Re: [Qemu-devel] [PATCH v3 01/20] tcg-arm: Use bic to implement and with constant

[Aurelien Jarno <aurelien@aurel32.net>]

On Thu, Mar 28, 2013 at 08:32:42AM -0700, Richard Henderson wrote:
> This greatly improves the code we can produce for deposit
> without armv7 support.
> 
> Signed-off-by: Richard Henderson <rth@twiddle.net>
> ---
>  tcg/arm/tcg-target.c | 52 ++++++++++++++++++++++++++++++++++++++++++----------
>  tcg/arm/tcg-target.h |  2 --
>  2 files changed, 42 insertions(+), 12 deletions(-)
> 
> diff --git a/tcg/arm/tcg-target.c b/tcg/arm/tcg-target.c
> index 94c6ca4..9972792 100644
> --- a/tcg/arm/tcg-target.c
> +++ b/tcg/arm/tcg-target.c
> @@ -145,6 +145,9 @@ static void patch_reloc(uint8_t *code_ptr, int type,
>      }
>  }
>  
> +#define TCG_CT_CONST_ARM 0x100
> +#define TCG_CT_CONST_INV 0x200
> +
>  /* parse target specific constraints */
>  static int target_parse_constraint(TCGArgConstraint *ct, const char **pct_str)
>  {
> @@ -155,6 +158,9 @@ static int target_parse_constraint(TCGArgConstraint *ct, const char **pct_str)
>      case 'I':
>           ct->ct |= TCG_CT_CONST_ARM;
>           break;
> +    case 'K':
> +         ct->ct |= TCG_CT_CONST_INV;
> +         break;
>  
>      case 'r':
>          ct->ct |= TCG_CT_REG;
> @@ -275,16 +281,19 @@ static inline int check_fit_imm(uint32_t imm)
>   * add, sub, eor...: ditto
>   */
>  static inline int tcg_target_const_match(tcg_target_long val,
> -                const TCGArgConstraint *arg_ct)
> +                                         const TCGArgConstraint *arg_ct)
>  {
>      int ct;
>      ct = arg_ct->ct;
> -    if (ct & TCG_CT_CONST)
> +    if (ct & TCG_CT_CONST) {
>          return 1;
> -    else if ((ct & TCG_CT_CONST_ARM) && check_fit_imm(val))
> +    } else if ((ct & TCG_CT_CONST_ARM) && check_fit_imm(val)) {
>          return 1;
> -    else
> +    } else if ((ct & TCG_CT_CONST_INV) && check_fit_imm(~val)) {
> +        return 1;
> +    } else {
>          return 0;
> +    }
>  }
>  
>  enum arm_data_opc_e {
> @@ -482,6 +491,27 @@ static inline void tcg_out_dat_rI(TCGContext *s, int cond, int opc, TCGArg dst,
>      }
>  }
>  
> +static void tcg_out_dat_rIK(TCGContext *s, int cond, int opc, int opinv,
> +                            TCGReg dst, TCGReg lhs, TCGArg rhs,
> +                            bool rhs_is_const)
> +{
> +    /* Emit either the reg,imm or reg,reg form of a data-processing insn.
> +     * rhs must satisfy the "rIK" constraint.
> +     */
> +    if (rhs_is_const) {
> +        int rot = encode_imm(rhs);
> +        if (rot < 0) {
> +            rhs = ~rhs;
> +            rot = encode_imm(rhs);
> +            assert(rot >= 0);
> +            opc = opinv;
> +        }
> +        tcg_out_dat_imm(s, cond, opc, dst, lhs, rotl(rhs, rot) | (rot << 7));
> +    } else {
> +        tcg_out_dat_reg(s, cond, opc, dst, lhs, rhs, SHIFT_IMM_LSL(0));
> +    }
> +}
> +
>  static inline void tcg_out_mul32(TCGContext *s,
>                  int cond, int rd, int rs, int rm)
>  {
> @@ -1610,11 +1640,13 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc,
>          c = ARITH_SUB;
>          goto gen_arith;
>      case INDEX_op_and_i32:
> -        c = ARITH_AND;
> -        goto gen_arith;
> +        tcg_out_dat_rIK(s, COND_AL, ARITH_AND, ARITH_BIC,
> +                        args[0], args[1], args[2], const_args[2]);
> +        break;
>      case INDEX_op_andc_i32:
> -        c = ARITH_BIC;
> -        goto gen_arith;
> +        tcg_out_dat_rIK(s, COND_AL, ARITH_BIC, ARITH_AND,
> +                        args[0], args[1], args[2], const_args[2]);
> +        break;
>      case INDEX_op_or_i32:
>          c = ARITH_ORR;
>          goto gen_arith;
> @@ -1802,8 +1834,8 @@ static const TCGTargetOpDef arm_op_defs[] = {
>      { INDEX_op_mul_i32, { "r", "r", "r" } },
>      { INDEX_op_mulu2_i32, { "r", "r", "r", "r" } },
>      { INDEX_op_muls2_i32, { "r", "r", "r", "r" } },
> -    { INDEX_op_and_i32, { "r", "r", "rI" } },
> -    { INDEX_op_andc_i32, { "r", "r", "rI" } },
> +    { INDEX_op_and_i32, { "r", "r", "rIK" } },
> +    { INDEX_op_andc_i32, { "r", "r", "rIK" } },
>      { INDEX_op_or_i32, { "r", "r", "rI" } },
>      { INDEX_op_xor_i32, { "r", "r", "rI" } },
>      { INDEX_op_neg_i32, { "r", "r" } },
> diff --git a/tcg/arm/tcg-target.h b/tcg/arm/tcg-target.h
> index b6eed1f..354dd8a 100644
> --- a/tcg/arm/tcg-target.h
> +++ b/tcg/arm/tcg-target.h
> @@ -49,8 +49,6 @@ typedef enum {
>  
>  #define TCG_TARGET_NB_REGS 16
>  
> -#define TCG_CT_CONST_ARM 0x100
> -
>  /* used for function call generation */
>  #define TCG_REG_CALL_STACK		TCG_REG_R13
>  #define TCG_TARGET_STACK_ALIGN		8

Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>


-- 
Aurelien Jarno                          GPG: 1024D/F1BCDB73
aurelien@aurel32.net                 http://www.aurel32.net