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| author | Sebastian Pop <sebastian.pop@amd.com> | 2008-05-16 16:02:02 +0000 |
|---|---|---|
| committer | Sebastian Pop <spop@gcc.gnu.org> | 2008-05-16 16:02:02 +0000 |
| commit | b3924be9712d2b49b59048aff6ba5d288227c40c (patch) | |
| tree | 3a23f8dccec8694c7100a8d3bb896105dd71f2a5 /gcc/tree-data-ref.c | |
| parent | 5b7971f01cf2b0709995c7249e6c21a38acc5f7b (diff) | |
| download | gcc-b3924be9712d2b49b59048aff6ba5d288227c40c.zip gcc-b3924be9712d2b49b59048aff6ba5d288227c40c.tar.gz gcc-b3924be9712d2b49b59048aff6ba5d288227c40c.tar.bz2 | |
re PR tree-optimization/36228 (redundant runtime check while vectorizing)
2008-05-16 Sebastian Pop <sebastian.pop@amd.com>
Jan Sjodin <jan.sjodin@amd.com>
PR tree-optimization/36228
* tree-data-ref.c (initialize_data_dependence_relation): Fast dependence
test when the references are the same, call compute_self_dependence.
* tree-data-ref.h (struct data_dependence_relation): Add self_reference_p.
(DDR_SELF_REFERENCE): New.
* testsuite/gcc.dg/vect/pr36228.c: New.
Co-Authored-By: Jan Sjodin <jan.sjodin@amd.com>
From-SVN: r135426
Diffstat (limited to 'gcc/tree-data-ref.c')
| -rw-r--r-- | gcc/tree-data-ref.c | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/gcc/tree-data-ref.c b/gcc/tree-data-ref.c index 90ce7e9..7e9c99f 100644 --- a/gcc/tree-data-ref.c +++ b/gcc/tree-data-ref.c @@ -1265,6 +1265,8 @@ dr_may_alias_p (const struct data_reference *a, const struct data_reference *b) return true; } +static void compute_self_dependence (struct data_dependence_relation *); + /* Initialize a data dependence relation between data accesses A and B. NB_LOOPS is the number of loops surrounding the references: the size of the classic distance/direction vectors. */ @@ -1299,6 +1301,20 @@ initialize_data_dependence_relation (struct data_reference *a, return res; } + /* When the references are exactly the same, don't spend time doing + the data dependence tests, just initialize the ddr and return. */ + if (operand_equal_p (DR_REF (a), DR_REF (b), 0)) + { + DDR_AFFINE_P (res) = true; + DDR_ARE_DEPENDENT (res) = NULL_TREE; + DDR_SUBSCRIPTS (res) = VEC_alloc (subscript_p, heap, DR_NUM_DIMENSIONS (a)); + DDR_LOOP_NEST (res) = loop_nest; + DDR_INNER_LOOP (res) = 0; + DDR_SELF_REFERENCE (res) = true; + compute_self_dependence (res); + return res; + } + /* If the references do not access the same object, we do not know whether they alias or not. */ if (!operand_equal_p (DR_BASE_OBJECT (a), DR_BASE_OBJECT (b), 0)) @@ -1324,6 +1340,7 @@ initialize_data_dependence_relation (struct data_reference *a, DDR_SUBSCRIPTS (res) = VEC_alloc (subscript_p, heap, DR_NUM_DIMENSIONS (a)); DDR_LOOP_NEST (res) = loop_nest; DDR_INNER_LOOP (res) = 0; + DDR_SELF_REFERENCE (res) = false; for (i = 0; i < DR_NUM_DIMENSIONS (a); i++) { @@ -3798,7 +3815,8 @@ compute_affine_dependence (struct data_dependence_relation *ddr, } /* Analyze only when the dependence relation is not yet known. */ - if (DDR_ARE_DEPENDENT (ddr) == NULL_TREE) + if (DDR_ARE_DEPENDENT (ddr) == NULL_TREE + && !DDR_SELF_REFERENCE (ddr)) { dependence_stats.num_dependence_tests++; |