On 2019-05-03 5:40 p.m., Helge Deller wrote: > + void *target = (void *)jump_entry_target(entry); > + int distance = target - addr; > + /* > + * Encode the PA1.1 "b,n" instruction with a 17-bit > + * displacement. In case we hit the BUG(), we could use > + * another branch instruction with a 22-bit displacement on > + * 64-bit CPUs instead. But this seems sufficient for now. > + */ Just a note on the comment. The branch instruction with 22-bit displacement uses the return pointer register %rp. It is available on 32 and 64-bit PA 2.0 machines but one would have to clobber %rp, or save and restore it on stack. The former would cause %rp to be saved and restored in the function's prologue and epilogue, respectively. Dave -- John David Anglin dave.anglin@xxxxxxxx
