SystemZCallingConv.h revision 360784 
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
16namespace llvm {
17namespace 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
25class SystemZCCState : public CCState {
26private:
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
39public:
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.
87inline 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
127inline bool CC_SystemZ_GHC_Error(unsigned &, MVT &, MVT &,
128                                 CCValAssign::LocInfo &, ISD::ArgFlagsTy &,
129                                 CCState &) {
130  report_fatal_error("No registers left in GHC calling convention");
131  return false;
132}
133
134} // end namespace llvm
135
136#endif
137