LCOV - code coverage report
Current view: top level - lib/CodeGen - CallingConvLower.cpp (source / functions) Hit Total Coverage
Test: llvm-toolchain.info Lines: 123 131 93.9 %
Date: 2017-09-14 15:23:50 Functions: 14 14 100.0 %
Legend: Lines: hit not hit

          Line data    Source code
       1             : //===-- CallingConvLower.cpp - Calling Conventions ------------------------===//
       2             : //
       3             : //                     The LLVM Compiler Infrastructure
       4             : //
       5             : // This file is distributed under the University of Illinois Open Source
       6             : // License. See LICENSE.TXT for details.
       7             : //
       8             : //===----------------------------------------------------------------------===//
       9             : //
      10             : // This file implements the CCState class, used for lowering and implementing
      11             : // calling conventions.
      12             : //
      13             : //===----------------------------------------------------------------------===//
      14             : 
      15             : #include "llvm/CodeGen/CallingConvLower.h"
      16             : #include "llvm/CodeGen/MachineFrameInfo.h"
      17             : #include "llvm/CodeGen/MachineRegisterInfo.h"
      18             : #include "llvm/IR/DataLayout.h"
      19             : #include "llvm/Support/Debug.h"
      20             : #include "llvm/Support/ErrorHandling.h"
      21             : #include "llvm/Support/SaveAndRestore.h"
      22             : #include "llvm/Support/raw_ostream.h"
      23             : #include "llvm/Target/TargetLowering.h"
      24             : #include "llvm/Target/TargetRegisterInfo.h"
      25             : #include "llvm/Target/TargetSubtargetInfo.h"
      26             : #include <algorithm>
      27             : 
      28             : using namespace llvm;
      29             : 
      30      948415 : CCState::CCState(CallingConv::ID CC, bool isVarArg, MachineFunction &mf,
      31      948415 :                  SmallVectorImpl<CCValAssign> &locs, LLVMContext &C)
      32             :     : CallingConv(CC), IsVarArg(isVarArg), MF(mf),
      33     3793660 :       TRI(*MF.getSubtarget().getRegisterInfo()), Locs(locs), Context(C) {
      34             :   // No stack is used.
      35      948415 :   StackOffset = 0;
      36      948415 :   MaxStackArgAlign = 1;
      37             : 
      38      948415 :   clearByValRegsInfo();
      39      948415 :   UsedRegs.resize((TRI.getNumRegs()+31)/32);
      40      948415 : }
      41             : 
      42             : /// Allocate space on the stack large enough to pass an argument by value.
      43             : /// The size and alignment information of the argument is encoded in
      44             : /// its parameter attribute.
      45        1456 : void CCState::HandleByVal(unsigned ValNo, MVT ValVT,
      46             :                           MVT LocVT, CCValAssign::LocInfo LocInfo,
      47             :                           int MinSize, int MinAlign,
      48             :                           ISD::ArgFlagsTy ArgFlags) {
      49        1456 :   unsigned Align = ArgFlags.getByValAlign();
      50        1456 :   unsigned Size  = ArgFlags.getByValSize();
      51        1456 :   if (MinSize > (int)Size)
      52          26 :     Size = MinSize;
      53        1456 :   if (MinAlign > (int)Align)
      54         208 :     Align = MinAlign;
      55        2912 :   ensureMaxAlignment(Align);
      56        1456 :   MF.getSubtarget().getTargetLowering()->HandleByVal(this, Size, Align);
      57        2912 :   Size = unsigned(alignTo(Size, MinAlign));
      58        1456 :   unsigned Offset = AllocateStack(Size, Align);
      59        2912 :   addLoc(CCValAssign::getMem(ValNo, ValVT, Offset, LocVT, LocInfo));
      60        1456 : }
      61             : 
      62             : /// Mark a register and all of its aliases as allocated.
      63      870557 : void CCState::MarkAllocated(unsigned Reg) {
      64    11848024 :   for (MCRegAliasIterator AI(Reg, &TRI, true); AI.isValid(); ++AI)
      65    15160365 :     UsedRegs[*AI/32] |= 1 << (*AI&31);
      66      870557 : }
      67             : 
      68          70 : bool CCState::IsShadowAllocatedReg(unsigned Reg) const {
      69          70 :   if (!isAllocated(Reg))
      70             :     return false;
      71             : 
      72         351 :   for (auto const &ValAssign : Locs) {
      73         197 :     if (ValAssign.isRegLoc()) {
      74         894 :       for (MCRegAliasIterator AI(ValAssign.getLocReg(), &TRI, true);
      75        1591 :            AI.isValid(); ++AI) {
      76         753 :         if (*AI == Reg)
      77          56 :           return false;
      78             :       }
      79             :     }
      80             :   }
      81             :   return true;
      82             : }
      83             : 
      84             : /// Analyze an array of argument values,
      85             : /// incorporating info about the formals into this state.
      86             : void
      87      104747 : CCState::AnalyzeFormalArguments(const SmallVectorImpl<ISD::InputArg> &Ins,
      88             :                                 CCAssignFn Fn) {
      89      209494 :   unsigned NumArgs = Ins.size();
      90             : 
      91      304146 :   for (unsigned i = 0; i != NumArgs; ++i) {
      92      398798 :     MVT ArgVT = Ins[i].VT;
      93      398798 :     ISD::ArgFlagsTy ArgFlags = Ins[i].Flags;
      94      199399 :     if (Fn(i, ArgVT, ArgVT, CCValAssign::Full, ArgFlags, *this)) {
      95             : #ifndef NDEBUG
      96             :       dbgs() << "Formal argument #" << i << " has unhandled type "
      97             :              << EVT(ArgVT).getEVTString() << '\n';
      98             : #endif
      99           0 :       llvm_unreachable(nullptr);
     100             :     }
     101             :   }
     102      104747 : }
     103             : 
     104             : /// Analyze the return values of a function, returning true if the return can
     105             : /// be performed without sret-demotion and false otherwise.
     106      313942 : bool CCState::CheckReturn(const SmallVectorImpl<ISD::OutputArg> &Outs,
     107             :                           CCAssignFn Fn) {
     108             :   // Determine which register each value should be copied into.
     109      762707 :   for (unsigned i = 0, e = Outs.size(); i != e; ++i) {
     110      271188 :     MVT VT = Outs[i].VT;
     111      271188 :     ISD::ArgFlagsTy ArgFlags = Outs[i].Flags;
     112      135594 :     if (Fn(i, VT, VT, CCValAssign::Full, ArgFlags, *this))
     113         771 :       return false;
     114             :   }
     115             :   return true;
     116             : }
     117             : 
     118             : /// Analyze the returned values of a return,
     119             : /// incorporating info about the result values into this state.
     120      122504 : void CCState::AnalyzeReturn(const SmallVectorImpl<ISD::OutputArg> &Outs,
     121             :                             CCAssignFn Fn) {
     122             :   // Determine which register each value should be copied into.
     123      350254 :   for (unsigned i = 0, e = Outs.size(); i != e; ++i) {
     124      210492 :     MVT VT = Outs[i].VT;
     125      210492 :     ISD::ArgFlagsTy ArgFlags = Outs[i].Flags;
     126      105246 :     if (Fn(i, VT, VT, CCValAssign::Full, ArgFlags, *this)) {
     127             : #ifndef NDEBUG
     128             :       dbgs() << "Return operand #" << i << " has unhandled type "
     129             :              << EVT(VT).getEVTString() << '\n';
     130             : #endif
     131           0 :       llvm_unreachable(nullptr);
     132             :     }
     133             :   }
     134      122504 : }
     135             : 
     136             : /// Analyze the outgoing arguments to a call,
     137             : /// incorporating info about the passed values into this state.
     138      187660 : void CCState::AnalyzeCallOperands(const SmallVectorImpl<ISD::OutputArg> &Outs,
     139             :                                   CCAssignFn Fn) {
     140      375320 :   unsigned NumOps = Outs.size();
     141      608202 :   for (unsigned i = 0; i != NumOps; ++i) {
     142      841084 :     MVT ArgVT = Outs[i].VT;
     143      841084 :     ISD::ArgFlagsTy ArgFlags = Outs[i].Flags;
     144      420542 :     if (Fn(i, ArgVT, ArgVT, CCValAssign::Full, ArgFlags, *this)) {
     145             : #ifndef NDEBUG
     146             :       dbgs() << "Call operand #" << i << " has unhandled type "
     147             :              << EVT(ArgVT).getEVTString() << '\n';
     148             : #endif
     149           0 :       llvm_unreachable(nullptr);
     150             :     }
     151             :   }
     152      187660 : }
     153             : 
     154             : /// Same as above except it takes vectors of types and argument flags.
     155        1520 : void CCState::AnalyzeCallOperands(SmallVectorImpl<MVT> &ArgVTs,
     156             :                                   SmallVectorImpl<ISD::ArgFlagsTy> &Flags,
     157             :                                   CCAssignFn Fn) {
     158        3040 :   unsigned NumOps = ArgVTs.size();
     159        5151 :   for (unsigned i = 0; i != NumOps; ++i) {
     160        7262 :     MVT ArgVT = ArgVTs[i];
     161        7262 :     ISD::ArgFlagsTy ArgFlags = Flags[i];
     162        3631 :     if (Fn(i, ArgVT, ArgVT, CCValAssign::Full, ArgFlags, *this)) {
     163             : #ifndef NDEBUG
     164             :       dbgs() << "Call operand #" << i << " has unhandled type "
     165             :              << EVT(ArgVT).getEVTString() << '\n';
     166             : #endif
     167           0 :       llvm_unreachable(nullptr);
     168             :     }
     169             :   }
     170        1520 : }
     171             : 
     172             : /// Analyze the return values of a call, incorporating info about the passed
     173             : /// values into this state.
     174      187529 : void CCState::AnalyzeCallResult(const SmallVectorImpl<ISD::InputArg> &Ins,
     175             :                                 CCAssignFn Fn) {
     176      404658 :   for (unsigned i = 0, e = Ins.size(); i != e; ++i) {
     177       59200 :     MVT VT = Ins[i].VT;
     178       59200 :     ISD::ArgFlagsTy Flags = Ins[i].Flags;
     179       29600 :     if (Fn(i, VT, VT, CCValAssign::Full, Flags, *this)) {
     180             : #ifndef NDEBUG
     181             :       dbgs() << "Call result #" << i << " has unhandled type "
     182             :              << EVT(VT).getEVTString() << '\n';
     183             : #endif
     184           0 :       llvm_unreachable(nullptr);
     185             :     }
     186             :   }
     187      187529 : }
     188             : 
     189             : /// Same as above except it's specialized for calls that produce a single value.
     190         322 : void CCState::AnalyzeCallResult(MVT VT, CCAssignFn Fn) {
     191         322 :   if (Fn(0, VT, VT, CCValAssign::Full, ISD::ArgFlagsTy(), *this)) {
     192             : #ifndef NDEBUG
     193             :     dbgs() << "Call result has unhandled type "
     194             :            << EVT(VT).getEVTString() << '\n';
     195             : #endif
     196           0 :     llvm_unreachable(nullptr);
     197             :   }
     198         322 : }
     199             : 
     200             : static bool isValueTypeInRegForCC(CallingConv::ID CC, MVT VT) {
     201          39 :   if (VT.isVector())
     202             :     return true; // Assume -msse-regparm might be in effect.
     203          21 :   if (!VT.isInteger())
     204             :     return false;
     205          21 :   if (CC == CallingConv::X86_VectorCall || CC == CallingConv::X86_FastCall)
     206             :     return true;
     207             :   return false;
     208             : }
     209             : 
     210          39 : void CCState::getRemainingRegParmsForType(SmallVectorImpl<MCPhysReg> &Regs,
     211             :                                           MVT VT, CCAssignFn Fn) {
     212          39 :   unsigned SavedStackOffset = StackOffset;
     213          39 :   unsigned SavedMaxStackArgAlign = MaxStackArgAlign;
     214          78 :   unsigned NumLocs = Locs.size();
     215             : 
     216             :   // Set the 'inreg' flag if it is used for this calling convention.
     217          39 :   ISD::ArgFlagsTy Flags;
     218          39 :   if (isValueTypeInRegForCC(CallingConv, VT))
     219             :     Flags.setInReg();
     220             : 
     221             :   // Allocate something of this value type repeatedly until we get assigned a
     222             :   // location in memory.
     223             :   bool HaveRegParm = true;
     224         387 :   while (HaveRegParm) {
     225         174 :     if (Fn(0, VT, VT, CCValAssign::Full, Flags, *this)) {
     226             : #ifndef NDEBUG
     227             :       dbgs() << "Call has unhandled type " << EVT(VT).getEVTString()
     228             :              << " while computing remaining regparms\n";
     229             : #endif
     230           0 :       llvm_unreachable(nullptr);
     231             :     }
     232         522 :     HaveRegParm = Locs.back().isRegLoc();
     233             :   }
     234             : 
     235             :   // Copy all the registers from the value locations we added.
     236             :   assert(NumLocs < Locs.size() && "CC assignment failed to add location");
     237         252 :   for (unsigned I = NumLocs, E = Locs.size(); I != E; ++I)
     238         522 :     if (Locs[I].isRegLoc())
     239         270 :       Regs.push_back(MCPhysReg(Locs[I].getLocReg()));
     240             : 
     241             :   // Clear the assigned values and stack memory. We leave the registers marked
     242             :   // as allocated so that future queries don't return the same registers, i.e.
     243             :   // when i64 and f64 are both passed in GPRs.
     244          39 :   StackOffset = SavedStackOffset;
     245          39 :   MaxStackArgAlign = SavedMaxStackArgAlign;
     246          39 :   Locs.resize(NumLocs);
     247          39 : }
     248             : 
     249          21 : void CCState::analyzeMustTailForwardedRegisters(
     250             :     SmallVectorImpl<ForwardedRegister> &Forwards, ArrayRef<MVT> RegParmTypes,
     251             :     CCAssignFn Fn) {
     252             :   // Oftentimes calling conventions will not user register parameters for
     253             :   // variadic functions, so we need to assume we're not variadic so that we get
     254             :   // all the registers that might be used in a non-variadic call.
     255          63 :   SaveAndRestore<bool> SavedVarArg(IsVarArg, false);
     256          63 :   SaveAndRestore<bool> SavedMustTail(AnalyzingMustTailForwardedRegs, true);
     257             : 
     258          81 :   for (MVT RegVT : RegParmTypes) {
     259          78 :     SmallVector<MCPhysReg, 8> RemainingRegs;
     260          39 :     getRemainingRegParmsForType(RemainingRegs, RegVT, Fn);
     261          39 :     const TargetLowering *TL = MF.getSubtarget().getTargetLowering();
     262          39 :     const TargetRegisterClass *RC = TL->getRegClassFor(RegVT);
     263         252 :     for (MCPhysReg PReg : RemainingRegs) {
     264         135 :       unsigned VReg = MF.addLiveIn(PReg, RC);
     265         270 :       Forwards.push_back(ForwardedRegister(VReg, PReg, RegVT));
     266             :     }
     267             :   }
     268          21 : }
     269             : 
     270        2489 : bool CCState::resultsCompatible(CallingConv::ID CalleeCC,
     271             :                                 CallingConv::ID CallerCC, MachineFunction &MF,
     272             :                                 LLVMContext &C,
     273             :                                 const SmallVectorImpl<ISD::InputArg> &Ins,
     274             :                                 CCAssignFn CalleeFn, CCAssignFn CallerFn) {
     275        2489 :   if (CalleeCC == CallerCC)
     276             :     return true;
     277         290 :   SmallVector<CCValAssign, 4> RVLocs1;
     278         580 :   CCState CCInfo1(CalleeCC, false, MF, RVLocs1, C);
     279         290 :   CCInfo1.AnalyzeCallResult(Ins, CalleeFn);
     280             : 
     281         580 :   SmallVector<CCValAssign, 4> RVLocs2;
     282         580 :   CCState CCInfo2(CallerCC, false, MF, RVLocs2, C);
     283         290 :   CCInfo2.AnalyzeCallResult(Ins, CallerFn);
     284             : 
     285         580 :   if (RVLocs1.size() != RVLocs2.size())
     286             :     return false;
     287         734 :   for (unsigned I = 0, E = RVLocs1.size(); I != E; ++I) {
     288         408 :     const CCValAssign &Loc1 = RVLocs1[I];
     289         408 :     const CCValAssign &Loc2 = RVLocs2[I];
     290         408 :     if (Loc1.getLocInfo() != Loc2.getLocInfo())
     291             :       return false;
     292         197 :     bool RegLoc1 = Loc1.isRegLoc();
     293         197 :     if (RegLoc1 != Loc2.isRegLoc())
     294             :       return false;
     295         197 :     if (RegLoc1) {
     296         197 :       if (Loc1.getLocReg() != Loc2.getLocReg())
     297             :         return false;
     298             :     } else {
     299           0 :       if (Loc1.getLocMemOffset() != Loc2.getLocMemOffset())
     300             :         return false;
     301             :     }
     302             :   }
     303             :   return true;
     304             : }

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