zerovm | Open-source lightweight virtualization platform | Infrastructure Automation library

I'm afraid your reference imlementation for strcmp() is both inaccurate and irrelevant:

• it is inaccurate because it compares characters using the char type instead of the unsigned char type as specified in the C11 Standard:

  7.24.4 Comparison functions

  The sign of a nonzero value returned by the comparison functions memcmp, strcmp, and strncmp is determined by the sign of the difference between the values of the first pair of characters (both interpreted as unsigned char) that differ in the objects being compared.

• It is irrelevant because the actual implementation used by modern compilers is much more sophisticated, expanded inline using hand-coded assembly language.

Any generic implementation is likely to be less optimal, especially if coded to remain portable across platforms.

Here are a few directions to explore if your program's bottleneck is comparing strings.

• Analyze your algorithms, try and find ways to reduce the number of comparisons: for example if you search for a string in an array, sorting that array and using a binary search with drastically reduce the number of comparisons.
• If your strings are tokens used in many different places, allocate unique copies of these tokens and use those as scalar values. The strings will be equal if and only if the pointers are equal. I use this trick in compilers and interpreters all the time with a hash table.
• If your strings have the same known length, you can use memcmp() instead of strcmp(). memcmp() is simpler than strcmp() and can be implemented even more efficiently in places where the strings are known to be properly aligned.

EDIT: with the extra information provided, you could use a structure like this for your strings: