On Wed, Feb 18, 2026 at 10:32:56PM +0100, Jakub Jelinek wrote:
> The following testcase ICEs starting with the removal of NON_DEPENDENT_EXPR
> in GCC 14. The problem is that while parsing templates if all the arguments
> of the overloaded builtins are non-dependent types,
> targetm.resolve_overloaded_builtin can be called on it. And trying to
> fold_convert or fold_build2 subexpressions of such arguments can ICE,
> because they can contain various FE specific trees, or standard trees
> with NULL_TREE types, or e.g. type mismatches in binary tree operands etc.
> All that goes away later when the trees are instantiated and
> targetm.resolve_overloaded_builtin is called again, but if it ICEs while
> doing that, it won't reach that point. And the reason to call that
> hook in that case if none of the arguments are type dependent is to figure
> out if the result type is also non-dependent.
>
> Given the general desire to fold stuff in the FE during parsing as little
> as possible and fold it only during cp_fold later on and because from the
> target *-c.cc files it isn't easily possible to find out if it is
> processing_template_decl or not, the following patch just stops folding
> anything in the arguments, calls convert instead of fold_convert and
> just build2 instead of fold_build2 etc. when in C++ (and keeps doing what
> it did for C).
>
> Bootstrapped/regtested on powerpc64le-linux, ok for trunk?
>
> 2026-02-18 Jakub Jelinek <[email protected]>
>
> PR target/124133
> * config/rs6000/rs6000-c.cc (c_fold_convert): New function.
> (c_fold_build2_loc): Likewise.
> (fully_fold_convert): Use c_fold_convert instead of fold_convert.
> (altivec_build_resolved_builtin): Likewise. Use c_fold_build2_loc
> instead of fold_build2.
> (resolve_vec_mul, resolve_vec_adde_sube, resolve_vec_addec_subec):
> Use c_fold_build2_loc instead of fold_build2_loc.
> (resolve_vec_splats, resolve_vec_extract): Use c_fold_convert instead
> of fold_convert.
> (resolve_vec_insert): Use c_fold_build2_loc instead of fold_build2.
> (altivec_resolve_overloaded_builtin): Use c_fold_convert instead
> of fold_convert.
>
> * g++.target/powerpc/pr124133.C: New test.
I'd like to ping this patch.
There is another testcase from llama.cpp affected by that too.
Thanks
Jakub
