This patch is still pending review: http://gcc.gnu.org/ml/gcc-patches/2011-07/msg02376.html
Georg-Johann Lay a écrit:
[...] So here is a cleaned up version that maps to QI shifts. Tested without regressions. Ok? Johann PR target/29560 * config/avr/avr.md (any_extend): New code interator. (extend_prefix): New code attribute. (*ashl<extend_prefix>qihiqi3): New insn-and-splits. (*ashl<extend_prefix>qihiqi3.mem): New insn-and-splits. (*ashlhiqi3): New insn-and-split. Add peephole2 to map ashlhi3 to ashlqi3 if high part of shift target is unused.