ref: a16c4e637079bb3d7f1cb93ae9b2348d710c003f
dir: /rt/common.s/
.text
/*
* counts the length of the string pointed to
* by %r8, returning len in %r9. Does not modify
* any registers outside of %r9
*/
cstrlen:
xorq %r9,%r9
jmp .lentest
.lenloop:
incq %r9
.lentest:
cmpb $0,(%r8,%r9)
jne .lenloop
ret
/*
* Counts the size of the null terminated string vector
* pointed to by %rbx. Clobbers %r10,%r11
*/
count:
xorq %r9,%r9
movq %rbx,%r11
.countloop:
movq (%r11),%r10
testq %r10,%r10
jz .countdone
addq $1,%r9
addq $8,%r11
jmp .countloop
.countdone:
ret
/*
* iterate over the strings for argc, and put
* them into the args array.
*
* argc in %rax, argv in %rbx, dest vector in %rcx
*/
cvt:
jmp .cvttest
.cvtloop:
subq $1,%rax
movq (%rbx),%r8
call cstrlen
movq %r8, (%rcx)
movq %r9, 8(%rcx)
addq $8, %rbx
addq $16, %rcx
.cvttest:
testq %rax,%rax
jnz .cvtloop
.cvtdone:
ret