Yesterday, 21:16 | #1 |
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C-code translated to assembler
I understannd much of C code, but not all.
While I tried to use the gadtools.library, I stumbled over this: Code:
struct Gadget *glist = NULL; gad = CreateContext(&glist); How does the similar code look in assmbler? Like this? Code:
lea glist(pc),a0 clr.l (a0) CALLGADTOOLS CreateContext glist DS.B gg_SIZEOF Code:
sub.l a0,a0 CALLGADTOOLS CreateContext Last edited by dissident; Yesterday at 21:23. |
Yesterday, 21:35 | #2 |
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The first snippet is correct.
glist should be ds.l 1 for proper alignment. Or dc.l 0, then you don't need the clr.l (a0). |
Yesterday, 21:36 | #3 |
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Globals are set to 0 or null at startup due to being initialized with MEMF_CLEAR but the NULL assignment is just making sure there is no phantom data in memory. The assignment should reduce out to nothing.
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Yesterday, 21:39 | #4 |
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It's a pointer to pointer, so it's the former (NULL is overwritten with a valid pointer on return, if successful). Passing a0=0 would be equivalent to CreateContext(NULL) and result in address 0 being trashed ("NULL ptr problem").
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Yesterday, 22:08 | #5 |
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Thx for your quick replies. Now I understand it much better.
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