Hello list,

The attached patch does two things for df_get_call_refs():
* First it uses HARD_REG_SETs for defs_generated and 
regs_invalidated_by_call, instead of bitmaps. Replacing in total more 
than 400K calls (for my testcase) to bitmap_bit_p() with the much faster 
TEST_HARD_REG_BIT, reduces the total instruction count from about 13M to 
1.5M.
* Second it produces the REFs in REGNO order, which is important to keep 
the collection_rec sorted most times, and avoid expensive calls to 
qsort(). Thanks to Paolo Bonzini for idea and mentoring.

The second part makes a big difference if accompanied with another patch 
in df_insn_refs_collect(). I'll post a followup patch, that is 
unfortunately unstable for some of my tests, so I'd appreciate any 
comments.


Thanks,
Dimitris