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Old 11 January 2020, 18:13   #2
Samurai_Crow
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Quote:
Originally Posted by sparhawk View Post
When I call an assembler function, d0/d1 and a0/a1 don't need to be saved?


The first four params are passed in d0/d1 and a0/a1, or does this depend on wether it's a pointer or value?


Is there some compiler hint to tell the compiler which registers a param might be expected in?
D0/D1/A0/A1 are scratch registers so yes. All other registers need to be preserved.

Whether it's a pointer or not matters.

Yes, GCC has register directives for passing parameters in to subroutines and especially inline Assembly.
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