2014-10-24 14:37 GMT+04:00 Georg-Johann Lay <a...@gjlay.de>: > Am 10/23/2014 08:16 PM schrieb Denis Chertykov: >>> >>> This optimization makes most sign-extensions one instruction shorter in >>> the >>> case when the source register may be clobbered and the register numbers >>> are >>> different. Source and destination may overlap. >>> >>> Ok for trunk? >>> >>> Johann >>> >>> gcc/ >>> * config/avr/avr.md (extendqihi2, extendqipsi2, extendqisi2) >>> (extendhipsi2, extendhisi2): Optimize if source reg is unused >>> after the insns and has different REGNO than destination. >> >> >> Approved. >> >> Denis. > > > Finally I switched to a solution that avoids all the ugly asm snippets and > special casing, and which is exact w.r.t code size. So allow me drop the > patch from above and to propose this one for trunk. Sorry for the > inconvenience. > > In any case it uses LSL/SBC idiom instead of the old CLR/SBRC/COM. > > > Johann > > * avr-protos.h (avr_out_sign_extend): New. > * avr.c (avr_adjust_insn_length) [ADJUST_LEN_SEXT]: Handle. > (avr_out_sign_extend): New function. > * avr.md (extendqihi2, extendqipsi2, extendqisi2, extendhipsi2) > (extendhisi2, extendpsisi2): Use it. > (adjust_len) [sext]: New. > > >
I'm agree with you. It's better. Approved. Denis.
