Re: [Qemu-devel] [PATCH 2/8] target-arm: Add symbolic constants for bitfields in TB flags

[Aurelien Jarno <aurelien@aurel32.net>]

On Tue, Jan 11, 2011 at 10:12:12PM +0000, Peter Maydell wrote:
> Add symbolic constants for the bitfields we use in the TB flags.
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>  target-arm/cpu.h |   45 +++++++++++++++++++++++++++++++++++++++------
>  1 files changed, 39 insertions(+), 6 deletions(-)

Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
 
> diff --git a/target-arm/cpu.h b/target-arm/cpu.h
> index 340933e..3adb118 100644
> --- a/target-arm/cpu.h
> +++ b/target-arm/cpu.h
> @@ -440,17 +440,50 @@ static inline void cpu_clone_regs(CPUState *env, target_ulong newsp)
>  
>  #include "cpu-all.h"
>  
> +/* Bit usage in the TB flags field: */
> +#define ARM_TBFLAG_THUMB_SHIFT      0
> +#define ARM_TBFLAG_THUMB_MASK       (1 << ARM_TBFLAG_THUMB_SHIFT)
> +#define ARM_TBFLAG_VECLEN_SHIFT     1
> +#define ARM_TBFLAG_VECLEN_MASK      (0x7 << ARM_TBFLAG_VECLEN_SHIFT)
> +#define ARM_TBFLAG_VECSTRIDE_SHIFT  4
> +#define ARM_TBFLAG_VECSTRIDE_MASK   (0x3 << ARM_TBFLAG_VECSTRIDE_SHIFT)
> +#define ARM_TBFLAG_PRIV_SHIFT       6
> +#define ARM_TBFLAG_PRIV_MASK        (1 << ARM_TBFLAG_PRIV_SHIFT)
> +#define ARM_TBFLAG_VFPEN_SHIFT      7
> +#define ARM_TBFLAG_VFPEN_MASK       (1 << ARM_TBFLAG_VFPEN_SHIFT)
> +#define ARM_TBFLAG_CONDEXEC_SHIFT   8
> +#define ARM_TBFLAG_CONDEXEC_MASK    (0xff << ARM_TBFLAG_CONDEXEC_SHIFT)
> +/* Bits 31..16 are currently unused. */
> +
> +/* some convenience accessor macros */
> +#define ARM_TBFLAG_THUMB(F) \
> +    (((F) & ARM_TBFLAG_THUMB_MASK) >> ARM_TBFLAG_THUMB_SHIFT)
> +#define ARM_TBFLAG_VECLEN(F) \
> +    (((F) & ARM_TBFLAG_VECLEN_MASK) >> ARM_TBFLAG_VECLEN_SHIFT)
> +#define ARM_TBFLAG_VECSTRIDE(F) \
> +    (((F) & ARM_TBFLAG_VECSTRIDE_MASK) >> ARM_TBFLAG_VECSTRIDE_SHIFT)
> +#define ARM_TBFLAG_PRIV(F) \
> +    (((F) & ARM_TBFLAG_PRIV_MASK) >> ARM_TBFLAG_PRIV_SHIFT)
> +#define ARM_TBFLAG_VFPEN(F) \
> +    (((F) & ARM_TBFLAG_VFPEN_MASK) >> ARM_TBFLAG_VFPEN_SHIFT)
> +#define ARM_TBFLAG_CONDEXEC(F) \
> +    (((F) & ARM_TBFLAG_CONDEXEC_MASK) >> ARM_TBFLAG_CONDEXEC_SHIFT)
> +
>  static inline void cpu_get_tb_cpu_state(CPUState *env, target_ulong *pc,
>                                          target_ulong *cs_base, int *flags)
>  {
>      *pc = env->regs[15];
>      *cs_base = 0;
> -    *flags = env->thumb | (env->vfp.vec_len << 1)
> -            | (env->vfp.vec_stride << 4) | (env->condexec_bits << 8);
> -    if ((env->uncached_cpsr & CPSR_M) != ARM_CPU_MODE_USR)
> -        *flags |= (1 << 6);
> -    if (env->vfp.xregs[ARM_VFP_FPEXC] & (1 << 30))
> -        *flags |= (1 << 7);
> +    *flags = (env->thumb << ARM_TBFLAG_THUMB_SHIFT)
> +        | (env->vfp.vec_len << ARM_TBFLAG_VECLEN_SHIFT)
> +        | (env->vfp.vec_stride << ARM_TBFLAG_VECSTRIDE_SHIFT)
> +        | (env->condexec_bits << ARM_TBFLAG_CONDEXEC_SHIFT);
> +    if ((env->uncached_cpsr & CPSR_M) != ARM_CPU_MODE_USR) {
> +        *flags |= ARM_TBFLAG_PRIV_MASK;
> +    }
> +    if (env->vfp.xregs[ARM_VFP_FPEXC] & (1 << 30)) {
> +        *flags |= ARM_TBFLAG_VFPEN_MASK;
> +    }
>  }
>  
>  #endif
> -- 
> 1.6.3.3
> 
> 
> 

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