[dpdk-dev] [PATCH v3 2/4] arm: detect NEON cpu feature by checking __ARM_NEON

Jan Viktorin viktorin at rehivetech.com
Sat Mar 19 20:58:03 CET 2016


The __ARM_NEON declares that the arm_neon.h is available which is not true for
the __ARM_NEON_FP. The __ARM_NEON_FP is not provided by aarch64 gcc.

 $ arm-linux-gnueabi-gcc -dM -E - < /dev/null  | grep "_FP\|_NEON"
 #define __ARM_FP 12
 #define __ARM_NEON_FP 4
 #define __VFP_FP__ 1

 $ arm-linux-gnueabi-gcc -mfpu=neon -dM -E - < /dev/null  | grep "_FP\|_NEON"
 #define __ARM_FP 12
 #define __ARM_NEON_FP 4
 #define __ARM_NEON__ 1
 #define __VFP_FP__ 1
 #define __ARM_NEON 1

 $ aarch64-linux-gnu-gcc -dM -E - < /dev/null | grep "NEON\|FP"
 #define __FP_FAST_FMAF 1
 #define __ARM_NEON 1
 #define __FP_FAST_FMA 1

Signed-off-by: Jan Viktorin <viktorin at rehivetech.com>
---
 mk/rte.cpuflags.mk | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mk/rte.cpuflags.mk b/mk/rte.cpuflags.mk
index 19a3e7e..529bcef 100644
--- a/mk/rte.cpuflags.mk
+++ b/mk/rte.cpuflags.mk
@@ -111,7 +111,7 @@ CPUFLAGS += VSX
 endif
 
 # ARM flags
-ifneq ($(filter $(AUTO_CPUFLAGS),__ARM_NEON_FP),)
+ifneq ($(filter $(AUTO_CPUFLAGS),__ARM_NEON),)
 CPUFLAGS += NEON
 endif
 
-- 
2.7.0



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