diff options
Diffstat (limited to 'llvm/lib/CodeGen')
| -rw-r--r-- | llvm/lib/CodeGen/RegAllocGreedy.cpp | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/llvm/lib/CodeGen/RegAllocGreedy.cpp b/llvm/lib/CodeGen/RegAllocGreedy.cpp index 644b80bd008..188021c2832 100644 --- a/llvm/lib/CodeGen/RegAllocGreedy.cpp +++ b/llvm/lib/CodeGen/RegAllocGreedy.cpp @@ -2223,10 +2223,21 @@ bool RAGreedy::tryRecoloringCandidates(PQueue &RecoloringQueue, DEBUG(dbgs() << "Try to recolor: " << *LI << '\n'); unsigned PhysReg; PhysReg = selectOrSplitImpl(*LI, NewVRegs, FixedRegisters, Depth + 1); - if (PhysReg == ~0u || !PhysReg) + // When splitting happens, the live-range may actually be empty. + // In that case, this is okay to continue the recoloring even + // if we did not find an alternative color for it. Indeed, + // there will not be anything to color for LI in the end. + if (PhysReg == ~0u || (!PhysReg && !LI->empty())) return false; + + if (!PhysReg) { + assert(LI->empty() && "Only empty live-range do not require a register"); + DEBUG(dbgs() << "Recoloring of " << *LI << " succeeded. Empty LI.\n"); + continue; + } DEBUG(dbgs() << "Recoloring of " << *LI << " succeeded with: " << PrintReg(PhysReg, TRI) << '\n'); + Matrix->assign(*LI, PhysReg); FixedRegisters.insert(LI->reg); } |
