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Move _heap.h to the compiler include dir.

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Create heap.inc and use that from the assembler code.
Rename heap related _h... variables to _heap...
Add _heapmaxavail and _heapmemavail functions.


git-svn-id: svn://svn.cc65.org/cc65/trunk@1912 b7a2c559-68d2-44c3-8de9-860c34a00d81
This commit is contained in:
cuz
2003-02-01 12:22:09 +00:00
parent 8012074ea0
commit 581c12ce40
11 changed files with 422 additions and 246 deletions
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155
libsrc/common/malloc.s
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@@ -106,50 +106,43 @@
.importzp ptr1, ptr2, ptr3
.import __hptr, __hfirst, __hlast, __hend
.export _malloc
.include "_heap.inc"
.macpack generic
; Offsets into struct freeblock and other constant stuff
size = 0
next = 2
prev = 4
admin_space = 2
min_size = 6
;-----------------------------------------------------------------------------
; Code
_malloc:
sta ptr1 ; Store size in ptr1
sta ptr1 ; Store size in ptr1
stx ptr1+1
; Check for a size of zero, if so, return NULL
ora ptr1+1
beq Done ; a/x already contains zero
beq Done ; a/x already contains zero
; Add the administration space and round up the size if needed
lda ptr1
add #admin_space
add #HEAP_ADMIN_SPACE
sta ptr1
bcc @L1
inc ptr1+1
@L1: ldx ptr1+1
bne @L2
cmp #min_size+1
cmp #HEAP_MIN_BLOCKSIZE+1
bcs @L2
lda #min_size
sta ptr1 ; High byte is already zero
lda #HEAP_MIN_BLOCKSIZE
sta ptr1 ; High byte is already zero
; Load a pointer to the freelist into ptr2
@L2: lda __hfirst
@L2: lda __heapfirst
sta ptr2
lda __hfirst+1
lda __heapfirst+1
sta ptr2+1
; Search the freelist for a block that is big enough. We will calculate
@@ -157,21 +150,21 @@ _malloc:
jmp @L4
@L3: ldy #size
@L3: ldy #freeblock_size
lda (ptr2),y
sub ptr1
tax ; Remember low byte for later
iny ; Y points to size+1
tax ; Remember low byte for later
iny ; Y points to freeblock_size+1
lda (ptr2),y
sbc ptr1+1
bcs BlockFound ; Beware: Contents of a/x/y are known!
bcs BlockFound ; Beware: Contents of a/x/y are known!
; Next block in list
iny ; Points to next
iny ; Points to freeblock_next
lda (ptr2),y
tax
iny ; Points to next+1
iny ; Points to freeblock_next+1
lda (ptr2),y
stx ptr2
sta ptr2+1
@@ -180,16 +173,16 @@ _malloc:
; We did not find a block big enough. Try to use new space from the heap top.
lda __hptr
add ptr1 ; _hptr + size
lda __heapptr
add ptr1 ; _heapptr + size
tay
lda __hptr+1
lda __heapptr+1
adc ptr1+1
bcs OutOfHeapSpace ; On overflow, we're surely out of space
bcs OutOfHeapSpace ; On overflow, we're surely out of space
cmp __hend+1
cmp __heapend+1
bne @L5
cpy __hend
cpy __heapend
@L5: bcc TakeFromTop
beq TakeFromTop
@@ -199,18 +192,18 @@ OutOfHeapSpace:
lda #0
tax
Done: rts
; There is enough space left, take it from the heap top
TakeFromTop:
ldx __hptr ; p = hptr;
ldx __heapptr ; p = _heapptr;
stx ptr2
ldx __hptr+1
ldx __heapptr+1
stx ptr2+1
sty __hptr ; hptr += size;
sta __hptr+1
jmp FillSizeAndRet ; Done
sty __heapptr ; _heapptr += size;
sta __heapptr+1
jmp FillSizeAndRet ; Done
; We found a block big enough. If the block can hold just the
; requested size, use the block in full. Beware: When slicing blocks,
@@ -220,73 +213,73 @@ TakeFromTop:
; flag is set if the high byte of this remaining size is zero.
BlockFound:
bne SliceBlock ; Block is large enough to slice
cpx #min_size+1 ; Check low byte
bcs SliceBlock ; Jump if block is large enough to slice
bne SliceBlock ; Block is large enough to slice
cpx #HEAP_MIN_BLOCKSIZE+1 ; Check low byte
bcs SliceBlock ; Jump if block is large enough to slice
; The block is too small to slice it. Use the block in full. The block
; does already contain the correct size word, all we have to do is to
; remove it from the free list.
ldy #prev+1 ; Load f->prev
ldy #freeblock_prev+1 ; Load f->prev
lda (ptr2),y
sta ptr3+1
dey
lda (ptr2),y
sta ptr3
dey ; Points to next+1
dey ; Points to freeblock_next+1
ora ptr3+1
beq @L1 ; Jump if f->prev zero
beq @L1 ; Jump if f->prev zero
; We have a previous block, ptr3 contains its address.
; Do f->prev->next = f->next
lda (ptr2),y ; Load high byte of f->next
sta (ptr3),y ; Store high byte of f->prev->next
dey ; Points to next
lda (ptr2),y ; Load low byte of f->next
sta (ptr3),y ; Store low byte of f->prev->next
lda (ptr2),y ; Load high byte of f->next
sta (ptr3),y ; Store high byte of f->prev->next
dey ; Points to next
lda (ptr2),y ; Load low byte of f->next
sta (ptr3),y ; Store low byte of f->prev->next
jmp @L2
; This is the first block, correct the freelist pointer
; Do _hfirst = f->next
@L1: lda (ptr2),y ; Load high byte of f->next
sta __hfirst+1
dey ; Points to next
lda (ptr2),y ; Load low byte of f->next
sta __hfirst
@L1: lda (ptr2),y ; Load high byte of f->next
sta __heapfirst+1
dey ; Points to next
lda (ptr2),y ; Load low byte of f->next
sta __heapfirst
; Check f->next. Y points always to next if we come here
@L2: lda (ptr2),y ; Load low byte of f->next
@L2: lda (ptr2),y ; Load low byte of f->next
sta ptr3
iny ; Points to next+1
lda (ptr2),y ; Load high byte of f->next
iny ; Points to next+1
lda (ptr2),y ; Load high byte of f->next
sta ptr3+1
iny ; Points to prev
iny ; Points to prev
ora ptr3
beq @L3 ; Jump if f->next zero
beq @L3 ; Jump if f->next zero
; We have a next block, ptr3 contains its address.
; Do f->next->prev = f->prev
lda (ptr2),y ; Load low byte of f->prev
sta (ptr3),y ; Store low byte of f->next->prev
iny ; Points to prev+1
lda (ptr2),y ; Load high byte of f->prev
sta (ptr3),y ; Store high byte of f->prev->next
jmp RetUserPtr ; Done
lda (ptr2),y ; Load low byte of f->prev
sta (ptr3),y ; Store low byte of f->next->prev
iny ; Points to prev+1
lda (ptr2),y ; Load high byte of f->prev
sta (ptr3),y ; Store high byte of f->prev->next
jmp RetUserPtr ; Done
; This is the last block, correct the freelist pointer.
; Do _hlast = f->prev
@L3: lda (ptr2),y ; Load low byte of f->prev
sta __hlast
iny ; Points to prev+1
lda (ptr2),y ; Load high byte of f->prev
sta __hlast+1
jmp RetUserPtr ; Done
@L3: lda (ptr2),y ; Load low byte of f->prev
sta __heaplast
iny ; Points to prev+1
lda (ptr2),y ; Load high byte of f->prev
sta __heaplast+1
jmp RetUserPtr ; Done
; We must slice the block found. Cut off space from the upper end, so we
; can leave the actual free block chain intact.
@@ -295,23 +288,23 @@ SliceBlock:
; Decrement the size of the block. Y points to size+1.
dey ; Points to size
lda (ptr2),y ; Low byte of f->size
dey ; Points to size
lda (ptr2),y ; Low byte of f->size
sub ptr1
sta (ptr2),y
tax ; Save low byte of f->size in X
iny ; Points to size+1
lda (ptr2),y ; High byte of f->size
tax ; Save low byte of f->size in X
iny ; Points to size+1
lda (ptr2),y ; High byte of f->size
sbc ptr1+1
sta (ptr2),y
; Set f to the space above the current block, which is the new block returned
; to the caller.
txa ; Get low byte of f->size
txa ; Get low byte of f->size
add ptr2
tax
lda (ptr2),y ; Get high byte of f->size
lda (ptr2),y ; Get high byte of f->size
adc ptr2+1
stx ptr2
sta ptr2+1
@@ -319,17 +312,17 @@ SliceBlock:
; Fill the size into the admin space of the block and return the user pointer
FillSizeAndRet:
ldy #size ; *p = size;
lda ptr1 ; Low byte of block size
ldy #freeblock_size ; *p = size;
lda ptr1 ; Low byte of block size
sta (ptr2),y
iny ; Points to size+1
iny ; Points to freeblock_size+1
lda ptr1+1
sta (ptr2),y
RetUserPtr:
lda ptr2 ; return ++p;
lda ptr2 ; return ++p;
ldx ptr2+1
add #admin_space
add #HEAP_ADMIN_SPACE
bcc @L9
inx
@L9: rts