On 12/12/19 10:16 AM, Richard Sandiford wrote:
As Jason pointed out in the review of the C++ gnu_vector_type_p patch:https://gcc.gnu.org/ml/gcc-patches/2019-12/msg00173.html the real fix for the XFAILs in acle/general-c++/gnu_vectors_*.C is to make same_type_p return false for two types if one is gnu_vector_type_p and the other isn't. This patch does that and fixes the fallout in the way Jason suggested above. I'd said at the time that some of the tests require: /* If the constructor already has the array type, it's been through digest_init, so we shouldn't try to do anything more. */ bool digested = same_type_p (atype, TREE_TYPE (init)); (build_vec_init) to be true for gnu vectors built from non-gnu vectors. I can no longer reproduce that, maybe because my original same_type_p change was bogus or because something in the later sizeless type support made it moot (or something else :-)). This means that sve-sizeless-2.C (the length-specific test) now reports some errors for comparisons and pointer differences that sve-sizeless-1.C (the length-agnostic test) already had. I think requiring a cast is OK for those cases, since there's no reason to mix GNU and non-GNU versions of the same vector in the same object. Even -flax-vector-conversions would require a cast for different vector types here, for both C and C++. same_type_p had: else if (strict == COMPARE_STRUCTURAL) return structural_comptypes (t1, t2, COMPARE_STRICT); else return structural_comptypes (t1, t2, strict); Since structural_comptypes ignored the COMPARE_STRUCTURAL bit of "strict" before the patch, the "else if" was harmless but AFAICT unnecessary.
The comment in cp-tree.h has
#define COMPARE_STRUCTURAL 8 /* The comparison is intended to be structural. The actual comparison will be identical to COMPARE_STRICT. */
So introducing differences between COMPARE_STRUCTURAL and COMPARE_STRICT other than that the first always calls structural_comptypes and the second sometimes compares TYPE_CANONICAL instead is to be avoided.
Do you want to use vector_types_convertible_p in similar_type_p? Jason
