SixtyPical/doc/Instruction_Support.markdown

SixtyPical: Instruction Support

Unsupported Opcodes

6502 opcodes with no language-level equivalent instructions in SixtyPical are brk, cli, pla, plp, rti, rts, tsx, txs. These may be inserted into the output program as a SixtyPical → 6502 compiler sees fit, however.

Note to self, the pl opcodes do change flags.

Instruction Support so far

A X indicates unsupported.

Funny syntax indicates use of a special form.

In these, absolute must be a reserved or located address. immediate must be a literal decimal or hexadecimal number (or in future, a declared constant.)

adc #immediate
adc absolute

and #immediate
and absolute

asl
asl absolute

if bcc { block } else { block }

if bcs { block } else { block }

if beq { block } else { block }

bit absolute

if bmi { block } else { block }

if bne { block } else { block }

if bpl { block } else { block }

if bvc { block } else { block }

if bvs { block } else { block }

clc

cld

clv

cmp #immediate
cmp absolute

cpx #immediate
cpx absolute

cpy #immediate
cpy absolute

dec absolute

dex

dey

eor #immediate
eor absolute

inc absolute

inx

iny

jsr routine

jmp (vector)

lda #immediate
lda absolute
lda absolute, x
lda absolute, y
lda (absolute), y

ldx #immediate
ldx absolute

ldy #immediate
ldy absolute

lsr
lsr absolute

nop

ora #immediate
ora absolute

pha { block }

php { block }

rol
rol absolute

ror
ror absolute

sbc #immediate
sbc absolute

sec

sed

sei { block }

sta absolute
sta absolute, x
sta absolute, y
sta (absolute), y

stx absolute

sty absolute

tax

tay

txa

tya

Tests

Should be merged with the above nicely someday.

-> Tests for functionality "Emit ASM for SixtyPical program"

Big test for parsing and emitting instructions.

| reserve word vword
| reserve byte vbyte
| assign byte table table 1024
| routine main {
|    lda #4
|    ldx #0
|    ldy #$FF
|    lda vbyte
|    lda table, x
|    lda table, y
|    lda (vword), y
|    lda <vword
|    lda >vword
|    inc vbyte
|    tax
|    inx
|    dex
|    stx vbyte
|    tay
|    iny
|    dey
|    sty vbyte
|    cmp vbyte
|    cmp #30
|    cmp <vword
|    cmp >vword
|    ldx vbyte
|    cpx vbyte
|    cpx #31
|    txa
|    ldy vbyte
|    cpy vbyte
|    cpy #32
|    tya
|    sta vbyte
|    sta table, x
|    sta table, y
|    sta (vword), y
|    sta <vword
|    sta >vword
|    dec vbyte
|    clc
|    cld
|    clv
|    sec
|    sed
|    adc #8
|    adc vbyte
|    and #8
|    and vbyte
|    sbc #8
|    sbc vbyte
|    ora #8
|    ora vbyte
| }
= main:
=   lda #4
=   ldx #0
=   ldy #255
=   lda vbyte
=   lda table, x
=   lda table, y
=   lda (vword), y
=   lda vword
=   lda vword+1
=   inc vbyte
=   tax
=   inx
=   dex
=   stx vbyte
=   tay
=   iny
=   dey
=   sty vbyte
=   cmp vbyte
=   cmp #30
=   cmp vword
=   cmp vword+1
=   ldx vbyte
=   cpx vbyte
=   cpx #31
=   txa
=   ldy vbyte
=   cpy vbyte
=   cpy #32
=   tya
=   sta vbyte
=   sta table, x
=   sta table, y
=   sta (vword), y
=   sta vword
=   sta vword+1
=   dec vbyte
=   clc
=   cld
=   clv
=   sec
=   sed
=   adc #8
=   adc vbyte
=   and #8
=   and vbyte
=   sbc #8
=   sbc vbyte
=   ora #8
=   ora vbyte
=   rts
= 
= vword: .word 0
= vbyte: .byte 0
= .alias table 1024

| reserve word vword
| reserve byte vbyte
| assign byte table table 1024
| routine main {
|    asl .a
|    asl vbyte
|    lsr .a
|    lsr vbyte
|    rol .a
|    rol vbyte
|    ror .a
|    ror vbyte
|    bit vbyte
|    eor #5
|    eor vbyte
| }
= main:
=   asl
=   asl vbyte
=   lsr
=   lsr vbyte
=   rol
=   rol vbyte
=   ror
=   ror vbyte
=   bit vbyte
=   eor #5
=   eor vbyte
=   rts
= 
= vword: .word 0
= vbyte: .byte 0
= .alias table 1024

| routine main {
|    pha {
|        sei {
|            php {
|                lda #0
|            }
|            lda #1
|        }
|        lda #2
|    }
| }
= main:
=   pha
=   sei
=   php
=   lda #0
=   plp
=   lda #1
=   cli
=   lda #2
=   pla
=   rts