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Adding CMR instruction.

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Russell-S-Harper 2018-09-14 06:24:35 -04:00
parent 68c4152f4b
commit 7ac0d7e04a
3 changed files with 36 additions and 10 deletions
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41
common/common.asm
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@ -416,12 +416,9 @@ _ADD .( ; ADD r pq ar pq Rr <- Rp + Rq - addition
JMP _RETI0X ; pull X, transfer I0 to r register, let it handle the return
.)
_SUB .( ; SUB r pq br pq Rr <- Rp - Rq - subtraction
TXA
PHA ; save r register for later
JSR _GETPQF
SEC ; set I0 to Rp - Rq
LDA _R0,X
_SBXYI0 .( ; set I0 to register pointed by X - register pointed by Y
LDA _R0,X ; set I0 to Rp - Rq
SEC
SBC _R0,Y
STA _I0
LDA _R0+1,X
@ -433,12 +430,20 @@ _SUB .( ; SUB r pq br pq Rr <- Rp - Rq - subtraction
LDA _R0+3,X
SBC _R0+3,Y
STA _I0+3
RTS
.)
_SUB .( ; SUB r pq br pq Rr <- Rp - Rq - subtraction
TXA
PHA ; save r register for later
JSR _GETPQF
JSR _SBXYI0
JMP _RETI0X ; pull X, transfer I0 to r register, let it handle the return
.)
_NEGX .( ; negates register at X
SEC
LDA #0
SEC
SBC _R0,X
STA _R0,X
LDA #0
@ -704,8 +709,8 @@ _1 RTS
.)
_UPDDM .( ; update DIV and MOD
SEC ; I0/I1 -= I2/I3
LDA _I0
LDA _I0 ; I0/I1 -= I2/I3
SEC
SBC _I2
STA _I0
LDA _I0+1
@ -987,6 +992,24 @@ _SVI .( ; SVI pq 0e pq (Rp:bbcc) <- Rq - save indirect to memory
.)
_CMR .( ; CMR pq 0f pq F <- Rp <=> Rq - compare registers
JSR _GETPQF
JSR _SBXYI0
LDA _F
AND #_MSK_C ; clear CMR bits
STA _F
LDA _I0+3 ; check highest byte
BMI _1 ; is less than
ORA _I0+2 ; could be greater than or equal to, OR with all other bytes
ORA _I0+1
ORA _I0
BNE _2 ; is greater than
LDA #_F_E ; set equal to flag
BNE _3
_1 LDA #_F_L ; set less than flag
BNE _3
_2 LDA #_F_G ; set greater than flag
_3 ORA _F
STA _F
RTS
.)

1
common/common.h
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@ -138,5 +138,6 @@ _EXT_C = $f0
_MSK_O = %11000000 ; mask for overflow
_MSK_R = %00111100 ; mask for registers
_MSK_T = (_F_Z + _F_P + _F_N)^$ff ; mask for TST
_MSK_C = (_F_E + _F_G + _F_L)^$ff ; mask for CMP
#endif /* __COMMON_H */

4
common/page6.src
View File

@ -6,7 +6,9 @@
HDR(DEMO)
CMN
BRA(FACTORIAL)
SET(R0, 999999.999)
SET(R1, -999999.999)
CMR(R0, R1)
ESC
BRK