1 files changed, 284 insertions, 0 deletions
diff --git a/llvm/lib/Target/ARM/ARMCallingConv.cpp b/llvm/lib/Target/ARM/ARMCallingConv.cpp
new file mode 100644
index 000000000000..92ebc542b423
--- /dev/null
+++ b/llvm/lib/Target/ARM/ARMCallingConv.cpp
@@ -0,0 +1,284 @@
+//=== ARMCallingConv.cpp - ARM Custom CC Routines ---------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains the custom routines for the ARM Calling Convention that
+// aren't done by tablegen, and includes the table generated implementations.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ARM.h"
+#include "ARMCallingConv.h"
+#include "ARMSubtarget.h"
+#include "ARMRegisterInfo.h"
+using namespace llvm;
+
+// APCS f64 is in register pairs, possibly split to stack
+static bool f64AssignAPCS(unsigned &ValNo, MVT &ValVT, MVT &LocVT,
+                          CCValAssign::LocInfo &LocInfo,
+                          CCState &State, bool CanFail) {
+  static const MCPhysReg RegList[] = { ARM::R0, ARM::R1, ARM::R2, ARM::R3 };
+
+  // Try to get the first register.
+  if (unsigned Reg = State.AllocateReg(RegList))
+    State.addLoc(CCValAssign::getCustomReg(ValNo, ValVT, Reg, LocVT, LocInfo));
+  else {
+    // For the 2nd half of a v2f64, do not fail.
+    if (CanFail)
+      return false;
+
+    // Put the whole thing on the stack.
+    State.addLoc(CCValAssign::getCustomMem(ValNo, ValVT,
+                                           State.AllocateStack(8, 4),
+                                           LocVT, LocInfo));
+    return true;
+  }
+
+  // Try to get the second register.
+  if (unsigned Reg = State.AllocateReg(RegList))
+    State.addLoc(CCValAssign::getCustomReg(ValNo, ValVT, Reg, LocVT, LocInfo));
+  else
+    State.addLoc(CCValAssign::getCustomMem(ValNo, ValVT,
+                                           State.AllocateStack(4, 4),
+                                           LocVT, LocInfo));
+  return true;
+}
+
+static bool CC_ARM_APCS_Custom_f64(unsigned &ValNo, MVT &ValVT, MVT &LocVT,
+                                   CCValAssign::LocInfo &LocInfo,
+                                   ISD::ArgFlagsTy &ArgFlags,
+                                   CCState &State) {
+  if (!f64AssignAPCS(ValNo, ValVT, LocVT, LocInfo, State, true))
+    return false;
+  if (LocVT == MVT::v2f64 &&
+      !f64AssignAPCS(ValNo, ValVT, LocVT, LocInfo, State, false))
+    return false;
+  return true;  // we handled it
+}
+
+// AAPCS f64 is in aligned register pairs
+static bool f64AssignAAPCS(unsigned &ValNo, MVT &ValVT, MVT &LocVT,
+                           CCValAssign::LocInfo &LocInfo,
+                           CCState &State, bool CanFail) {
+  static const MCPhysReg HiRegList[] = { ARM::R0, ARM::R2 };
+  static const MCPhysReg LoRegList[] = { ARM::R1, ARM::R3 };
+  static const MCPhysReg ShadowRegList[] = { ARM::R0, ARM::R1 };
+  static const MCPhysReg GPRArgRegs[] = { ARM::R0, ARM::R1, ARM::R2, ARM::R3 };
+
+  unsigned Reg = State.AllocateReg(HiRegList, ShadowRegList);
+  if (Reg == 0) {
+
+    // If we had R3 unallocated only, now we still must to waste it.
+    Reg = State.AllocateReg(GPRArgRegs);
+    assert((!Reg || Reg == ARM::R3) && "Wrong GPRs usage for f64");
+
+    // For the 2nd half of a v2f64, do not just fail.
+    if (CanFail)
+      return false;
+
+    // Put the whole thing on the stack.
+    State.addLoc(CCValAssign::getCustomMem(ValNo, ValVT,
+                                           State.AllocateStack(8, 8),
+                                           LocVT, LocInfo));
+    return true;
+  }
+
+  unsigned i;
+  for (i = 0; i < 2; ++i)
+    if (HiRegList[i] == Reg)
+      break;
+
+  unsigned T = State.AllocateReg(LoRegList[i]);
+  (void)T;
+  assert(T == LoRegList[i] && "Could not allocate register");
+
+  State.addLoc(CCValAssign::getCustomReg(ValNo, ValVT, Reg, LocVT, LocInfo));
+  State.addLoc(CCValAssign::getCustomReg(ValNo, ValVT, LoRegList[i],
+                                         LocVT, LocInfo));
+  return true;
+}
+
+static bool CC_ARM_AAPCS_Custom_f64(unsigned &ValNo, MVT &ValVT, MVT &LocVT,
+                                    CCValAssign::LocInfo &LocInfo,
+                                    ISD::ArgFlagsTy &ArgFlags,
+                                    CCState &State) {
+  if (!f64AssignAAPCS(ValNo, ValVT, LocVT, LocInfo, State, true))
+    return false;
+  if (LocVT == MVT::v2f64 &&
+      !f64AssignAAPCS(ValNo, ValVT, LocVT, LocInfo, State, false))
+    return false;
+  return true;  // we handled it
+}
+
+static bool f64RetAssign(unsigned &ValNo, MVT &ValVT, MVT &LocVT,
+                         CCValAssign::LocInfo &LocInfo, CCState &State) {
+  static const MCPhysReg HiRegList[] = { ARM::R0, ARM::R2 };
+  static const MCPhysReg LoRegList[] = { ARM::R1, ARM::R3 };
+
+  unsigned Reg = State.AllocateReg(HiRegList, LoRegList);
+  if (Reg == 0)
+    return false; // we didn't handle it
+
+  unsigned i;
+  for (i = 0; i < 2; ++i)
+    if (HiRegList[i] == Reg)
+      break;
+
+  State.addLoc(CCValAssign::getCustomReg(ValNo, ValVT, Reg, LocVT, LocInfo));
+  State.addLoc(CCValAssign::getCustomReg(ValNo, ValVT, LoRegList[i],
+                                         LocVT, LocInfo));
+  return true;
+}
+
+static bool RetCC_ARM_APCS_Custom_f64(unsigned &ValNo, MVT &ValVT, MVT &LocVT,
+                                      CCValAssign::LocInfo &LocInfo,
+                                      ISD::ArgFlagsTy &ArgFlags,
+                                      CCState &State) {
+  if (!f64RetAssign(ValNo, ValVT, LocVT, LocInfo, State))
+    return false;
+  if (LocVT == MVT::v2f64 && !f64RetAssign(ValNo, ValVT, LocVT, LocInfo, State))
+    return false;
+  return true;  // we handled it
+}
+
+static bool RetCC_ARM_AAPCS_Custom_f64(unsigned &ValNo, MVT &ValVT, MVT &LocVT,
+                                       CCValAssign::LocInfo &LocInfo,
+                                       ISD::ArgFlagsTy &ArgFlags,
+                                       CCState &State) {
+  return RetCC_ARM_APCS_Custom_f64(ValNo, ValVT, LocVT, LocInfo, ArgFlags,
+                                   State);
+}
+
+static const MCPhysReg RRegList[] = { ARM::R0,  ARM::R1,  ARM::R2,  ARM::R3 };
+
+static const MCPhysReg SRegList[] = { ARM::S0,  ARM::S1,  ARM::S2,  ARM::S3,
+                                      ARM::S4,  ARM::S5,  ARM::S6,  ARM::S7,
+                                      ARM::S8,  ARM::S9,  ARM::S10, ARM::S11,
+                                      ARM::S12, ARM::S13, ARM::S14,  ARM::S15 };
+static const MCPhysReg DRegList[] = { ARM::D0, ARM::D1, ARM::D2, ARM::D3,
+                                      ARM::D4, ARM::D5, ARM::D6, ARM::D7 };
+static const MCPhysReg QRegList[] = { ARM::Q0, ARM::Q1, ARM::Q2, ARM::Q3 };
+
+
+// Allocate part of an AAPCS HFA or HVA. We assume that each member of the HA
+// has InConsecutiveRegs set, and that the last member also has
+// InConsecutiveRegsLast set. We must process all members of the HA before
+// we can allocate it, as we need to know the total number of registers that
+// will be needed in order to (attempt to) allocate a contiguous block.
+static bool CC_ARM_AAPCS_Custom_Aggregate(unsigned &ValNo, MVT &ValVT,
+                                          MVT &LocVT,
+                                          CCValAssign::LocInfo &LocInfo,
+                                          ISD::ArgFlagsTy &ArgFlags,
+                                          CCState &State) {
+  SmallVectorImpl<CCValAssign> &PendingMembers = State.getPendingLocs();
+
+  // AAPCS HFAs must have 1-4 elements, all of the same type
+  if (PendingMembers.size() > 0)
+    assert(PendingMembers[0].getLocVT() == LocVT);
+
+  // Add the argument to the list to be allocated once we know the size of the
+  // aggregate. Store the type's required alignmnent as extra info for later: in
+  // the [N x i64] case all trace has been removed by the time we actually get
+  // to do allocation.
+  PendingMembers.push_back(CCValAssign::getPending(ValNo, ValVT, LocVT, LocInfo,
+                                                   ArgFlags.getOrigAlign()));
+
+  if (!ArgFlags.isInConsecutiveRegsLast())
+    return true;
+
+  // Try to allocate a contiguous block of registers, each of the correct
+  // size to hold one member.
+  auto &DL = State.getMachineFunction().getDataLayout();
+  unsigned StackAlign = DL.getStackAlignment().value();
+  unsigned Align = std::min(PendingMembers[0].getExtraInfo(), StackAlign);
+
+  ArrayRef<MCPhysReg> RegList;
+  switch (LocVT.SimpleTy) {
+  case MVT::i32: {
+    RegList = RRegList;
+    unsigned RegIdx = State.getFirstUnallocated(RegList);
+
+    // First consume all registers that would give an unaligned object. Whether
+    // we go on stack or in regs, no-one will be using them in future.
+    unsigned RegAlign = alignTo(Align, 4) / 4;
+    while (RegIdx % RegAlign != 0 && RegIdx < RegList.size())
+      State.AllocateReg(RegList[RegIdx++]);
+
+    break;
+  }
+  case MVT::f16:
+  case MVT::f32:
+    RegList = SRegList;
+    break;
+  case MVT::v4f16:
+  case MVT::f64:
+    RegList = DRegList;
+    break;
+  case MVT::v8f16:
+  case MVT::v2f64:
+    RegList = QRegList;
+    break;
+  default:
+    llvm_unreachable("Unexpected member type for block aggregate");
+    break;
+  }
+
+  unsigned RegResult = State.AllocateRegBlock(RegList, PendingMembers.size());
+  if (RegResult) {
+    for (SmallVectorImpl<CCValAssign>::iterator It = PendingMembers.begin();
+         It != PendingMembers.end(); ++It) {
+      It->convertToReg(RegResult);
+      State.addLoc(*It);
+      ++RegResult;
+    }
+    PendingMembers.clear();
+    return true;
+  }
+
+  // Register allocation failed, we'll be needing the stack
+  unsigned Size = LocVT.getSizeInBits() / 8;
+  if (LocVT == MVT::i32 && State.getNextStackOffset() == 0) {
+    // If nothing else has used the stack until this point, a non-HFA aggregate
+    // can be split between regs and stack.
+    unsigned RegIdx = State.getFirstUnallocated(RegList);
+    for (auto &It : PendingMembers) {
+      if (RegIdx >= RegList.size())
+        It.convertToMem(State.AllocateStack(Size, Size));
+      else
+        It.convertToReg(State.AllocateReg(RegList[RegIdx++]));
+
+      State.addLoc(It);
+    }
+    PendingMembers.clear();
+    return true;
+  } else if (LocVT != MVT::i32)
+    RegList = SRegList;
+
+  // Mark all regs as unavailable (AAPCS rule C.2.vfp for VFP, C.6 for core)
+  for (auto Reg : RegList)
+    State.AllocateReg(Reg);
+
+  // After the first item has been allocated, the rest are packed as tightly as
+  // possible. (E.g. an incoming i64 would have starting Align of 8, but we'll
+  // be allocating a bunch of i32 slots).
+  unsigned RestAlign = std::min(Align, Size);
+
+  for (auto &It : PendingMembers) {
+    It.convertToMem(State.AllocateStack(Size, Align));
+    State.addLoc(It);
+    Align = RestAlign;
+  }
+
+  // All pending members have now been allocated
+  PendingMembers.clear();
+
+  // This will be allocated by the last member of the aggregate
+  return true;
+}
+
+// Include the table generated calling convention implementations.
+#include "ARMGenCallingConv.inc"