Skip to content
  1. May 18, 2010
  2. May 17, 2010
  3. May 16, 2010
  4. May 15, 2010
  5. May 14, 2010
  6. May 13, 2010
  7. May 12, 2010
    • Evan Cheng's avatar
      Remove a dead fixme. · 5aa20d6c
      Evan Cheng authored
      llvm-svn: 103642
      5aa20d6c
    • Rafael Espindola's avatar
      b69c7b76
    • Evan Cheng's avatar
      vst instructions are modeled as this: · a2ff4fc9
      Evan Cheng authored
      v1024 = REG_SEQUENCE ...
      v1025 = EXTRACT_SUBREG v1024, 5
      v1026 = EXTRACR_SUBREG v1024, 6
            = VSTxx <addr>, v1025, v1026
      
      The REG_SEQUENCE ensures the sources that feed into the VST instruction
      are getting the right register allocation so they form a large super-
      register. The extract_subreg will be coalesced away all would just work:
      v1024 = REG_SEQUENCE ...
            = VSTxx <addr>, v1024:5, v1024:6
      
      The problem is if the coalescer isn't run, the extract_subreg instructions
      would stick around and there is no assurance v1025 and v1026 will get the
      right registers.
      
      As a short term workaround, teach the NEON pre-allocation pass to transfer
      the sub-register indices over. An alternative would be do it 2addr pass
      when reg_sequence's are eliminated. But that *seems* wrong and require
      updating liveness information.
      
      Another alternative is to do this in the scheduler when the instructions are
      created. But that would mean somehow the scheduler this has to be done for
      correctness reason. That's yucky as well. So for now, we are leaving this
      in the target specific pass.
      
      llvm-svn: 103540
      a2ff4fc9
  8. May 11, 2010
  9. May 10, 2010
  10. May 07, 2010
Loading