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linux/arch/arm/lib/muldi3.S

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[ARM] 3049/1: More optimized libgcc functions Patch from Nicolas Pitre This patch gets rid of the last C implementations of needed libgcc functions for the kernel, replacing them with optimized assembly versions. Those functions are: __ashldi3 __ashrdi3 __lshrdi3 __muldi3 __ucmpdi2 The first 3 were lifted from gcc, the other two were written from scratch. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-10-30 23:08:03 +00:00
/*
* linux/arch/arm/lib/muldi3.S
*
* Author: Nicolas Pitre
* Created: Oct 19, 2005
* Copyright: Monta Vista Software, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/linkage.h>
ARM: convert all "mov.* pc, reg" to "bx reg" for ARMv6+ ARMv6 and greater introduced a new instruction ("bx") which can be used to return from function calls. Recent CPUs perform better when the "bx lr" instruction is used rather than the "mov pc, lr" instruction, and this sequence is strongly recommended to be used by the ARM architecture manual (section A.4.1.1). We provide a new macro "ret" with all its variants for the condition code which will resolve to the appropriate instruction. Rather than doing this piecemeal, and miss some instances, change all the "mov pc" instances to use the new macro, with the exception of the "movs" instruction and the kprobes code. This allows us to detect the "mov pc, lr" case and fix it up - and also gives us the possibility of deploying this for other registers depending on the CPU selection. Reported-by: Will Deacon <will.deacon@arm.com> Tested-by: Stephen Warren <swarren@nvidia.com> # Tegra Jetson TK1 Tested-by: Robert Jarzmik <robert.jarzmik@free.fr> # mioa701_bootresume.S Tested-by: Andrew Lunn <andrew@lunn.ch> # Kirkwood Tested-by: Shawn Guo <shawn.guo@freescale.com> Tested-by: Tony Lindgren <tony@atomide.com> # OMAPs Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com> # Armada XP, 375, 385 Acked-by: Sekhar Nori <nsekhar@ti.com> # DaVinci Acked-by: Christoffer Dall <christoffer.dall@linaro.org> # kvm/hyp Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com> # PXA3xx Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> # Xen Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> # ARMv7M Tested-by: Simon Horman <horms+renesas@verge.net.au> # Shmobile Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-06-30 15:29:12 +00:00
#include <asm/assembler.h>
[ARM] 3049/1: More optimized libgcc functions Patch from Nicolas Pitre This patch gets rid of the last C implementations of needed libgcc functions for the kernel, replacing them with optimized assembly versions. Those functions are: __ashldi3 __ashrdi3 __lshrdi3 __muldi3 __ucmpdi2 The first 3 were lifted from gcc, the other two were written from scratch. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-10-30 23:08:03 +00:00
#ifdef __ARMEB__
#define xh r0
#define xl r1
#define yh r2
#define yl r3
#else
#define xl r0
#define xh r1
#define yl r2
#define yh r3
#endif
ENTRY(__muldi3)
[ARM] 3104/1: ARM EABI: new helper function names Patch from Nicolas Pitre The ARM EABI defines new names for GCC helper functions. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-01-14 16:18:29 +00:00
ENTRY(__aeabi_lmul)
[ARM] 3049/1: More optimized libgcc functions Patch from Nicolas Pitre This patch gets rid of the last C implementations of needed libgcc functions for the kernel, replacing them with optimized assembly versions. Those functions are: __ashldi3 __ashrdi3 __lshrdi3 __muldi3 __ucmpdi2 The first 3 were lifted from gcc, the other two were written from scratch. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-10-30 23:08:03 +00:00
mul xh, yl, xh
mla xh, xl, yh, xh
[ARM] Fix muldi3.S When shifting the low-parts of signed numbers, a logical shift should be used to avoid sign-extending a bit which isn't a sign bit. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-03-08 17:25:33 +00:00
mov ip, xl, lsr #16
mov yh, yl, lsr #16
[ARM] 3049/1: More optimized libgcc functions Patch from Nicolas Pitre This patch gets rid of the last C implementations of needed libgcc functions for the kernel, replacing them with optimized assembly versions. Those functions are: __ashldi3 __ashrdi3 __lshrdi3 __muldi3 __ucmpdi2 The first 3 were lifted from gcc, the other two were written from scratch. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-10-30 23:08:03 +00:00
bic xl, xl, ip, lsl #16
bic yl, yl, yh, lsl #16
mla xh, yh, ip, xh
mul yh, xl, yh
mul xl, yl, xl
mul ip, yl, ip
adds xl, xl, yh, lsl #16
adc xh, xh, yh, lsr #16
adds xl, xl, ip, lsl #16
adc xh, xh, ip, lsr #16
ARM: convert all "mov.* pc, reg" to "bx reg" for ARMv6+ ARMv6 and greater introduced a new instruction ("bx") which can be used to return from function calls. Recent CPUs perform better when the "bx lr" instruction is used rather than the "mov pc, lr" instruction, and this sequence is strongly recommended to be used by the ARM architecture manual (section A.4.1.1). We provide a new macro "ret" with all its variants for the condition code which will resolve to the appropriate instruction. Rather than doing this piecemeal, and miss some instances, change all the "mov pc" instances to use the new macro, with the exception of the "movs" instruction and the kprobes code. This allows us to detect the "mov pc, lr" case and fix it up - and also gives us the possibility of deploying this for other registers depending on the CPU selection. Reported-by: Will Deacon <will.deacon@arm.com> Tested-by: Stephen Warren <swarren@nvidia.com> # Tegra Jetson TK1 Tested-by: Robert Jarzmik <robert.jarzmik@free.fr> # mioa701_bootresume.S Tested-by: Andrew Lunn <andrew@lunn.ch> # Kirkwood Tested-by: Shawn Guo <shawn.guo@freescale.com> Tested-by: Tony Lindgren <tony@atomide.com> # OMAPs Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com> # Armada XP, 375, 385 Acked-by: Sekhar Nori <nsekhar@ti.com> # DaVinci Acked-by: Christoffer Dall <christoffer.dall@linaro.org> # kvm/hyp Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com> # PXA3xx Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> # Xen Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> # ARMv7M Tested-by: Simon Horman <horms+renesas@verge.net.au> # Shmobile Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-06-30 15:29:12 +00:00
ret lr
[ARM] 3049/1: More optimized libgcc functions Patch from Nicolas Pitre This patch gets rid of the last C implementations of needed libgcc functions for the kernel, replacing them with optimized assembly versions. Those functions are: __ashldi3 __ashrdi3 __lshrdi3 __muldi3 __ucmpdi2 The first 3 were lifted from gcc, the other two were written from scratch. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-10-30 23:08:03 +00:00
[ARM] 5227/1: Add the ENDPROC declarations to the .S files This declaration specifies the "function" type and size for various assembly functions, mainly needed for generating the correct branch instructions in Thumb-2. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-08-28 10:22:32 +00:00
ENDPROC(__muldi3)
ENDPROC(__aeabi_lmul)
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