meta_v2.c

#include <stdlib.h>
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <x86intrin.h>

const char keywords[][16] = {
    "alignof",
    "auto",
    "break",
    "case",
    "char",
    "const",
    "continue",
    "default",
    "do",
    "double",
    "else",
    "enum",
    "extern",
    "float",
    "for",
    "goto",
    "if",
    "inline",
    "int",
    "long",
    "register",
    "restrict",
    "return",
    "short",
    "signed",
    "sizeof",
    "static",
    "struct",
    "switch",
    "typedef",
    "union",
    "unsigned",
    "void",
    "volatile",
    "while",
    "_Alignas",
    "_Atomic",
    "_Bool",
    "_Complex",
    "_Generic",
    "_Imaginary",
    "_Noreturn",
    "_Static_assert",
    "_Thread_local"
};

static uint32_t fnv1a(const void* data) {
	const unsigned char* ptr = (const unsigned char*)data;
	uint32_t hash = 0x811C9DC5;
	
	while (*ptr) {
		hash = ((*ptr++) ^ hash) * 0x01000193;
	}
	
	return hash;
}

// This thing just prints to the console some source code you copy into the code
enum { num_keywords = sizeof(keywords) / sizeof(*keywords) };

inline static uint64_t next_pow2(uint64_t x) {
	return x == 1 ? 1 : 1 << (64 - __builtin_clzl(x - 1));
}

int compare_ints(const void* a, const void* b) {
    uint32_t arg1 = *(const uint32_t*)a;
    uint32_t arg2 = *(const uint32_t*)b;
 
    if (arg1 < arg2) return -1;
    if (arg1 > arg2) return 1;
    return 0;
}

int main() {
    uint32_t hashes[2 * num_keywords];
    for (uint64_t i = 0; i < num_keywords; i++) {
        hashes[(2 * i)] = fnv1a(keywords[i]);
        hashes[(2 * i) + 1] = i;
    }

    qsort(hashes, num_keywords, 2 * sizeof(uint32_t), compare_ints);
    size_t padded_len = next_pow2(num_keywords);
    
    printf("// BINARY SEARCH ARRAYS\n");
    printf("const static uint32_t keys[%d] = {\n\n\t", padded_len);
    for (uint64_t i = 0; i < padded_len; i++) {
        if (i < num_keywords) printf("0x%08X,", hashes[2 * i]);
        else printf("0xFFFFFFFF,");

        if (i % 8 == 7) printf("\n\t");
    }
    printf("\n};\n");

    printf("const static uint32_t values[%d] = {\n\t", padded_len);
    for (uint64_t i = 0; i < num_keywords; i++) {
        printf("%d,", hashes[2 * i + 1]);
    }
    printf("\n};\n\n");

    return 1;
}