Re: [PATCH 4/7] target/arm: Handle writeback in VLDR/VSTR sysreg with no memory access

From: Richard Henderson <richard.henderson@linaro.org>
To: Peter Maydell <peter.maydell@linaro.org>,
	qemu-arm@nongnu.org, qemu-devel@nongnu.org
Subject: Re: [PATCH 4/7] target/arm: Handle writeback in VLDR/VSTR sysreg with no memory access
Date: Fri, 18 Jun 2021 09:15:04 -0700	[thread overview]
Message-ID: <73b67dcb-6d84-03d8-cc37-f8b8b3f94905@linaro.org> (raw)
In-Reply-To: <20210618141019.10671-5-peter.maydell@linaro.org>

On 6/18/21 7:10 AM, Peter Maydell wrote:
> @@ -633,9 +665,11 @@ static void fp_sysreg_to_memory(DisasContext *s, void *opaque, TCGv_i32 value)
>           gen_helper_v8m_stackcheck(cpu_env, addr);
>       }
>   
> -    gen_aa32_st_i32(s, value, addr, get_mem_index(s),
> -                    MO_UL | MO_ALIGN | s->be_data);
> -    tcg_temp_free_i32(value);
> +    if (do_access) {
> +        gen_aa32_st_i32(s, value, addr, get_mem_index(s),
> +                        MO_UL | MO_ALIGN | s->be_data);
> +        tcg_temp_free_i32(value);
> +    }

So, this bit looked funny at first glance -- are we missing the free of value?  But of 
course value == NULL when !do_access.  Which made me wonder if it wouldn't be better to 
just use value == NULL and not add the extra argument?

Either way,
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~