AnsweredAssumed Answered

Question about vfpv3 and neon

Question asked by Richard Li on May 13, 2015
Latest reply on May 13, 2015 by Yuri Muhin

Dear All,

 

I am confused about vfpv3 and neon.

As shown in i.MX 6Dual/6Quad Reference Manual, it supports neon and vfpv3, also in kernel defconfig, the related config is

"CONFIG_VFP=y

CONFIG_VFPv3=y

CONFIG_NEON=y".

 

Question1:

In L3.0.35_4.1.0_ER_SOURCE_BSP release package, the cflags is "-march=armv7-a -mfpu=vfpv3 -mfloat-abi=softfp",

but in android_jb4.3_1.1.0-ga_source release package, the arch_variant_cflags is "-march=armv7-a -mfpu=neon -mfloat-abi=softfp".

what is the difference?

 

Question2: Does the option only used in cflags? not uesd in ldflags?

For example:

arm-fsl-linux-gnueabi-gcc -c helloworld.c -march=armv7-a -mfpu=vfpv3 -mfloat-abi=softfp

 

arm-fsl-linux-gnueabi-gcc -o helloworld helloworld.o [-march=armv7-a -mfpu=vfpv3 -mfloat-abi=softfp]

Is it need to add the ldflags "-march=armv7-a -mfpu=vfpv3 -mfloat-abi=softfp" ?

 

 

Best Regards,

Richard

Outcomes