[arm-gnu] Regarding Double Data Type Support on Cortex M4

[Freddie Chopin]

W dniu 2012-06-01 21:11, Carlos O'Donell pisze:
> Sourcery CodeBench Lite for ARM EABI does support compiling application code for the Cortex-M4F.
>
> The FPU on the Cortex-M4F is not a full VFP so you need to pass:
>
> `-mfpu=fpv4-sp-d16 -mfloat-abi=softfp`

CodeSourcery supports generating code for this chip, but it does not 
support the FPU... With linaro you can use:

-mfloat-abi=hard -mfpu=fpv4-sp-d16 -ffast-math

Guess which is faster (;

CodeSourcery:

c:\Program 
Files\CodeSourcery\Sourcery_CodeBench_Lite_for_ARM_EABI\bin>arm-none-eabi-gcc 
-print-multi-lib
.;
thumb;@mthumb
armv6-m;@mthumb at march=armv6-m
thumb2;@mthumb at march=armv7 at mfix-cortex-m3-ldrd

linaro:

c:\Program Files\linaro\4.6 2012q1\bin>arm-none-eabi-gcc -print-multi-lib
.;
thumb;@mthumb
fpu;@mfloat-abi=hard
armv6-m;@mthumb at march=armv6s-m
armv7-m;@mthumb at march=armv7-m
armv7e-m;@mthumb at march=armv7e-m
armv7-r/thumb;@mthumb at march=armv7-r
armv7-r/thumb/fpu;@mthumb at mfloat-abi=hard at march=armv7-r at mfpu=vfpv3-d16
armv7e-m/fpu;@mthumb at mfloat-abi=hard at march=armv7e-m at mfpu=fpv4-sp-d16
armv7-r/thumb/softfp;@mthumb at mfloat-abi=softfp at march=armv7-r at mfpu=vfpv3-d16
armv7e-m/softfp;@mthumb at mfloat-abi=softfp at march=armv7e-m at mfpu=fpv4-sp-d16

4\/3!!