arm7l softfp hardfp fmac

라즈베리의 cpuinfo에서 arm7l 이라고 나와서 검색

느낌으로는.. 걍 붙는 접두 같긴한데.. (armel armhf랑은 다르게)

h는 hard

t는 thumb

n은 neon의 스멜이... -_-a

Mer port name	OBS scheduler name	RPM architectures	OBS project name in MDS	OBS repository name in MDS	Description
i486	i586	i486	Core:i486	Core_i486	Generic i486+ X86 port
i586	i586	i586, i686	Core:i586	Core_i586	SSSE3 enabled X86 port
x86_64	x86_64	x86_64	Core:x86_64	Core_x86_64	Generic 64 bit port
armv6l	armv7el	armv6l	Core:armv6l	Core_armv6l	ARMv6 + VFP port
armv7l	armv7el	armv7l	Core:armv7l	Core_armv7l	ARMv7 VFPv3-D16 port, softfp ABI
armv7hl	armv8el	armv7hl	Core:armv7hl	Core_armv7hl	ARMv7 VFPv3-D16 port, hardfp ABI
armv7tnhl	armv8el	armv7hl, armv7nhl, armv7tnhl, armv7thl	Core:armv7tnhl	Core_armv7tnhl	ARMv7 VFPv3-D16 port, hardfp ABI, NEON, Thumb2
mipsel	mips	mipsel	Core:mipsel	Core_mipsel	MIPS32 O32 ABI port, hardfloat

[링크 : https://wiki.merproject.org/wiki/OBS_architecture_naming]

그리고 VFPv4 에서는 FMAC를 탑재하고

soft는 소프트웨어 부동소수점 흉내내기(에뮬레이션)

softfp는 소프트웨어적으로 흉내내는 방식을 따르나 자동으로 vfp 레지스터에 쓰도록 하고

hardfp는 vfp 하드웨어 레지스터에 바로 쓰도록 하는 차이가 있다고 한다.

Soft Full software floating point - compiler should refuse to generate a real FPU instruction and -mfpu= is ignored. FPU operations are emulated by the compiler Function calls are generated to pass FP arguments (float, double) in integer registers (one for float, a pair of registers for double) Softfp To reiterate, function calls are generated to pass FP arguments in integer registers Compiler can make smart choices about when and if it generates emulated or real FPU instructions depending on chosen FPU type (-mfpu=) This means soft and softfp code can be intermixed Hardfp Full hardware floating point. FP arguments are passed directly in FPU registers Cannot possibly run without the FPU defined in -mfpu= (or a superset of the FPU defined, where relevant) FPU instructions could be emulated by the kernel so that FPU-less systems could run with this ABI but as far as we know this does not exist No function prologue or epilogue requirements for FP arguments, no pipeline stalls, maximum performance (just like in PowerPC and MIPS) [링크 : https://wiki.debian.org/ArmHardFloatPort/VfpComparison]

FMAC는 Fused Multiply ACCumulator로

하드웨어로 구성된 다중 누산기 라고 해석하면 되려나?

[링크 : http://en.wikipedia.org/wiki/Multiply–accumulate_operation]