unsigned int mis = dr_misalignment (dr_info, vectype, off);
mis = negative ? mis : -mis;
if (mis != 0)
npeel_tmp = (mis & (target_align - 1)) / dr_size;
@@ -2238,8 +2245,13 @@ vect_enhance_data_refs_alignment (loop_vec_info loop_vinfo)
updating DR_MISALIGNMENT values. The peeling factor is the
vectorization factor minus the misalignment as an element
count. */
+ tree vectype = STMT_VINFO_VECTYPE (stmt_info);
+ poly_int64 off = 0;
+ if (negative)
+ off = ((TYPE_VECTOR_SUBPARTS (vectype) - 1)
+ * -TREE_INT_CST_LOW (TYPE_SIZE_UNIT (TREE_TYPE (vectype))));
unsigned int mis
- = dr_misalignment (dr0_info, STMT_VINFO_VECTYPE (stmt_info));
+ = dr_misalignment (dr0_info, vectype, off);
mis = negative ? mis : -mis;
/* If known_alignment_for_access_p then we have set
DR_MISALIGNMENT which is only done if we know it at compiler
@@ -2383,19 +2395,27 @@ vect_enhance_data_refs_alignment (loop_vec_info loop_vinfo)
FOR_EACH_VEC_ELT (datarefs, i, dr)
{
dr_vec_info *dr_info = loop_vinfo->lookup_dr (dr);
- stmt_vec_info stmt_info = dr_info->stmt;
- tree vectype = STMT_VINFO_VECTYPE (stmt_info);
- int misalignment;
- if ((misalignment = dr_misalignment (dr_info, vectype)) == 0
- || !vect_relevant_for_alignment_p (dr_info))
+ if (!vect_relevant_for_alignment_p (dr_info))
continue;
+ stmt_vec_info stmt_info = dr_info->stmt;
if (STMT_VINFO_STRIDED_P (stmt_info))
{
do_versioning = false;
break;
}
+ tree vectype = STMT_VINFO_VECTYPE (stmt_info);
+ bool negative = tree_int_cst_compare (DR_STEP (dr),
+ size_zero_node) < 0;
+ poly_int64 off = 0;
+ if (negative)
+ off = ((TYPE_VECTOR_SUBPARTS (vectype) - 1)
+ * -TREE_INT_CST_LOW (TYPE_SIZE_UNIT (TREE_TYPE (vectype))));
+ int misalignment;
+ if ((misalignment = dr_misalignment (dr_info, vectype, off)) == 0)
+ continue;
+
enum dr_alignment_support supportable_dr_alignment
= vect_supportable_dr_alignment (loop_vinfo, dr_info, vectype,
misalignment);
diff --git a/gcc/tree-vect-stmts.c b/gcc/tree-vect-stmts.c
index 1f56e10709e..3cd338a73eb 100644
--- a/gcc/tree-vect-stmts.c
+++ b/gcc/tree-vect-stmts.c
@@ -2001,7 +2001,7 @@ get_negative_load_store_type (vec_info *vinfo,
*poffset = ((-TYPE_VECTOR_SUBPARTS (vectype) + 1)
* TREE_INT_CST_LOW (TYPE_SIZE_UNIT (TREE_TYPE (vectype))));
- int misalignment = dr_misalignment (dr_info, vectype);
+ int misalignment = dr_misalignment (dr_info, vectype, *poffset);
alignment_support_scheme
= vect_supportable_dr_alignment (vinfo, dr_info, vectype, misalignment);
if (alignment_support_scheme != dr_aligned
@@ -2010,8 +2010,8 @@ get_negative_load_store_type (vec_info *vinfo,
if (dump_enabled_p ())
dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
"negative step but alignment required.\n");
- return VMAT_ELEMENTWISE;
*poffset = 0;
+ return VMAT_ELEMENTWISE;
}
if (vls_type == VLS_STORE_INVARIANT)
@@ -2320,7 +2320,7 @@ get_group_load_store_type (vec_info *vinfo, stmt_vec_info stmt_info,
}
else
{
- *misalignment = dr_misalignment (first_dr_info, vectype);
+ *misalignment = dr_misalignment (first_dr_info, vectype, *poffset);
*alignment_support_scheme
= vect_supportable_dr_alignment (vinfo, first_dr_info, vectype,
*misalignment);
@@ -2470,7 +2470,7 @@ get_load_store_type (vec_info *vinfo, stmt_vec_info stmt_info,
else
*memory_access_type = VMAT_CONTIGUOUS;
*misalignment = dr_misalignment (STMT_VINFO_DR_INFO (stmt_info),
- vectype);
+ vectype, *poffset);
*alignment_support_scheme
= vect_supportable_dr_alignment (vinfo,
STMT_VINFO_DR_INFO (stmt_info),
@@ -8252,10 +8252,7 @@ vectorizable_store (vec_info *vinfo,
align = known_alignment (DR_TARGET_ALIGNMENT (first_dr_info));
if (alignment_support_scheme == dr_aligned)
- {
- gcc_assert (aligned_access_p (first_dr_info, vectype));
- misalign = 0;
- }
+ misalign = 0;
else if (misalignment == DR_MISALIGNMENT_UNKNOWN)
{
align = dr_alignment (vect_dr_behavior (vinfo, first_dr_info));
@@ -8340,7 +8337,7 @@ vectorizable_store (vec_info *vinfo,
? dataref_offset
: build_int_cst (ref_type, 0));
if (alignment_support_scheme == dr_aligned)
- gcc_assert (aligned_access_p (first_dr_info, vectype));
+ ;
else
TREE_TYPE (data_ref)
= build_aligned_type (TREE_TYPE (data_ref),
@@ -9589,10 +9586,7 @@ vectorizable_load (vec_info *vinfo,
align =
known_alignment (DR_TARGET_ALIGNMENT (first_dr_info));
if (alignment_support_scheme == dr_aligned)
- {
- gcc_assert (aligned_access_p (first_dr_info, vectype));
- misalign = 0;
- }
+ misalign = 0;
else if (misalignment == DR_MISALIGNMENT_UNKNOWN)
{
align = dr_alignment
diff --git a/gcc/tree-vectorizer.h b/gcc/tree-vectorizer.h
index 866d813a12c..52cdfbfae02 100644
--- a/gcc/tree-vectorizer.h
+++ b/gcc/tree-vectorizer.h
@@ -1606,7 +1606,8 @@ set_dr_misalignment (dr_vec_info *dr_info, int val)
dr_info->misalignment = val;
}
-extern int dr_misalignment (dr_vec_info *dr_info, tree vectype);
+extern int dr_misalignment (dr_vec_info *dr_info, tree vectype,
+ poly_int64 offset = 0);
#define SET_DR_MISALIGNMENT(DR, VAL) set_dr_misalignment (DR, VAL)
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2021-10-26 10:30 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-10-26 10:30 [gcc r12-4706] Move negative stride bias out of dr_misalignment Richard Biener
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).