Currently we diagnose vector lowering of V1mode operations that
are not natively supported into V_C_E, scalar op plus CTOR with
-Wvector-operation-performance but that's hardly useful behavior
even though the way we lower things can be improved.
The following disables the diagnostics for the cases the vect.exp
testsuite runs into, on x86 that are vect-cond-11.c and
vect-singleton_1.c.
Bootstrap / regtest pending on x86_64-unknown-linux-gnu.
Comments?
Thanks,
Richard.
2022-01-19 Richard Biener <rguent...@suse.de>
PR tree-optimization/104114
* tree-vect-generic.c (expand_vector_piecewise): Do not diagnose
single element vector decomposition.
---
gcc/tree-vect-generic.cc | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/gcc/tree-vect-generic.cc b/gcc/tree-vect-generic.cc
index 5814a71a5bb..f4fc7d16119 100644
--- a/gcc/tree-vect-generic.cc
+++ b/gcc/tree-vect-generic.cc
@@ -317,7 +317,10 @@ expand_vector_piecewise (gimple_stmt_iterator *gsi,
elem_op_func f,
int i;
location_t loc = gimple_location (gsi_stmt (*gsi));
- if (ret_type || !parallel_p)
+ if (nunits == 1)
+ /* Do not diagnose decomposing single element vectors. */
+ ;
+ else if (ret_type || !parallel_p)
warning_at (loc, OPT_Wvector_operation_performance,
"vector operation will be expanded piecewise");
else
--
2.31.1
