[dpdk-dev] [PATCH v3] build: fix SVE compile error with gcc8.3

[Chengwen Feng <fengchengwen@huawei.com>]

If the target machine has SVE feature (e.g. "-march=armv8.2-a+sve'),
and the compiler are gcc8.3, it will compile error:
	In file included from ../dpdk-next-net/lib/eal/common/
	eal_common_options.c:38:
	../dpdk-next-net/lib/eal/arm/include/rte_vect.h:13:10: fatal
	error: arm_sve.h: No such file or directory
	#include <arm_sve.h>
	       ^~~~~~~~~~~
	compilation terminated.

The root cause is that gcc8.3 supports SVE (the macro
__ARM_FEATURE_SVE was 1), but it doesn't support SVE ACLE [1].

The solution:
a) Detect compiler whether support SVE ACLE, if support then define
CC_SVE_ACLE_SUPPORT macro.
b) Use the CC_SVE_ACLE_SUPPORT macro to include SVE header file.

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

Fixes: 67b68824a82d ("lpm/arm: support SVE")

Signed-off-by: Chengwen Feng <fengchengwen@huawei.com>
---
v3:
* double-indent 'cc.check_header('arm_sve.h')' line
* move set 'CC_SVE_ACLE_SUPPORT' logic to the back (not in the middle
  of compile_time_cpuflags setting)
* fix minor syntax error in commit log
v2:
* modify title start with 'build'

---
 config/arm/meson.build         | 5 +++++
 lib/eal/arm/include/rte_vect.h | 2 +-
 lib/lpm/rte_lpm.h              | 2 +-
 3 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/config/arm/meson.build b/config/arm/meson.build
index e83a56e..08299b0 100644
--- a/config/arm/meson.build
+++ b/config/arm/meson.build
@@ -488,3 +488,8 @@ if cc.get_define('__ARM_FEATURE_CRYPTO', args: machine_args) != ''
     compile_time_cpuflags += ['RTE_CPUFLAG_AES', 'RTE_CPUFLAG_PMULL',
     'RTE_CPUFLAG_SHA1', 'RTE_CPUFLAG_SHA2']
 endif
+
+if (cc.get_define('__ARM_FEATURE_SVE', args: machine_args) != '' and
+        cc.check_header('arm_sve.h'))
+    dpdk_conf.set('CC_SVE_ACLE_SUPPORT', 1)
+endif
diff --git a/lib/eal/arm/include/rte_vect.h b/lib/eal/arm/include/rte_vect.h
index 093e912..277b656 100644
--- a/lib/eal/arm/include/rte_vect.h
+++ b/lib/eal/arm/include/rte_vect.h
@@ -9,7 +9,7 @@
 #include "generic/rte_vect.h"
 #include "rte_debug.h"
 #include "arm_neon.h"
-#ifdef __ARM_FEATURE_SVE
+#ifdef CC_SVE_ACLE_SUPPORT
 #include <arm_sve.h>
 #endif
 
diff --git a/lib/lpm/rte_lpm.h b/lib/lpm/rte_lpm.h
index 28b5768..9262814 100644
--- a/lib/lpm/rte_lpm.h
+++ b/lib/lpm/rte_lpm.h
@@ -402,7 +402,7 @@ rte_lpm_lookupx4(const struct rte_lpm *lpm, xmm_t ip, uint32_t hop[4],
 	uint32_t defv);
 
 #if defined(RTE_ARCH_ARM)
-#ifdef __ARM_FEATURE_SVE
+#ifdef CC_SVE_ACLE_SUPPORT
 #include "rte_lpm_sve.h"
 #else
 #include "rte_lpm_neon.h"
-- 
2.8.1