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avra: add "Rd + bit" instructions
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@ -55,8 +55,13 @@ instrNames:
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.db "SBCI", 0
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.db "SBR", 0
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.db "SUBI", 0
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.equ I_BLD 38
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.db "BLD", 0
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.db "BST", 0
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.db "SBRC", 0
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.db "SBRS", 0
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; no arg (from here, instrUpMasks2)
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.equ I_BREAK 38
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.equ I_BREAK 42
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.db "BREAK", 0
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.db "CLC", 0
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.db "CLH", 0
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@ -84,7 +89,7 @@ instrNames:
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.db "SLEEP", 0
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.db "WDR", 0
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; Rd(5)
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.equ I_ASR 64
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.equ I_ASR 68
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.db "ASR", 0
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.db "COM", 0
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.db "DEC", 0
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@ -119,7 +124,7 @@ instrUpMasks1:
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.db 0b00101000 ; OR
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.db 0b00001000 ; SBC
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.db 0b00011000 ; SUB
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; Rd(5) + K(8): XXXXKKKK ddddKKKK
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; Rd(4) + K(8): XXXXKKKK ddddKKKK
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.db 0b01110000 ; ANDI
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.db 0b00110000 ; CPI
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.db 0b11100000 ; LDI
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@ -127,6 +132,12 @@ instrUpMasks1:
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.db 0b01000000 ; SBCI
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.db 0b01100000 ; SBR
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.db 0b01010000 ; SUBI
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; Rd(5) + bit: XXXXXXXd ddddXbbb: lonely bit in LSB is 0 in all cases, so we
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; ignore it.
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.db 0b11111000 ; BLD
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.db 0b11111010 ; BST
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.db 0b11111100 ; SBRC
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.db 0b11111110 ; SBRS
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; 16-bit constant masks associated with each instruction. In the same order as
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; in instrNames
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@ -231,27 +242,29 @@ getInstID:
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parseInstruction:
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; BC, during .spit, is ORred to the spitted opcode.
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ld bc, 0
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; Save Instr ID in D, which is less volatile than A. In almost all
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; cases, we fetch the opcode constant at the end of the processing.
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ld d, a
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cp I_ADC
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jp c, .BR
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cp I_ANDI
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jr c, .spitRd5Rr5
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cp I_BREAK
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cp I_BLD
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jr c, .spitRdK8
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cp I_BREAK
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jr c, .spitRdBit
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cp I_ASR
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jr c, .spitNoArg
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; spitRd5
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ld d, a ; save A for later
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call .readR5
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ret nz
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call .placeRd
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ld a, d ; restore A
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; continue to .spitNoArg
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.spitNoArg:
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call .getUp2
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jr .spit
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.spitRd5Rr5:
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ld d, a ; save A for later
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call .readR5
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ret nz
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call .placeRd
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@ -270,13 +283,11 @@ parseInstruction:
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rra \ rra \ rra
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or b
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ld b, a
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ld a, d ; restore A
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call .getUp1
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; now that's our MSB
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jr .spitMSB
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.spitRdK8:
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ld d, a ; save A for later
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call .readR4
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ret nz
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call .placeRd
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@ -299,9 +310,20 @@ parseInstruction:
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and 0xf0
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rra \ rra \ rra \ rra
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ld b, a
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ld a, d ; restore A
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call .getUp1
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; now that's our MSB
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jr .spitMSB
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.spitRdBit:
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call .readR5
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ret nz
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call .placeRd
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call readComma
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ret nz
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call .readBit
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ret nz
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; LSB is in A and is ready to go
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call ioPutB
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call .getUp1
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jr .spitMSB
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.spit:
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@ -378,13 +400,8 @@ parseInstruction:
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; upcode becomes 0b111101
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inc b
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.rdBRBS:
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call readWord
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call .readBit
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ret nz
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call parseExpr
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ld a, 7
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call .IX2A
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ret nz
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ld c, a
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call readComma
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ret nz
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jr .spitBR2
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@ -398,14 +415,16 @@ parseInstruction:
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ld c, a
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ret
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; Fetch a 8-bit upcode specified by instr index in A and set that upcode in HL
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; Fetch a 8-bit upcode specified by instr index in D and set that upcode in HL
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.getUp1:
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ld a, d
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sub I_ADC
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ld hl, instrUpMasks1
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jp addHL
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; Fetch a 16-bit upcode specified by instr index in A and set that upcode in HL
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; Fetch a 16-bit upcode specified by instr index in D and set that upcode in HL
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.getUp2:
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ld a, d
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sub I_BREAK
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sla a ; A * 2
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ld hl, instrUpMasks2
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@ -434,6 +453,17 @@ parseInstruction:
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ld a, 31
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jr .IX2A
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.readBit:
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call readWord
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ret nz
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call parseExpr
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ld a, 7
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call .IX2A
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ret nz
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or c
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ld c, a
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cp a ; ensure Z
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ret
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; Put IX's LSB into A and, additionally, ensure that the new value is <=
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; than what was previously in A.
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@ -8,3 +8,4 @@ asr r20
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bar:
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brbs 6, foo
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ori r22, 0x34+4
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sbrs r1, 3
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@ -1 +1 @@
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<08><><EFBFBD><EFBFBD><EFBFBD> <09>E<EFBFBD><45><EFBFBD>hc
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<08><><EFBFBD><EFBFBD><EFBFBD> <09>E<EFBFBD><45><EFBFBD>hc<13>
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