diff options
Diffstat (limited to 'llvm/lib/Target/PowerPC')
| -rw-r--r-- | llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp | 25 |
1 files changed, 23 insertions, 2 deletions
diff --git a/llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp b/llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp index 6f8f566337b..150b0c81398 100644 --- a/llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp +++ b/llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp @@ -633,6 +633,13 @@ static unsigned getInt64CountDirect(int64_t Imm) { // If no shift, we're done. if (!Shift) return Result; + // If Hi word == Lo word, + // we can use rldimi to insert the Lo word into Hi word. + if ((unsigned)(Imm & 0xFFFFFFFF) == Remainder) { + ++Result; + return Result; + } + // Shift for next step if the upper 32-bits were not zero. if (Imm) ++Result; @@ -731,6 +738,14 @@ static SDNode *getInt64Direct(SelectionDAG *CurDAG, const SDLoc &dl, // If no shift, we're done. if (!Shift) return Result; + // If Hi word == Lo word, + // we can use rldimi to insert the Lo word into Hi word. + if ((unsigned)(Imm & 0xFFFFFFFF) == Remainder) { + SDValue Ops[] = + { SDValue(Result, 0), SDValue(Result, 0), getI32Imm(Shift), getI32Imm(0)}; + return CurDAG->getMachineNode(PPC::RLDIMI, dl, MVT::i64, Ops); + } + // Shift for next step if the upper 32-bits were not zero. if (Imm) { Result = CurDAG->getMachineNode(PPC::RLDICR, dl, MVT::i64, @@ -1659,9 +1674,12 @@ class BitPermutationSelector { unsigned NumRLInsts = 0; bool FirstBG = true; + bool MoreBG = false; for (auto &BG : BitGroups) { - if (!MatchingBG(BG)) + if (!MatchingBG(BG)) { + MoreBG = true; continue; + } NumRLInsts += SelectRotMask64Count(BG.RLAmt, BG.Repl32, BG.StartIdx, BG.EndIdx, !FirstBG); @@ -1679,7 +1697,10 @@ class BitPermutationSelector { // because that exposes more opportunities for CSE. if (NumAndInsts > NumRLInsts) continue; - if (Use32BitInsts && NumAndInsts == NumRLInsts) + // When merging multiple bit groups, instruction or is used. + // But when rotate is used, rldimi can inert the rotated value into any + // register, so instruction or can be avoided. + if ((Use32BitInsts || MoreBG) && NumAndInsts == NumRLInsts) continue; DEBUG(dbgs() << "\t\t\t\tusing masking\n"); |
