diff options
| -rw-r--r-- | lib/CodeGen/RegisterClassInfo.cpp | 7 | ||||
| -rw-r--r-- | lib/CodeGen/RegisterClassInfo.h | 13 |
2 files changed, 18 insertions, 2 deletions
diff --git a/lib/CodeGen/RegisterClassInfo.cpp b/lib/CodeGen/RegisterClassInfo.cpp index 5a77e47bc5..786d279c2b 100644 --- a/lib/CodeGen/RegisterClassInfo.cpp +++ b/lib/CodeGen/RegisterClassInfo.cpp @@ -99,11 +99,16 @@ void RegisterClassInfo::compute(const TargetRegisterClass *RC) const { // CSR aliases go after the volatile registers, preserve the target's order. std::copy(CSRAlias.begin(), CSRAlias.end(), &RCI.Order[N]); + // Check if RC is a proper sub-class. + if (const TargetRegisterClass *Super = TRI->getLargestLegalSuperClass(RC)) + if (Super != RC && getNumAllocatableRegs(Super) > RCI.NumRegs) + RCI.ProperSubClass = true; + DEBUG({ dbgs() << "AllocationOrder(" << RC->getName() << ") = ["; for (unsigned I = 0; I != RCI.NumRegs; ++I) dbgs() << ' ' << PrintReg(RCI.Order[I], TRI); - dbgs() << " ]\n"; + dbgs() << (RCI.ProperSubClass ? " ] (sub-class)\n" : " ]\n"); }); // RCI is now up-to-date. diff --git a/lib/CodeGen/RegisterClassInfo.h b/lib/CodeGen/RegisterClassInfo.h index 90c0a7ee4a..2c1407096c 100644 --- a/lib/CodeGen/RegisterClassInfo.h +++ b/lib/CodeGen/RegisterClassInfo.h @@ -28,9 +28,10 @@ class RegisterClassInfo { struct RCInfo { unsigned Tag; unsigned NumRegs; + bool ProperSubClass; OwningArrayPtr<unsigned> Order; - RCInfo() : Tag(0), NumRegs(0) {} + RCInfo() : Tag(0), NumRegs(0), ProperSubClass(false) {} operator ArrayRef<unsigned>() const { return makeArrayRef(Order.get(), NumRegs); } @@ -87,6 +88,16 @@ public: return get(RC); } + /// isProperSubClass - Returns true if RC has a legal super-class with more + /// allocatable registers. + /// + /// Register classes like GR32_NOSP are not proper sub-classes because %esp + /// is not allocatable. Similarly, tGPR is not a proper sub-class in Thumb + /// mode because the GPR super-class is not legal. + bool isProperSubClass(const TargetRegisterClass *RC) const { + return get(RC).ProperSubClass; + } + /// getLastCalleeSavedAlias - Returns the last callee saved register that /// overlaps PhysReg, or 0 if Reg doesn't overlap a CSR. unsigned getLastCalleeSavedAlias(unsigned PhysReg) const { |