Re: [Qemu-devel] [PATCH 01/12] target-s390x: Fix wrong argument in call of tcg_gen_shl_i64()

[Alexander Graf]

On 25.05.2011, at 22:25, Stefan Weil wrote:

> tcg_gen_shl_i64 needs an argument of type TCGv_i64.
> Using tmp4 needs some additional changes.
> 
> Signed-off-by: Stefan Weil <address@hidden>
> ---
> target-s390x/translate.c |    8 +++++---
> 1 files changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/target-s390x/translate.c b/target-s390x/translate.c
> index 8e71df3..3614516 100644
> --- a/target-s390x/translate.c
> +++ b/target-s390x/translate.c
> @@ -2056,7 +2056,6 @@ do_mh:
>            even for very long ones... */
>         tmp = get_address(s, 0, b2, d2);
>         tmp3 = tcg_const_i64(stm_len);
> -        tmp4 = tcg_const_i64(32);
>         for (i = r1;; i = (i + 1) % 16) {
>             switch (op) {
>             case 0x4:
> @@ -2070,7 +2069,9 @@ do_mh:
> #else
>                 tmp2 = tcg_temp_new_i64();
>                 tcg_gen_qemu_ld32u(tmp2, tmp, get_mem_index(s));
> -                tcg_gen_shl_i64(tmp2, tmp2, 4);
> +                tmp4 = tcg_const_i64(4);
> +                tcg_gen_shl_i64(tmp2, tmp2, tmp4);
> +                tcg_temp_free_i64(tmp4);
>                 tcg_gen_ext32u_i64(regs[i], regs[i]);
>                 tcg_gen_or_i64(regs[i], regs[i], tmp2);
> #endif
> @@ -2081,7 +2082,9 @@ do_mh:
>                 break;
>             case 0x26:
>                 tmp2 = tcg_temp_new_i64();
> +                tmp4 = tcg_const_i64(32);

This moves the const inside the loop, which is exactly what I was trying to 
avoid here. The problem is that every new const generated here issues 1 
additional tcg op, which really sums up when there's too many of them. I've had 
the buffer exceed here plenty of times.


Alex