Re: [Qemu-devel] [PATCH 13/17] ppc: compute mask from BI using right shift

[Tom Musta]

On 8/28/2014 12:15 PM, Paolo Bonzini wrote:
> This will match the code we use in fpu_helper.c when we flip
> CRF_* bit-endianness.
> 
> Signed-off-by: Paolo Bonzini <address@hidden>
> ---
>  target-ppc/translate.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/target-ppc/translate.c b/target-ppc/translate.c
> index 48c7b66..4ce7af4 100644
> --- a/target-ppc/translate.c
> +++ b/target-ppc/translate.c
> @@ -794,7 +794,7 @@ static void gen_isel(DisasContext *ctx)
>      TCGv_i32 t0;
>      TCGv t1, true_op, zero;
>  
> -    mask = 1 << (3 - (bi & 0x03));
> +    mask = 0x08 >> (bi & 0x03);
>      t0 = tcg_temp_new_i32();
>      tcg_gen_andi_i32(t0, cpu_crf[bi >> 2], mask);
>      t1 = tcg_temp_new();
> @@ -3870,7 +3870,7 @@ static inline void gen_bcond(DisasContext *ctx, int 
> type)
>      if ((bo & 0x10) == 0) {
>          /* Test CR */
>          uint32_t bi = BI(ctx->opcode);
> -        uint32_t mask = 1 << (3 - (bi & 0x03));
> +        uint32_t mask = 0x08 >> (bi & 0x03);
>          TCGv_i32 temp = tcg_temp_new_i32();
>  
>          if (bo & 0x8) {
> @@ -3952,7 +3952,7 @@ static void glue(gen_, name)(DisasContext *ctx)
>      else                                                                     
>  \
>          tcg_gen_mov_i32(t1, cpu_crf[crbB(ctx->opcode) >> 2]);                
>  \
>      tcg_op(t0, t0, t1);                                                      
>  \
> -    bitmask = 1 << (3 - (crbD(ctx->opcode) & 0x03));                         
>  \
> +    bitmask = 0x08 >> (crbD(ctx->opcode) & 0x03);                            
>  \
>      tcg_gen_andi_i32(t0, t0, bitmask);                                       
>  \
>      tcg_gen_andi_i32(t1, cpu_crf[crbD(ctx->opcode) >> 2], ~bitmask);         
>  \
>      tcg_gen_or_i32(cpu_crf[crbD(ctx->opcode) >> 2], t0, t1);                 
>  \
> 

Reviewed-by: Tom Musta <address@hidden>
Tested-by: Tom Musta <address@hidden>