> IMHO that would be useful to establish the current state of the patch set from > a performance standpoint, especially since you've added code intended to > mitigate the regression.
Ok. > +#define COMP_CRC32C_SMALL(crc, data, len) \ > + ((crc) = pg_comp_crc32c_sse42((crc), (data), (len))) > > My interpretation of Andres's upthread suggestion is that we'd add the length > check within the macro instead of introducing a separate one. We'd expect > the compiler to optimize out comparisons for small lengths known at compile > time and always call the existing implementation (which may still involve a > function pointer in most cases). How does the m4/compiler know the difference between a const "len" and a dynamic "len"? I already when the code and changed constant sizes (structure sizes) to the new macro. Can you give an example of how this could work? Paul
