From: Richard Henderson <rth@twiddle.net>
To: Peter Maydell <peter.maydell@linaro.org>
Cc: aliguori@us.ibm.com, claudio.fontana@huawei.com,
qemu-devel@nongnu.org, afaerber@suse.de
Subject: Re: [Qemu-devel] [PATCH v3 08/14] tcg-arm: Make use of conditional availability of opcodes for divide
Date: Thu, 04 Jul 2013 10:33:49 -0700 [thread overview]
Message-ID: <51D5B1FD.7060407@twiddle.net> (raw)
In-Reply-To: <CAFEAcA-tHxg4zi15=vSJufJdgW6oDqtmqpt0T0PB4YQPD7T9uw@mail.gmail.com>
On 07/04/2013 04:02 AM, Peter Maydell wrote:
>
> My ARM system doesn't have a sys/auxv.h, which renders most of this patch
> a bit moot (and certainly untestable :-)). Do newer glibc have this?
glibc 2.16 has this.
I've also got another pending patch set that implements getauxval inside
qemu if it's not present in the system library. Which means that we can
eliminate some of the ifdefery seen here.
>> + unsigned long hwcap = getauxval(AT_HWCAP);
>> + use_idiv_instructions = hwcap & (HWCAP_ARM_IDIVA | HWCAP_ARM_IDIVT);
>
> Doesn't this mean we'll try to use the ARM division
> insns even if the CPU only supports the Thumb encodings?
> I think you should only be testing for whether HWCAP_ARM_IDIVA
> is set.
I suppose. Though later kernels have actually merged these bits:
uapi/asm/hwcap.h:27:#define HWCAP_IDIV (HWCAP_IDIVA | HWCAP_IDIVT)
r~
next prev parent reply other threads:[~2013-07-04 17:34 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-03 21:29 [Qemu-devel] [PATCH v3 00/14] tcg: remainder and tcg-arm updates Richard Henderson
2013-07-03 21:29 ` [Qemu-devel] [PATCH v3 01/14] tcg: Add myself to general TCG maintainership Richard Henderson
2013-07-04 10:38 ` Peter Maydell
2013-07-03 21:29 ` [Qemu-devel] [PATCH v3 02/14] tcg: Split rem requirement from div requirement Richard Henderson
2013-07-04 10:44 ` Peter Maydell
2013-07-03 21:29 ` [Qemu-devel] [PATCH v3 03/14] tcg-arm: Don't implement rem Richard Henderson
2013-07-04 10:45 ` Peter Maydell
2013-07-03 21:29 ` [Qemu-devel] [PATCH v3 04/14] tcg-ppc: " Richard Henderson
2013-07-03 21:29 ` [Qemu-devel] [PATCH v3 05/14] tcg-ppc64: " Richard Henderson
2013-07-03 21:29 ` [Qemu-devel] [PATCH v3 06/14] tcg: Allow non-constant control macros Richard Henderson
2013-07-04 10:53 ` Peter Maydell
2013-07-04 17:28 ` Richard Henderson
2013-07-03 21:29 ` [Qemu-devel] [PATCH v3 07/14] tcg: Simplify logic using TCG_OPF_NOT_PRESENT Richard Henderson
2013-07-04 10:54 ` Peter Maydell
2013-07-03 21:29 ` [Qemu-devel] [PATCH v3 08/14] tcg-arm: Make use of conditional availability of opcodes for divide Richard Henderson
2013-07-04 11:02 ` Peter Maydell
2013-07-04 17:33 ` Richard Henderson [this message]
2013-07-04 17:39 ` Peter Maydell
2013-07-03 21:29 ` [Qemu-devel] [PATCH v3 09/14] tcg-arm: Simplify logic in detecting the ARM ISA in use Richard Henderson
2013-07-04 11:22 ` Peter Maydell
2013-07-04 17:44 ` Richard Henderson
2013-07-04 19:29 ` Peter Maydell
2013-07-03 21:29 ` [Qemu-devel] [PATCH v3 10/14] tcg-arm: Use AT_PLATFORM to detect the host ISA Richard Henderson
2013-07-03 21:29 ` [Qemu-devel] [PATCH v3 11/14] tcg: Fix high_pc fields in .debug_info Richard Henderson
2013-07-04 11:25 ` Peter Maydell
2013-07-03 21:29 ` [Qemu-devel] [PATCH v3 12/14] tcg: Move the CIE and FDE header definitions to common code Richard Henderson
2013-07-04 11:29 ` Peter Maydell
2013-07-03 21:29 ` [Qemu-devel] [PATCH v3 13/14] tcg-i386: Use QEMU_BUILD_BUG_ON instead of assert for frame size Richard Henderson
2013-07-03 21:29 ` [Qemu-devel] [PATCH v3 14/14] tcg-arm: Implement tcg_register_jit Richard Henderson
2013-07-04 11:29 ` Peter Maydell
2013-07-04 9:28 ` [Qemu-devel] [PATCH v3 00/14] tcg: remainder and tcg-arm updates Claudio Fontana
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