https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66285
vries at gcc dot gnu.org changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |missed-optimization
--- Comment #1 from vries at gcc dot gnu.org ---
FWIW, this patch puts pass_parallelize_loops before pass_vectorize:
...
diff --git a/gcc/passes.def b/gcc/passes.def
index 4690e23..f0629ff 100644
--- a/gcc/passes.def
+++ b/gcc/passes.def
@@ -243,14 +243,14 @@ along with GCC; see the file COPYING3. If not see
NEXT_PASS (pass_dce);
POP_INSERT_PASSES ()
NEXT_PASS (pass_iv_canon);
- NEXT_PASS (pass_parallelize_loops);
- PUSH_INSERT_PASSES_WITHIN (pass_parallelize_loops)
- NEXT_PASS (pass_expand_omp_ssa);
- POP_INSERT_PASSES ()
NEXT_PASS (pass_if_conversion);
/* pass_vectorize must immediately follow pass_if_conversion.
Please do not add any other passes in between. */
NEXT_PASS (pass_vectorize);
+ NEXT_PASS (pass_parallelize_loops);
+ PUSH_INSERT_PASSES_WITHIN (pass_parallelize_loops)
+ NEXT_PASS (pass_expand_omp_ssa);
+ POP_INSERT_PASSES ()
PUSH_INSERT_PASSES_WITHIN (pass_vectorize)
NEXT_PASS (pass_dce);
POP_INSERT_PASSES ()
...
And that makes the problem go away (btw, dump file names need adapting in
investigate.sh):
...
$ ./investigate.sh
parloops_factor: 0, index_type: int:
vectorized: 1, parallelized: 0
parloops_factor: 0, index_type: unsigned int:
vectorized: 1, parallelized: 0
parloops_factor: 0, index_type: long:
vectorized: 1, parallelized: 0
parloops_factor: 0, index_type: unsigned long:
vectorized: 1, parallelized: 0
parloops_factor: 2, index_type: int:
vectorized: 1, parallelized: 1
parloops_factor: 2, index_type: unsigned int:
vectorized: 1, parallelized: 1
parloops_factor: 2, index_type: long:
vectorized: 1, parallelized: 1
parloops_factor: 2, index_type: unsigned long:
vectorized: 1, parallelized: 1
...
Of course, the patch means we're no longer vectorizing parallelized loops, but
parallelizing vectorized loops.
