toolchain/src/libc/ldiv.src at 3e58681f41bb9cedb61c3cd2108c2dd58c2c7840 · CE-Programming/toolchain · GitHub

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	.assume	adl=1

	.section	.text
	.global	_ldiv
	.type	_ldiv, @function

; REMEMBER to keep ldivu.src, lremu.src, and ldiv.src in sync with this choice
.if 1

_ldiv:
	pop	hl
	pop	iy
	pop	de
	pop	bc
	ld	a, c
	pop	bc
	ex	(sp), hl
	ex	de, hl

	ld	d, a
	xor	a, e
	push	af

	ld	a, e
	ld	e, d
	push	de

	bit	7, e
	call	__ldivs_lrems_common

	call	__ldivu_lremu_common

	exx
	ld	e, a
	pop	af
	call	m, __lneg
	ld	(iy + 4), hl
	ld	(iy + 7), e

	exx
	pop	af
	call	m, __lneg
	ld	(iy), hl
	ld	(iy + 3), e

	ex	(sp), hl
	push	de
	push	de
	push	de
	push	de
	bit	2, c
	jr	z, .L.ei_skip
	ei
.L.ei_skip:
	jp	(hl)

	.extern	__ldivu_lremu_common

.else

_ldiv:
	pop	hl		; return address
	pop	iy		; ldiv_t pointer
	pop	de		; [ 0:23] numerator
	pop	bc		; [24:31] numerator
	ld	a, c
	pop	bc		; [ 0:23] denominator
	ex	(sp), hl	; [24:31] denominator
	ex	de, hl

	push	ix		; preserve IX since __ldvrmu destroys it
	ld	d, a
	xor	a, e
	push	af		; quotient sign

	ld	a, e
	ld	e, d
	push	de		; remainder sign

	bit	7, e
	call	__ldivs_lrems_common

	push	iy		; preserve IY since __ldvrmu destroys it
	; E:UHL = numerator
	; A:UBC = denominator
	call	__ldvrmu
	; E:UIX = quotient
	; A:UHL = remainder
	pop	iy		; restore IY = ldiv_t pointer

	ld	d, e		; preserve E
	ld	e, a
	pop	af		; remainder sign

	; E:UHL = remainder
	call	m, __lneg
	ld	(iy + 4), hl
	ld	(iy + 7), e

	pop	af		; quotient sign

	lea	hl, ix + 0
	pop	ix		; restore IX
	ld	e, d		; restore E
	; E:UHL = quotient
	call	m, __lneg
	ld	(iy), hl
	ld	(iy + 3), e

	ex	(sp), hl	; HL = return address
	push	de
	push	de
	push	de
	push	de
	jp	(hl)

	.extern	__ldvrmu

.endif

	.extern	__ldivs_lrems_common
	.extern	__lneg