toolchain/src/libc/strcat.src at aa8363b36c475c956c065694b45606220d85514f · CE-Programming/toolchain · GitHub

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	.assume	adl=1

	.section	.text

	.global	_strcat
	.type	_strcat, @function

.ifdef PREFER_CE_LIBC

	.set	_strcat, 0x0000C0

.else

_strcat:
	pop	iy
	pop	de
	ex	(sp), hl	; src
	push	de		; dst

	; move to the end of src
	xor	a, a
	ld	bc, 0
	push	hl		; src
	cpir
	sbc	hl, hl
	sbc	hl, bc		; carry is set
	ex	(sp), hl
	ex	de, hl
	; move to the end of dst

	; not needed unless the strlen(dst) + strlen(src) > 16777215 bytes,
	; which would imply that the resulting string would not fit into memory
	; ld bc, 0
	cpir
	dec	hl

	pop	bc
	ex	de, hl
	; DE = dst + strlen(dst)
	; HL = src
	; BC = strlen(src) + 1
	ldir
	ex	(sp), hl	; return value
	jp	(iy)

.endif