From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] arm64: LLVMLinux: Fix inline arm64 assembly for use with clang
Date: Tue, 9 Sep 2014 11:15:15 +0100 [thread overview]
Message-ID: <20140909101515.GB1754@arm.com> (raw)
In-Reply-To: <CAFzeTN2Q-RkOeDx4jG5jiEtiN7i+gkfmyvBC1b3B1wpDPUDdxw@mail.gmail.com>
On Mon, Sep 08, 2014 at 07:35:47PM +0100, Mark Charlebois wrote:
> When I compile
>
> int main()
> {
> u64 foo, tmp;
>
> // This fails for clang but not gcc
> asm volatile(
> " mrs %0, mair_el1\n"
> " bfi %0, %1, #%2, #8\n"
> " msr mair_el1, %0\n"
> " isb\n"
> : "=&r" (tmp)
> : "r" (foo), "i" (MT_NORMAL * 8));
> }
>
> Clang fails and GCC generates:
>
> 00000000004004f0 <main>:
> 4004f0: d538a208 mrs x8, mair_el1
> 4004f4: b3601d08 bfi x8, x8, #32, #8
> 4004f8: d518a208 msr mair_el1, x8
> 4004fc: d5033fdf isb
> 400500: 2a1f03e0 mov w0, wzr
> 400504: d65f03c0 ret
Ok, so we can just drop the '#' prefix as it probably shouldn't be there
anyway. Can you send a patch making just that change, please?
Will
WARNING: multiple messages have this Message-ID (diff)
From: Will Deacon <will.deacon@arm.com>
To: Mark Charlebois <charlebm@gmail.com>
Cc: "behanw@converseincode.com" <behanw@converseincode.com>,
"anderson@redhat.com" <anderson@redhat.com>,
Catalin Marinas <Catalin.Marinas@arm.com>,
"cl@linux.com" <cl@linux.com>,
"cov@codeaurora.org" <cov@codeaurora.org>,
"jays.lee@samsung.com" <jays.lee@samsung.com>,
"msalter@redhat.com" <msalter@redhat.com>,
"sandeepa.prabhu@linaro.org" <sandeepa.prabhu@linaro.org>,
"srivatsa.bhat@linux.vnet.ibm.com"
<srivatsa.bhat@linux.vnet.ibm.com>,
"steve.capper@linaro.org" <steve.capper@linaro.org>,
Sudeep Holla <Sudeep.Holla@arm.com>,
"takahiro.akashi@linaro.org" <takahiro.akashi@linaro.org>,
"Vijaya.Kumar@caviumnetworks.com"
<Vijaya.Kumar@caviumnetworks.com>,
"a.p.zijlstra@chello.nl" <a.p.zijlstra@chello.nl>,
"acme@kernel.org" <acme@kernel.org>,
"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>,
Marc Zyngier <Marc.Zyngier@arm.com>,
Matthew Leach <Matthew.Leach@arm.com>,
"mingo@redhat.com" <mingo@redhat.com>,
"olof@lixom.net" <olof@lixom.net>,
"paulus@samba.org" <paulus@samba.org>
Subject: Re: [PATCH] arm64: LLVMLinux: Fix inline arm64 assembly for use with clang
Date: Tue, 9 Sep 2014 11:15:15 +0100 [thread overview]
Message-ID: <20140909101515.GB1754@arm.com> (raw)
In-Reply-To: <CAFzeTN2Q-RkOeDx4jG5jiEtiN7i+gkfmyvBC1b3B1wpDPUDdxw@mail.gmail.com>
On Mon, Sep 08, 2014 at 07:35:47PM +0100, Mark Charlebois wrote:
> When I compile
>
> int main()
> {
> u64 foo, tmp;
>
> // This fails for clang but not gcc
> asm volatile(
> " mrs %0, mair_el1\n"
> " bfi %0, %1, #%2, #8\n"
> " msr mair_el1, %0\n"
> " isb\n"
> : "=&r" (tmp)
> : "r" (foo), "i" (MT_NORMAL * 8));
> }
>
> Clang fails and GCC generates:
>
> 00000000004004f0 <main>:
> 4004f0: d538a208 mrs x8, mair_el1
> 4004f4: b3601d08 bfi x8, x8, #32, #8
> 4004f8: d518a208 msr mair_el1, x8
> 4004fc: d5033fdf isb
> 400500: 2a1f03e0 mov w0, wzr
> 400504: d65f03c0 ret
Ok, so we can just drop the '#' prefix as it probably shouldn't be there
anyway. Can you send a patch making just that change, please?
Will
next prev parent reply other threads:[~2014-09-09 10:15 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-05 23:24 [PATCH] arm64: LLVMLinux: Fix inline arm64 assembly for use with clang behanw at converseincode.com
2014-09-05 23:24 ` behanw
2014-09-08 9:30 ` Olof Johansson
2014-09-08 9:30 ` Olof Johansson
2014-09-10 17:38 ` Will Deacon
2014-09-10 17:38 ` Will Deacon
2014-09-10 17:49 ` Ard Biesheuvel
2014-09-10 17:49 ` Ard Biesheuvel
2014-09-08 10:53 ` Will Deacon
2014-09-08 10:53 ` Will Deacon
2014-09-08 18:35 ` Mark Charlebois
2014-09-08 18:35 ` Mark Charlebois
2014-09-09 10:15 ` Will Deacon [this message]
2014-09-09 10:15 ` Will Deacon
2014-09-15 5:30 ` behanw at converseincode.com
2014-09-15 5:30 ` behanw
2014-09-15 16:02 ` Will Deacon
2014-09-15 16:02 ` Will Deacon
2014-09-15 16:26 ` Catalin Marinas
2014-09-15 16:26 ` Catalin Marinas
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