Re: [Qemu-devel] [PATCH v5 10/19] tcg-arm: Implement division instructions

[Aurelien Jarno]

On Sun, Mar 31, 2013 at 03:34:56PM -0700, Richard Henderson wrote:
> An armv7 extension implements division, present on Cortex A15.
> 
> Signed-off-by: Richard Henderson <address@hidden>
> ---
>  disas/arm.c          |  4 ++++
>  tcg/arm/tcg-target.c | 36 ++++++++++++++++++++++++++++++++++++
>  tcg/arm/tcg-target.h |  7 ++++++-
>  3 files changed, 46 insertions(+), 1 deletion(-)
> 
> diff --git a/disas/arm.c b/disas/arm.c
> index 4927d8a..76e97a8 100644
> --- a/disas/arm.c
> +++ b/disas/arm.c
> @@ -819,6 +819,10 @@ static const struct opcode32 arm_opcodes[] =
>    {ARM_EXT_V3M, 0x00800090, 0x0fa000f0, "%22?sumull%20's%c\t%12-15r, 
> %16-19r, %0-3r, %8-11r"},
>    {ARM_EXT_V3M, 0x00a00090, 0x0fa000f0, "%22?sumlal%20's%c\t%12-15r, 
> %16-19r, %0-3r, %8-11r"},
>  
> +  /* IDIV instructions.  */
> +  {ARM_EXT_DIV, 0x0710f010, 0x0ff0f0f0, "sdiv%c\t%16-19r, %0-3r, %8-11r"},
> +  {ARM_EXT_DIV, 0x0730f010, 0x0ff0f0f0, "udiv%c\t%16-19r, %0-3r, %8-11r"},
> +
>    /* V7 instructions.  */
>    {ARM_EXT_V7, 0xf450f000, 0xfd70f000, "pli\t%P"},
>    {ARM_EXT_V7, 0x0320f0f0, 0x0ffffff0, "dbg%c\t#%0-3d"},
> diff --git a/tcg/arm/tcg-target.c b/tcg/arm/tcg-target.c
> index 1044c68..e3d2cfa 100644
> --- a/tcg/arm/tcg-target.c
> +++ b/tcg/arm/tcg-target.c
> @@ -591,6 +591,16 @@ static inline void tcg_out_smull32(TCGContext *s,
>      }
>  }
>  
> +static inline void tcg_out_sdiv(TCGContext *s, int cond, int rd, int rn, int 
> rm)
> +{
> +    tcg_out32(s, 0x0710f010 | (cond << 28) | (rd << 16) | rn | (rm << 8));
> +}
> +
> +static inline void tcg_out_udiv(TCGContext *s, int cond, int rd, int rn, int 
> rm)
> +{
> +    tcg_out32(s, 0x0730f010 | (cond << 28) | (rd << 16) | rn | (rm << 8));
> +}
> +
>  static inline void tcg_out_ext8s(TCGContext *s, int cond,
>                                   int rd, int rn)
>  {
> @@ -1869,6 +1879,25 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode 
> opc,
>                          args[3], args[4], const_args[2]);
>          break;
>  
> +    case INDEX_op_div_i32:
> +        tcg_out_sdiv(s, COND_AL, args[0], args[1], args[2]);
> +        break;
> +    case INDEX_op_divu_i32:
> +        tcg_out_udiv(s, COND_AL, args[0], args[1], args[2]);
> +        break;
> +    case INDEX_op_rem_i32:
> +        tcg_out_sdiv(s, COND_AL, TCG_REG_R8, args[1], args[2]);
> +        tcg_out_mul32(s, COND_AL, TCG_REG_R8, TCG_REG_R8, args[2]);
> +        tcg_out_dat_reg(s, COND_AL, ARITH_SUB, args[0], args[1], TCG_REG_R8,
> +                        SHIFT_IMM_LSL(0));
> +        break;
> +    case INDEX_op_remu_i32:
> +        tcg_out_udiv(s, COND_AL, TCG_REG_R8, args[1], args[2]);
> +        tcg_out_mul32(s, COND_AL, TCG_REG_R8, TCG_REG_R8, args[2]);
> +        tcg_out_dat_reg(s, COND_AL, ARITH_SUB, args[0], args[1], TCG_REG_R8,
> +                        SHIFT_IMM_LSL(0));
> +        break;
> +
>      default:
>          tcg_abort();
>      }
> @@ -1955,6 +1984,13 @@ static const TCGTargetOpDef arm_op_defs[] = {
>  
>      { INDEX_op_deposit_i32, { "r", "0", "ri" } },
>  
> +#if TCG_TARGET_HAS_div_i32
> +    { INDEX_op_div_i32, { "r", "r", "r" } },
> +    { INDEX_op_rem_i32, { "r", "r", "r" } },
> +    { INDEX_op_divu_i32, { "r", "r", "r" } },
> +    { INDEX_op_remu_i32, { "r", "r", "r" } },
> +#endif
> +
>      { -1 },
>  };
>  
> diff --git a/tcg/arm/tcg-target.h b/tcg/arm/tcg-target.h
> index 209f585..3be41cc 100644
> --- a/tcg/arm/tcg-target.h
> +++ b/tcg/arm/tcg-target.h
> @@ -56,7 +56,6 @@ typedef enum {
>  #define TCG_TARGET_CALL_STACK_OFFSET 0
>  
>  /* optional instructions */
> -#define TCG_TARGET_HAS_div_i32          0
>  #define TCG_TARGET_HAS_ext8s_i32        1
>  #define TCG_TARGET_HAS_ext16s_i32       1
>  #define TCG_TARGET_HAS_ext8u_i32        0 /* and r0, r1, #0xff */
> @@ -75,6 +74,12 @@ typedef enum {
>  #define TCG_TARGET_HAS_movcond_i32      1
>  #define TCG_TARGET_HAS_muls2_i32        1
>  
> +#ifdef __ARM_ARCH_EXT_IDIV__
> +#define TCG_TARGET_HAS_div_i32          1
> +#else
> +#define TCG_TARGET_HAS_div_i32          0
> +#endif
> +
>  extern bool tcg_target_deposit_valid(int ofs, int len);
>  #define TCG_TARGET_deposit_i32_valid  tcg_target_deposit_valid
>  

Reviewed-by: Aurelien Jarno <address@hidden>

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