net/hns3: fix Arm SVE build with GCC 8.3

[ upstream commit 699fa1d ]

If the target machine has SVE feature (e.g. '-march=armv8.2-a+sve'),
and compiler is gcc-8.3, it will fail, the error is arm_sve.h:
no such file or directory.

The solution:
a. If RTE_HAS_SVE_ACLE defined (it means the minimum instruction set
support SVE ACLE) then compiles it.
b. Else if the compiler support SVE ACLE then compiles it.
c. Otherwise don't compile it.

Fixes: 8c25b02 ("net/hns3: fix enabling SVE Rx/Tx")
Fixes: 952ebac ("net/hns3: support SVE Rx")

Signed-off-by: Chengwen Feng <fengchengwen@huawei.com>
Acked-by: Ruifeng Wang <ruifeng.wang@arm.com>

drivers/net/hns3/hns3_rxtx.c

@@ -2561,7 +2561,7 @@ hns3_get_default_vec_support(void)
 static bool
 hns3_check_sve_support(void)
 {
-#if defined(RTE_ARCH_ARM64) && defined(__ARM_FEATURE_SVE)
+#if defined(RTE_HAS_SVE_ACLE)
 	if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_SVE))
 		return true;
 #endif

drivers/net/hns3/meson.build

@@ -31,7 +31,25 @@ deps += ['hash']
 
 if arch_subdir == 'arm' and dpdk_conf.get('RTE_ARCH_64')
 	sources += files('hns3_rxtx_vec.c')
-	if cc.get_define('__ARM_FEATURE_SVE', args: machine_args) != ''
+
+	# compile SVE when:
+	# a. support SVE in minimum instruction set baseline
+	# b. it's not minimum instruction set, but compiler support
+	if dpdk_conf.has('RTE_HAS_SVE_ACLE')
 		sources += files('hns3_rxtx_vec_sve.c')
+	elif cc.has_argument('-march=armv8.2-a+sve') and cc.check_header('arm_sve.h')
+		cflags += ['-DRTE_HAS_SVE_ACLE=1']
+		sve_cflags = []
+		foreach flag: cflags
+			if not (flag.startswith('-march=') or flag.startswith('-mcpu=') or flag.startswith('-mtune='))
+				sve_cflags += flag
+			endif
+		endforeach
+		hns3_sve_lib = static_library('hns3_sve_lib',
+						'hns3_rxtx_vec_sve.c',
+						dependencies: [static_rte_ethdev],
+						include_directories: includes,
+						c_args: [sve_cflags, '-march=armv8.2-a+sve'])
+		objs += hns3_sve_lib.extract_objects('hns3_rxtx_vec_sve.c')
 	endif
 endif