Re: [PATCH v3 13/18] target/s390x: Simplify helper_lra

[David Hildenbrand]

On 26.09.19 18:26, Richard Henderson wrote:
> We currently call trigger_pgm_exception to set cs->exception_index
> and env->int_pgm_code and then read the values back and then
> reset cs->exception_index so that the exception is not delivered.
> 
> Instead, use the exception type that we already have directly
> without ever triggering an exception that must be suppressed.
> 
> Signed-off-by: Richard Henderson <address@hidden>
> ---
>  target/s390x/mem_helper.c | 17 +++--------------
>  1 file changed, 3 insertions(+), 14 deletions(-)
> 
> diff --git a/target/s390x/mem_helper.c b/target/s390x/mem_helper.c
> index e15aa296dd..4254548935 100644
> --- a/target/s390x/mem_helper.c
> +++ b/target/s390x/mem_helper.c
> @@ -2361,34 +2361,23 @@ void HELPER(sturg)(CPUS390XState *env, uint64_t addr, 
> uint64_t v1)
>  /* load real address */
>  uint64_t HELPER(lra)(CPUS390XState *env, uint64_t addr)
>  {
> -    CPUState *cs = env_cpu(env);
> -    uint32_t cc = 0;
>      uint64_t asc = env->psw.mask & PSW_MASK_ASC;
>      uint64_t ret, tec;
> -    int old_exc, flags, exc;
> +    int flags, exc, cc;
>  
>      /* XXX incomplete - has more corner cases */
>      if (!(env->psw.mask & PSW_MASK_64) && (addr >> 32)) {
>          tcg_s390_program_interrupt(env, PGM_SPECIAL_OP, GETPC());
>      }
>  
> -    old_exc = cs->exception_index;
>      exc = mmu_translate(env, addr, 0, asc, &ret, &flags, &tec);
>      if (exc) {
> -        /*
> -         * We don't care about ILEN or TEC, as we're not going to
> -         * deliver the exception -- thus resetting exception_index below.
> -         * TODO: clean this up.
> -         */
> -        trigger_pgm_exception(env, exc, ILEN_UNWIND);
>          cc = 3;
> -    }
> -    if (cs->exception_index == EXCP_PGM) {
> -        ret = env->int_pgm_code | 0x80000000;
> +        ret = exc | 0x80000000;
>      } else {
> +        cc = 0;
>          ret |= addr & ~TARGET_PAGE_MASK;
>      }
> -    cs->exception_index = old_exc;
>  
>      env->cc_op = cc;
>      return ret;
> 


Much better

Reviewed-by: David Hildenbrand <address@hidden>

-- 

Thanks,

David / dhildenb