cpu_capabilities(3alleg4)

💅 cpu_capabilities — the Allegro manual, but make it make sense ✨

okay bestie, welcome to Allegro — yes, the game programming library, the iconic one 🎀. Today's main character is a little global variable called cpu_capabilities, and honestly? she's doing a LOT. let's get into it 💖

🌸 SYNOPSIS 🌸

#include <allegro.h>

extern int cpu_capabilities;

✨ DESCRIPTION ✨

So cpu_capabilities holds CPU flags that tell you which features your current CPU actually has. and when I say "any combination", I mean it — these flags can mix and match however your silicon feels like it 🦋:

• CPU_ID — says the "cpuid" instruction is available. and here's the tea: if this flag is set, then all Allegro CPU variables are 100% reliable. if it's NOT set? there may be some mistakes. 😭
• CPU_FPU — an FPU is available.
• CPU_IA64 — you're running on an Intel 64 bit CPU.
• CPU_AMD64 — you're running on an AMD 64 bit CPU.
• CPU_MMX — Intel MMX instruction set is available.
• CPU_MMXPLUS — Intel MMX+ instruction set is available.
• CPU_SSE — Intel SSE instruction set is available.
• CPU_SSE2 — Intel SSE2 instruction set is available.
• CPU_SSE3 — Intel SSE3 instruction set is available.
• CPU_3DNOW — AMD 3DNow! instruction set is available.
• CPU_ENH3DNOW — AMD Enhanced 3DNow! instruction set is available.
• CPU_CMOV — Pentium Pro "cmov" instruction is available.

🧚 checking for multiple things at once (the way that… 👑)

you can vibe check several features at the same time by OR-ing the flags together. for example, wanna know if the CPU has both an FPU and MMX instructions? boom:

if ((cpu_capabilities & (CPU_FPU | CPU_MMX)) ==
    (CPU_FPU | CPU_MMX)) {
   printf("CPU has both an FPU and MMX instructions!\n");
}

periodt. that's it, that's the whole flex 💅

🫶 when can I read this?? (important, bestie)

you can read this variable after you have called check_cpu() — which, btw, is automatically called by allegro_init(). so like… if you haven't inited Allegro yet, don't come for her. 🙈

💜 SEE ALSO 💜

• check_cpu(3alleg4)
• cpu_vendor(3alleg4)
• cpu_family(3alleg4)
• cpu_model(3alleg4)
• cpu_capabilities(3alleg4)
• allegro_init(3alleg4)

okay that's the whole page, no notes 💖 this was the Allegro manual, version 4.4.3, and yeah — that's the whole vibe. go forth and detect some CPU features, you absolute icon 👑✨🦋🌸