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I was using the options:

-O3
-march=armv7-a
-mtune=cortex-a8
-ftree-vectorize
-mfloat-abi=softfp
-fsigned-char
-Wall
-save-temps

for cross compiling for arm-v7 (32 bit) using ArmLinuxToolChain.

What is the equivalent compiler options for gcc-linaro-aarch64-linux-gnu-4.8-2014.04_linux to build for armv8? I tried using those same options with -march=armv8-a -mtune=cortex-a53 and got:

aarch64-linux-gnu-g++: error: unrecognized command line option '-mfloat-abi=softfp'

Michael
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srat
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  • "but it's not working" is a hideously bad problem report :-) What are you actually seeing out of the compiler? – paxdiablo Apr 09 '15 at 05:57
  • actual error messege is : aarch64-linux-gnu-g++: error: unrecognized command line option â-mfloat-abi=softfpâ – srat Apr 09 '15 at 06:04
  • I'd start by trying _without_ that option. `softfp` is just software based floating point support and you may find it's not necessary. – paxdiablo Apr 09 '15 at 06:06

1 Answers1

4

The GCC options beginning with -m are machine-dependent options, so the availability of -m* options varies between targets. This is one such case. There is no soft float ABI defined for Aarch64, so GCC does not provide the ARM-specific -mfloat-abi option.

If you simply remove -mfloat-abi=softfp then your problem should be solved.

I would suggest you investigate whether you need -save-temps, which is normally only used for debugging or reporting compiler problems.

Charles Baylis
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