Re: [Qemu-devel] [PATCH v2 56/60] target-i386: Tidy gen_add_A0_im

[Peter Maydell]

On 29 November 2013 03:00, Richard Henderson <address@hidden> wrote:
> Merge gen_op_addl_A0_im and gen_op_addq_A0_im into gen_add_A0_im
> and clean up the ifdef.
>
> Replace the one remaining user of gen_op_addl_A0_im with gen_add_A0_im.
>
> Signed-off-by: Richard Henderson <address@hidden>
> ---
>  target-i386/translate.c | 27 +++++----------------------
>  1 file changed, 5 insertions(+), 22 deletions(-)
>
> diff --git a/target-i386/translate.c b/target-i386/translate.c
> index 19cabf6..ee9d586 100644
> --- a/target-i386/translate.c
> +++ b/target-i386/translate.c
> @@ -376,29 +376,12 @@ static inline void gen_op_mov_v_reg(TCGMemOp ot, TCGv 
> t0, int reg)
>      }
>  }
>
> -static inline void gen_op_addl_A0_im(int32_t val)
> -{
> -    tcg_gen_addi_tl(cpu_A0, cpu_A0, val);
> -#ifdef TARGET_X86_64
> -    tcg_gen_andi_tl(cpu_A0, cpu_A0, 0xffffffff);
> -#endif
> -}
> -
> -#ifdef TARGET_X86_64
> -static inline void gen_op_addq_A0_im(int64_t val)
> -{
> -    tcg_gen_addi_tl(cpu_A0, cpu_A0, val);
> -}
> -#endif
> -
>  static void gen_add_A0_im(DisasContext *s, int val)
>  {
> -#ifdef TARGET_X86_64
> -    if (CODE64(s))
> -        gen_op_addq_A0_im(val);
> -    else
> -#endif
> -        gen_op_addl_A0_im(val);
> +    tcg_gen_addi_tl(cpu_A0, cpu_A0, val);
> +    if (!CODE64(s)) {
> +        tcg_gen_ext32u_tl(cpu_A0, cpu_A0);
> +    }
>  }
>
>  static inline void gen_op_jmp_T0(void)
> @@ -6231,7 +6214,7 @@ static target_ulong disas_insn(CPUX86State *env, 
> DisasContext *s,
>                 exception */
>              gen_op_jmp_T0();
>              /* pop selector */
> -            gen_op_addl_A0_im(1 << dflag);
> +            gen_add_A0_im(s, 1 << dflag);

Why is it OK that we no longer zero extend the result of
the add from 32 to 64 bits if CODE64(s) ? Previously we
did the extend unconditionally.


>              gen_op_ld_v(s, dflag, cpu_T[0], cpu_A0);
>              gen_op_movl_seg_T0_vm(R_CS);
>              /* add stack offset */

thanks
-- PMM