diff options
Diffstat (limited to 'programs/sub-suite/tmp-stuff/free-old.s')
| -rw-r--r-- | programs/sub-suite/tmp-stuff/free-old.s | 200 |
1 files changed, 200 insertions, 0 deletions
diff --git a/programs/sub-suite/tmp-stuff/free-old.s b/programs/sub-suite/tmp-stuff/free-old.s new file mode 100644 index 0000000..7f75edd --- /dev/null +++ b/programs/sub-suite/tmp-stuff/free-old.s @@ -0,0 +1,200 @@ +.include "declare.s" + +.org 0 + +; free: Free allocated memory. +; Input: A = Pointer to allocated memory. +; Output: none. +; Caller preserved registers: none. +; Callie preserved registers: A, B, Y. + +free: + pha.q ; Preserve A. + phb.q ; Preserve B. + phy.q ; Preserve Y. + pha.q ; Push the pointer argument to the stack. + and #0 ; Reset A. + tay ; Reset Y. + sbs #$18 ; Allocate 3 local variables onto the stack. + lda.q sp+25 ; Get the passed pointer. + ora.d sp+29 ; Is the passed pointer NULL? + bne @getrealblk ; No, so get the real block. + bra @end ; Yes, so we're done. +@getrealblk: + lda.q sp+25 ; Get the passed pointer. + sec ; Prepare for a non borrowing subtract. + sbc #8 ; Move the passed pointer back by one. + sta.q sp+25 ; Set the first local variable to the start of the used block. + lda.q (sp+25) ; Get the real block address. + sta.q sp+25 ; Set the passed pointer to the start of the real block. + ldy #ublk.size ; Get the size of the real block. + lda.q (sp+25), y; + sta.q sp+17 ; Save the size of the real block. + clc ; Prepare for a non carrying add. + adc.q sp+25 ; Add the size of the real block with the start of the real block. + cmp.q heapptr ; Is this block on top of the heap? + bne @heapadd ; No, so add it to the free block list. +@dectop: + lda.q sp+25 ; Get the block. + sta.q heapptr ; Set the top of the heap to it. +@chklastblk: + lda.q heapl ; Get the last free list entry. + sta.q sp+17 ; Copy it into the second local variable. + ora.d sp+21 ; Is the free list empty? + beq @end ; Yes, so we're done. + lda.q sp+17 ; No, so Get the last free list entry. + ldy #fblk.size ; Get the size of the block. + lda.q (sp+17), y; + clc ; Prepare for a non carrying add. + adc.q sp+17 ; Add the size of the block, with the address of the block entry. + cmp.q heapptr ; Is the last block on top of the heap? + bne @end ; No, so we're done. +@delblk: + lda.q sp+17 ; Yes, so remove the last block. + sta.q heapptr ; +@correctblk: + ldy #fblk.prev ; Get the previous block. + lda.q (sp+17), y; + sta.q sp+25 ; Save the previous block for now. + sta.q heapl ; Set the last block to the previous block. + ora.d sp+29 ; Is the previous block non NULL? + bne @delnxtblk ; Yes, so delete the next block. + sta.q heapf ; No, so empty the free list. + bra @end ; We are done. +@delnxtblk: + and #0 ; Reset A. + ldy #fblk.next ; Delete the next block. + sta.q (sp+25), y; +@end: + ads #$20 ; Clean up the stack frame. + ply.q ; Restore Y. + plb.q ; Restore B. + pla.q ; Restore A. + rts ; End of free. + + +@heapadd: + lda.q heapf ; Get the first block. + sta.q sp+9 ; Copy it into the third local variable. + ora.d sp+13 ; Is the free list empty? + bne @srchflst ; No, so start searching the free list. +@empty: + ldy #fblk.next ; Clear the next block. + sta.q (sp+25), y; + ldy #fblk.prev ; Clear the previous block. + sta.q (sp+25), y; + lda.q sp+25 ; Reset A. + sta.q heapf ; Clear the first block entry. + sta.q heapf ; Clear the last block entry. + bra @end ; We are done. +@srchflst: + and #0 ; Reset A. + sta.q sp+1 ; Reset the left pointer. + ldy #fblk.next ; Setup for the loop. +@loop: + lda.q sp+9 ; Get the right pointer. + cmp.q sp+25 ; Is the right pointer at, or below the current block? + beq @nextright ; Yes, so get the next right pointer. + bcs @chkrmerge ; No, so do the right block merge. +@nextright: + sta.q sp+1 ; Set the left pointer, to the right pointer. + lda.q (sp+9), y ; Get the next right pointer. + sta.q sp+9 ; Set the current right pointer to the next right pointer. + ora.d sp+13 ; Is the next right pointer NULL? + bne @loop ; No, so keep looping. +@st_lmerge2: + sta.q (sp+25), y; Clear the next block. + lda.q sp+25 ; Get the current block. + sta.q heapl ; Set the last free block entry to it. + bra @chklmerge2 ; Do the left block merge. +@chkrmerge: + lda.q sp+25 ; Get the current block. + clc ; Prepare for a non carrying add. + adc.q sp+17 ; Add the size of the current block, to the current block. + cmp.q sp+9 ; Is the right pointer NULL? + bne @normerge ; No, so don't merge the right block. +@rmerge: + ldy #fblk.size ; Get the size of the right pointer. + lda.q sp+17 ; Get the size of the current block. + clc ; Prepare for a non carrying add. + adc.q (sp+9), y ; Add the size of the current block, with the size of the right pointer. + sta.q (sp+25), y; Set the size of the current block, to the new size. +@rmerge2: + ldy #fblk.next ; Get the next right pointer. + lda.q (sp+9), y ; + sta.q (sp+25), y; Set the next block, to the next right pointer. + sta.q sp+17 ; Save the next block in the second local variable. + ora.d sp+21 ; Is the next block NULL? + beq @setheapl ; Yes, so set the last block. +@setprev: + lda.q sp+25 ; Get the current block. + ldy #fblk.prev ; Set the previous block to the current block. + sta.q (sp+17), y; + bra @chklmerge ; Do the left block merge. +@setheapl: + lda.q sp+25 ; Get the current block. + sta.q heapl ; Set the last block to the current block. + bra @chklmerge ; Do the left block merge. +@normerge: + lda.q sp+9 ; Get the right pointer. + ldy #fblk.next ; Set the next block to the right pointer. + sta.q (sp+25), y; + lda.q sp+25 ; Get the current block. + ldy #fblk.prev ; Set the previous right pointer to the current block. + lda.q (sp+9), y ; +@chklmerge: + lda.q sp+1 ; Get the left pointer. + ora.d sp+5 ; Is the left pointer NULL? + bne @chklmerge2 ; No, so keep checking. +@newstart: + ldy #fblk.prev ; Clear the previous block. + sta.q (sp+25), y; + lda.q sp+25 ; Get the current block. + sta.q heapf ; Set the first block, to the current block. + bra @end2 ; We are done. +@chklmerge2: + ldy #fblk.size ; Get the size of the left block. + lda.q (sp+1), y ; + clc ; Prepare for a non carrying add. + adc.q sp+1 ; Add the size of the left block, to the left pointer. + cmp.q sp+25 ; Is the left block adjacent? + bne @nolmerge ; No, so don't merge the left block. +@lmerge: + lda.q (sp+1), y ; Get the size of the left block. + clc ; Prepare for a non carrying add. + ldb.q (sp+25), y; Get the size of the current block. + adc b ; Add the size of the left block, with the size of the current block. + sta.q (sp+1), y ; Set the size of the left block to the new size. +@lmerge2: + ldy #fblk.next ; Get the next block. + lda.q (sp+25), y; + sta.q (sp+1), y ; Set the next left pointer, to the next block. + sta.q sp+17 ; Set the second local variable to the next block. + ora.d sp+21 ; Is the next left pointer NULL? + beq @newlast ; Yes, so set the last block. +@lprev: + lda.q sp+1 ; Get the left pointer. + ldy #fblk.prev ; Set the next left pointer's previous pointer to the left pointer. + sta.q (sp+17), y; + bra @end2 ; We are done. +@newlast: + lda.q sp+1 ; Get the left pointer. + sta.q heapl ; Set the last block, to the left pointer. + bra @end2 ; We are done. +@nolmerge: + lda.q sp+25 ; Get the current block. + ldy #fblk.next ; Set the next left pointer, to the current block. + sta.q (sp+1), y ; +@nolmerge2: + lda.q sp+1 ; Get the left pointer. + ldy #fblk.prev ; Set the previous block, to the left pointer. + sta.q (sp+25), y; +@end2: + ads #$20 ; Clean up the stack frame. + ply.q ; Restore Y. + plb.q ; Restore B. + pla.q ; Restore A. + rts ; End of free. + +a +q |