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65 lines
1.1 KiB
ArmAsm
65 lines
1.1 KiB
ArmAsm
;
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; Ullrich von Bassewitz, 15.11.2001
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;
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; Allocate a block and zero it.
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;
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; void* __fastcall__ calloc (size_t count, size_t size);
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;
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.export _calloc
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.import _malloc, _memset
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.import tosumulax, pushax, push0
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; -------------------------------------------------------------------------
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.proc _calloc
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; We have the first argument in a/x and the second on the stack. Calling
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; tosumulax will give the product of both in a/x.
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jsr tosumulax
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; Save size for later
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sta Size
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stx Size+1
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; malloc() is a fastcall function, so we do already have the argument in
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; the right place
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jsr _malloc
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; Check for a NULL pointer
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cpx #0
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bne ClearBlock
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cmp #0
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beq ClearBlock
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; We have a NULL pointer, bail out
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rts
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; No NULL pointer, clear the block. memset will return a pointer to the
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; block which is exactly what we want.
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ClearBlock:
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jsr pushax ; ptr
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jsr push0 ; #0
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lda Size
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ldx Size+1 ; Size
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jmp _memset
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.endproc
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; -------------------------------------------------------------------------
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; Data
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.bss
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Size: .res 2
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