[Buildroot] [PATCH] nettle: disable assembly optimizations for ARMv7M

[Buildroot] [PATCH] nettle: disable assembly optimizations for ARMv7M

[Gustavo Zacarias]

It's thumb2-only and it requires ARM instructions.
Since V4 and V5 aren't enough either use the V7M knob to avoid
over-complicating the conditional. Fixes:
http://autobuild.buildroot.net/results/354/35418d33efa902d3a1a82b2cd58d8db1b1172e49/

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
---
 package/nettle/nettle.mk | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/package/nettle/nettle.mk b/package/nettle/nettle.mk
index c133839..a94a7fc 100644
--- a/package/nettle/nettle.mk
+++ b/package/nettle/nettle.mk
@@ -15,7 +15,7 @@ NETTLE_LICENSE_FILES = COPYING.LESSERv3 COPYINGv2
 NETTLE_CONF_OPTS = --disable-openssl
 
 # ARM assembly requires v6+ ISA
-ifeq ($(BR2_ARM_CPU_ARMV4)$(BR2_ARM_CPU_ARMV5),y)
+ifeq ($(BR2_ARM_CPU_ARMV4)$(BR2_ARM_CPU_ARMV5)$(BR2_ARM_CPU_ARMV7M),y)
 NETTLE_CONF_OPTS += --disable-assembler
 endif
 
-- 
2.7.3

[Buildroot] [PATCH] nettle: disable assembly optimizations for ARMv7M

[Thomas Petazzoni]

Hello,

On Sun, 24 Jul 2016 21:15:59 -0300, Gustavo Zacarias wrote:
> It's thumb2-only and it requires ARM instructions.
> Since V4 and V5 aren't enough either use the V7M knob to avoid
> over-complicating the conditional. Fixes:
> http://autobuild.buildroot.net/results/354/35418d33efa902d3a1a82b2cd58d8db1b1172e49/
> 
> Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
> ---
>  package/nettle/nettle.mk | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/package/nettle/nettle.mk b/package/nettle/nettle.mk
> index c133839..a94a7fc 100644
> --- a/package/nettle/nettle.mk
> +++ b/package/nettle/nettle.mk
> @@ -15,7 +15,7 @@ NETTLE_LICENSE_FILES = COPYING.LESSERv3 COPYINGv2
>  NETTLE_CONF_OPTS = --disable-openssl
>  
>  # ARM assembly requires v6+ ISA
> -ifeq ($(BR2_ARM_CPU_ARMV4)$(BR2_ARM_CPU_ARMV5),y)
> +ifeq ($(BR2_ARM_CPU_ARMV4)$(BR2_ARM_CPU_ARMV5)$(BR2_ARM_CPU_ARMV7M),y)

I've applied, but in the end, I'm wondering if the condition wouldn't
be simpler as:

ifeq ($(BR2_ARM_CPU_ARMV6)$(BR2_ARM_CPU_ARMV6),)
NETTLE_CONF_OPTS += --disable-assembler
endif

Thanks,

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

[Buildroot] [PATCH] nettle: disable assembly optimizations for ARMv7M

[Peter Korsgaard]

>>>>> "Thomas" == Thomas Petazzoni <thomas.petazzoni@free-electrons.com> writes:

 > Hello,
 > On Sun, 24 Jul 2016 21:15:59 -0300, Gustavo Zacarias wrote:
 >> It's thumb2-only and it requires ARM instructions.
 >> Since V4 and V5 aren't enough either use the V7M knob to avoid
 >> over-complicating the conditional. Fixes:
 >> http://autobuild.buildroot.net/results/354/35418d33efa902d3a1a82b2cd58d8db1b1172e49/
 >> 
 >> Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
 >> ---
 >> package/nettle/nettle.mk | 2 +-
 >> 1 file changed, 1 insertion(+), 1 deletion(-)
 >> 
 >> diff --git a/package/nettle/nettle.mk b/package/nettle/nettle.mk
 >> index c133839..a94a7fc 100644
 >> --- a/package/nettle/nettle.mk
 >> +++ b/package/nettle/nettle.mk
 >> @@ -15,7 +15,7 @@ NETTLE_LICENSE_FILES = COPYING.LESSERv3 COPYINGv2
 >> NETTLE_CONF_OPTS = --disable-openssl
 >> 
 >> # ARM assembly requires v6+ ISA
 >> -ifeq ($(BR2_ARM_CPU_ARMV4)$(BR2_ARM_CPU_ARMV5),y)
 >> +ifeq ($(BR2_ARM_CPU_ARMV4)$(BR2_ARM_CPU_ARMV5)$(BR2_ARM_CPU_ARMV7M),y)

 > I've applied, but in the end, I'm wondering if the condition wouldn't
 > be simpler as:

 > ifeq ($(BR2_ARM_CPU_ARMV6)$(BR2_ARM_CPU_ARMV6),)

I take it that you mean:

ifeq ($(BR2_ARM_CPU_ARMV6)$(BR2_ARM_CPU_ARMV7A),)

We could also simply check for ARM and THUMB2 instructions, E.G.:

# needs thumb2 and arm instructions support
ifneq ($(BR2_ARM_CPU_HAS_ARM)$(BR2_ARM_CPU_HAS_THUMB2),yy)

-- 
Bye, Peter Korsgaard

[Buildroot] [PATCH] nettle: disable assembly optimizations for ARMv7M

[Thomas Petazzoni]

Hello,

On Tue, 26 Jul 2016 23:18:37 +0200, Peter Korsgaard wrote:

>  > ifeq ($(BR2_ARM_CPU_ARMV6)$(BR2_ARM_CPU_ARMV6),)  
> 
> I take it that you mean:
> 
> ifeq ($(BR2_ARM_CPU_ARMV6)$(BR2_ARM_CPU_ARMV7A),)

Indeed, bad copy/paste.

> We could also simply check for ARM and THUMB2 instructions, E.G.:
> 
> # needs thumb2 and arm instructions support
> ifneq ($(BR2_ARM_CPU_HAS_ARM)$(BR2_ARM_CPU_HAS_THUMB2),yy)

I don't think this is equivalent. Indeed, ARMv6 doesn't have Thumb2 (at
least from Buildroot point of view), while the assembly code in Nettle
is OK for ARMv6.

Best regards,

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

[Buildroot] [PATCH] nettle: disable assembly optimizations for ARMv7M

[Peter Korsgaard]

>>>>> "Thomas" == Thomas Petazzoni <thomas.petazzoni@free-electrons.com> writes:

Hi,

 >> We could also simply check for ARM and THUMB2 instructions, E.G.:
 >> 
 >> # needs thumb2 and arm instructions support
 >> ifneq ($(BR2_ARM_CPU_HAS_ARM)$(BR2_ARM_CPU_HAS_THUMB2),yy)

 > I don't think this is equivalent. Indeed, ARMv6 doesn't have Thumb2 (at
 > least from Buildroot point of view), while the assembly code in Nettle
 > is OK for ARMv6.

True, but then the commit message doesn't make any sense as it said it
required thumb2 and classic in structions.

-- 
Venlig hilsen,
Peter Korsgaard 

[Buildroot] [PATCH] nettle: disable assembly optimizations for ARMv7M

[Thomas Petazzoni]

Hello,

On Wed, 27 Jul 2016 10:03:17 +0200, Peter Korsgaard wrote:

>  > I don't think this is equivalent. Indeed, ARMv6 doesn't have Thumb2 (at
>  > least from Buildroot point of view), while the assembly code in Nettle
>  > is OK for ARMv6.  
> 
> True, but then the commit message doesn't make any sense as it said it
> required thumb2 and classic in structions.

That's not what the commit message said. The commit message said:

"""
    nettle: disable assembly optimizations for ARMv7M
    
    It's thumb2-only and it requires ARM instructions.
"""

So it did not say at all that nettle requires Thumb-2 *and* classic. It
said that ARMv7M provides only thumb2, and that nettle requires ARM
instructions.

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

[Buildroot] [PATCH] nettle: disable assembly optimizations for ARMv7M

[Peter Korsgaard]

>>>>> "Thomas" == Thomas Petazzoni <thomas.petazzoni@free-electrons.com> writes:

Hi,

 > That's not what the commit message said. The commit message said:

 > """
 >     nettle: disable assembly optimizations for ARMv7M
    
 >     It's thumb2-only and it requires ARM instructions.
 > """

 > So it did not say at all that nettle requires Thumb-2 *and* classic. It
 > said that ARMv7M provides only thumb2, and that nettle requires ARM
 > instructions.

Ahh, I read "It" as referring to the nettle code, not ARMv7M cores.

-- 
Venlig hilsen,
Peter Korsgaard