[dpdk-dev] [PATCH v2] net/hns3: fix compile error with gcc8.3 and thunderx2

[Chengwen Feng <fengchengwen@huawei.com>]

Compile error with gcc8.3 and crossfile arm64_thunderx2_linux_gcc:
	../drivers/net/hns3/hns3_rxtx_vec_sve.c
	cc1: error: switch ‘-mcpu=armv8.1-a’ conflicts with
	‘-march=armv8.2-a’ switch [-Werror]
	../drivers/net/hns3/hns3_rxtx_vec_sve.c:5:10: fatal error:
	arm_sve.h: No such file or directory
	    5 | #include <arm_sve.h>

The root cause is that gcc8.3 supports SVE, but it doesn't support
compile ACLE[1] SVE code, and the hns3_rxtx_vec_sve.c was written
by ACLE SVE code.

This patch also filters out '-march=' '-mcpu' '-mtune' when compile
with hns3_rxtx_vec_sve.c.

[1] ACLE: Arm C Language Extensions, user should include <arm_sve.h>
when writing ACLE SVE code.

Fixes: 203fbaf8813d ("net/hns3: refactor SVE code compile method")

Signed-off-by: Chengwen Feng <fengchengwen@huawei.com>
---
v2:
* fix check tool error
---
 drivers/net/hns3/meson.build | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/net/hns3/meson.build b/drivers/net/hns3/meson.build
index 8563d70..5f9af9b 100644
--- a/drivers/net/hns3/meson.build
+++ b/drivers/net/hns3/meson.build
@@ -39,16 +39,22 @@ if arch_subdir == 'arm' and dpdk_conf.get('RTE_ARCH_64')
     # compile SVE when:
     # a. support SVE in minimum instruction set baseline
     # b. it's not minimum instruction set, but compiler support
-    if cc.get_define('__ARM_FEATURE_SVE', args: machine_args) != ''
+    if cc.get_define('__ARM_FEATURE_SVE', args: machine_args) != '' and cc.check_header('arm_sve.h')
         cflags += ['-DCC_SVE_SUPPORT']
         sources += files('hns3_rxtx_vec_sve.c')
-    elif cc.has_argument('-march=armv8.2-a+sve')
-        cflags += ['-DCC_SVE_SUPPORT']
+    elif cc.has_argument('-march=armv8.2-a+sve') and cc.check_header('arm_sve.h')
+        sve_cflags = ['-DCC_SVE_SUPPORT']
+        foreach flag: cflags
+            # filterout -march -mcpu -mtune
+            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: [cflags, '-march=armv8.2-a+sve'])
+                        c_args: [sve_cflags, '-march=armv8.2-a+sve'])
         objs += hns3_sve_lib.extract_objects('hns3_rxtx_vec_sve.c')
     endif
 endif
-- 
2.8.1