Alias analysis was treating .MASK_LOAD as storing a full vector
which means we disambiguate against decls of smaller than vector size.
This complements the previous patch handling .MASK_STORE and fixes
runtime execution FAILs of gfortran.dg/matmul_3.f90 and
gfortran.dg/inline_sum_2.f90 when using AVX512 with full masked loop
vectorization on Zen4.
Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.
* tree-ssa-alias.cc (ref_maybe_used_by_call_p_1): For
.MASK_LOAD and friends set the size of the access to unknown.
---
gcc/tree-ssa-alias.cc | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/gcc/tree-ssa-alias.cc b/gcc/tree-ssa-alias.cc
index b5476e8b41e..e1bc04b82ba 100644
--- a/gcc/tree-ssa-alias.cc
+++ b/gcc/tree-ssa-alias.cc
@@ -2829,6 +2829,9 @@ ref_maybe_used_by_call_p_1 (gcall *call, ao_ref *ref,
bool tbaa_p)
ao_ref_init_from_ptr_and_size (&rhs_ref,
gimple_call_arg (call, 0),
TYPE_SIZE_UNIT (TREE_TYPE (lhs)));
+ /* We cannot make this a known-size access since otherwise
+ we disambiguate against refs to decls that are smaller. */
+ rhs_ref.size = -1;
rhs_ref.ref_alias_set = rhs_ref.base_alias_set
= tbaa_p ? get_deref_alias_set (TREE_TYPE
(gimple_call_arg (call, 1))) : 0;
@@ -3073,7 +3076,7 @@ call_may_clobber_ref_p_1 (gcall *call, ao_ref *ref, bool
tbaa_p)
ao_ref_init_from_ptr_and_size (&lhs_ref, gimple_call_arg (call, 0),
TYPE_SIZE_UNIT (TREE_TYPE (rhs)));
/* We cannot make this a known-size access since otherwise
- we disambiguate against stores to decls that are smaller. */
+ we disambiguate against refs to decls that are smaller. */
lhs_ref.size = -1;
lhs_ref.ref_alias_set = lhs_ref.base_alias_set
= tbaa_p ? get_deref_alias_set
--
2.35.3
