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| author | Richard Sandiford <richard.sandiford@linaro.org> | 2018-01-23 10:42:10 +0000 |
|---|---|---|
| committer | Richard Sandiford <rsandifo@gcc.gnu.org> | 2018-01-23 10:42:10 +0000 |
| commit | 97e52238b292ca744368f66980533c578838e94c (patch) | |
| tree | 5fceb56c5088a09714affe78100c8e617f08cd51 /gcc/tree-vect-patterns.c | |
| parent | 9f4b0885e77f836169c290e93faa87b58ab34276 (diff) | |
| download | gcc-97e52238b292ca744368f66980533c578838e94c.zip gcc-97e52238b292ca744368f66980533c578838e94c.tar.gz gcc-97e52238b292ca744368f66980533c578838e94c.tar.bz2 | |
Disable some patterns for fold-left reductions (PR 83965)
In this PR we recognised a PLUS_EXPR as a fold-left reduction,
then applied pattern matching to convert it to a WIDEN_SUM_EXPR.
We need to keep the original code in this case since we implement
the reduction using scalar rather than vector operations.
2018-01-23 Richard Sandiford <richard.sandiford@linaro.org>
gcc/
PR tree-optimization/83965
* tree-vect-patterns.c (vect_reassociating_reduction_p): New function.
(vect_recog_dot_prod_pattern, vect_recog_sad_pattern): Use it
instead of checking only for a reduction.
(vect_recog_widen_sum_pattern): Likewise.
gcc/testsuite/
PR tree-optimization/83965
* gcc.dg/vect/pr83965.c: New test.
From-SVN: r256976
Diffstat (limited to 'gcc/tree-vect-patterns.c')
| -rw-r--r-- | gcc/tree-vect-patterns.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/gcc/tree-vect-patterns.c b/gcc/tree-vect-patterns.c index 0831b7e..1279352 100644 --- a/gcc/tree-vect-patterns.c +++ b/gcc/tree-vect-patterns.c @@ -217,6 +217,16 @@ vect_recog_temp_ssa_var (tree type, gimple *stmt) return make_temp_ssa_name (type, stmt, "patt"); } +/* Return true if STMT_VINFO describes a reduction for which reassociation + is allowed. */ + +static bool +vect_reassociating_reduction_p (stmt_vec_info stmt_vinfo) +{ + return (STMT_VINFO_DEF_TYPE (stmt_vinfo) == vect_reduction_def + && STMT_VINFO_REDUC_TYPE (stmt_vinfo) != FOLD_LEFT_REDUCTION); +} + /* Function vect_recog_dot_prod_pattern Try to find the following pattern: @@ -336,7 +346,7 @@ vect_recog_dot_prod_pattern (vec<gimple *> *stmts, tree *type_in, { gimple *def_stmt; - if (STMT_VINFO_DEF_TYPE (stmt_vinfo) != vect_reduction_def + if (!vect_reassociating_reduction_p (stmt_vinfo) && ! STMT_VINFO_GROUP_FIRST_ELEMENT (stmt_vinfo)) return NULL; oprnd0 = gimple_assign_rhs1 (last_stmt); @@ -557,7 +567,7 @@ vect_recog_sad_pattern (vec<gimple *> *stmts, tree *type_in, { gimple *def_stmt; - if (STMT_VINFO_DEF_TYPE (stmt_vinfo) != vect_reduction_def + if (!vect_reassociating_reduction_p (stmt_vinfo) && ! STMT_VINFO_GROUP_FIRST_ELEMENT (stmt_vinfo)) return NULL; plus_oprnd0 = gimple_assign_rhs1 (last_stmt); @@ -1181,7 +1191,7 @@ vect_recog_widen_sum_pattern (vec<gimple *> *stmts, tree *type_in, if (gimple_assign_rhs_code (last_stmt) != PLUS_EXPR) return NULL; - if (STMT_VINFO_DEF_TYPE (stmt_vinfo) != vect_reduction_def + if (!vect_reassociating_reduction_p (stmt_vinfo) && ! STMT_VINFO_GROUP_FIRST_ELEMENT (stmt_vinfo)) return NULL; |