Re: [PATCH v3 07/20] exec: Cache TARGET_PAGE_MASK for TARGET_PAGE_BITS_VARY

[David Hildenbrand]

On 22.09.19 05:54, Richard Henderson wrote:
> This eliminates a set of runtime shifts.  It turns out that we
> require TARGET_PAGE_MASK more often than TARGET_PAGE_SIZE, so
> redefine TARGET_PAGE_SIZE based on TARGET_PAGE_MASK instead of
> the other way around.
> 
> Reviewed-by: Paolo Bonzini <address@hidden>
> Signed-off-by: Richard Henderson <address@hidden>
> ---
>  include/exec/cpu-all.h | 8 ++++++--
>  exec-vary.c            | 1 +
>  2 files changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/include/exec/cpu-all.h b/include/exec/cpu-all.h
> index 5246770271..2db73c7a27 100644
> --- a/include/exec/cpu-all.h
> +++ b/include/exec/cpu-all.h
> @@ -213,19 +213,23 @@ static inline void stl_phys_notdirty(AddressSpace *as, 
> hwaddr addr, uint32_t val
>  typedef struct {
>      bool decided;
>      int bits;
> +    target_long mask;
>  } TargetPageBits;
>  extern const TargetPageBits target_page;
>  # ifdef CONFIG_DEBUG_TCG
>  #  define TARGET_PAGE_BITS (assert(target_page.decided), target_page.bits)
> +#  define TARGET_PAGE_MASK (assert(target_page.decided), target_page.mask)
>  # else
>  #  define TARGET_PAGE_BITS target_page.bits
> +#  define TARGET_PAGE_MASK target_page.mask
>  # endif
> +# define TARGET_PAGE_SIZE  ((int)-TARGET_PAGE_MASK)
>  #else
>  #define TARGET_PAGE_BITS_MIN TARGET_PAGE_BITS
> +#define TARGET_PAGE_SIZE   (1 << TARGET_PAGE_BITS)
> +#define TARGET_PAGE_MASK   ((target_long)-1 << TARGET_PAGE_BITS)
>  #endif
>  
> -#define TARGET_PAGE_SIZE (1 << TARGET_PAGE_BITS)
> -#define TARGET_PAGE_MASK ((target_long)-1 << TARGET_PAGE_BITS)
>  #define TARGET_PAGE_ALIGN(addr) \
>      (((addr) + ~TARGET_PAGE_MASK) & TARGET_PAGE_MASK)
>  
> diff --git a/exec-vary.c b/exec-vary.c
> index 67cdf57a9c..26daf281f2 100644
> --- a/exec-vary.c
> +++ b/exec-vary.c
> @@ -83,5 +83,6 @@ void finalize_target_page_bits(void)
>          init_target_page.bits = TARGET_PAGE_BITS_MIN;
>      }
>      init_target_page.decided = true;
> +    init_target_page.mask = (target_long)-1 << init_target_page.bits;
>  #endif
>  }
> 

Reviewed-by: David Hildenbrand <address@hidden>

-- 

Thanks,

David / dhildenb