From: Richard Biener Date: Mon, 12 Jun 2023 12:09:45 +0000 (+0200) Subject: Fix disambiguation against .MASK_STORE X-Git-Tag: basepoints/gcc-15~8424 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=8d3eb3ad5388d2f523e4a6f886c4b3364f77f51f;p=thirdparty%2Fgcc.git Fix disambiguation against .MASK_STORE Alias analysis was treating .MASK_STORE as storing a full vector which means we disambiguate against decls of smaller than vector size. That's of course wrong and a similar issue was fixed for DSE already. The following makes sure we set the size of the access to unknown and only constrain max_size. This fixes runtime execution FAILs of gfortran.dg/matmul_2.f90, gfortran.dg/matmul_6.f90 and gfortran.dg/pr91577.f90 when using AVX512 with full masked loop vectorization on Zen4. * tree-ssa-alias.cc (call_may_clobber_ref_p_1): For .MASK_STORE and friend set the size of the access to unknown. --- diff --git a/gcc/tree-ssa-alias.cc b/gcc/tree-ssa-alias.cc index 79ed956e300b..b5476e8b41ee 100644 --- a/gcc/tree-ssa-alias.cc +++ b/gcc/tree-ssa-alias.cc @@ -3072,6 +3072,9 @@ call_may_clobber_ref_p_1 (gcall *call, ao_ref *ref, bool tbaa_p) ao_ref lhs_ref; 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. */ + lhs_ref.size = -1; lhs_ref.ref_alias_set = lhs_ref.base_alias_set = tbaa_p ? get_deref_alias_set (TREE_TYPE (gimple_call_arg (call, 1))) : 0;