Helge Deller <deller@xxxxxx> writes: > On 5/17/22 14:49, Helge Deller wrote: >> In 2004 Randolph added the shr() assembly macro and noted that the >> source and target register could not be the same. >> >> I did not find any confindence in the docs for this restriction. Maybe >> it's related that on PA2.0 the upper bits may be clobbered? > > Looking at the generated kernel code from C-files, I'll find all over usages of > extru source, x,y, target > where source and target are the same register. > So, at least for 32-bit this restriction can't be true. I did a quick objdump on the 64 bit HP-UX kernel and that one also uses extrd/extrw where target and source are the same register. So i don't think that restriction is true.
