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| author | Richard Biener <rguenther@suse.de> | 2020-10-27 11:03:27 +0100 |
|---|---|---|
| committer | Richard Biener <rguenther@suse.de> | 2020-10-27 13:16:35 +0100 |
| commit | 5af1e827bbb624eb28f80d2c5e0da46185af3708 (patch) | |
| tree | 14498c1e161ef861cfe7bc4b6f7e72e1eb3c39e0 /gcc/tree-vect-slp.c | |
| parent | 4e6e941db7ced1fb967beed5f15b69b4d56bce61 (diff) | |
| download | gcc-5af1e827bbb624eb28f80d2c5e0da46185af3708.zip gcc-5af1e827bbb624eb28f80d2c5e0da46185af3708.tar.gz gcc-5af1e827bbb624eb28f80d2c5e0da46185af3708.tar.bz2 | |
Avoid uniform lane BB vectorization
This makes sure to use splats early when facing uniform internal
operands in BB SLP discovery rather than relying on the late
heuristincs re-building nodes from scratch.
2020-10-27 Richard Biener <rguenther@suse.de>
* tree-vect-slp.c (vect_build_slp_tree_2): When vectorizing
BBs splat uniform operands and stop SLP discovery.
* gcc.target/i386/pr95866-1.c: Adjust.
Diffstat (limited to 'gcc/tree-vect-slp.c')
| -rw-r--r-- | gcc/tree-vect-slp.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/gcc/tree-vect-slp.c b/gcc/tree-vect-slp.c index 894f045..85865da 100644 --- a/gcc/tree-vect-slp.c +++ b/gcc/tree-vect-slp.c @@ -1486,6 +1486,28 @@ vect_build_slp_tree_2 (vec_info *vinfo, continue; } + if (is_a <bb_vec_info> (vinfo) + && oprnd_info->first_dt == vect_internal_def) + { + /* For BB vectorization, if all defs are the same do not + bother to continue the build along the single-lane + graph but use a splat of the scalar value. */ + stmt_vec_info first_def = oprnd_info->def_stmts[0]; + for (j = 1; j < group_size; ++j) + if (oprnd_info->def_stmts[j] != first_def) + break; + if (j == group_size + /* But avoid doing this for loads where we may be + able to CSE things. */ + && !gimple_vuse (first_def->stmt)) + { + if (dump_enabled_p ()) + dump_printf_loc (MSG_NOTE, vect_location, + "Using a splat of the uniform operand\n"); + oprnd_info->first_dt = vect_external_def; + } + } + if (oprnd_info->first_dt != vect_internal_def && oprnd_info->first_dt != vect_reduction_def && oprnd_info->first_dt != vect_induction_def) |