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| author | Richard Sandiford <rsandifo@gcc.gnu.org> | 2017-08-04 10:40:35 +0000 |
|---|---|---|
| committer | Richard Sandiford <rsandifo@gcc.gnu.org> | 2017-08-04 10:40:35 +0000 |
| commit | 9adee3052156ae36271be28e3ad47dd975c26f42 (patch) | |
| tree | 6f0ef701d303fb3c40566aa3bcbea2eea6ba1a52 /gcc/tree-vect-loop.c | |
| parent | dfbddbeb1ca912c9f9f806d8cff55a6ac2887d89 (diff) | |
| download | gcc-9adee3052156ae36271be28e3ad47dd975c26f42.zip gcc-9adee3052156ae36271be28e3ad47dd975c26f42.tar.gz gcc-9adee3052156ae36271be28e3ad47dd975c26f42.tar.bz2 | |
Use base inequality for some vector alias checks
This patch checks whether two data references x and y cannot
partially overlap and so are independent whenever &x != &y.
We can then use this in the vectoriser to optimise alias checks.
gcc/
2016-08-04 Richard Sandiford <richard.sandiford@linaro.org>
* hash-traits.h (pair_hash): New struct.
* tree-data-ref.h (data_dependence_relation): Add object_a and
object_b fields.
(DDR_OBJECT_A, DDR_OBJECT_B): New macros.
* tree-data-ref.c (initialize_data_dependence_relation): Initialize
DDR_OBJECT_A and DDR_OBJECT_B.
* tree-vectorizer.h (vec_object_pair): New type.
(_loop_vec_info): Add a check_unequal_addrs field.
(LOOP_VINFO_CHECK_UNEQUAL_ADDRS): New macro.
(LOOP_REQUIRES_VERSIONING_FOR_ALIAS): Return true if there is an
entry in check_unequal_addrs. Check comp_alias_ddrs instead of
may_alias_ddrs.
* tree-vect-loop.c (destroy_loop_vec_info): Release
LOOP_VINFO_CHECK_UNEQUAL_ADDRS.
(vect_analyze_loop_2): Likewise, when restarting.
(vect_estimate_min_profitable_iters): Estimate the cost of
LOOP_VINFO_CHECK_UNEQUAL_ADDRS.
* tree-vect-data-refs.c: Include tree-hash-traits.h.
(vect_prune_runtime_alias_test_list): Try to handle conflicts
using LOOP_VINFO_CHECK_UNEQUAL_ADDRS, if the data dependence allows.
Count such tests in the final summary.
* tree-vect-loop-manip.c (chain_cond_expr): New function.
(vect_create_cond_for_align_checks): Use it.
(vect_create_cond_for_unequal_addrs): New function.
(vect_loop_versioning): Call it.
gcc/testsuite/
* gcc.dg/vect/vect-alias-check-6.c: New test.
From-SVN: r250868
Diffstat (limited to 'gcc/tree-vect-loop.c')
| -rw-r--r-- | gcc/tree-vect-loop.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c index 8740a75..9723f13 100644 --- a/gcc/tree-vect-loop.c +++ b/gcc/tree-vect-loop.c @@ -1275,6 +1275,8 @@ destroy_loop_vec_info (loop_vec_info loop_vinfo, bool clean_stmts) destroy_cost_data (LOOP_VINFO_TARGET_COST_DATA (loop_vinfo)); loop_vinfo->scalar_cost_vec.release (); + LOOP_VINFO_CHECK_UNEQUAL_ADDRS (loop_vinfo).release (); + free (loop_vinfo); loop->aux = NULL; } @@ -2343,6 +2345,7 @@ again: } /* Free optimized alias test DDRS. */ LOOP_VINFO_COMP_ALIAS_DDRS (loop_vinfo).release (); + LOOP_VINFO_CHECK_UNEQUAL_ADDRS (loop_vinfo).release (); /* Reset target cost data. */ destroy_cost_data (LOOP_VINFO_TARGET_COST_DATA (loop_vinfo)); LOOP_VINFO_TARGET_COST_DATA (loop_vinfo) @@ -3434,6 +3437,11 @@ vect_estimate_min_profitable_iters (loop_vec_info loop_vinfo, unsigned len = LOOP_VINFO_COMP_ALIAS_DDRS (loop_vinfo).length (); (void) add_stmt_cost (target_cost_data, len, vector_stmt, NULL, 0, vect_prologue); + len = LOOP_VINFO_CHECK_UNEQUAL_ADDRS (loop_vinfo).length (); + if (len) + /* Count LEN - 1 ANDs and LEN comparisons. */ + (void) add_stmt_cost (target_cost_data, len * 2 - 1, scalar_stmt, + NULL, 0, vect_prologue); dump_printf (MSG_NOTE, "cost model: Adding cost of checks for loop " "versioning aliasing.\n"); |