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| author | Richard Sandiford <richard.sandiford@arm.com> | 2019-11-13 09:05:59 +0000 |
|---|---|---|
| committer | Richard Sandiford <rsandifo@gcc.gnu.org> | 2019-11-13 09:05:59 +0000 |
| commit | 6eed64b96d886da2518d86eae5bc0a5ed66cabe0 (patch) | |
| tree | 37497aa97fda968edca614ae83fa11d8b58c66d0 /gcc/tree-vect-loop-manip.c | |
| parent | d4b44b834e3ac1b92ffb165e7bdaf641a211c34b (diff) | |
| download | gcc-6eed64b96d886da2518d86eae5bc0a5ed66cabe0.zip gcc-6eed64b96d886da2518d86eae5bc0a5ed66cabe0.tar.gz gcc-6eed64b96d886da2518d86eae5bc0a5ed66cabe0.tar.bz2 | |
Avoid accounting for non-existent vector loop versioning
vect_analyze_loop_costing uses two profitability thresholds: a runtime
one and a static compile-time one. The runtime one is simply the point
at which the vector loop is cheaper than the scalar loop, while the
static one also takes into account the cost of choosing between the
scalar and vector loops at runtime. We compare this static cost against
the expected execution frequency to decide whether it's worth generating
any vector code at all.
However, we never reclaimed the cost of applying the runtime threshold
if it turned out that the vector code can always be used. And we only
know whether that's true once we've calculated what the runtime
threshold would be.
2019-11-13 Richard Sandiford <richard.sandiford@arm.com>
gcc/
* tree-vectorizer.h (vect_apply_runtime_profitability_check_p):
New function.
* tree-vect-loop-manip.c (vect_loop_versioning): Use it.
* tree-vect-loop.c (vect_analyze_loop_2): Likewise.
(vect_transform_loop): Likewise.
(vect_analyze_loop_costing): Don't take the cost of versioning
into account for the static profitability threshold if it turns
out that no versioning is needed.
From-SVN: r278124
Diffstat (limited to 'gcc/tree-vect-loop-manip.c')
| -rw-r--r-- | gcc/tree-vect-loop-manip.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/gcc/tree-vect-loop-manip.c b/gcc/tree-vect-loop-manip.c index 559d59b..beee5fe 100644 --- a/gcc/tree-vect-loop-manip.c +++ b/gcc/tree-vect-loop-manip.c @@ -3171,8 +3171,7 @@ vect_loop_versioning (loop_vec_info loop_vinfo) = LOOP_REQUIRES_VERSIONING_FOR_SIMD_IF_COND (loop_vinfo); unsigned th = LOOP_VINFO_COST_MODEL_THRESHOLD (loop_vinfo); - if (th >= vect_vf_for_cost (loop_vinfo) - && !LOOP_VINFO_NITERS_KNOWN_P (loop_vinfo) + if (vect_apply_runtime_profitability_check_p (loop_vinfo) && !ordered_p (th, versioning_threshold)) cond_expr = fold_build2 (GE_EXPR, boolean_type_node, scalar_loop_iters, build_int_cst (TREE_TYPE (scalar_loop_iters), |