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| author | Richard Biener <rguenther@suse.de> | 2016-09-29 07:16:10 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2016-09-29 07:16:10 +0000 |
| commit | ea60dd34cd352452eeab30aba4b84a204f2caef5 (patch) | |
| tree | e30ecb562876ab20fab51104cf717d611ff43429 /gcc | |
| parent | ca0e1607e9f7a185b9c0e29509b2ab84727d9041 (diff) | |
| download | gcc-ea60dd34cd352452eeab30aba4b84a204f2caef5.zip gcc-ea60dd34cd352452eeab30aba4b84a204f2caef5.tar.gz gcc-ea60dd34cd352452eeab30aba4b84a204f2caef5.tar.bz2 | |
tree-vect-stmts.c (vectorizable_load): Avoid emitting vector constructors with vector elements.
2016-09-29 Richard Biener <rguenther@suse.de>
* tree-vect-stmts.c (vectorizable_load): Avoid emitting vector
constructors with vector elements.
From-SVN: r240611
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/tree-vect-stmts.c | 41 |
2 files changed, 41 insertions, 5 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index eac9546..56f7255 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,5 +1,10 @@ 2016-09-29 Richard Biener <rguenther@suse.de> + * tree-vect-stmts.c (vectorizable_load): Avoid emitting vector + constructors with vector elements. + +2016-09-29 Richard Biener <rguenther@suse.de> + PR tree-optimization/77768 * tree-ssa-sccvn.c (visit_reference_op_store): Properly deal with stores to a place we know has a constant value. diff --git a/gcc/tree-vect-stmts.c b/gcc/tree-vect-stmts.c index 47770ad..d698785 100644 --- a/gcc/tree-vect-stmts.c +++ b/gcc/tree-vect-stmts.c @@ -6862,17 +6862,40 @@ vectorizable_load (gimple *stmt, gimple_stmt_iterator *gsi, gimple **vec_stmt, int nloads = nunits; int lnel = 1; tree ltype = TREE_TYPE (vectype); + tree lvectype = vectype; auto_vec<tree> dr_chain; if (memory_access_type == VMAT_STRIDED_SLP) { - nloads = nunits / group_size; if (group_size < nunits) { - lnel = group_size; - ltype = build_vector_type (TREE_TYPE (vectype), group_size); + /* Avoid emitting a constructor of vector elements by performing + the loads using an integer type of the same size, + constructing a vector of those and then re-interpreting it + as the original vector type. This works around the fact + that the vec_init optab was only designed for scalar + element modes and thus expansion goes through memory. + This avoids a huge runtime penalty due to the general + inability to perform store forwarding from smaller stores + to a larger load. */ + unsigned lsize + = group_size * TYPE_PRECISION (TREE_TYPE (vectype)); + enum machine_mode elmode = mode_for_size (lsize, MODE_INT, 0); + enum machine_mode vmode = mode_for_vector (elmode, + nunits / group_size); + /* If we can't construct such a vector fall back to + element loads of the original vector type. */ + if (VECTOR_MODE_P (vmode) + && optab_handler (vec_init_optab, vmode) != CODE_FOR_nothing) + { + nloads = nunits / group_size; + lnel = group_size; + ltype = build_nonstandard_integer_type (lsize, 1); + lvectype = build_vector_type (ltype, nloads); + } } else { + nloads = 1; lnel = nunits; ltype = vectype; } @@ -6925,9 +6948,17 @@ vectorizable_load (gimple *stmt, gimple_stmt_iterator *gsi, gimple **vec_stmt, } if (nloads > 1) { - tree vec_inv = build_constructor (vectype, v); - new_temp = vect_init_vector (stmt, vec_inv, vectype, gsi); + tree vec_inv = build_constructor (lvectype, v); + new_temp = vect_init_vector (stmt, vec_inv, lvectype, gsi); new_stmt = SSA_NAME_DEF_STMT (new_temp); + if (lvectype != vectype) + { + new_stmt = gimple_build_assign (make_ssa_name (vectype), + VIEW_CONVERT_EXPR, + build1 (VIEW_CONVERT_EXPR, + vectype, new_temp)); + vect_finish_stmt_generation (stmt, new_stmt, gsi); + } } if (slp) |