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| author | Kewen Lin <linkw@linux.ibm.com> | 2023-05-17 02:48:40 -0500 |
|---|---|---|
| committer | Kewen Lin <linkw@linux.ibm.com> | 2023-05-17 02:48:40 -0500 |
| commit | a04bf39f61ce7814d197d712760f08c206daf4f1 (patch) | |
| tree | e64824b0486009a69cb6c5f1d1755917441c3c49 | |
| parent | e0f2f4711794e3117db9e97164c674bd96a52fe6 (diff) | |
| download | gcc-a04bf39f61ce7814d197d712760f08c206daf4f1.tar.gz | |
vect: Don't retry if the previous analysis fails
When working on a cost tweaking patch, I found that a newly
added test case has different dumpings with stage-1 and
bootstrapped gcc. By looking into it, the apparent reason
is vect_analyze_loop_2 doesn't get slp_done_for_suggested_uf
set expectedly, the following retrying will use the garbage
slp_done_for_suggested_uf instead. In fact, the setting of
slp_done_for_suggested_uf only happens when the previous
analysis succeeds, for the mentioned test case, its previous
analysis does fail, it's unexpected to use the value of
slp_done_for_suggested_uf any more.
In function vect_analyze_loop_1, we only return success when
res is true, which is the result of 1st analysis. It means
we never try to vectorize with unroll_vinfo if the previous
analysis fails. So this patch shouldn't break anything, and
just stop some useless analysis early.
gcc/ChangeLog:
* tree-vect-loop.cc (vect_analyze_loop_1): Don't retry analysis with
suggested unroll factor once the previous analysis fails.
| -rw-r--r-- | gcc/tree-vect-loop.cc | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc index ed0166fedab..905145ae97b 100644 --- a/gcc/tree-vect-loop.cc +++ b/gcc/tree-vect-loop.cc @@ -3044,7 +3044,7 @@ vect_analyze_loop_1 (class loop *loop, vec_info_shared *shared, res ? "succeeded" : " failed", GET_MODE_NAME (loop_vinfo->vector_mode)); - if (!main_loop_vinfo && suggested_unroll_factor > 1) + if (res && !main_loop_vinfo && suggested_unroll_factor > 1) { if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, |