git.y1.nz

commit df9112a7c4657af4975dcf3006c97c2a312118ff
parent 9dd685cb3c61af89af71b71b6297416603a6e16e
Author: Toxa <untoxa@mail.ru>
Date:   Fri, 27 Jan 2023 19:04:01 +0300

GB: new faster vmemcpy()/set_data()/get_data()

Diffstat:
M
gbdk-lib/include/gb/gb.h
6
+++---
M
gbdk-lib/libc/targets/sm83/cpy_data.s
95
+++++++++++++++++++++++++++++++++++++++++++++++--------------------------------

2 files changed, 60 insertions(+), 41 deletions(-)
diff --git a/gbdk-lib/include/gb/gb.h b/gbdk-lib/include/gb/gb.h
@@ -1843,7 +1843,7 @@ inline void hide_sprite(uint8_t nb) {
 
     @see set_bkg_data, set_win_data, set_bkg_tiles, set_win_tiles, set_tile_data, set_tiles
 */
-void set_data(uint8_t *vram_addr, const uint8_t *data, uint16_t len) OLDCALL PRESERVES_REGS(b, c);
+void set_data(uint8_t *vram_addr, const uint8_t *data, uint16_t len);
 
 
 /** Copies arbitrary data from an address in VRAM into a buffer
@@ -1861,7 +1861,7 @@ void set_data(uint8_t *vram_addr, const uint8_t *data, uint16_t len) OLDCALL PRE
 
     @see get_bkg_data, get_win_data, get_bkg_tiles, get_win_tiles, get_tiles
 */
-void get_data(uint8_t *data, uint8_t *vram_addr, uint16_t len) OLDCALL PRESERVES_REGS(b, c);
+void get_data(uint8_t *data, uint8_t *vram_addr, uint16_t len);
 
 /** Copies arbitrary data from an address in VRAM into a buffer
 
@@ -1875,7 +1875,7 @@ void get_data(uint8_t *data, uint8_t *vram_addr, uint16_t len) OLDCALL PRESERVES
     \li VBK_REG = @ref VBK_BANK_0 indicates the first bank
     \li VBK_REG = @ref VBK_BANK_1 indicates the second
 */
-void vmemcpy(uint8_t *dest, uint8_t *sour, uint16_t len) OLDCALL PRESERVES_REGS(b, c);
+void vmemcpy(uint8_t *dest, uint8_t *sour, uint16_t len);
 
 
 
diff --git a/gbdk-lib/libc/targets/sm83/cpy_data.s b/gbdk-lib/libc/targets/sm83/cpy_data.s
@@ -1,44 +1,63 @@
-        .include	"global.s"
+	.include	"global.s"
 
-        .area	_HOME
+	.area   _CODE
 
-        ;; Copy part (size = DE) of the VRAM from (BC) to (HL)
-.copy_vram::
-        INC     D
-        INC     E
-        JR      2$
-1$:
-        WAIT_STAT
+	.globl	_vmemcpy2, _set_data2, _get_data2
 
-        LD	A,(BC)
-        LD	(HL+),A
-        INC	BC
-2$:
-        DEC     E
-        JR      NZ, 1$
-        DEC     D
-        JR      NZ, 1$
-        RET
+_vmemcpy2::
+_set_data2::
+_get_data2::
+	;dest in de
+	;src in bc
+	;n in sp+2,sp+3
+	ldhl	sp, #3
+	ld	a, (hl-)
+	ld	l, (hl)
+	ld	h, b
+	ld	b, a
+	ld	a, l
+	ld	l, c
+	srl	b
+	rra
+	ld	c, a
 
-_vmemcpy::
-_set_data::
-_get_data::
-        PUSH	BC
+	;dest in de (backup in sp+0,sp+1)
+	;src in hl
+	;n/2 in bc
+	;LSB of bc in carry
+	jr nc, skip_one
 
-        LDA	HL,9(SP)	; Skip return address and registers
-        LD	A,(HL-)		; DE = len
-        LD	D, A
-        LD	A,(HL-)
-        LD	E, A
-        LD	A,(HL-)		; BC = src
-        LD	B, A
-        LD	A,(HL-)
-        LD	C, A
-        LD	A,(HL-)		; HL = dst
-        LD	L,(HL)
-        LD	H,A
+	WAIT_STAT
+	ld	a, (hl+)
+	ld	(de), a
+	inc	de
+skip_one:
+	;n/2 in bc
+	;shift second LSB to carry
+	srl	b
+	rr	c
+	;n/4 in bc
+	inc	b
+	inc	c
+	jr nc, test
+	jr	copy_two
+.irp	idx,copy_four,copy_two
+	idx:
+	.rept	2
+		WAIT_STAT
+		ld	a, (hl+)
+		ld	(de), a
+		inc	de
+	.endm
+.endm
+test:
+.irp	idx,c,b
+	dec	idx
+	jr	nz, copy_four
+.endm
 
-        CALL	.copy_vram
-
-        POP	BC
-        RET
+	;get return address
+	pop	hl
+	;throw away n
+	pop	af
+	jp	(hl)

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