Feature
The x64 backend has a helper named emit_cmp in inst.isle that is used when emitting comparisons. Currently it will always use x64_cmp to emit the comparison, but for cases of equality comparisons with 0, x64_test would be a better choice. Additionally, the select lowering does not use emit_cmp right now, and could be refactored to do so with this change in place.
Benefit
This will generate better code for cases where emit_cmp is used to compile a use of icmp in the x64 backend.
Feature
The x64 backend has a helper named
emit_cmpininst.islethat is used when emitting comparisons. Currently it will always usex64_cmpto emit the comparison, but for cases of equality comparisons with0,x64_testwould be a better choice. Additionally, theselectlowering does not useemit_cmpright now, and could be refactored to do so with this change in place.Benefit
This will generate better code for cases where
emit_cmpis used to compile a use oficmpin the x64 backend.