//=== ARMCallingConv.h - ARM Custom Calling Convention Routines -*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the custom routines for the ARM Calling Convention that
// aren't done by tablegen.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIB_TARGET_ARM_ARMCALLINGCONV_H
#define LLVM_LIB_TARGET_ARM_ARMCALLINGCONV_H
#include "ARM.h"
#include "ARMBaseInstrInfo.h"
#include "ARMSubtarget.h"
#include "llvm/CodeGen/CallingConvLower.h"
#include "llvm/IR/CallingConv.h"
#include "llvm/Target/TargetInstrInfo.h"
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();
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 = RoundUpToAlignment(Align, 4) / 4;
while (RegIdx % RegAlign != 0 && RegIdx < RegList.size())
State.AllocateReg(RegList[RegIdx++]);
break;
}
case MVT::f32:
RegList = SRegList;
break;
case MVT::f64:
RegList = DRegList;
break;
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);
for (auto &It : PendingMembers) {
It.convertToMem(State.AllocateStack(Size, Align));
State.addLoc(It);
// 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).
Align = Size;
}
// All pending members have now been allocated
PendingMembers.clear();
// This will be allocated by the last member of the aggregate
return true;
}
} // End llvm namespace
#endif