-----Original Message-----
From: Juraj Linkeš <redacted>
Sent: Wednesday, December 23, 2020 7:48 PM
To: bruce.richardson@intel.com; Ruifeng Wang <redacted>;
Honnappa Nagarahalli [off-list ref]; Phil Yang
[off-list ref]; vcchunga@amazon.com; Dharmik Thakkar
[off-list ref]; jerinjacobk@gmail.com;
hemant.agrawal@nxp.com; Ajit Khaparde (ajit.khaparde@broadcom.com)
[off-list ref]; ferruh.yigit@intel.com
Cc: dev@dpdk.org; Juraj Linkeš <redacted>
Subject: [PATCH v14 07/12] build: use native machine args in Arm native build

Letting the compiler decide is going to yield the best results for native builds,
so use native machine args usable for both GCC and Clang.

Signed-off-by: Juraj Linkeš <redacted>
---
 config/arm/meson.build | 54 ++++++++++++++++++++++--------------------
 1 file changed, 28 insertions(+), 26 deletions(-)

diff --git a/config/arm/meson.build b/config/arm/meson.build index

403e1a02f..4508f369c 100644

--- a/config/arm/meson.build
+++ b/config/arm/meson.build

@@ -2,8 +2,6 @@
 # Copyright(c) 2017 Intel Corporation.
 # Copyright(c) 2017 Cavium, Inc

-arm_force_native_march = false
-
 # common flags to all aarch64 builds, with lowest priority  flags_common = [
 	# Accelerate rte_memcpy. Be sure to run unit test

(memcpy_perf_autotest) @@ -26,6 +24,7 @@ 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 @@ -47,7 +46,6 @@ implementer_generic
= {  }

 part_number_config_arm = {
-	'native': {'machine_args':  ['-march=native']},
 	'0xd03': {'machine_args':  ['-mcpu=cortex-a53']},
 	'0xd04': {'machine_args':  ['-mcpu=cortex-a35']},
 	'0xd07': {'machine_args':  ['-mcpu=cortex-a57']}, @@ -95,7 +93,6 @@
implementer_cavium = {
 		['RTE_MAX_NUMA_NODES', 2]
 	],
 	'part_number_config': {
-		'native': {'machine_args': ['-march=native']},
 		'0xa1': {
 			'machine_args': ['-mcpu=thunderxt88'],
 			'flags': flags_part_number_thunderx

@@ -145,8 +142,7 @@ implementer_ampere = {
 	],
 	'part_number_config': {
 		'0x0': {'machine_args':  ['-march=armv8-a+crc+crypto',
-					  '-mtune=emag']},
-		'native': {'machine_args':  ['-march=native']}
+					  '-mtune=emag']}
 	}
 }

@@ -195,26 +191,27 @@ if dpdk_conf.get('RTE_ARCH_32')
 	machine_args += '-mfpu=neon'
 else
 	# aarch64 build
-	if machine == 'default' and not meson.is_cross_build()
-		# default build
-		implementer_id = 'generic'
-		part_number = 'generic'
-	elif not meson.is_cross_build()
-		# native build
-		# The script returns ['Implementer', 'Variant', 'Architecture',
-		# 'Primary Part number', 'Revision']
-		detect_vendor = find_program(join_paths(
-				meson.current_source_dir(),

'armv8_machine.py'))
-		cmd = run_command(detect_vendor.path())
-		if cmd.returncode() == 0
-			cmd_output = cmd.stdout().to_lower().strip().split(' ')
-			implementer_id = cmd_output[0]
-			part_number = cmd_output[3]
+	use_native_machine_args = false
+	if not meson.is_cross_build()
+		if machine == 'default'
+			# default build
+			implementer_id = 'generic'
+			part_number = 'generic'
 		else
-			error('Error when getting Arm Implementer ID and
part number.')
-		endif
-		if arm_force_native_march == true
-			part_number = 'native'
+			# native build
+			# The script returns ['Implementer', 'Variant',
'Architecture',
+			# 'Primary Part number', 'Revision']
+			detect_vendor = find_program(join_paths(
+					meson.current_source_dir(),
'armv8_machine.py'))
+			cmd = run_command(detect_vendor.path())
+			if cmd.returncode() == 0
+				cmd_output =
cmd.stdout().to_lower().strip().split(' ')
+				implementer_id = cmd_output[0]
+				part_number = cmd_output[3]
+			else
+				error('Error when getting Arm Implementer
ID and part number.')
+			endif
+			use_native_machine_args = true
 		endif
 	else
 		# cross build

@@ -250,7 +247,12 @@ else

 	# apply supported machine args
 	machine_args = [] # Clear previous machine args
-	foreach flag: part_number_config['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
 		if cc.has_argument(flag)
 			machine_args += flag
 		endif
--
2.20.1