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mirror of https://github.com/hsoft/collapseos.git synced 2024-12-25 05:18:06 +11:00

zasm: add generic handling of BIT argument

This reduces the need for special handling routine and will make my
life easier in my upcoming generic tratment of IX/IY prefix in upcodes
This commit is contained in:
Virgil Dupras 2019-11-10 10:24:36 -05:00
parent 553b346b92
commit 999ab56366

View File

@ -248,16 +248,13 @@ parseArg:
; Returns, with Z, whether A is a groupId
isGroupId:
cp 0xc ; max group id + 1
jr nc, .notgroup ; >= 0xc? not a group
cp 0
jr z, .notgroup ; 0? not supposed to happen. something's wrong.
or a
jp z, unsetZ ; not a group
cp 0xd ; max group id + 1
jp nc, unsetZ ; >= 0xd? not a group
; A is a group. ensure Z is set
cp a
ret
.notgroup:
call unsetZ
ret
; Find argspec A in group id H.
; Set Z according to whether we found the argspec
@ -345,11 +342,16 @@ matchArg:
; not an exact match. Before we continue: is A zero? Because if it is,
; we have to stop right here: no match possible.
or a
jr nz, .checkIfNumber ; not a zero, we can continue
jr nz, .skip ; not a zero, we can continue
; zero, stop here
call unsetZ
cp 1 ; unset Z
ret
.checkIfNumber:
.skip:
; Alright, let's start with a special case. Is it part of the special
; "BIT" group, 0xc? If yes, we actually expect a number, which will
; then be ORed like a regular group index.
cp 0xc
jr z, .expectsBIT
; not an exact match, let's check for numerical constants.
call upcase
call checkNOrM
@ -363,6 +365,21 @@ matchArg:
cp (hl)
ret ; whether we match or not, the result of Z is
; the good one.
.expectsBIT:
ld a, (hl)
cp 'N'
inc hl
ld a, (hl)
dec hl
cp 8
jr c, .isBit ; A < 8
; not a bit
or a ; unset Z
ret
.isBit:
cp a ; set Z
ret
.notNumber:
; A bit of a delicate situation here: we want A to go in H but also
; (HL) to go in A. If not careful, we overwrite each other. EXX is
@ -444,28 +461,6 @@ handleBIT:
ld c, 0
jp unsetZ
handleBITHL:
ld b, 0b01000110
jr _handleBITHL
handleSETHL:
ld b, 0b11000110
jr _handleBITHL
handleRESHL:
ld b, 0b10000110
_handleBITHL:
call handleBIT
ret nz ; error
ld a, 0xcb ; first upcode
ld (INS_UPCODE), a
ld a, (INS_CURARG1+1) ; 0-7
rla
rla
rla
or b ; 2nd upcode
ld (INS_UPCODE+1), a
ld c, 2
ret
handleBITIX:
ld a, 0xdd
ld b, 0b01000110
@ -981,6 +976,10 @@ argGrpCC:
argGrpABCDEHL:
.db "BCDEHL_A" ; 0xb
; SPECIAL GROUP "BIT": 0xc
; When special group "0xc" shows up in argspec, it means: accept a number
; between 0 and 7. The value is then treated like a regular group value.
; Each row is 4 bytes wide, fill with zeroes
instrNames:
.db "ADC", 0
@ -1086,7 +1085,7 @@ instrTBl:
.db I_AND, 'n', 0, 0, 0xe6 , 0 ; AND n
.db I_AND, 'x', 0, 0, 0xdd, 0xa6 ; AND (IX+d)
.db I_AND, 'y', 0, 0, 0xfd, 0xa6 ; AND (IY+d)
.db I_BIT, 'n', 'l', 0x20 \ .dw handleBITHL ; BIT b, (HL)
.db I_BIT, 0xc, 'l', 0x43, 0xcb, 0b01000110 ; BIT b, (HL)
.db I_BIT, 'n', 'x', 0x20 \ .dw handleBITIX ; BIT b, (IX+d)
.db I_BIT, 'n', 'y', 0x20 \ .dw handleBITIY ; BIT b, (IY+d)
.db I_BIT, 'n', 0xb, 0x20 \ .dw handleBITR ; BIT b, r
@ -1199,7 +1198,7 @@ instrTBl:
.db I_PUSH,'X', 0, 0, 0xdd, 0xe5 ; PUSH IX
.db I_PUSH,'Y', 0, 0, 0xfd, 0xe5 ; PUSH IY
.db I_PUSH,0x1, 0, 4, 0b11000101 , 0 ; PUSH qq
.db I_RES, 'n', 'l', 0x20 \ .dw handleRESHL ; RES b, (HL)
.db I_RES, 0xc, 'l', 0x43, 0xcb, 0b10000110 ; RES b, (HL)
.db I_RES, 'n', 'x', 0x20 \ .dw handleRESIX ; RES b, (IX+d)
.db I_RES, 'n', 'y', 0x20 \ .dw handleRESIY ; RES b, (IY+d)
.db I_RES, 'n', 0xb, 0x20 \ .dw handleRESR ; RES b, r
@ -1219,7 +1218,7 @@ instrTBl:
.db I_SBC, 'A', 0xb, 0, 0b10011000 , 0 ; SBC A, r
.db I_SBC,'h',0x3,0x44, 0xed, 0b01000010 ; SBC HL, ss
.db I_SCF, 0, 0, 0, 0x37 , 0 ; SCF
.db I_SET, 'n', 'l', 0x20 \ .dw handleSETHL ; SET b, (HL)
.db I_SET, 0xc, 'l', 0x43, 0xcb, 0b11000110 ; SET b, (HL)
.db I_SET, 'n', 'x', 0x20 \ .dw handleSETIX ; SET b, (IX+d)
.db I_SET, 'n', 'y', 0x20 \ .dw handleSETIY ; SET b, (IY+d)
.db I_SET, 'n', 0xb, 0x20 \ .dw handleSETR ; SET b, r