Skip to content

Parser size opts #130

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
dmsc merged 7 commits into from
Oct 22, 2026
Merged

Parser size opts #130

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
7 commits
Select commit Hold shift + click to select a range
4cdb225
Simplify name_new in vars.asm (-9 bytes)
dmsc Oct 22, 2026
7df79fc
Emit FR0 with a loop in E_NUMBER_FP (-10 bytes in FP builds)
dmsc Oct 22, 2026
78f71a1
Share loop-popping tail and use bcc for check_loop_exit (-8 bytes)
dmsc Oct 22, 2026
5a9ec9c
Count Y down in add_laddr_list and remove unreachable rts (-2 bytes)
dmsc Oct 22, 2026
5a85a7a
Clear pptr+1 in zp_clear and push it in parser_sub (-2 bytes)
dmsc Oct 22, 2026
1823fc4
Use move_source from alloc_laddr in add_laddr_list (-8 bytes)
dmsc Oct 22, 2026
ec3c8a2
Fall through from E_LABEL_DEF to add_laddr_list (-2 bytes)
dmsc Oct 22, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
218 changes: 104 additions & 114 deletions src/actions.asm
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -38,10 +38,12 @@
.import read_word
; From vars.asm
.import var_search, name_new, label_search
.importzp var_namelen, label_count, var_count
.importzp label_count, var_count
; From alloc.asm
.import alloc_laddr
.importzp prog_ptr, laddr_ptr, laddr_buf, var_ptr, label_ptr
; From interpreter.asm
.importzp move_source
; From parser.asm
.import parser_error, parser_skipws, parser_emit_byte, parser_inc_opos
; From error.asm
Expand Down Expand Up @@ -300,60 +302,15 @@ cbyte: stx tmp2+1
.proc E_NUMBER_FP
jsr read_fp
bcs E_CONST_STRING::xrts
lda FR0
ldx FR0+1
jsr emit_AX
lda FR0+2
ldx FR0+3
jsr emit_AX
lda FR0+4
ldx FR0+5
jmp emit_AX
.endproc
.endif ; FASTBASIC_FP

; Variable matching.
; The parser calls the routine to check if there is a variable
; with the correct type
.proc E_VAR_SEARCH
jsr get_last_tok ; Get variable TYPE from last token
.byte $2C ; Skip 2 bytes over next "LDA"
.endproc ; Fall through
.proc E_VAR_WORD
lda #VT_WORD
sta tmp3 ; Store variable type
; Check if we have a valid name - this exits on error!
; Search existing var
jsr var_search
bcs exit
cmp tmp3
beq emit_varn
not_found:
sec
exit:
ldx #256-6
loop:
lda <(FR0 - 250), x
jsr parser_emit_byte
inx
bne loop
rts
.endproc

; Creates a new variable, with no type (the type will be set by parser next)
.proc E_VAR_CREATE
; Check if we have a valid name - this exits on error!
; Search existing var
jsr var_search
bcc E_VAR_WORD::not_found ; Exit with error if already exists
; Create new variable - exits on error
ldx #var_ptr - prog_ptr
jsr name_new
ldx var_count
inc var_count
; Fall through
.endproc
; Emits the variable, advancing pointers.
.proc emit_varn
; Store VARN
txa
clc
jmp parser_emit_byte
.endproc
.endif ; FASTBASIC_FP

; Sets the type of a variable - variable number and new type must be in the stack:
.proc E_VAR_SET_TYPE
Expand Down Expand Up @@ -473,34 +430,48 @@ xit: rts
bne comp ; Assume laddr_buf+1 is never 0
.endproc

; Adds a label address pointer to the list
.proc add_laddr_list
pha

lda laddr_ptr
sta tmp2
lda laddr_ptr+1
sta tmp2+1

lda #4
jsr alloc_laddr

ldy #0
lda laddr_search_num
sta (tmp2), y

pla
; Variable matching.
; The parser calls the routine to check if there is a variable
; with the correct type
.proc E_VAR_SEARCH
jsr get_last_tok ; Get variable TYPE from last token
.byte $2C ; Skip 2 bytes over next "LDA"
.endproc ; Fall through
.proc E_VAR_WORD
lda #VT_WORD
sta tmp3 ; Store variable type
; Check if we have a valid name - this exits on error!
; Search existing var
jsr var_search
bcs exit
cmp tmp3
beq emit_varn
::xit_label_err:
not_found:
sec
exit:
rts
.endproc

iny
sta (tmp2), y
jsr get_codep
ldy #3
sta (tmp2), y
dey
; Creates a new variable, with no type (the type will be set by parser next)
.proc E_VAR_CREATE
; Check if we have a valid name - this exits on error!
; Search existing var
jsr var_search
bcc E_VAR_WORD::not_found ; Exit with error if already exists
; Create new variable - exits on error
ldx #var_ptr - prog_ptr
jsr name_new
ldx var_count
inc var_count
; Fall through
.endproc
; Emits the variable, advancing pointers.
.proc emit_varn
; Store VARN
txa
sta (tmp2), y
; clc ; get_codep clears carry
xit: rts
clc
jmp parser_emit_byte
.endproc

; Pushes the PROC/DATA loop, search, create a label and define the location
Expand Down Expand Up @@ -533,7 +504,49 @@ cloop: bmi xit_label_err
; No more entries, adds our address as a "definition" (A = 128)
nfound:
lda #128
bmi add_laddr_list
.endproc ; Fall through

; Adds a label address pointer to the list
; Note: relies on alloc_laddr expanding laddr_ptr = mem_end, where move_dwn is
; called with length = 0 and returns with move_source unchanged (pointing to
; the newly allocated 4-byte slot).
.proc add_laddr_list
pha

lda #4
jsr alloc_laddr

jsr get_codep
ldy #3
sta (move_source), y
dey
txa
sta (move_source), y
dey
pla
sta (move_source), y
dey
lda laddr_search_num
sta (move_source), y
; clc ; get_codep clears carry
xit: rts
.endproc

; Label search and create if not exists
.proc E_LABEL_CREATE
jsr label_search
txa
jsr push_var ; Does not modify C
; Already defined, just store index
bcc E_VAR_WORD::exit

do_create:
; Create a new label
ldx #label_ptr - prog_ptr
jsr name_new
inc label_count
clc
rts
.endproc

; Label search on use
Expand All @@ -543,15 +556,14 @@ nfound:

; Check if we have a valid name - this exits on error!
jsr label_search
bcs xit
bcs E_VAR_WORD::exit

; Check if type is compatible
cmp tmp3
beq start_searching
::xit_label_err:
sec
xit: rts
bne xit_label_err

; Search the label address in the label list (X = label index)
beq start_searching
; Get EXEC label address and store - this is split because we first parse the
; label (and create it if needed), then parse arguments and at last emit the
; call address
Expand All @@ -577,25 +589,6 @@ cloop:
nfound: lda #0
jsr add_laddr_list
bcc emit_addr
ret: rts
.endproc

; Label search and create if not exists
.proc E_LABEL_CREATE
jsr label_search
txa
jsr push_var ; Does not modify C
; Already defined, just store index
bcc ret

do_create:
; Create a new label
ldx #label_ptr - prog_ptr
jsr name_new
inc label_count
clc
ret: rts

.endproc

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
Expand Down Expand Up @@ -744,7 +737,7 @@ bad_return:
jsr pop_codep::get
jsr patch_codep
; And check for more possible EXIT's
jmp check_loop_exit
bcc check_loop_exit
.endproc

.proc E_EXIT_LOOP
Expand Down Expand Up @@ -796,16 +789,13 @@ move:
lda #LT_WHILE_2
; Save current position
jsr pop_patch_codep
; Pop saved "loop reentry" position
lda #LT_WHILE_1
; And store
dec opos
dec opos
jsr pop_emit_addr
; Checks for an "EXIT"
jmp check_loop_exit
.endproc

; Pop saved "loop reentry" position
lda #LT_WHILE_1
.byte $2C ; Skip 2 bytes over next "LDA"
.endproc ; Fall through
.proc E_POP_LOOP
; Pop saved position, store
lda #LT_DO_LOOP
Expand All @@ -816,7 +806,7 @@ move:
lda #LT_REPEAT
jsr pop_emit_addr
; Checks for an "EXIT"
jmp check_loop_exit
bcc check_loop_exit
.endproc

.proc E_POP_FOR
Expand All @@ -831,7 +821,7 @@ move:
; Save current position
jsr pop_patch_codep
; Checks for an "EXIT"
jmp check_loop_exit
bcc check_loop_exit
.endproc

.proc E_POP_IF
Expand Down
4 changes: 4 additions & 0 deletions src/alloc.asm
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -94,6 +94,10 @@ alloc_size= tmp1
.endproc ; Fall through

.proc alloc_laddr
; Note: add_laddr_list relies on laddr_ptr being at mem_end (so the
; move length is 0 and move_dwn leaves move_source pointing to the old
; laddr_ptr; if length != 0, move_dwn returns move_source - 1).
.assert laddr_ptr = mem_end, error, "laddr_ptr must be at mem_end"
ldx #laddr_ptr - mem_start
.endproc ; Fall through

Expand Down
12 changes: 6 additions & 6 deletions src/parse.asm
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -50,11 +50,12 @@
.segment "IDEZP": zeropage
buf_ptr:.res 2
bmax: .res 1
pptr: .res 2
parse_err: .res 1 ; Error to report if the statement does not parse
pptr: .res 1

; This variables are cleared in one loop:
zp_clear_start:
.res 1 ; pptr+1
opos: .res 1
linenum: .res 2
loop_sp: .res 1
Expand Down Expand Up @@ -260,16 +261,16 @@ ucase_end:
inc buf_ptr+1
:

lda #0
parse_start:
; Parse statement, A=0 on input
; Parse statement, pptr+1=0 on input
ldx #ERR_PARSE
stx parse_err
ldx #<(PARSE_START-1)
ldy #>(PARSE_START-1)

; Parser sub
parser_sub:
lda pptr+1
pha
lda pptr
pha
Expand Down Expand Up @@ -339,7 +340,6 @@ pcall:
bcc pcall_ml

tay
lda pptr+1
bcs parser_sub ; Jump always

pemit_ret:
Expand All @@ -362,14 +362,14 @@ pexit_ok:
inc bpos
lda (bptr), y
eor #':' ; Colon: continue parsing line
beq parse_start ; jump with A=0
beq parse_start

; Current syntax file always checks for EOL at the end of parsing,
; no need to check here
; eor #$9B^':'
; bne set_parse_error

; End parsing of current line, jump with A=0
; End parsing of current line
jmp parse_line

; Calls a machine-language subroutine
Expand Down
Loading
Loading