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Date: Tue, 24 Dec 2013 06:25:32 -0800
From: Richard Henderson <rth@twiddle.net>
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Subject: Re: [Qemu-devel] [PATCH v2 5/9] target-sh4: optimize negc using
 add2 and sub2
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To: Aurelien Jarno <aurelien@aurel32.net>, qemu-devel@nongnu.org

On 12/22/2013 03:50 AM, Aurelien Jarno wrote:
> +            TCGv t0 = tcg_const_i32(0);
> +            tcg_gen_add2_i32(REG(B11_8), cpu_sr_t,
> +                             REG(B7_4), t0, cpu_sr_t, t0);
> +            tcg_gen_sub2_i32(REG(B11_8), cpu_sr_t,
> +                             t0, t0, REG(B11_8), cpu_sr_t);

While this formulation is correct, I wonder why you strayed from the two
subtracts model of subc, since negc is similarly described in the manual?

Otherwise,

Reviewed-by: Richard Henderson <rth@twiddle.net>


r~