On Mon, 14 Oct 2024, Tamar Christina wrote: > Hi All, > > In GCC 14 VEC_PERM_EXPR was relaxed to be able to permute to a 2x larger > vector > than the size of the input vectors. However various passes and > transformations > were not updated to account for this. > > I have patches in these area that I will be upstreaming with individual > patches > that expose them. > > This one is that vectlower tries to lower based on the size of the input > vectors > rather than the size of the output. As a consequence it creates an invalid > vector of half the size. > > Luckily we ICE because the resulting nunits doesn't match the vector size. > > Tests in the AArch64 patch test for this behaviour. > > Bootstrapped Regtested on aarch64-none-linux-gnu, arm-none-linux-gnueabihf, > x86_64-pc-linux-gnu -m32, -m64 and no issues. > > Ok for master?
OK. Do you have a testcase btw? > Thanks, > Tamar > > gcc/ChangeLog: > > * tree-vect-generic.cc (lower_vec_perm): Use output vector size instead > of input vector when determining output nunits. > > --- > diff --git a/gcc/tree-vect-generic.cc b/gcc/tree-vect-generic.cc > index > 3041fb8fcf235ba86f37ef73aa089330a2fd0b77..f86f7eabb255fde50b30fa3b85db367df930f321 > 100644 > --- a/gcc/tree-vect-generic.cc > +++ b/gcc/tree-vect-generic.cc > @@ -1500,6 +1500,7 @@ lower_vec_perm (gimple_stmt_iterator *gsi) > tree mask = gimple_assign_rhs3 (stmt); > tree vec0 = gimple_assign_rhs1 (stmt); > tree vec1 = gimple_assign_rhs2 (stmt); > + tree res_vect_type = TREE_TYPE (gimple_assign_lhs (stmt)); > tree vect_type = TREE_TYPE (vec0); > tree mask_type = TREE_TYPE (mask); > tree vect_elt_type = TREE_TYPE (vect_type); > @@ -1512,7 +1513,7 @@ lower_vec_perm (gimple_stmt_iterator *gsi) > location_t loc = gimple_location (gsi_stmt (*gsi)); > unsigned i; > > - if (!TYPE_VECTOR_SUBPARTS (vect_type).is_constant (&elements)) > + if (!TYPE_VECTOR_SUBPARTS (res_vect_type).is_constant (&elements)) > return; > > if (TREE_CODE (mask) == SSA_NAME) > @@ -1672,9 +1673,9 @@ lower_vec_perm (gimple_stmt_iterator *gsi) > } > > if (constant_p) > - constr = build_vector_from_ctor (vect_type, v); > + constr = build_vector_from_ctor (res_vect_type, v); > else > - constr = build_constructor (vect_type, v); > + constr = build_constructor (res_vect_type, v); > gimple_assign_set_rhs_from_tree (gsi, constr); > update_stmt (gsi_stmt (*gsi)); > } > > > > > -- Richard Biener <rguent...@suse.de> SUSE Software Solutions Germany GmbH, Frankenstrasse 146, 90461 Nuernberg, Germany; GF: Ivo Totev, Andrew McDonald, Werner Knoblich; (HRB 36809, AG Nuernberg)
