The following fixes the excessive peeling for gaps we do when doing
SLP now that I removed most of the restrictions on having gaps in
the first place.
This should make low-trip vectorized loops more efficient (sth
also the combine-epilogue-with-vectorized-body-by-masking patches
claim to do).
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.
Richard.
2015-11-27 Richard Biener <rguent...@suse.de>
PR tree-optimization/68559
* tree-vect-data-refs.c (vect_analyze_group_access_1): Move
peeling for gap checks ...
* tree-vect-stmts.c (vectorizable_load): ... here and relax
for SLP.
* tree-vect-loop.c (vect_analyze_loop_2): Re-set
LOOP_VINFO_PEELING_FOR_GAPS before re-trying without SLP.
* gcc.dg/vect/slp-perm-4.c: Adjust again.
* gcc.dg/vect/pr45752.c: Likewise.
Index: gcc/tree-vect-stmts.c
===================================================================
*** gcc/tree-vect-stmts.c (revision 230998)
--- gcc/tree-vect-stmts.c (working copy)
*************** vectorizable_load (gimple *stmt, gimple_
*** 6246,6260 ****
that leaves unused vector loads around punt - we at least create
very sub-optimal code in that case (and blow up memory,
see PR65518). */
if (first_stmt == stmt
! && !GROUP_NEXT_ELEMENT (stmt_info)
! && GROUP_SIZE (stmt_info) > TYPE_VECTOR_SUBPARTS (vectype))
{
if (dump_enabled_p ())
dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
! "single-element interleaving not supported "
! "for not adjacent vector loads\n");
! return false;
}
if (slp && SLP_TREE_LOAD_PERMUTATION (slp_node).exists ())
--- 6250,6294 ----
that leaves unused vector loads around punt - we at least create
very sub-optimal code in that case (and blow up memory,
see PR65518). */
+ bool force_peeling = false;
if (first_stmt == stmt
! && !GROUP_NEXT_ELEMENT (stmt_info))
! {
! if (GROUP_SIZE (stmt_info) > TYPE_VECTOR_SUBPARTS (vectype))
! {
! if (dump_enabled_p ())
! dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
! "single-element interleaving not supported "
! "for not adjacent vector loads\n");
! return false;
! }
!
! /* Single-element interleaving requires peeling for gaps. */
! force_peeling = true;
! }
!
! /* If there is a gap in the end of the group or the group size cannot
! be made a multiple of the vector element count then we access excess
! elements in the last iteration and thus need to peel that off. */
! if (loop_vinfo
! && ! STMT_VINFO_STRIDED_P (stmt_info)
! && (force_peeling
! || GROUP_GAP (vinfo_for_stmt (first_stmt)) != 0
! || (!slp && vf % GROUP_SIZE (vinfo_for_stmt (first_stmt)) != 0)))
{
if (dump_enabled_p ())
dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
! "Data access with gaps requires scalar "
! "epilogue loop\n");
! if (loop->inner)
! {
! if (dump_enabled_p ())
! dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
! "Peeling for outer loop is not supported\n");
! return false;
! }
!
! LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo) = true;
}
if (slp && SLP_TREE_LOAD_PERMUTATION (slp_node).exists ())
Index: gcc/testsuite/gcc.dg/vect/slp-perm-4.c
===================================================================
*** gcc/testsuite/gcc.dg/vect/slp-perm-4.c (revision 230998)
--- gcc/testsuite/gcc.dg/vect/slp-perm-4.c (working copy)
***************
*** 33,39 ****
#define M34 7716
#define M44 16
! #define N 40
void foo (unsigned int *__restrict__ pInput, unsigned int *__restrict__
pOutput)
{
--- 33,39 ----
#define M34 7716
#define M44 16
! #define N 20
void foo (unsigned int *__restrict__ pInput, unsigned int *__restrict__
pOutput)
{
*************** int main (int argc, const char* argv[])
*** 60,68 ****
unsigned int input[N], output[N], i;
unsigned int check_results[N]
= {3208, 1334, 28764, 35679, 2789, 13028, 4754, 168364, 91254, 12399,
! 22848, 8174, 307964, 146829, 22009, 32668, 11594, 447564, 202404, 31619,
! 42488, 15014, 587164, 257979, 41229, 52308, 18434, 726764, 313554, 50839,
! 62128, 21854, 866364, 369129, 60449, 71948, 25274, 1005964, 424704,
70059};
check_vect ();
--- 60,66 ----
unsigned int input[N], output[N], i;
unsigned int check_results[N]
= {3208, 1334, 28764, 35679, 2789, 13028, 4754, 168364, 91254, 12399,
! 22848, 8174, 307964, 146829, 22009, 32668, 11594, 447564, 202404, 31619};
check_vect ();
*************** int main (int argc, const char* argv[])
*** 85,89 ****
}
/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" } } */
/* { dg-final { scan-tree-dump-times "vectorizing stmts using SLP" 1 "vect" {
target vect_perm } } } */
-
--- 83,87 ----
}
/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" } } */
+ /* { dg-final { scan-tree-dump-times "gaps requires scalar epilogue loop" 0
"vect" } } */
/* { dg-final { scan-tree-dump-times "vectorizing stmts using SLP" 1 "vect" {
target vect_perm } } } */
Index: gcc/testsuite/gcc.dg/vect/pr45752.c
===================================================================
*** gcc/testsuite/gcc.dg/vect/pr45752.c (revision 230998)
--- gcc/testsuite/gcc.dg/vect/pr45752.c (working copy)
***************
*** 33,39 ****
#define M34 7716
#define M44 16
! #define N 40
void foo (unsigned int *__restrict__ pInput,
unsigned int *__restrict__ pOutput,
--- 33,39 ----
#define M34 7716
#define M44 16
! #define N 20
void foo (unsigned int *__restrict__ pInput,
unsigned int *__restrict__ pOutput,
*************** int main (int argc, const char* argv[])
*** 77,90 ****
unsigned int input[N], output[N], i, input2[N], output2[N];
unsigned int check_results[N]
= {3208, 1334, 28764, 35679, 2789, 13028, 4754, 168364, 91254, 12399,
! 22848, 8174, 307964, 146829, 22009, 32668, 11594, 447564, 202404, 31619,
! 42488, 15014, 587164, 257979, 41229, 52308, 18434, 726764, 313554, 50839,
! 62128, 21854, 866364, 369129, 60449, 71948, 25274, 1005964, 424704,
70059};
unsigned int check_results2[N]
= {7136, 2702, 84604, 57909, 6633, 16956, 6122, 224204, 113484, 16243,
! 26776, 9542, 363804, 169059, 25853, 36596, 12962, 503404, 224634, 35463,
! 46416, 16382, 643004, 280209, 45073, 56236, 19802, 782604, 335784, 54683,
! 66056, 23222, 922204, 391359, 64293, 75876, 26642, 1061804, 446934,
73903};
check_vect ();
--- 77,86 ----
unsigned int input[N], output[N], i, input2[N], output2[N];
unsigned int check_results[N]
= {3208, 1334, 28764, 35679, 2789, 13028, 4754, 168364, 91254, 12399,
! 22848, 8174, 307964, 146829, 22009, 32668, 11594, 447564, 202404, 31619 };
unsigned int check_results2[N]
= {7136, 2702, 84604, 57909, 6633, 16956, 6122, 224204, 113484, 16243,
! 26776, 9542, 363804, 169059, 25853, 36596, 12962, 503404, 224634, 35463 };
check_vect ();
*************** int main (int argc, const char* argv[])
*** 108,111 ****
--- 104,108 ----
}
/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" } } */
+ /* { dg-final { scan-tree-dump-times "gaps requires scalar epilogue loop" 0
"vect" } } */
/* { dg-final { scan-tree-dump-times "vectorizing stmts using SLP" 2 "vect" {
target vect_perm } } } */
Index: gcc/tree-vect-loop.c
===================================================================
--- gcc/tree-vect-loop.c (revision 230998)
+++ gcc/tree-vect-loop.c (working copy)
@@ -2190,6 +2190,7 @@ again:
= init_cost (LOOP_VINFO_LOOP (loop_vinfo));
/* Reset assorted flags. */
LOOP_VINFO_PEELING_FOR_NITER (loop_vinfo) = false;
+ LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo) = false;
LOOP_VINFO_COST_MODEL_THRESHOLD (loop_vinfo) = 0;
goto start_over;
Index: gcc/tree-vect-data-refs.c
===================================================================
--- gcc/tree-vect-data-refs.c (revision 231005)
+++ gcc/tree-vect-data-refs.c (working copy)
@@ -2166,10 +2166,6 @@ vect_analyze_group_access_1 (struct data
HOST_WIDE_INT dr_step = -1;
HOST_WIDE_INT groupsize, last_accessed_element = 1;
bool slp_impossible = false;
- struct loop *loop = NULL;
-
- if (loop_vinfo)
- loop = LOOP_VINFO_LOOP (loop_vinfo);
/* For interleaving, GROUPSIZE is STEP counted in elements, i.e., the
size of the interleaving group (including gaps). */
@@ -2227,24 +2223,6 @@ vect_analyze_group_access_1 (struct data
dump_printf (MSG_NOTE, "\n");
}
- if (loop_vinfo)
- {
- if (dump_enabled_p ())
- dump_printf_loc (MSG_NOTE, vect_location,
- "Data access with gaps requires scalar "
- "epilogue loop\n");
- if (loop->inner)
- {
- if (dump_enabled_p ())
- dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
- "Peeling for outer loop is not"
- " supported\n");
- return false;
- }
-
- LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo) = true;
- }
-
return true;
}
@@ -2399,29 +2377,6 @@ vect_analyze_group_access_1 (struct data
if (bb_vinfo)
BB_VINFO_GROUPED_STORES (bb_vinfo).safe_push (stmt);
}
-
- /* If there is a gap in the end of the group or the group size cannot
- be made a multiple of the vector element count then we access excess
- elements in the last iteration and thus need to peel that off. */
- if (loop_vinfo
- && (groupsize - last_accessed_element > 0
- || exact_log2 (groupsize) == -1))
-
- {
- if (dump_enabled_p ())
- dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
- "Data access with gaps requires scalar "
- "epilogue loop\n");
- if (loop->inner)
- {
- if (dump_enabled_p ())
- dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
- "Peeling for outer loop is not supported\n");
- return false;
- }
-
- LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo) = true;
- }
}
return true;
