clang: _rotl32 not found for architecture arm64

Question

On Apple M1, I'm trying to compile the following code:

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

inline uint32_t rotl32(uint32_t x, int32_t bits)
{
    return x<<bits | x>>(32-bits);      // C idiom
}

uint32_t bad_hash32(char const *input) { 
    uint32_t result = 0xC0FF117;
    while (*input) { 
        result ^= *input++;
        result = rotl32(result, 5);
    }
    return result;
}

int main(int argc, char* argv[])
{
    char const* const input = argv[1];
    printf("%08x\n", bad_hash32(input));
    return 0;
}

Command:

gcc bad_hash.c -o bad_hash

It produces the following error:

Undefined symbols for architecture arm64:
  "_rotl32", referenced from:
      _bad_hash32 in bad_hash-4c8a24.o
ld: symbol(s) not found for architecture arm64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

What's the issue here? I tried to upgrade gcc to the latest.

Clang version:

Apple clang version 13.0.0 (clang-1300.0.29.30)
Target: arm64-apple-darwin21.2.0
Thread model: posix

Answer 1

Removing the inline specifier fixes the issue.

Though I still don't know why this happens.