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From: Richard Henderson <rth@twiddle.net>
To: Peter Maydell <peter.maydell@linaro.org>
Cc: QEMU Developers <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] [PATCH v2 04/11] target-arm: Use setcond and movcond for csel
Date: Mon, 7 Sep 2015 22:12:40 -0700	[thread overview]
Message-ID: <55EE6E48.3070806@twiddle.net> (raw)
In-Reply-To: <CAFEAcA9ShVr92O4zSW1_59sqx8wUgbnmhwwjQeYC9NjE+Sd+nQ@mail.gmail.com>

On 09/07/2015 10:17 AM, Peter Maydell wrote:
>> +    c64->value = tcg_temp_new_i64();
>> +    c64->cond = c32.cond;
>> +    if (c32.cond == TCG_COND_EQ || c32.cond == TCG_COND_NE) {
>> +        tcg_gen_extu_i32_i64(c64->value, c32.value);
>> +    } else {
>> +        tcg_gen_ext_i32_i64(c64->value, c32.value);
>> +    }
>
> Signed extend would work for EQ and NE as well, wouldn't it?

Yes.

> Why prefer the unsigned extension in those cases? If there's
> a reason, it could do with being commented.

I dunno what I was really thinking there.


r~

  reply	other threads:[~2015-09-08  5:13 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-09-02 17:57 [Qemu-devel] [PATCH v2 00/11] target-arm improvements for aarch64 Richard Henderson
2015-09-02 17:57 ` [Qemu-devel] [PATCH v2 01/11] target-arm: Share all common TCG temporaries Richard Henderson
2015-09-07 16:57   ` Peter Maydell
2015-09-08  5:13     ` Richard Henderson
2015-09-02 17:57 ` [Qemu-devel] [PATCH v2 02/11] target-arm: Introduce DisasCompare Richard Henderson
2015-09-07 17:09   ` Peter Maydell
2015-09-08  5:09     ` Richard Henderson
2015-09-08  8:13       ` Peter Maydell
2015-09-02 17:57 ` [Qemu-devel] [PATCH v2 03/11] target-arm: Handle always condition codes within arm_test_cc Richard Henderson
2015-09-07 17:11   ` Peter Maydell
2015-09-02 17:57 ` [Qemu-devel] [PATCH v2 04/11] target-arm: Use setcond and movcond for csel Richard Henderson
2015-09-07 17:17   ` Peter Maydell
2015-09-08  5:12     ` Richard Henderson [this message]
2015-09-02 17:57 ` [Qemu-devel] [PATCH v2 05/11] target-arm: Implement ccmp branchless Richard Henderson
2015-09-07 17:31   ` Peter Maydell
2015-09-08  5:18     ` Richard Henderson
2015-09-08  8:19       ` Peter Maydell
2015-09-08 15:20         ` Richard Henderson
2015-09-02 17:57 ` [Qemu-devel] [PATCH v2 06/11] target-arm: Implement fcsel with movcond Richard Henderson
2015-09-07 17:42   ` Peter Maydell
2015-09-08 15:21     ` Richard Henderson
2015-09-02 17:57 ` [Qemu-devel] [PATCH v2 07/11] target-arm: Recognize SXTB, SXTH, SXTW, ASR Richard Henderson
2015-09-07 17:47   ` Peter Maydell
2015-09-02 17:57 ` [Qemu-devel] [PATCH v2 08/11] target-arm: Recognize UXTB, UXTH, LSR, LSL Richard Henderson
2015-09-07 18:00   ` Peter Maydell
2015-09-02 17:57 ` [Qemu-devel] [PATCH v2 09/11] target-arm: Eliminate unnecessary zero-extend in disas_bitfield Richard Henderson
2015-09-07 18:02   ` Peter Maydell
2015-09-02 17:57 ` [Qemu-devel] [PATCH v2 10/11] target-arm: Recognize ROR Richard Henderson
2015-09-07 18:06   ` Peter Maydell
2015-09-02 17:57 ` [Qemu-devel] [PATCH v2 11/11] target-arm: Use tcg_gen_extrh_i64_i32 Richard Henderson
2015-09-07 18:11   ` Peter Maydell

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