Re: [Qemu-devel] [PATCH v4 13/35] tcg: Add atomic helpers

[Alex Bennée]

Richard Henderson <address@hidden> writes:

> Add all of cmpxchg, op_fetch, fetch_op, and xchg.
> Handle both endian-ness, and sizes up to 8.
> Handle expanding non-atomically, when emulating in serial.
>
> Signed-off-by: Richard Henderson <address@hidden>
> ---
<snip>
> diff --git a/tcg/tcg-op.c b/tcg/tcg-op.c
> index 291d50b..65e3663 100644
> --- a/tcg/tcg-op.c
> +++ b/tcg/tcg-op.c
<snip>
> +void tcg_gen_atomic_cmpxchg_i32(TCGv_i32 retv, TCGv addr, TCGv_i32 cmpv,
> +                                TCGv_i32 newv, TCGArg idx, TCGMemOp memop)
> +{
> +    memop = tcg_canonicalize_memop(memop, 0, 0);
> +
> +    if (!parallel_cpus) {

This breaks the compile because parallel_cpus isn't visible to the
function. However I suspect it's because there is a missing patch in
this series (I checked my email and the archive). What happened to 06/35?

> +        TCGv_i32 t1 = tcg_temp_new_i32();
> +        TCGv_i32 t2 = tcg_temp_new_i32();
> +
> +        tcg_gen_ext_i32(t2, cmpv, memop & MO_SIZE);
> +
> +        tcg_gen_qemu_ld_i32(t1, addr, idx, memop & ~MO_SIGN);
> +        tcg_gen_movcond_i32(TCG_COND_EQ, t2, t1, t2, newv, t1);
> +        tcg_gen_qemu_st_i32(t2, addr, idx, memop);
> +        tcg_temp_free_i32(t2);
> +
> +        if (memop & MO_SIGN) {
> +            tcg_gen_ext_i32(retv, t1, memop);
> +        } else {
> +            tcg_gen_mov_i32(retv, t1);
> +        }
> +        tcg_temp_free_i32(t1);
> +    } else {
> +        gen_atomic_cx_i32 gen;
> +
> +        gen = table_cmpxchg[memop & (MO_SIZE | MO_BSWAP)];
> +        tcg_debug_assert(gen != NULL);
> +
> +#ifdef CONFIG_SOFTMMU
> +        {
> +            TCGv_i32 oi = tcg_const_i32(make_memop_idx(memop & ~MO_SIGN, 
> idx));
> +            gen(retv, tcg_ctx.tcg_env, addr, cmpv, newv, oi);
> +            tcg_temp_free_i32(oi);
> +        }
> +#else
> +        gen(retv, tcg_ctx.tcg_env, addr, cmpv, newv);
> +#endif
> +
> +        if (memop & MO_SIGN) {
> +            tcg_gen_ext_i32(retv, retv, memop);
> +        }
> +    }
> +}
> +
> +void tcg_gen_atomic_cmpxchg_i64(TCGv_i64 retv, TCGv addr, TCGv_i64 cmpv,
> +                                TCGv_i64 newv, TCGArg idx, TCGMemOp memop)
> +{
> +    memop = tcg_canonicalize_memop(memop, 1, 0);
> +
> +    if (!parallel_cpus) {
> +        TCGv_i64 t1 = tcg_temp_new_i64();
> +        TCGv_i64 t2 = tcg_temp_new_i64();
> +
> +        tcg_gen_ext_i64(t2, cmpv, memop & MO_SIZE);


--
Alex Bennée