diff --git a/ruapu.h b/ruapu.h
index b62398b..6990f6e 100644
--- a/ruapu.h
+++ b/ruapu.h
@@ -7,14 +7,262 @@
 #ifndef RUAPU_H
 #define RUAPU_H
 
+void raupu_init();
+
+int ruapu_supports(const char* isa);
+
+#ifdef RUAPU_IMPLEMENTATION
+
+#include <setjmp.h>
+#include <string.h>
+
+#if defined _WIN32
+
+#include <windows.h>
+
+static int g_ruapu_sigill_caught = 0;
+static jmp_buf g_ruapu_jmpbuf;
+
+typedef const void* ruapu_some_inst;
+
+static LONG CALLBACK ruapu_catch_sigill(struct _EXCEPTION_POINTERS* ExceptionInfo)
+{
+    if (ExceptionInfo->ExceptionRecord->ExceptionCode == EXCEPTION_ILLEGAL_INSTRUCTION)
+    {
+        g_ruapu_sigill_caught = 1;
+        longjmp(g_ruapu_jmpbuf, -1);
+    }
+
+    return EXCEPTION_CONTINUE_SEARCH;
+}
+
+static int ruapu_detect_isa(const void* some_inst)
+{
+    g_ruapu_sigill_caught = 0;
+
+    PVOID eh = AddVectoredExceptionHandler(1, ruapu_catch_sigill);
+
+    if (setjmp(g_ruapu_jmpbuf) == 0)
+    {
+        ((void (*)())some_inst)();
+    }
+
+    RemoveVectoredExceptionHandler(eh);
+
+    return g_ruapu_sigill_caught ? 0 : 1;
+}
+
+#if defined(__i386__) || defined(__x86_64__) || defined(_M_IX86) || defined(_M_X64)
+#ifdef _MSC_VER
+#define RUAPU_INSTCODE(isa, ...) __pragma(section(".text")) __declspec(allocate(".text")) static unsigned char ruapu_some_##isa[] = { __VA_ARGS__, 0xc3 };
+#else
+#define RUAPU_INSTCODE(isa, ...) __attribute__((section(".text"))) static unsigned char ruapu_some_##isa[] = { __VA_ARGS__, 0xc3 };
+#endif
+
+#elif __aarch64__
+#ifdef _MSC_VER
+#define RUAPU_INSTCODE(isa, ...) __pragma(section(".text")) __declspec(allocate(".text")) static unsigned int ruapu_some_##isa[] = { __VA_ARGS__, 0xd65f03c0 };
+#else
+#define RUAPU_INSTCODE(isa, ...) __attribute__((section(".text"))) static unsigned int ruapu_some_##isa[] = { __VA_ARGS__, 0xd65f03c0 };
+#endif
+
+#elif __arm__
+#ifdef _MSC_VER
+#define RUAPU_INSTCODE(isa, ...) __pragma(section(".text")) __declspec(allocate(".text")) static unsigned int ruapu_some_##isa[] = { __VA_ARGS__, 0x4770 };
+#else
+#define RUAPU_INSTCODE(isa, ...) __attribute__((section(".text"))) static unsigned int ruapu_some_##isa[] = { __VA_ARGS__, 0x4770bf00 };
+#endif
+
+#endif
+
+
+#else
+#include <signal.h>
+
+static int g_ruapu_sigill_caught = 0;
+static sigjmp_buf g_ruapu_jmpbuf;
+
+typedef void (*ruapu_some_inst)();
+
+static void ruapu_catch_sigill(int signo, siginfo_t* si, void* data)
+{
+    (void)signo;
+    (void)si;
+    (void)data;
+
+    g_ruapu_sigill_caught = 1;
+    siglongjmp(g_ruapu_jmpbuf, -1);
+}
+
+static int ruapu_detect_isa(ruapu_some_inst some_inst)
+{
+    g_ruapu_sigill_caught = 0;
+
+    struct sigaction sa = { 0 };
+    struct sigaction old_sa;
+    sa.sa_flags = SA_ONSTACK | SA_RESTART | SA_SIGINFO;
+    sa.sa_sigaction = ruapu_catch_sigill;
+    sigaction(SIGILL, &sa, &old_sa);
+
+    if (sigsetjmp(g_ruapu_jmpbuf, 1) == 0)
+    {
+        some_inst();
+    }
+
+    sigaction(SIGILL, &old_sa, NULL);
+
+    return g_ruapu_sigill_caught ? 0 : 1;
+}
+
+#if defined(__i386__) || defined(__x86_64__) || defined(_M_IX86) || defined(_M_X64)
+#define RUAPU_INSTCODE(isa, ...) static void ruapu_some_##isa() { asm volatile(".byte " #__VA_ARGS__ : : : ); };
+#elif __aarch64__
+#define RUAPU_INSTCODE(isa, ...) static void ruapu_some_##isa() { asm volatile(".word " #__VA_ARGS__ : : : ); };
+#elif __arm__
+#define RUAPU_INSTCODE(isa, ...) static void ruapu_some_##isa() { asm volatile(".word " #__VA_ARGS__ : : : ); };
+#endif
+
+#endif
+
+struct ruapu_isa_entry
+{
+    const char* isa;
+    ruapu_some_inst inst;
+    int capable;
+};
+
+#if defined(__i386__) || defined(__x86_64__) || defined(_M_IX86) || defined(_M_X64)
+RUAPU_INSTCODE(mmx, 0x0f, 0xdb, 0xc0) // pand mm0,mm0
+RUAPU_INSTCODE(sse, 0x0f, 0x54, 0xc0) // andps xmm0,xmm0
+RUAPU_INSTCODE(sse2, 0x66, 0x0f, 0xfe, 0xc0) // paddd xmm0,xmm0
+RUAPU_INSTCODE(sse3, 0xf2, 0x0f, 0x7c, 0xc0) // haddps xmm0,xmm0
+RUAPU_INSTCODE(ssse3, 0x66, 0x0f, 0x38, 0x06, 0xc0) // phsubd xmm0,xmm0
+RUAPU_INSTCODE(sse41, 0x66, 0x0f, 0x38, 0x3d, 0xc0) // pmaxsd xmm0,xmm0
+RUAPU_INSTCODE(sse42, 0x66, 0x0f, 0x38, 0x37, 0xc0) // pcmpgtq xmm0,xmm0
+RUAPU_INSTCODE(sse4a, 0x66, 0x0f, 0x79, 0xc0) // extrq xmm0,xmm0
+RUAPU_INSTCODE(xop, 0x8f, 0xe8, 0x78, 0xb6, 0xc0, 0x00)  // vpmadcswd %xmm0,%xmm0,%xmm0,%xmm0
+RUAPU_INSTCODE(avx, 0xc5, 0xfc, 0x54, 0xc0) // vandps ymm0,ymm0,ymm0
+RUAPU_INSTCODE(f16c, 0xc4, 0xe2, 0x7d, 0x13, 0xc0) // vcvtph2ps ymm0,xmm0
+RUAPU_INSTCODE(fma, 0xc4, 0xe2, 0x7d, 0x98, 0xc0) // vfmadd132ps ymm0,ymm0,ymm0
+RUAPU_INSTCODE(avx2, 0xc5, 0xfd, 0xfe, 0xc0) // vpaddd ymm0,ymm0,ymm0
+RUAPU_INSTCODE(avx512f, 0x62, 0xf1, 0x7c, 0x48, 0x58, 0xc0) // vaddps zmm0,zmm0,zmm0
+RUAPU_INSTCODE(avx512bw, 0x62, 0xf1, 0x7d, 0x48, 0xfd, 0xc0) // vpaddw zmm0,zmm0,zmm0
+RUAPU_INSTCODE(avx512cd, 0x62, 0xf2, 0xfd, 0x48, 0x44, 0xc0) // vplzcntq zmm0,zmm0
+RUAPU_INSTCODE(avx512dq, 0x62, 0xf1, 0x7c, 0x48, 0x54, 0xc0) // vandps zmm0,zmm0,zmm0
+RUAPU_INSTCODE(avx512vl, 0x62, 0xf2, 0xfd, 0x28, 0x1f, 0xc0) // vpabsq ymm0,ymm0
+RUAPU_INSTCODE(avx512vnni, 0x62, 0xf2, 0x7d, 0x48, 0x52, 0xc0) // vpdpwssd %zmm0,%zmm0,%zmm0
+RUAPU_INSTCODE(avx512bf16, 0x62, 0xf2, 0x7e, 0x48, 0x52, 0xc0) // vdpbf16ps %zmm0,%zmm0,%zmm0
+RUAPU_INSTCODE(avx512ifma, 0x62, 0xf2, 0xfd, 0x48, 0xb4, 0xc0) // vpmadd52luq %zmm0,%zmm0,%zmm0
+RUAPU_INSTCODE(avx512vbmi, 0x62, 0xf2, 0x7d, 0x48, 0x75, 0xc0) // vpermi2b %zmm0,%zmm0,%zmm0
+RUAPU_INSTCODE(avx512vbmi2, 0x62, 0xf2, 0x7d, 0x48, 0x71, 0xc0) // vpshldvd %zmm0,%zmm0,%zmm0
+RUAPU_INSTCODE(avx512fp16, 0x62, 0xf6, 0x7d, 0x48, 0x98, 0xc0) // vfmadd132ph %zmm0,%zmm0,%zmm0
+RUAPU_INSTCODE(avxvnni, 0x62, 0xf2, 0x7d, 0x28, 0x52, 0xc0) // vpdpwssd ymm0,ymm0,ymm0
+RUAPU_INSTCODE(avxvnniint8, 0xc4, 0xe2, 0x7f, 0x50, 0xc0) // vpdpbssd ymm0,ymm0,ymm0
+RUAPU_INSTCODE(avxifma, 0x62, 0xf2, 0xfd, 0x28, 0xb4, 0xc0) // vpmadd52luq %ymm0,%ymm0,%ymm0
+
+#elif __aarch64__
+RUAPU_INSTCODE(neon, 0x4e20d400) // fadd v0.4s,v0.4s,v0.4s
+RUAPU_INSTCODE(vfpv4, 0x0e216800) // fcvtn v0.4h,v0.4s
+RUAPU_INSTCODE(cpuid, 0xd5380000) // mrs x0,midr_el1
+RUAPU_INSTCODE(asimdhp, 0x0e401400) // fadd v0.4h,v0.4h,v0.4h
+RUAPU_INSTCODE(asimddp, 0x4e809400) // sdot v0.4h,v0.16b,v0.16b
+RUAPU_INSTCODE(asimdfhm, 0x4e20ec00) // fmlal v0.4s,v0.4h,v0.4h
+RUAPU_INSTCODE(bf16, 0x6e40ec00) // bfmmla v0.4h,v0.8h,v0.8h
+RUAPU_INSTCODE(i8mm, 0x4e80a400) // smmla v0.4h,v0.16b,v0.16b
+RUAPU_INSTCODE(sve, 0x65608000) // fmad z0.h,p0/m,z0.h,z0.h
+RUAPU_INSTCODE(sve2, 0x44405000) // smlslb z0.h,z0.b,z0.b
+RUAPU_INSTCODE(svebf16, 0x6460e400) // bfmmla z0.s,z0.h,z0.h
+RUAPU_INSTCODE(svei8mm, 0x45009800) // smmla z0.s,z0.b,z0.b
+RUAPU_INSTCODE(svef32mm, 0x64a0e400) // fmmla z0.s,z0.s,z0.s
+
+#elif __arm__
+RUAPU_INSTCODE(edsp, 0x0000fb20) // smlad r0,r0,r0,r0
+RUAPU_INSTCODE(neon, 0x0d40ef00) // vadd.f32 q0,q0,q0
+RUAPU_INSTCODE(vfpv4, 0x0600ffb6) // vcvt.f16.f32 d0,q0
+
+#endif
+
+#undef RUAPU_INSTCODE
+
+#define RUAPU_ISAENTRY(isa) { #isa, (ruapu_some_inst)ruapu_some_##isa, 0 },
+
+struct ruapu_isa_entry g_ruapu_isa_map[] = {
+
+#if defined(__i386__) || defined(__x86_64__) || defined(_M_IX86) || defined(_M_X64)
+RUAPU_ISAENTRY(mmx)
+RUAPU_ISAENTRY(sse)
+RUAPU_ISAENTRY(sse2)
+RUAPU_ISAENTRY(sse3)
+RUAPU_ISAENTRY(ssse3)
+RUAPU_ISAENTRY(sse41)
+RUAPU_ISAENTRY(sse42)
+RUAPU_ISAENTRY(sse4a)
+RUAPU_ISAENTRY(xop)
+RUAPU_ISAENTRY(avx)
+RUAPU_ISAENTRY(f16c)
+RUAPU_ISAENTRY(fma)
+RUAPU_ISAENTRY(avx2)
+RUAPU_ISAENTRY(avx512f)
+RUAPU_ISAENTRY(avx512bw)
+RUAPU_ISAENTRY(avx512cd)
+RUAPU_ISAENTRY(avx512dq)
+RUAPU_ISAENTRY(avx512vl)
+RUAPU_ISAENTRY(avx512vnni)
+RUAPU_ISAENTRY(avx512bf16)
+RUAPU_ISAENTRY(avx512ifma)
+RUAPU_ISAENTRY(avx512vbmi)
+RUAPU_ISAENTRY(avx512vbmi2)
+RUAPU_ISAENTRY(avx512fp16)
+RUAPU_ISAENTRY(avxvnni)
+RUAPU_ISAENTRY(avxvnniint8)
+RUAPU_ISAENTRY(avxifma)
+
+#elif __aarch64__
+RUAPU_ISAENTRY(neon)
+RUAPU_ISAENTRY(vfpv4)
+RUAPU_ISAENTRY(cpuid)
+RUAPU_ISAENTRY(asimdhp)
+RUAPU_ISAENTRY(asimddp)
+RUAPU_ISAENTRY(asimdfhm)
+RUAPU_ISAENTRY(bf16)
+RUAPU_ISAENTRY(i8mm)
+RUAPU_ISAENTRY(sve)
+RUAPU_ISAENTRY(sve2)
+RUAPU_ISAENTRY(svebf16)
+RUAPU_ISAENTRY(svei8mm)
+RUAPU_ISAENTRY(svef32mm)
+
+#elif __arm__
+RUAPU_ISAENTRY(edsp)
+RUAPU_ISAENTRY(neon)
+RUAPU_ISAENTRY(vfpv4)
+
+#endif
+};
+
+#undef RUAPU_ISAENTRY
+
 void raupu_init()
 {
+    for (size_t i = 0; i < sizeof(g_ruapu_isa_map) / sizeof(g_ruapu_isa_map[0]); i++)
+    {
+        g_ruapu_isa_map[i].capable = ruapu_detect_isa(g_ruapu_isa_map[i].inst);
+    }
 }
 
 int ruapu_supports(const char* isa)
 {
-    (void)isa;
+    for (size_t i = 0; i < sizeof(g_ruapu_isa_map) / sizeof(g_ruapu_isa_map[0]); i++)
+    {
+        if (strcmp(g_ruapu_isa_map[i].isa, isa) == 0)
+        {
+            return g_ruapu_isa_map[i].capable;
+        }
+    }
+
     return 0;
 }
 
+#endif // RUAPU_IMPLEMENTATION
+
 #endif // RUAPU_H