https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112962
--- Comment #12 from Hongtao Liu <liuhongt at gcc dot gnu.org> ---
(In reply to Jakub Jelinek from comment #8)
> Of course, yet another option is:
> --- gcc/config/i386/i386.cc 2023-12-12 08:54:39.821148670 +0100
> +++ gcc/config/i386/i386.cc 2023-12-12 11:07:03.795286363 +0100
> @@ -19377,7 +19377,10 @@ ix86_gimple_fold_builtin (gimple_stmt_it
> do_shift:
> gcc_assert (n_args >= 2);
> if (!gimple_call_lhs (stmt))
> - break;
> + {
> + gsi_replace (gsi, gimple_build_nop (), false);
> + return true;
> + }
> arg0 = gimple_call_arg (stmt, 0);
> arg1 = gimple_call_arg (stmt, 1);
> elems = TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0));
> @@ -19523,7 +19526,10 @@ ix86_gimple_fold_builtin (gimple_stmt_it
> case IX86_BUILTIN_PABSD256_MASK:
> gcc_assert (n_args >= 1);
> if (!gimple_call_lhs (stmt))
> - break;
> + {
> + gsi_replace (gsi, gimple_build_nop (), false);
> + return true;
> + }
> arg0 = gimple_call_arg (stmt, 0);
> elems = TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0));
> /* For masked ABS, only optimize if the mask is all ones. */
> (and I wonder why all the gsi_replace calls in that function are with false,
> IMHO they should use true).
I prefer this solution, that's what we did for blendvps case.
I don't know either, just follow what we did before (with false) when folding
builtins.
