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From: Florian K. <fl...@ei...> - 2014-03-22 15:19:11
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On 03/22/2014 08:51 AM, Domingues Luis Filipe wrote: > Hello, > > I'm using dirty-calls on a tool I'm building. And I want to know what's > the limitations of the parameters for dirty-calls (Types, how many...) The answer depends on the architecture you're using. E.g. for x86-64 you may pass up to 6 arguments; for s390 you may pass up to 5. In general, minimising the number of arguments of a helper call is a good idea because instruction selection will often generate register-to-register moves for the arguments and the register allocator does not do a very good job throwing them out. Take a look at VEX/priv/host_ARCH_isel.c to find out what is allowed for the architecture you have in mind. Search for Ist_Dirty. AFAIK only integer arguments are allowed. Florian |