On Sun, Sep 28, 2025 at 7:33 PM Richard Henderson
<[email protected]> wrote:
>
> Use extract2 to implement rotri. To make this easier,
> redefine rotli in terms of rotri, rather than the reverse.
>
> Signed-off-by: Richard Henderson <[email protected]>
> ---
> tcg/tcg-op.c | 70 ++++++++++++++++++++++++++++++----------------------
> 1 file changed, 41 insertions(+), 29 deletions(-)
>
> diff --git a/tcg/tcg-op.c b/tcg/tcg-op.c
> index 4caf77da1e..3e10a3ad16 100644
> --- a/tcg/tcg-op.c
> +++ b/tcg/tcg-op.c
> @@ -834,23 +834,12 @@ void tcg_gen_rotl_i32(TCGv_i32 ret, TCGv_i32 arg1,
> TCGv_i32 arg2)
> void tcg_gen_rotli_i32(TCGv_i32 ret, TCGv_i32 arg1, int32_t arg2)
> {
> tcg_debug_assert(arg2 >= 0 && arg2 < 32);
> - /* some cases can be optimized here */
> if (arg2 == 0) {
> tcg_gen_mov_i32(ret, arg1);
> } else if (tcg_op_supported(INDEX_op_rotl, TCG_TYPE_I32, 0)) {
> - TCGv_i32 t0 = tcg_constant_i32(arg2);
> - tcg_gen_op3_i32(INDEX_op_rotl, ret, arg1, t0);
> - } else if (tcg_op_supported(INDEX_op_rotr, TCG_TYPE_I32, 0)) {
> - TCGv_i32 t0 = tcg_constant_i32(32 - arg2);
> - tcg_gen_op3_i32(INDEX_op_rotr, ret, arg1, t0);
> + tcg_gen_op3_i32(INDEX_op_rotl, ret, arg1, tcg_constant_i32(arg2));
> } else {
> - TCGv_i32 t0 = tcg_temp_ebb_new_i32();
> - TCGv_i32 t1 = tcg_temp_ebb_new_i32();
> - tcg_gen_shli_i32(t0, arg1, arg2);
> - tcg_gen_shri_i32(t1, arg1, 32 - arg2);
> - tcg_gen_or_i32(ret, t0, t1);
> - tcg_temp_free_i32(t0);
> - tcg_temp_free_i32(t1);
> + tcg_gen_rotri_i32(ret, arg1, -arg2 & 31);
> }
> }
>
> @@ -878,7 +867,16 @@ void tcg_gen_rotr_i32(TCGv_i32 ret, TCGv_i32 arg1,
> TCGv_i32 arg2)
> void tcg_gen_rotri_i32(TCGv_i32 ret, TCGv_i32 arg1, int32_t arg2)
> {
> tcg_debug_assert(arg2 >= 0 && arg2 < 32);
> - tcg_gen_rotli_i32(ret, arg1, -arg2 & 31);
> + if (arg2 == 0) {
> + tcg_gen_mov_i32(ret, arg1);
> + } else if (tcg_op_supported(INDEX_op_rotr, TCG_TYPE_I64, 0)) {
> + tcg_gen_op3_i32(INDEX_op_rotr, ret, arg1, tcg_constant_i32(arg2));
> + } else if (tcg_op_supported(INDEX_op_rotl, TCG_TYPE_I64, 0)) {
> + tcg_gen_op3_i32(INDEX_op_rotl, ret, arg1, tcg_constant_i32(32 -
> arg2));
> + } else {
> + /* Do not recurse with the rotri simplification. */
> + tcg_gen_op4i_i32(INDEX_op_extract2, ret, arg1, arg1, arg2);
> + }
> }
>
> void tcg_gen_deposit_i32(TCGv_i32 ret, TCGv_i32 arg1, TCGv_i32 arg2,
> @@ -2417,23 +2415,12 @@ void tcg_gen_rotl_i64(TCGv_i64 ret, TCGv_i64 arg1,
> TCGv_i64 arg2)
> void tcg_gen_rotli_i64(TCGv_i64 ret, TCGv_i64 arg1, int64_t arg2)
> {
> tcg_debug_assert(arg2 >= 0 && arg2 < 64);
> - /* some cases can be optimized here */
> if (arg2 == 0) {
> tcg_gen_mov_i64(ret, arg1);
> - } else if (tcg_op_supported(INDEX_op_rotl, TCG_TYPE_I64, 0)) {
> - TCGv_i64 t0 = tcg_constant_i64(arg2);
> - tcg_gen_op3_i64(INDEX_op_rotl, ret, arg1, t0);
> - } else if (tcg_op_supported(INDEX_op_rotr, TCG_TYPE_I64, 0)) {
> - TCGv_i64 t0 = tcg_constant_i64(64 - arg2);
> - tcg_gen_op3_i64(INDEX_op_rotr, ret, arg1, t0);
> + } else if (tcg_op_supported(INDEX_op_rotl, TCG_TYPE_I32, 0)) {
Shouldn't this be:
s/TCG_TYPE_I32/TCG_TYPE_I64
?
> + tcg_gen_op3_i64(INDEX_op_rotl, ret, arg1, tcg_constant_i64(arg2));
> } else {
> - TCGv_i64 t0 = tcg_temp_ebb_new_i64();
> - TCGv_i64 t1 = tcg_temp_ebb_new_i64();
> - tcg_gen_shli_i64(t0, arg1, arg2);
> - tcg_gen_shri_i64(t1, arg1, 64 - arg2);
> - tcg_gen_or_i64(ret, t0, t1);
> - tcg_temp_free_i64(t0);
> - tcg_temp_free_i64(t1);
> + tcg_gen_rotri_i64(ret, arg1, -arg2 & 63);
> }
> }
>
> @@ -2461,7 +2448,32 @@ void tcg_gen_rotr_i64(TCGv_i64 ret, TCGv_i64 arg1,
> TCGv_i64 arg2)
> void tcg_gen_rotri_i64(TCGv_i64 ret, TCGv_i64 arg1, int64_t arg2)
> {
> tcg_debug_assert(arg2 >= 0 && arg2 < 64);
> - tcg_gen_rotli_i64(ret, arg1, -arg2 & 63);
> + if (arg2 == 0) {
> + tcg_gen_mov_i64(ret, arg1);
> + } else if (TCG_TARGET_REG_BITS == 32) {
> + TCGv_i32 rl = tcg_temp_ebb_new_i32();
> + TCGv_i32 rh = TCGV_HIGH(ret);
> + TCGv_i32 t0, t1;
> +
> + if (arg2 & 32) {
> + t0 = TCGV_HIGH(arg1);
> + t1 = TCGV_LOW(arg1);
> + } else {
> + t0 = TCGV_LOW(arg1);
> + t1 = TCGV_HIGH(arg1);
> + }
> + tcg_gen_extract2_i32(rl, t0, t1, arg2 & 31);
> + tcg_gen_extract2_i32(rh, t1, t0, arg2 & 31);
> + tcg_gen_mov_i32(TCGV_LOW(ret), rl);
> + tcg_temp_free_i32(rl);
> + } else if (tcg_op_supported(INDEX_op_rotr, TCG_TYPE_I64, 0)) {
> + tcg_gen_op3_i64(INDEX_op_rotr, ret, arg1, tcg_constant_i64(arg2));
> + } else if (tcg_op_supported(INDEX_op_rotl, TCG_TYPE_I64, 0)) {
> + tcg_gen_op3_i64(INDEX_op_rotl, ret, arg1, tcg_constant_i64(64 -
> arg2));
> + } else {
> + /* Do not recurse with the rotri simplification. */
> + tcg_gen_op4i_i64(INDEX_op_extract2, ret, arg1, arg1, arg2);
> + }
> }
>
> void tcg_gen_deposit_i64(TCGv_i64 ret, TCGv_i64 arg1, TCGv_i64 arg2,
> --
> 2.43.0
>
>
