# Linux Kernel Module Cheat
The perfect emulation setup to study and develop the <<linux-kernel>> v5.9.2, kernel modules, <<qemu-buildroot-setup,QEMU>>, <<gem5-buildroot-setup,gem5>> and x86_64, ARMv7 and ARMv8 <<userland-assembly,userland>> and <<baremetal-setup,baremetal>> assembly, <<c,ANSI C>>, <<cpp,C++>> and <<posix,POSIX>>. <<gdb>> and <<kgdb>> just work. Powered by <<about-the-qemu-buildroot-setup,Buildroot>> and <<about-the-baremetal-setup,crosstool-NG>>. Highly automated. Thoroughly documented. Automated <<test-this-repo,tests>>.

#### 29.11.1. x86 x87 FPU vs SIMD

https://stackoverflow.com/questions/1844669/benefits-of-x87-over-sse

Modern x86 has two main ways of doing floating point operations:

- x86 x87 FPU instructions

- x86 SIMD

Advantages of FPU:

- present in old CPUs, while SSE2 is only required in x86-64

- contains some instructions no present in SSE, e.g. trigonometric

- higher precision: FPU holds 80 bit Intel extension, while SSE2 only does up to 64 bit operations despite having the 128-bit register

In GCC, you can choose between them with `-mfpmath=`.