Re: [PATCH for-5.2] tcg: Remove assert from set_jmp_reset_offset

[Philippe Mathieu-Daudé]

On 11/3/20 4:39 AM, Richard Henderson wrote:
> The range check done here is done later, more appropriately,
> at the end of tcg_gen_code.

Maybe mention commit 6e6c4efed99 ("tcg: Restart after TB code generation
overflow")? (no need to repost).

>  There, a failing range check
> results in a returned error code, which causes the TB to be
> restarted at half the size.
> 
> Reported-by: Sai Pavan Boddu <saipava@xilinx.com>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
> 
> Sai, would you try this against your failing testcase?
> 
> 
> r~
> 
> ---
>  tcg/tcg.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/tcg/tcg.c b/tcg/tcg.c
> index f49f1a7f35..43c6cf8f52 100644
> --- a/tcg/tcg.c
> +++ b/tcg/tcg.c
> @@ -335,10 +335,11 @@ static bool tcg_resolve_relocs(TCGContext *s)
>  
>  static void set_jmp_reset_offset(TCGContext *s, int which)
>  {
> -    size_t off = tcg_current_code_size(s);
> -    s->tb_jmp_reset_offset[which] = off;
> -    /* Make sure that we didn't overflow the stored offset.  */
> -    assert(s->tb_jmp_reset_offset[which] == off);
> +    /*
> +     * We will check for overflow at the end of the opcode loop in
> +     * tcg_gen_code, where we bound tcg_current_code_size to UINT16_MAX.
> +     */
> +    s->tb_jmp_reset_offset[which] = tcg_current_code_size(s);
>  }
>  
>  #include "tcg-target.c.inc"
> 

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>