Branch optimizations, removed two octave tables and replaced them by a tiny bit of code.

README.md

@@ -90,7 +90,7 @@ The original code compressed with *Blueberry's* Shrinkler goes from
 18052 bytes down to 9023 bytes.
 
 Raspberry Casket, depending on the features compiled in, is about
-5942 bytes and goes down to ~4202 bytes (in isolation).
+5900 bytes and goes down to ~4176 bytes (in isolation).
 
 So this means that the optimization is not just "on the outside".
 
@@ -145,8 +145,10 @@ solve this problem.
 - Optimized some more code paths for Raspberry Casket replayer.
 - In the wave generator optimized away a table (32 words), replacement code is even smaller!
 - Replaced the period table by byte-deltas, saved 36 bytes and compression is even better!
+- Optimized some code paths for octave selection.
+- Removed two 25 bytes tables each, saving another 42 bytes.
 - Added Presto player draft.
-- Drop-in replacement code size: 5942 bytes.
+- Drop-in replacement code size: 5900 bytes.
 
 ### V1.x (unreleased)
 - Fixed a bug regarding the copper output mode with looping waves having a loop-offset.

src/raspberry_casket.asm

@@ -87,7 +87,7 @@
 ; 18052 bytes down to 9023 bytes.
 ;
 ; Raspberry Casket, depending on the features compiled in, is about
-; 5942 bytes and goes down to ~4202 bytes (in isolation).
+; 5900 bytes and goes down to ~4176 bytes (in isolation).
 ;
 ; So this means that the optimization is not just "on the outside".
 ;
@@ -2110,21 +2110,28 @@ pre_PlayerTick:
 ; select right sample corresponding to current pitch
 
         move.w  pcd_out_len_w(a5),d3
-        cmp.w   #$219,d0
-        ble     .noclippitchhigh
-        move.w  #$231,d6                    ; That's probably B-3+1, mapping to period $71 (although $7c is the last safe value)
-        btst    #2,wi_flags_b(a3)
-        beq     .noclippitchlow2
-
-        ; select high pitch version of the sample
-        moveq.l #0,d2
-        move.w  wi_chipram_w(a3),d2
         move.w  d0,d5
         sub.w   #$219,d5
-        lsr.w   #6,d5
+        ble     .is_normal_octave
-        lea     pre_octave_select_table(pc),a1
+        btst    #2,wi_flags_b(a3)
-        moveq.l #0,d1
+        beq     .clippitchhigh
-        move.b  (a1,d5.w),d1                ; higher octave 1-3
+
+        ; select high pitch version of the sample
+        moveq.l #1,d1
+        sub.w   #NOTES_IN_OCTAVE*16,d0
+        sub.w   #3*64,d5
+        blt.s   .oct1
+        addq.w  #1,d1
+        sub.w   #NOTES_IN_OCTAVE*16,d0
+        sub.w   #3*64,d5
+        blt.s   .oct2
+        addq.w  #1,d1
+        sub.w   #NOTES_IN_OCTAVE*16,d0
+.oct2
+.oct1
+
+        moveq.l #0,d2
+        move.w  wi_chipram_w(a3),d2
 
         move.l  pcd_out_ptr_l(a5),d4
         move.w  pcd_out_lof_w(a5),d7
@@ -2177,22 +2184,18 @@ pre_PlayerTick:
         move.l  d4,pcd_out_ptr_l(a5)        ; move trigger start pos to right octave wave
 
 .no_retrigger_new
-.is_normal_octave
-        moveq.l #0,d1
-        move.b  pre_octave_note_offset_table-pre_octave_select_table(a1,d5.w),d1
-        add.w   d1,d1
-        add.w   d1,d1
-        sub.w   d1,d0
         cmp.w   #$231,d0
         ble.s   .noclippitchhigh
-        move.w  #$231,d0
+.clippitchhigh
+        move.w  #$231,d0                    ; That's probably B-3+1, mapping to period $71 (although $7c is the last safe value)
 .noclippitchhigh
-        tst.w   d0
+.is_normal_octave
+        add.w   d0,d0
         bge.s   .noclippitchlow
         moveq.l #0,d0
 .noclippitchlow
-        move.w  d0,d6
+        move.w  pv_period_table(a4,d0.w),pcd_out_per_w(a5)
-.noclippitchlow2
+
         tst.b   pcd_out_trg_b(a5)
         beq.s   .wasnottriggered
         ; this code seems to move the sample start to "loop offset" for first trigger
@@ -2220,8 +2223,6 @@ pre_PlayerTick:
         ENDC
         move.b  d3,pcd_out_trg_b(a5)
 .hassamesamlen
-        add.w   d6,d6
-        move.w  pv_period_table(a4,d6.w),pcd_out_per_w(a5)
 
 ; ----------------------------------------
 ; track delay handling
@@ -2495,7 +2496,7 @@ pre_PlayerTick:
         rts
 
 ;--------------------------------------------------------------------
-; table data currently about 496 bytes
+; table data currently about 446 bytes
         ; Tables used by WaveGen
 pre_roll_off_table: ; used by WaveGen
         dc.w    $400,$200,$180,$140,$100,$C0,$A0,$80,$78,$74,$6E
@@ -2535,38 +2536,6 @@ pre_fast_roll_off_16:
         dc.w    $400,$200,$80,$64,$50,$40,$30,$20,$10,14,12,10,8
         dc.w    4,2,1
 
-pre_octave_note_offset_table:
-        dc.b    1*NOTES_IN_OCTAVE*4,1*NOTES_IN_OCTAVE*4,1*NOTES_IN_OCTAVE*4
-        dc.b    2*NOTES_IN_OCTAVE*4,2*NOTES_IN_OCTAVE*4,2*NOTES_IN_OCTAVE*4
-        dc.b    3*NOTES_IN_OCTAVE*4,3*NOTES_IN_OCTAVE*4,3*NOTES_IN_OCTAVE*4
-        dc.b    3*NOTES_IN_OCTAVE*4,3*NOTES_IN_OCTAVE*4,3*NOTES_IN_OCTAVE*4
-        dc.b    3*NOTES_IN_OCTAVE*4,3*NOTES_IN_OCTAVE*4,3*NOTES_IN_OCTAVE*4
-        IFNE    PRETRACKER_PARANOIA_MODE
-        dc.b    3*NOTES_IN_OCTAVE*4,3*NOTES_IN_OCTAVE*4,3*NOTES_IN_OCTAVE*4
-        dc.b    3*NOTES_IN_OCTAVE*4,3*NOTES_IN_OCTAVE*4,3*NOTES_IN_OCTAVE*4
-        dc.b    3*NOTES_IN_OCTAVE*4,3*NOTES_IN_OCTAVE*4,3*NOTES_IN_OCTAVE*4
-        ELSE
-        dc.b    3*NOTES_IN_OCTAVE*4
-        ENDC
-        even
-
-        ; based on pitch $219 (537), covers up to pitch 0x819 (2073).
-        ; In practice, I was unable to get higher than $5ff
-pre_octave_select_table:
-        dc.b    1,1,1
-        dc.b    2,2,2
-        dc.b    3,3,3
-        dc.b    3,3,3
-        dc.b    3,3,3
-        dc.b    3,3,3
-        IFNE    PRETRACKER_PARANOIA_MODE
-        dc.b    3,3,3
-        dc.b    3,3,3
-        ELSE
-        dc.b    3
-        ENDC
-        even
-
         IFNE     PRETRACKER_DUBIOUS_PITCH_SHIFT_FOR_DELAYED_TRACK
         ; -4,-3,-1,1,2,3,4,0
 pre_minus4plus4_table: