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| author | Tim Northover <t.p.northover@gmail.com> | 2021-05-11 09:57:18 +0100 |
|---|---|---|
| committer | Tim Northover <t.p.northover@gmail.com> | 2021-05-19 11:00:24 +0100 |
| commit | c1dc267258e06bb69e1ca217d1d8ce2d15b8757f (patch) | |
| tree | 10d529c26b7d863886276e773208a37aa748215c /llvm/lib/CodeGen/RegAllocFast.cpp | |
| parent | 4f86aa650c40196754df22c421d551d129c9149a (diff) | |
| download | llvm-c1dc267258e06bb69e1ca217d1d8ce2d15b8757f.zip llvm-c1dc267258e06bb69e1ca217d1d8ce2d15b8757f.tar.gz llvm-c1dc267258e06bb69e1ca217d1d8ce2d15b8757f.tar.bz2 | |
MachineBasicBlock: add liveout iterator aware of which liveins are defined by the runtime.
Using this in RegAlloc fast reduces register pressure, and in some cases allows
x86 code to compile that wouldn't before.
Diffstat (limited to 'llvm/lib/CodeGen/RegAllocFast.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/RegAllocFast.cpp | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/llvm/lib/CodeGen/RegAllocFast.cpp b/llvm/lib/CodeGen/RegAllocFast.cpp index b6d4cd2..8a964ef 100644 --- a/llvm/lib/CodeGen/RegAllocFast.cpp +++ b/llvm/lib/CodeGen/RegAllocFast.cpp @@ -1452,10 +1452,8 @@ void RegAllocFast::allocateBasicBlock(MachineBasicBlock &MBB) { RegUnitStates.assign(TRI->getNumRegUnits(), regFree); assert(LiveVirtRegs.empty() && "Mapping not cleared from last block?"); - for (MachineBasicBlock *Succ : MBB.successors()) { - for (const MachineBasicBlock::RegisterMaskPair &LI : Succ->liveins()) - setPhysRegState(LI.PhysReg, regPreAssigned); - } + for (auto &LiveReg : MBB.liveouts()) + setPhysRegState(LiveReg.PhysReg, regPreAssigned); Coalesced.clear(); |