Re: [Qemu-devel] [PATCH 6/8] tcg: Add tcg_debug_assert

[Aurelien Jarno]

On Fri, Sep 21, 2012 at 05:18:14PM -0700, Richard Henderson wrote:
> Like the C assert macro, except only enabled for CONFIG_DEBUG_TCG,
> and without having to set _NDEBUG and disable all other asserts at
> the same time.
> 
> The use of __builtin_unreachable (when available) gives the compiler
> the same information, which may (or may not) help it optimize better.
> 
> Signed-off-by: Richard Henderson <address@hidden>
> ---
>  tcg/tcg.h | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/tcg/tcg.h b/tcg/tcg.h
> index 48a56f0..4501c15 100644
> --- a/tcg/tcg.h
> +++ b/tcg/tcg.h
> @@ -530,6 +530,15 @@ do {\
>      abort();\
>  } while (0)
>  
> +#ifdef CONFIG_DEBUG_TCG
> +# define tcg_debug_assert(X) do { assert(X); } while (0)
> +#elif QEMU_GNUC_PREREQ(4, 5)
> +# define tcg_debug_assert(X) \
> +    do { if (!(X)) { __builtin_unreachable(); } } while (0)
> +#else
> +# define tcg_debug_assert(X) do { (void)(X); } while (0)
> +#endif
> +
>  void tcg_add_target_add_op_defs(const TCGTargetOpDef *tdefs);
>  
>  #if TCG_TARGET_REG_BITS == 32
> -- 
> 1.7.11.4
> 

Reviewed-by: Aurelien Jarno <address@hidden>

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