From: Richard Henderson <rth@twiddle.net>
To: Paolo Bonzini <pbonzini@redhat.com>, qemu-devel@nongnu.org
Cc: aurelien@aurel32.net
Subject: Re: [Qemu-devel] [PATCH 5/5] tcg/i386: Use SHLX/SHRX/SARX instructions
Date: Sun, 16 Feb 2014 09:57:41 -0800 [thread overview]
Message-ID: <5300FC15.6090003@twiddle.net> (raw)
In-Reply-To: <5300C968.9040609@redhat.com>
On 02/16/2014 06:21 AM, Paolo Bonzini wrote:
> Il 31/01/2014 15:43, Richard Henderson ha scritto:
>> + gen_shift_maybe_vex:
>> + if (have_bmi2 && !const_args[2]) {
>> + tcg_out_vex_modrm(s, vexop + rexw, args[0], args[2], args[1]);
>> + break;
>> + }
>> + /* FALLTHRU */
>
> What if args[2] happens to be ECX?
shlx handles that just fine. I don't think it's worth an extra check to
fall back to shl on the off-chance that ecx is used; it's pretty far down
on the register allocation order list, so it wouldn't happen often.
r~
next prev parent reply other threads:[~2014-02-16 17:58 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-31 14:43 [Qemu-devel] [PATCH 0/5] tcg/i386 support for bmi Richard Henderson
2014-01-31 14:43 ` [Qemu-devel] [PATCH 1/5] disas/i386: Disassemble ANDN/SHLX/SHRX/SHAX Richard Henderson
2014-02-16 18:12 ` Aurelien Jarno
2014-01-31 14:43 ` [Qemu-devel] [PATCH 2/5] tcg/i386: Move TCG_CT_CONST_* to tcg-target.c Richard Henderson
2014-02-16 18:12 ` Aurelien Jarno
2014-01-31 14:43 ` [Qemu-devel] [PATCH 3/5] tcg/i386: Add tcg_out_vex_modrm Richard Henderson
2014-02-16 18:12 ` Aurelien Jarno
2014-01-31 14:43 ` [Qemu-devel] [PATCH 4/5] tcg/i386: Use ANDN instruction Richard Henderson
2014-02-16 18:12 ` Aurelien Jarno
2014-02-17 16:18 ` Richard Henderson
2014-02-20 16:25 ` Peter Maydell
2014-02-20 16:42 ` Peter Maydell
2014-02-20 16:43 ` Richard Henderson
2014-02-20 17:38 ` Peter Maydell
2014-01-31 14:43 ` [Qemu-devel] [PATCH 5/5] tcg/i386: Use SHLX/SHRX/SARX instructions Richard Henderson
2014-02-16 14:21 ` Paolo Bonzini
2014-02-16 17:57 ` Richard Henderson [this message]
2014-02-17 16:01 ` Richard Henderson
2014-02-16 18:12 ` Aurelien Jarno
2014-02-14 21:44 ` [Qemu-devel] [PATCH 0/5] tcg/i386 support for bmi Richard Henderson
2014-02-16 14:22 ` Paolo Bonzini
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