lib/Target/SystemZ/SystemZCallingConv.h

   1 //===-- SystemZCallingConv.h - Calling conventions for SystemZ --*- C++ -*-===//
   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 #ifndef LLVM_LIB_TARGET_SYSTEMZ_SYSTEMZCALLINGCONV_H
  11 #define LLVM_LIB_TARGET_SYSTEMZ_SYSTEMZCALLINGCONV_H
  12
  13 #include "llvm/ADT/SmallVector.h"
  14 #include "llvm/CodeGen/CallingConvLower.h"
  15 #include "llvm/MC/MCRegisterInfo.h"
  16
  17 namespace llvm {
  18 namespace SystemZ {
  19   const unsigned NumArgGPRs = 5;
  20   extern const MCPhysReg ArgGPRs[NumArgGPRs];
  21
  22   const unsigned NumArgFPRs = 4;
  23   extern const MCPhysReg ArgFPRs[NumArgFPRs];
  24 } // end namespace SystemZ
  25
  26 class SystemZCCState : public CCState {
  27 private:
  28   /// Records whether the value was a fixed argument.
  29   /// See ISD::OutputArg::IsFixed.
  30   SmallVector<bool, 4> ArgIsFixed;
  31
  32   /// Records whether the value was widened from a short vector type.
  33   SmallVector<bool, 4> ArgIsShortVector;
  34
  35   // Check whether ArgVT is a short vector type.
  36   bool IsShortVectorType(EVT ArgVT) {
  37     return ArgVT.isVector() && ArgVT.getStoreSize() <= 8;
  38   }
  39
  40 public:
  41   SystemZCCState(CallingConv::ID CC, bool isVarArg, MachineFunction &MF,
  42                  SmallVectorImpl<CCValAssign> &locs, LLVMContext &C)
  43       : CCState(CC, isVarArg, MF, locs, C) {}
  44
  45   void AnalyzeFormalArguments(const SmallVectorImpl<ISD::InputArg> &Ins,
  46                               CCAssignFn Fn) {
  47     // Formal arguments are always fixed.
  48     ArgIsFixed.clear();
  49     for (unsigned i = 0; i < Ins.size(); ++i)
  50       ArgIsFixed.push_back(true);
  51     // Record whether the call operand was a short vector.
  52     ArgIsShortVector.clear();
  53     for (unsigned i = 0; i < Ins.size(); ++i)
  54       ArgIsShortVector.push_back(IsShortVectorType(Ins[i].ArgVT));
  55
  56     CCState::AnalyzeFormalArguments(Ins, Fn);
  57   }
  58
  59   void AnalyzeCallOperands(const SmallVectorImpl<ISD::OutputArg> &Outs,
  60                            CCAssignFn Fn) {
  61     // Record whether the call operand was a fixed argument.
  62     ArgIsFixed.clear();
  63     for (unsigned i = 0; i < Outs.size(); ++i)
  64       ArgIsFixed.push_back(Outs[i].IsFixed);
  65     // Record whether the call operand was a short vector.
  66     ArgIsShortVector.clear();
  67     for (unsigned i = 0; i < Outs.size(); ++i)
  68       ArgIsShortVector.push_back(IsShortVectorType(Outs[i].ArgVT));
  69
  70     CCState::AnalyzeCallOperands(Outs, Fn);
  71   }
  72
  73   // This version of AnalyzeCallOperands in the base class is not usable
  74   // since we must provide a means of accessing ISD::OutputArg::IsFixed.
  75   void AnalyzeCallOperands(const SmallVectorImpl<MVT> &Outs,
  76                            SmallVectorImpl<ISD::ArgFlagsTy> &Flags,
  77                            CCAssignFn Fn) = delete;
  78
  79   bool IsFixed(unsigned ValNo) { return ArgIsFixed[ValNo]; }
  80   bool IsShortVector(unsigned ValNo) { return ArgIsShortVector[ValNo]; }
  81 };
  82
  83 // Handle i128 argument types.  These need to be passed by implicit
  84 // reference.  This could be as simple as the following .td line:
  85 //    CCIfType<[i128], CCPassIndirect<i64>>,
  86 // except that i128 is not a legal type, and therefore gets split by
  87 // common code into a pair of i64 arguments.
  88 inline bool CC_SystemZ_I128Indirect(unsigned &ValNo, MVT &ValVT,
  89                                     MVT &LocVT,
  90                                     CCValAssign::LocInfo &LocInfo,
  91                                     ISD::ArgFlagsTy &ArgFlags,
  92                                     CCState &State) {
  93   SmallVectorImpl<CCValAssign> &PendingMembers = State.getPendingLocs();
  94
  95   // ArgFlags.isSplit() is true on the first part of a i128 argument;
  96   // PendingMembers.empty() is false on all subsequent parts.
  97   if (!ArgFlags.isSplit() && PendingMembers.empty())
  98     return false;
  99
 100   // Push a pending Indirect value location for each part.
 101   LocVT = MVT::i64;
 102   LocInfo = CCValAssign::Indirect;
 103   PendingMembers.push_back(CCValAssign::getPending(ValNo, ValVT,
 104                                                    LocVT, LocInfo));
 105   if (!ArgFlags.isSplitEnd())
 106     return true;
 107
 108   // OK, we've collected all parts in the pending list.  Allocate
 109   // the location (register or stack slot) for the indirect pointer.
 110   // (This duplicates the usual i64 calling convention rules.)
 111   unsigned Reg = State.AllocateReg(SystemZ::ArgGPRs);
 112   unsigned Offset = Reg ? 0 : State.AllocateStack(8, 8);
 113
 114   // Use that same location for all the pending parts.
 115   for (auto &It : PendingMembers) {
 116     if (Reg)
 117       It.convertToReg(Reg);
 118     else
 119       It.convertToMem(Offset);
 120     State.addLoc(It);
 121   }
 122
 123   PendingMembers.clear();
 124
 125   return true;
 126 }
 127
 128 } // end namespace llvm
 129
 130 #endif