[RFC,v1] config/arm: fix native machine args
Checks
Commit Message
There are compiler issues when building with -mcpu=native with popular
compilers, such as GCC-8.4 and clang (which doesn't define
__ARM_FEATURE_ATOMIC). Fix this by always specifying the proper machine
args and never using the native flags.
Fixes: 78ac8eac7e8a ("config/arm: use native machine build arguments")
Cc: juraj.linkes@pantheon.tech
Signed-off-by: Juraj Linkeš <juraj.linkes@pantheon.tech>
---
config/arm/meson.build | 10 +---------
1 file changed, 1 insertion(+), 9 deletions(-)
Comments
01/02/2021 15:55, Juraj Linkeš:
> There are compiler issues when building with -mcpu=native with popular
> compilers, such as GCC-8.4 and clang (which doesn't define
> __ARM_FEATURE_ATOMIC).
What are the issues? Maybe worth pasting a log.
> Fix this by always specifying the proper machine
> args and never using the native flags.
The title says "fix" but it seems to be "remove".
[...]
> -native_machine_args = ['-mcpu=native']
This is the culprit?
Could you provide a "Fixes:" line?
> -----Original Message-----
> From: Thomas Monjalon <thomas@monjalon.net>
> Sent: Monday, February 1, 2021 4:16 PM
> To: Juraj Linkeš <juraj.linkes@pantheon.tech>
> Cc: bruce.richardson@intel.com; Ruifeng.Wang@arm.com;
> Honnappa.Nagarahalli@arm.com; jerinjacobk@gmail.com;
> ferruh.yigit@intel.com; dev@dpdk.org
> Subject: Re: [RFC PATCH v1] config/arm: fix native machine args
>
> 01/02/2021 15:55, Juraj Linkeš:
> > There are compiler issues when building with -mcpu=native with popular
> > compilers, such as GCC-8.4 and clang (which doesn't define
> > __ARM_FEATURE_ATOMIC).
>
> What are the issues? Maybe worth pasting a log.
>
I can include this in the commit log from GCC-8.4 (the same thing works with GCC-10.2):
In file included from ../lib/librte_eal/arm/include/rte_vect.h:11,
from ../lib/librte_net/net_crc_neon.c:10:
../lib/librte_net/net_crc_neon.c: In function ‘crcr32_folding_round’:
/usr/lib/gcc/aarch64-linux-gnu/8/include/arm_neon.h:26094:1: error: inlining failed in call to always_inline ‘vmull_p64’: target specific option mismatch
vmull_p64 (poly64_t a, poly64_t b)
^~~~~~~~~
../lib/librte_net/net_crc_neon.c:50:20: note: called from here
uint64x2_t tmp1 = vreinterpretq_u64_p128(vmull_p64(
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
vgetq_lane_p64(vreinterpretq_p64_u64(fold), 0),
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
vgetq_lane_p64(vreinterpretq_p64_u64(precomp), 1)));
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
And for clang:
gcc -E -dM -mcpu="native" - < /dev/null | grep __ARM_FEATURE_ATOMICS
#define __ARM_FEATURE_ATOMICS 1 # gcc support
clang-9 -E -dM -mcpu="native" - < /dev/null | grep __ARM_FEATURE_ATOMICS
<no output> # clang no support
> > Fix this by always specifying the proper machine args and never using
> > the native flags.
>
> The title says "fix" but it seems to be "remove".
Yes. The fix is to remove the usage of native flags and instead always use the part_number flags.
>
> [...]
> > -native_machine_args = ['-mcpu=native']
>
> This is the culprit?
> Could you provide a "Fixes:" line?
There already is one:
Fixes: 78ac8eac7e8a ("config/arm: use native machine build arguments")
>
>
@@ -24,7 +24,6 @@ flags_common = [
['RTE_ARCH_ARM64', true],
['RTE_CACHE_LINE_SIZE', 128]
]
-native_machine_args = ['-mcpu=native']
## Part numbers are specific to Arm implementers
# implementer specific aarch64 flags have middle priority
@@ -193,7 +192,6 @@ if dpdk_conf.get('RTE_ARCH_32')
machine_args += '-mfpu=neon'
else
# aarch64 build
- use_native_machine_args = false
if not meson.is_cross_build()
if machine == 'default'
# default build
@@ -213,7 +211,6 @@ else
else
error('Error when getting Arm Implementer ID and part number.')
endif
- use_native_machine_args = true
endif
else
# cross build
@@ -249,12 +246,7 @@ else
# apply supported machine args
machine_args = [] # Clear previous machine args
- if use_native_machine_args
- candidate_machine_args = native_machine_args
- else
- candidate_machine_args = part_number_config['machine_args']
- endif
- foreach flag: candidate_machine_args
+ foreach flag: part_number_config['machine_args']
if cc.has_argument(flag)
machine_args += flag
endif