git.y1.nz

commit f27a0d76062463bbf86e812d06618bf207a3dd0c
parent 1b5f9f1255849e36b52b3d60787b171507d77f39
Author: Toxa <untoxa@mail.ru>
Date:   Thu, 26 Aug 2021 14:39:41 +0300

SMS/GG: optimize set_tile_2bpp_data(); set_*_2bpp_data takes into account corner case for 256 tiles

Diffstat:
M
gbdk-lib/include/sms/sms.h
4
++--
M
gbdk-lib/libc/targets/z80/set_2bpp_data.s
40
+++++++++++++++++++++++++---------------

2 files changed, 27 insertions(+), 17 deletions(-)
diff --git a/gbdk-lib/include/sms/sms.h b/gbdk-lib/include/sms/sms.h
@@ -356,10 +356,10 @@ inline void set_2bpp_palette(uint16_t palette) {
 }
 void set_tile_2bpp_data(uint16_t start, uint16_t ntiles, const void *src, uint16_t palette) __z88dk_callee __preserves_regs(iyh,iyl);
 inline void set_bkg_2bpp_data(uint16_t start, uint16_t ntiles, const void *src) {
-    set_tile_2bpp_data(start, ntiles, src, _current_2bpp_palette);
+    set_tile_2bpp_data(start, (ntiles)?ntiles:256, src, _current_2bpp_palette);
 }
 inline void set_sprite_2bpp_data(uint16_t start, uint16_t ntiles, const void *src) {
-    set_tile_2bpp_data((uint8_t)(start) + 0x100u, ntiles, src, _current_2bpp_palette);
+    set_tile_2bpp_data((uint8_t)(start) + 0x100u, (ntiles)?ntiles:256, src, _current_2bpp_palette);
 }
 
 /** Copies arbitrary data to an address in VRAM
diff --git a/gbdk-lib/libc/targets/z80/set_2bpp_data.s b/gbdk-lib/libc/targets/z80/set_2bpp_data.s
@@ -70,22 +70,33 @@ _set_tile_2bpp_data::
 
         push de                 ; save palette
 
-        or a
-        jr z, 4$
-
-3$:
-        srl d
-        rr e
-        srl d
-        rr e
-        srl d
-        rr e
-        srl d
-        rr e
+        inc a
         dec a
-        jr nz, 3$
-4$:
+        jr nz, 10$
+        ; zero
         ld a, e
+        jr 13$
+10$:
+        dec a
+        jr nz, 11$
+        ; one
+        ld a, e
+        jr 14$
+11$:
+        dec a
+        jr nz, 12$
+        ; two
+        ld a, d
+        jr 13$
+12$:
+        ;three
+        ld a, d
+14$:
+        rra
+        rra
+        rra
+        rra
+13$:
         and #0x0F
 
         rra
@@ -116,7 +127,6 @@ _set_tile_2bpp_data::
 
         dec ixh
         jr nz, 6$
-
 2$:
         ex (sp), hl
 

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