lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <50886B43.3080001@zytor.com>
Date:	Wed, 24 Oct 2012 15:27:15 -0700
From:	"H. Peter Anvin" <hpa@...or.com>
To:	Juri Lelli <juri.lelli@...il.com>
CC:	peterz@...radead.org, tglx@...utronix.de, mingo@...hat.com,
	rostedt@...dmis.org, oleg@...hat.com, fweisbec@...il.com,
	darren@...art.com, johan.eker@...csson.com, p.faure@...tech.ch,
	linux-kernel@...r.kernel.org, claudio@...dence.eu.com,
	michael@...rulasolutions.com, fchecconi@...il.com,
	tommaso.cucinotta@...up.it, nicola.manica@...i.unitn.it,
	luca.abeni@...tn.it, dhaval.giani@...il.com, hgu1972@...il.com,
	paulmck@...ux.vnet.ibm.com, raistlin@...ux.it,
	insop.song@...csson.com, liming.wang@...driver.com,
	jkacur@...hat.com, harald.gustafsson@...csson.com,
	vincent.guittot@...aro.org,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Ingo Molnar <mingo@...nel.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Linus Torvalds <torvalds@...ux-foundation.org>
Subject: Re: [PATCH 02/16] math128, x86_64: Implement {mul,add}_u128 in 64bit
 asm

On 10/24/2012 02:53 PM, Juri Lelli wrote:
> diff --git a/arch/x86/include/asm/math128.h b/arch/x86/include/asm/math128.h
> new file mode 100644
> index 0000000..c0e2a6c
> --- /dev/null
> +++ b/arch/x86/include/asm/math128.h
> @@ -0,0 +1,39 @@
> +#ifndef _ASM_MATH128_H
> +#define _ASM_MATH128_H
> +
> +#ifdef CONFIG_X86_64
> +
> +#ifdef __SIZEOF_INT128__
> +#define ARCH_HAS_INT128
> +#endif
> +
> +#ifndef ARCH_HAS_INT128
> +
> +static inline u128 mul_u64_u64(u64 a, u64 b)
> +{
> +       u128 res;
> +
> +       asm("mulq %2"
> +               : "=a" (res.lo), "=d" (res.hi)
> +               :  "rm" (b), "0" (a));
> +
> +       return res;
> +}
> +#define mul_u64_u64 mul_u64_u64
> +
> +static inline u128 add_u128(u128 a, u128 b)
> +{
> +       u128 res;
> +
> +       asm("addq %2,%0;\n"
> +           "adcq %3,%1;\n"
> +               : "=rm" (res.lo), "=rm" (res.hi)
> +               : "r" (b.lo), "r" (b.hi), "0" (a.lo), "1" (a.hi));
> +
> +       return res;
> +}
> +#define add_u128 add_u128
> +

How could this work since u128 presumably has not yet been defined as a
structure?  After all, isn't it the absence of ARCH_HAS_INT128 which
makes that happen?

	-hpa

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ