core: remove cpHLDE

It wasn't used much, so I replaced its use in the kernel with direct code
and moved the routine in apps/ed, the only other place where it was used.
This commit is contained in:
Virgil Dupras 2019-12-12 15:53:14 -05:00
parent c002c69208
commit 4f7a05e3b7
7 changed files with 65 additions and 42 deletions

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@ -33,6 +33,7 @@
.inc "core.asm"
.inc "lib/util.asm"
.inc "lib/parse.asm"
.inc "ed/util.asm"
.equ IO_RAMSTART USER_RAMSTART
.inc "ed/io.asm"
.equ BUF_RAMSTART IO_RAMEND

8
apps/ed/util.asm Normal file
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@ -0,0 +1,8 @@
; Compare HL with DE and sets Z and C in the same way as a regular cp X where
; HL is A and DE is X.
cpHLDE:
push hl
or a ;reset carry flag
sbc hl, de ;There is no 'sub hl, de', so we must use sbc
pop hl
ret

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@ -57,15 +57,6 @@ intoIX:
pop ix
ret
; Compare HL with DE and sets Z and C in the same way as a regular cp X where
; HL is A and DE is X.
cpHLDE:
push hl
or a ;reset carry flag
sbc hl, de ;There is no 'sub hl, de', so we must use sbc
pop hl
ret
; Write the contents of HL in (DE)
; de and hl are preserved, so no pushing/popping necessary
writeHLinDE:

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@ -413,17 +413,17 @@ fsPlaceH:
; Sets Z according to whether HL is within bounds for file handle at (IX), that
; is, if it is smaller than file size.
fsWithinBounds:
push de
; file size
ld e, (ix+4)
ld d, (ix+5)
call cpHLDE
pop de
jr nc, .outOfBounds ; HL >= DE
ld a, h
cp (ix+5)
jr c, .within ; H < (IX+5)
jp nz, unsetZ ; H > (IX+5)
; H == (IX+5)
ld a, l
cp (ix+4)
jp nc, unsetZ ; L >= (IX+4)
.within:
cp a ; ensure Z
ret
.outOfBounds:
jp unsetZ ; returns
; Set size of file handle (IX) to value in HL.
; This writes directly in handle's metadata.

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@ -13,8 +13,10 @@
_mmapAddr:
push de
ld de, MMAP_LEN
call cpHLDE
or a ; reset carry flag
sbc hl, de
jr nc, .outOfBounds ; HL >= DE
add hl, de ; old HL value
ld de, MMAP_START
add hl, de
cp a ; ensure Z

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@ -5,8 +5,6 @@
jp test
.inc "core.asm"
dummyLabel:
testNum: .db 1
@ -48,30 +46,11 @@ test:
; test that "@" is updated by a .org directive
ld hl, AFTER_ORG
ld de, 0x1234
call cpHLDE
or a ; clear carry
sbc hl, de
jp nz, fail
call nexttest
; *** cpHLDE ***
ld hl, 0x42
ld de, 0x42
call cpHLDE
jp nz, fail
jp c, fail
call nexttest
ld de, 0x4242
call cpHLDE
jp z, fail
jp nc, fail
call nexttest
ld hl, 0x4243
call cpHLDE
jp z, fail
jp c, fail
call nexttest
; success
xor a
halt

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@ -0,0 +1,42 @@
jp test
.inc "ed/util.asm"
test:
ld sp, 0xffff
; *** cpHLDE ***
ld hl, 0x42
ld de, 0x42
call cpHLDE
jp nz, fail
jp c, fail
call nexttest
ld de, 0x4242
call cpHLDE
jp z, fail
jp nc, fail
call nexttest
ld hl, 0x4243
call cpHLDE
jp z, fail
jp c, fail
call nexttest
; success
xor a
halt
testNum: .db 1
nexttest:
ld a, (testNum)
inc a
ld (testNum), a
ret
fail:
ld a, (testNum)
halt