Re: [Qemu-devel] [PATCH] tcg: Complete handling of ALWAYS and NEVER

[Laurent Desnogues <laurent.desnogues@gmail.com>]

Hi Richard,

On Fri, Feb 20, 2015 at 8:19 PM, Richard Henderson <rth@twiddle.net> wrote:
> Missing from movcond, and brcondi_i32 (but not brcondi_i64).
>
> Signed-off-by: Richard Henderson <rth@twiddle.net>

Tested-by: Laurent Desnogues <laurent.desnogues@gmail.com>

> ---
>  tcg/tcg-op.c | 22 +++++++++++++++++-----
>  1 file changed, 17 insertions(+), 5 deletions(-)
> ---
>
> On 02/20/2015 05:05 AM, Laurent Desnogues wrote:> Hi Richard,
>>
>> this patch results in movcond with always as a condition to be
>> generated for csel al.  The issue is that optimize.c did not get
>> patched to accept that which results in some tcg_abort to fire (in
>> do_constant_folding_cond_64 in this case).
>
> Consider this patch to precede 08/11.

Works fine.

Thanks,

Laurent

>
> r~
> ---
>
> diff --git a/tcg/tcg-op.c b/tcg/tcg-op.c
> index 6674bb4..f7a2767 100644
> --- a/tcg/tcg-op.c
> +++ b/tcg/tcg-op.c
> @@ -286,9 +286,13 @@ void tcg_gen_brcond_i32(TCGCond cond, TCGv_i32 arg1, TCGv_i32 arg2, TCGLabel *l)
>
>  void tcg_gen_brcondi_i32(TCGCond cond, TCGv_i32 arg1, int32_t arg2, TCGLabel *l)
>  {
> -    TCGv_i32 t0 = tcg_const_i32(arg2);
> -    tcg_gen_brcond_i32(cond, arg1, t0, l);
> -    tcg_temp_free_i32(t0);
> +    if (cond == TCG_COND_ALWAYS) {
> +        tcg_gen_br(l);
> +    } else if (cond != TCG_COND_NEVER) {
> +        TCGv_i32 t0 = tcg_const_i32(arg2);
> +        tcg_gen_brcond_i32(cond, arg1, t0, l);
> +        tcg_temp_free_i32(t0);
> +    }
>  }
>
>  void tcg_gen_setcond_i32(TCGCond cond, TCGv_i32 ret,
> @@ -546,7 +550,11 @@ void tcg_gen_deposit_i32(TCGv_i32 ret, TCGv_i32 arg1, TCGv_i32 arg2,
>  void tcg_gen_movcond_i32(TCGCond cond, TCGv_i32 ret, TCGv_i32 c1,
>                           TCGv_i32 c2, TCGv_i32 v1, TCGv_i32 v2)
>  {
> -    if (TCG_TARGET_HAS_movcond_i32) {
> +    if (cond == TCG_COND_ALWAYS) {
> +        tcg_gen_mov_i32(ret, v1);
> +    } else if (cond == TCG_COND_NEVER) {
> +        tcg_gen_mov_i32(ret, v2);
> +    } else if (TCG_TARGET_HAS_movcond_i32) {
>          tcg_gen_op6i_i32(INDEX_op_movcond_i32, ret, c1, c2, v1, v2, cond);
>      } else {
>          TCGv_i32 t0 = tcg_temp_new_i32();
> @@ -1590,7 +1598,11 @@ void tcg_gen_deposit_i64(TCGv_i64 ret, TCGv_i64 arg1, TCGv_i64 arg2,
>  void tcg_gen_movcond_i64(TCGCond cond, TCGv_i64 ret, TCGv_i64 c1,
>                           TCGv_i64 c2, TCGv_i64 v1, TCGv_i64 v2)
>  {
> -    if (TCG_TARGET_REG_BITS == 32) {
> +    if (cond == TCG_COND_ALWAYS) {
> +        tcg_gen_mov_i64(ret, v1);
> +    } else if (cond == TCG_COND_NEVER) {
> +        tcg_gen_mov_i64(ret, v2);
> +    } else if (TCG_TARGET_REG_BITS == 32) {
>          TCGv_i32 t0 = tcg_temp_new_i32();
>          TCGv_i32 t1 = tcg_temp_new_i32();
>          tcg_gen_op6i_i32(INDEX_op_setcond2_i32, t0,
> --
> 2.1.0
>