On 11 okt '12, Jonas Maebe wrote:
> As mentioned before, it not only depends on the platform, but also on the contents of the object/record. E.g., a badly misaligned double will generally give much worse performance even on Intel. > >> This makes me wonder if >> choosing a proper value for $PACKRECORDS could make my file readable >> safely on all platforms, only needing to convert the endianess if >> applicable. This would not force me to do manual padding in my structs. >> Say I use a value of 16 would that cover all ABI's FPC currently >> supports? > > Yes. So misalignment of for instance a double (or whatever type) will only happen if the record is packed and the packed value is smaller than what the ABI prescribes, correct? Let's assume I set the record to packed 16bytes, this would make reading and writing records as a whole safe on all platform/architecture combinations right? Apart from a few padding bytes, what are the performance penalties of doing this then? Why would there be penalties? Darius
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