Re: [Qemu-devel] [PATCH] target-mips: Fix some helper functions (VR54xx multiplication)

[Aurelien Jarno]

On Sun, Mar 04, 2012 at 08:21:39AM +0100, Stefan Weil wrote:
> Commits b5dc7732e1cc2fb549e48b7b5d664f2c79628e2e and
> be24bb4f3007c3e07cbf1934f7e781493d876ab7 optimized the code
> and removed the correct setting of t0. Fix this.
> 
> gcc-4.7 detected this bug because parameter arg1 was unused
> but set in set_HIT0_LO and set_HI_LOT0.
> 
> Cc: Aurelien Jarno <address@hidden>
> Signed-off-by: Stefan Weil <address@hidden>
> ---
> 
> Is anybody using QEMU with MIPS VR5432 code which uses the
> special multiply opcodes? I don't have such code, so I could
> not test my patch.
> 
> Regards,
> Stefan Weil

Thanks, applied.

>  target-mips/op_helper.c |   75 ++++++++++++++++++----------------------------
>  1 files changed, 29 insertions(+), 46 deletions(-)
> 
> diff --git a/target-mips/op_helper.c b/target-mips/op_helper.c
> index c51b9cb..8556c17 100644
> --- a/target-mips/op_helper.c
> +++ b/target-mips/op_helper.c
> @@ -199,115 +199,98 @@ static inline void set_HILO (uint64_t HILO)
>      env->active_tc.HI[0] = (int32_t)(HILO >> 32);
>  }
>  
> -static inline void set_HIT0_LO (target_ulong arg1, uint64_t HILO)
> +static inline target_ulong set_HIT0_LO(uint64_t HILO)
>  {
> +    target_ulong tmp;
>      env->active_tc.LO[0] = (int32_t)(HILO & 0xFFFFFFFF);
> -    arg1 = env->active_tc.HI[0] = (int32_t)(HILO >> 32);
> +    tmp = env->active_tc.HI[0] = (int32_t)(HILO >> 32);
> +    return tmp;
>  }
>  
> -static inline void set_HI_LOT0 (target_ulong arg1, uint64_t HILO)
> +static inline target_ulong set_HI_LOT0(uint64_t HILO)
>  {
> -    arg1 = env->active_tc.LO[0] = (int32_t)(HILO & 0xFFFFFFFF);
> +    target_ulong tmp = env->active_tc.LO[0] = (int32_t)(HILO & 0xFFFFFFFF);
>      env->active_tc.HI[0] = (int32_t)(HILO >> 32);
> +    return tmp;
>  }
>  
>  /* Multiplication variants of the vr54xx. */
>  target_ulong helper_muls (target_ulong arg1, target_ulong arg2)
>  {
> -    set_HI_LOT0(arg1, 0 - ((int64_t)(int32_t)arg1 * (int64_t)(int32_t)arg2));
> -
> -    return arg1;
> +    return set_HI_LOT0(0 - ((int64_t)(int32_t)arg1 * 
> (int64_t)(int32_t)arg2));
>  }
>  
>  target_ulong helper_mulsu (target_ulong arg1, target_ulong arg2)
>  {
> -    set_HI_LOT0(arg1, 0 - ((uint64_t)(uint32_t)arg1 * 
> (uint64_t)(uint32_t)arg2));
> -
> -    return arg1;
> +    return set_HI_LOT0(0 - (uint64_t)(uint32_t)arg1 * 
> (uint64_t)(uint32_t)arg2);
>  }
>  
>  target_ulong helper_macc (target_ulong arg1, target_ulong arg2)
>  {
> -    set_HI_LOT0(arg1, ((int64_t)get_HILO()) + ((int64_t)(int32_t)arg1 * 
> (int64_t)(int32_t)arg2));
> -
> -    return arg1;
> +    return set_HI_LOT0((int64_t)get_HILO() + (int64_t)(int32_t)arg1 *
> +                                             (int64_t)(int32_t)arg2);
>  }
>  
>  target_ulong helper_macchi (target_ulong arg1, target_ulong arg2)
>  {
> -    set_HIT0_LO(arg1, ((int64_t)get_HILO()) + ((int64_t)(int32_t)arg1 * 
> (int64_t)(int32_t)arg2));
> -
> -    return arg1;
> +    return set_HIT0_LO((int64_t)get_HILO() + (int64_t)(int32_t)arg1 *
> +                                             (int64_t)(int32_t)arg2);
>  }
>  
>  target_ulong helper_maccu (target_ulong arg1, target_ulong arg2)
>  {
> -    set_HI_LOT0(arg1, ((uint64_t)get_HILO()) + ((uint64_t)(uint32_t)arg1 * 
> (uint64_t)(uint32_t)arg2));
> -
> -    return arg1;
> +    return set_HI_LOT0((uint64_t)get_HILO() + (uint64_t)(uint32_t)arg1 *
> +                                              (uint64_t)(uint32_t)arg2);
>  }
>  
>  target_ulong helper_macchiu (target_ulong arg1, target_ulong arg2)
>  {
> -    set_HIT0_LO(arg1, ((uint64_t)get_HILO()) + ((uint64_t)(uint32_t)arg1 * 
> (uint64_t)(uint32_t)arg2));
> -
> -    return arg1;
> +    return set_HIT0_LO((uint64_t)get_HILO() + (uint64_t)(uint32_t)arg1 *
> +                                              (uint64_t)(uint32_t)arg2);
>  }
>  
>  target_ulong helper_msac (target_ulong arg1, target_ulong arg2)
>  {
> -    set_HI_LOT0(arg1, ((int64_t)get_HILO()) - ((int64_t)(int32_t)arg1 * 
> (int64_t)(int32_t)arg2));
> -
> -    return arg1;
> +    return set_HI_LOT0((int64_t)get_HILO() - (int64_t)(int32_t)arg1 *
> +                                             (int64_t)(int32_t)arg2);
>  }
>  
>  target_ulong helper_msachi (target_ulong arg1, target_ulong arg2)
>  {
> -    set_HIT0_LO(arg1, ((int64_t)get_HILO()) - ((int64_t)(int32_t)arg1 * 
> (int64_t)(int32_t)arg2));
> -
> -    return arg1;
> +    return set_HIT0_LO((int64_t)get_HILO() - (int64_t)(int32_t)arg1 *
> +                                             (int64_t)(int32_t)arg2);
>  }
>  
>  target_ulong helper_msacu (target_ulong arg1, target_ulong arg2)
>  {
> -    set_HI_LOT0(arg1, ((uint64_t)get_HILO()) - ((uint64_t)(uint32_t)arg1 * 
> (uint64_t)(uint32_t)arg2));
> -
> -    return arg1;
> +    return set_HI_LOT0((uint64_t)get_HILO() - (uint64_t)(uint32_t)arg1 *
> +                                              (uint64_t)(uint32_t)arg2);
>  }
>  
>  target_ulong helper_msachiu (target_ulong arg1, target_ulong arg2)
>  {
> -    set_HIT0_LO(arg1, ((uint64_t)get_HILO()) - ((uint64_t)(uint32_t)arg1 * 
> (uint64_t)(uint32_t)arg2));
> -
> -    return arg1;
> +    return set_HIT0_LO((uint64_t)get_HILO() - (uint64_t)(uint32_t)arg1 *
> +                                              (uint64_t)(uint32_t)arg2);
>  }
>  
>  target_ulong helper_mulhi (target_ulong arg1, target_ulong arg2)
>  {
> -    set_HIT0_LO(arg1, (int64_t)(int32_t)arg1 * (int64_t)(int32_t)arg2);
> -
> -    return arg1;
> +    return set_HIT0_LO((int64_t)(int32_t)arg1 * (int64_t)(int32_t)arg2);
>  }
>  
>  target_ulong helper_mulhiu (target_ulong arg1, target_ulong arg2)
>  {
> -    set_HIT0_LO(arg1, (uint64_t)(uint32_t)arg1 * (uint64_t)(uint32_t)arg2);
> -
> -    return arg1;
> +    return set_HIT0_LO((uint64_t)(uint32_t)arg1 * (uint64_t)(uint32_t)arg2);
>  }
>  
>  target_ulong helper_mulshi (target_ulong arg1, target_ulong arg2)
>  {
> -    set_HIT0_LO(arg1, 0 - ((int64_t)(int32_t)arg1 * (int64_t)(int32_t)arg2));
> -
> -    return arg1;
> +    return set_HIT0_LO(0 - (int64_t)(int32_t)arg1 * (int64_t)(int32_t)arg2);
>  }
>  
>  target_ulong helper_mulshiu (target_ulong arg1, target_ulong arg2)
>  {
> -    set_HIT0_LO(arg1, 0 - ((uint64_t)(uint32_t)arg1 * 
> (uint64_t)(uint32_t)arg2));
> -
> -    return arg1;
> +    return set_HIT0_LO(0 - (uint64_t)(uint32_t)arg1 * 
> (uint64_t)(uint32_t)arg2);
>  }
>  
>  #ifdef TARGET_MIPS64
> -- 
> 1.7.9
> 
> 
> 

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