## -*- asm -*-

        ## AMD64 assembly word count subroutine.  On entry we expect a
        ## pointer to an ASCIZ NUL-terminated string in RDI, and
        ## return the return value in RAX, as per standard AMD64 ABI.
        ## Unfinished; currently it only counts characters.
        .intel_syntax noprefix
        .text
        .globl count_words_asm
count_words_asm:
        xor rax, rax              # initialize return value
        dec rax                   # to compensate for terminating NUL
    1:  
        inc rax
        movzx esi, byte ptr [rdi] # load byte
        inc rdi                   # increment pointer
	test rsi, rsi             # bail out if end of string
        jne 1b
    2:  ret

        .data
isalpha:
        .byte 0
isnonalpha:
        .byte 0