On Mon, 14 Jun 2021 at 09:52, Richard Henderson
<[email protected]> wrote:
>
> Implement the new semantics in the fallback expansion.
> Change all callers to supply the flags that keep the
> semantics unchanged locally.
>
> Signed-off-by: Richard Henderson <[email protected]>
> diff --git a/tcg/tcg-op.c b/tcg/tcg-op.c
> index dc65577e2f..3763285bb0 100644
> --- a/tcg/tcg-op.c
> +++ b/tcg/tcg-op.c
> @@ -1001,20 +1001,35 @@ void tcg_gen_ext16u_i32(TCGv_i32 ret, TCGv_i32 arg)
> }
> }
>
> -/* Note: we assume the two high bytes are set to zero */
> -void tcg_gen_bswap16_i32(TCGv_i32 ret, TCGv_i32 arg)
> +void tcg_gen_bswap16_i32(TCGv_i32 ret, TCGv_i32 arg, int flags)
> {
> + /* Only one extension flag may be present. */
> + tcg_debug_assert(!(flags & TCG_BSWAP_OS) || !(flags & TCG_BSWAP_OZ));
> +
> if (TCG_TARGET_HAS_bswap16_i32) {
> - tcg_gen_op3i_i32(INDEX_op_bswap16_i32, ret, arg,
> - TCG_BSWAP_IZ | TCG_BSWAP_OZ);
> + tcg_gen_op3i_i32(INDEX_op_bswap16_i32, ret, arg, flags);
> } else {
> TCGv_i32 t0 = tcg_temp_new_i32();
> + TCGv_i32 t1 = tcg_temp_new_i32();
>
> - tcg_gen_ext8u_i32(t0, arg);
> - tcg_gen_shli_i32(t0, t0, 8);
> - tcg_gen_shri_i32(ret, arg, 8);
> - tcg_gen_or_i32(ret, ret, t0);
> + tcg_gen_shri_i32(t0, arg, 8);
> + if (!(flags & TCG_BSWAP_IZ)) {
> + tcg_gen_ext8u_i32(t0, t0);
> + }
> +
> + if (flags & TCG_BSWAP_OS) {
> + tcg_gen_shli_i32(t1, t1, 24);
t1 hasn't been initialized yet. Should this be "tcg_gen_shli_i32(t1, arg, 24)" ?
> + tcg_gen_sari_i32(t1, t1, 16);
> + } else if (flags & TCG_BSWAP_OZ) {
> + tcg_gen_ext8u_i32(t1, arg);
> + tcg_gen_shli_i32(t1, t1, 8);
> + } else {
> + tcg_gen_shli_i32(t1, arg, 8);
> + }
> +
> + tcg_gen_or_i32(ret, t0, t1);
> tcg_temp_free_i32(t0);
> + tcg_temp_free_i32(t1);
> }
> } else {
> TCGv_i64 t0 = tcg_temp_new_i64();
> + TCGv_i64 t1 = tcg_temp_new_i64();
>
> - tcg_gen_ext8u_i64(t0, arg);
> - tcg_gen_shli_i64(t0, t0, 8);
> - tcg_gen_shri_i64(ret, arg, 8);
> - tcg_gen_or_i64(ret, ret, t0);
> + tcg_gen_shri_i64(t0, arg, 8);
> + if (!(flags & TCG_BSWAP_IZ)) {
> + tcg_gen_ext8u_i64(t0, t0);
> + }
> +
> + if (flags & TCG_BSWAP_OS) {
> + tcg_gen_shli_i64(t1, t1, 56);
Similarly here.
> + tcg_gen_sari_i64(t1, t1, 48);
> + } else if (flags & TCG_BSWAP_OZ) {
> + tcg_gen_ext8u_i64(t1, arg);
> + tcg_gen_shli_i64(t1, t1, 8);
> + } else {
> + tcg_gen_shli_i64(t1, arg, 8);
> + }
> +
> + tcg_gen_or_i64(ret, t0, t1);
> tcg_temp_free_i64(t0);
> + tcg_temp_free_i64(t1);
> }
> }
Otherwise
Reviewed-by: Peter Maydell <[email protected]>
thanks
-- PMM
