Richard Henderson <r...@redhat.com> writes:
> + /* Use PUL/PLU to produce { L, H } op { H, L }.
> + By reversing the pair order, rather a pure interleave high,
> + we don't produce erroneous exceptional conditions. */
"rather than". We don't produce erroneous exceptional conditions
that would result from H op H? It probably should be obvious,
but it took me a few seconds to work out...
> + case V4HImode:
> + /* Perform the first reduction with interleave,
> + and subsequent reductions with shifts. */
> + emit_insn (gen_loongson_punpckhwd_hi (tmp, in, in));
> + emit_insn (gen (in, in, tmp));
> + emit_insn (gen_vec_shr_v4hi (tmp, in, force_reg (SImode, GEN_INT
> (16))));
> + break;
> +
> + case V8QImode:
> + emit_insn (gen_loongson_punpckhwd_qi (tmp, in, in));
> + emit_insn (gen (in, in, tmp));
> + emit_insn (gen_vec_shr_v8qi (tmp, in, force_reg (SImode, GEN_INT
> (16))));
> + emit_insn (gen (in, in, tmp));
> + emit_insn (gen_vec_shr_v8qi (tmp, in, force_reg (SImode, GEN_INT
> (8))));
> + break;
Seems safer to have a second temporary rather than assign to the input here.
Richard
