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llvm-mirror/lib/Target/ARM/ARMCallingConv.h
Chandler Carruth ae65e281f3 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00

292 lines
11 KiB
C++

//=== ARMCallingConv.h - ARM Custom Calling Convention 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.
//
//===----------------------------------------------------------------------===//
#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/CodeGen/TargetInstrInfo.h"
#include "llvm/IR/CallingConv.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 = 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;
}
} // End llvm namespace
#endif