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cc65/libsrc/common/_heapadd.s
2022-08-29 19:55:48 +02:00

53 lines
1.3 KiB
ArmAsm

;
; Ullrich von Bassewitz, 21.7.2000
;
; Add a block to the heap free list
;
; void __fastcall__ _heapadd (void* mem, size_t size);
;
;
.importzp ptr1, ptr2
.import popax
.import heapadd
.export ___heapadd
.include "_heap.inc"
.macpack generic
;-----------------------------------------------------------------------------
; Code
___heapadd:
sta ptr1 ; Store size in ptr1
stx ptr1+1
jsr popax ; Get the block pointer
sta ptr2
stx ptr2+1 ; Store block pointer in ptr2
; Check if size is greater or equal than min_size. Otherwise we don't care
; about the block (this may only happen for user supplied blocks, blocks
; from the heap are always large enough to hold a freeblock structure).
lda ptr1 ; Load low byte
ldx ptr1+1 ; Load/check high byte
bne @L1
cmp #HEAP_MIN_BLOCKSIZE
bcs @L1
rts ; Block not large enough
; The block is large enough. Set the size field in the block.
@L1: ldy #usedblock::size
sta (ptr2),y
iny
txa
sta (ptr2),y
; Call the internal function since variables are now setup correctly
jmp heapadd