lib/Target/SystemZ/SystemZCallingConv.h

   1 //===-- SystemZCallingConv.h - Calling conventions for SystemZ --*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #ifndef LLVM_LIB_TARGET_SYSTEMZ_SYSTEMZCALLINGCONV_H
  10 #define LLVM_LIB_TARGET_SYSTEMZ_SYSTEMZCALLINGCONV_H
  11
  12 #include "llvm/ADT/SmallVector.h"
  13 #include "llvm/CodeGen/CallingConvLower.h"
  14 #include "llvm/MC/MCRegisterInfo.h"
  15
  16 namespace llvm {
  17 namespace SystemZ {
  18   const unsigned NumArgGPRs = 5;
  19   extern const MCPhysReg ArgGPRs[NumArgGPRs];
  20
  21   const unsigned NumArgFPRs = 4;
  22   extern const MCPhysReg ArgFPRs[NumArgFPRs];
  23 } // end namespace SystemZ
  24
  25 class SystemZCCState : public CCState {
  26 private:
  27   /// Records whether the value was a fixed argument.
  28   /// See ISD::OutputArg::IsFixed.
  29   SmallVector<bool, 4> ArgIsFixed;
  30
  31   /// Records whether the value was widened from a short vector type.
  32   SmallVector<bool, 4> ArgIsShortVector;
  33
  34   // Check whether ArgVT is a short vector type.
  35   bool IsShortVectorType(EVT ArgVT) {
  36     return ArgVT.isVector() && ArgVT.getStoreSize() <= 8;
  37   }
  38
  39 public:
  40   SystemZCCState(CallingConv::ID CC, bool isVarArg, MachineFunction &MF,
  41                  SmallVectorImpl<CCValAssign> &locs, LLVMContext &C)
  42       : CCState(CC, isVarArg, MF, locs, C) {}
  43
  44   void AnalyzeFormalArguments(const SmallVectorImpl<ISD::InputArg> &Ins,
  45                               CCAssignFn Fn) {
  46     // Formal arguments are always fixed.
  47     ArgIsFixed.clear();
  48     for (unsigned i = 0; i < Ins.size(); ++i)
  49       ArgIsFixed.push_back(true);
  50     // Record whether the call operand was a short vector.
  51     ArgIsShortVector.clear();
  52     for (unsigned i = 0; i < Ins.size(); ++i)
  53       ArgIsShortVector.push_back(IsShortVectorType(Ins[i].ArgVT));
  54
  55     CCState::AnalyzeFormalArguments(Ins, Fn);
  56   }
  57
  58   void AnalyzeCallOperands(const SmallVectorImpl<ISD::OutputArg> &Outs,
  59                            CCAssignFn Fn) {
  60     // Record whether the call operand was a fixed argument.
  61     ArgIsFixed.clear();
  62     for (unsigned i = 0; i < Outs.size(); ++i)
  63       ArgIsFixed.push_back(Outs[i].IsFixed);
  64     // Record whether the call operand was a short vector.
  65     ArgIsShortVector.clear();
  66     for (unsigned i = 0; i < Outs.size(); ++i)
  67       ArgIsShortVector.push_back(IsShortVectorType(Outs[i].ArgVT));
  68
  69     CCState::AnalyzeCallOperands(Outs, Fn);
  70   }
  71
  72   // This version of AnalyzeCallOperands in the base class is not usable
  73   // since we must provide a means of accessing ISD::OutputArg::IsFixed.
  74   void AnalyzeCallOperands(const SmallVectorImpl<MVT> &Outs,
  75                            SmallVectorImpl<ISD::ArgFlagsTy> &Flags,
  76                            CCAssignFn Fn) = delete;
  77
  78   bool IsFixed(unsigned ValNo) { return ArgIsFixed[ValNo]; }
  79   bool IsShortVector(unsigned ValNo) { return ArgIsShortVector[ValNo]; }
  80 };
  81
  82 // Handle i128 argument types.  These need to be passed by implicit
  83 // reference.  This could be as simple as the following .td line:
  84 //    CCIfType<[i128], CCPassIndirect<i64>>,
  85 // except that i128 is not a legal type, and therefore gets split by
  86 // common code into a pair of i64 arguments.
  87 inline bool CC_SystemZ_I128Indirect(unsigned &ValNo, MVT &ValVT,
  88                                     MVT &LocVT,
  89                                     CCValAssign::LocInfo &LocInfo,
  90                                     ISD::ArgFlagsTy &ArgFlags,
  91                                     CCState &State) {
  92   SmallVectorImpl<CCValAssign> &PendingMembers = State.getPendingLocs();
  93
  94   // ArgFlags.isSplit() is true on the first part of a i128 argument;
  95   // PendingMembers.empty() is false on all subsequent parts.
  96   if (!ArgFlags.isSplit() && PendingMembers.empty())
  97     return false;
  98
  99   // Push a pending Indirect value location for each part.
 100   LocVT = MVT::i64;
 101   LocInfo = CCValAssign::Indirect;
 102   PendingMembers.push_back(CCValAssign::getPending(ValNo, ValVT,
 103                                                    LocVT, LocInfo));
 104   if (!ArgFlags.isSplitEnd())
 105     return true;
 106
 107   // OK, we've collected all parts in the pending list.  Allocate
 108   // the location (register or stack slot) for the indirect pointer.
 109   // (This duplicates the usual i64 calling convention rules.)
 110   unsigned Reg = State.AllocateReg(SystemZ::ArgGPRs);
 111   unsigned Offset = Reg ? 0 : State.AllocateStack(8, 8);
 112
 113   // Use that same location for all the pending parts.
 114   for (auto &It : PendingMembers) {
 115     if (Reg)
 116       It.convertToReg(Reg);
 117     else
 118       It.convertToMem(Offset);
 119     State.addLoc(It);
 120   }
 121
 122   PendingMembers.clear();
 123
 124   return true;
 125 }
 126
 127 } // end namespace llvm
 128
 129 #endif