1 //===- AlphaRegisterInfo.cpp - Alpha Register Information -------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains the Alpha implementation of the MRegisterInfo class.
12 //===----------------------------------------------------------------------===//
14 #define DEBUG_TYPE "reginfo"
16 #include "AlphaRegisterInfo.h"
17 #include "llvm/Constants.h"
18 #include "llvm/Type.h"
19 #include "llvm/CodeGen/ValueTypes.h"
20 #include "llvm/CodeGen/MachineInstrBuilder.h"
21 #include "llvm/CodeGen/MachineFunction.h"
22 #include "llvm/CodeGen/MachineFrameInfo.h"
23 #include "llvm/Target/TargetFrameInfo.h"
24 #include "llvm/Target/TargetMachine.h"
25 #include "llvm/Target/TargetOptions.h"
26 #include "llvm/Support/CommandLine.h"
27 #include "llvm/Support/Debug.h"
28 #include "llvm/ADT/STLExtras.h"
34 static const int64_t IMM_LOW = 0xffffffffffff8000LL;
35 static const int IMM_HIGH = 0x0000000000007fffLL;
36 static const int IMM_MULT = 65536;
38 static long getUpper16(long l)
40 long y = l / IMM_MULT;
41 if (l % IMM_MULT > IMM_HIGH)
46 static long getLower16(long l)
48 long h = getUpper16(l);
49 return l - h * IMM_MULT;
52 AlphaRegisterInfo::AlphaRegisterInfo()
53 : AlphaGenRegisterInfo(Alpha::ADJUSTSTACKDOWN, Alpha::ADJUSTSTACKUP)
57 static const TargetRegisterClass *getClass(unsigned SrcReg) {
58 if (Alpha::FPRCRegisterClass->contains(SrcReg))
59 return Alpha::FPRCRegisterClass;
60 assert(Alpha::GPRCRegisterClass->contains(SrcReg) && "Reg not FPR or GPR");
61 return Alpha::GPRCRegisterClass;
65 AlphaRegisterInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
66 MachineBasicBlock::iterator MI,
67 unsigned SrcReg, int FrameIdx) const {
68 //std::cerr << "Trying to store " << getPrettyName(SrcReg) << " to " << FrameIdx << "\n";
69 //BuildMI(MBB, MI, Alpha::WTF, 0).addReg(SrcReg);
70 if (getClass(SrcReg) == Alpha::FPRCRegisterClass)
71 BuildMI(MBB, MI, Alpha::STT, 3).addReg(SrcReg).addFrameIndex(FrameIdx).addReg(Alpha::F31);
72 else if (getClass(SrcReg) == Alpha::GPRCRegisterClass)
73 BuildMI(MBB, MI, Alpha::STQ, 3).addReg(SrcReg).addFrameIndex(FrameIdx).addReg(Alpha::F31);
79 AlphaRegisterInfo::loadRegFromStackSlot(MachineBasicBlock &MBB,
80 MachineBasicBlock::iterator MI,
81 unsigned DestReg, int FrameIdx) const{
82 //std::cerr << "Trying to load " << getPrettyName(DestReg) << " to " << FrameIdx << "\n";
83 if (getClass(DestReg) == Alpha::FPRCRegisterClass)
84 BuildMI(MBB, MI, Alpha::LDT, 2, DestReg).addFrameIndex(FrameIdx).addReg(Alpha::F31);
85 else if (getClass(DestReg) == Alpha::GPRCRegisterClass)
86 BuildMI(MBB, MI, Alpha::LDQ, 2, DestReg).addFrameIndex(FrameIdx).addReg(Alpha::F31);
91 void AlphaRegisterInfo::copyRegToReg(MachineBasicBlock &MBB,
92 MachineBasicBlock::iterator MI,
93 unsigned DestReg, unsigned SrcReg,
94 const TargetRegisterClass *RC) const {
95 // std::cerr << "copyRegToReg " << DestReg << " <- " << SrcReg << "\n";
96 if (RC == Alpha::GPRCRegisterClass) {
97 BuildMI(MBB, MI, Alpha::BIS, 2, DestReg).addReg(SrcReg).addReg(SrcReg);
98 } else if (RC == Alpha::FPRCRegisterClass) {
99 BuildMI(MBB, MI, Alpha::CPYS, 2, DestReg).addReg(SrcReg).addReg(SrcReg);
101 std::cerr << "Attempt to copy register that is not GPR or FPR";
106 //===----------------------------------------------------------------------===//
107 // Stack Frame Processing methods
108 //===----------------------------------------------------------------------===//
110 // hasFP - Return true if the specified function should have a dedicated frame
111 // pointer register. This is true if the function has variable sized allocas or
112 // if frame pointer elimination is disabled.
114 static bool hasFP(MachineFunction &MF) {
115 MachineFrameInfo *MFI = MF.getFrameInfo();
116 return MFI->hasVarSizedObjects();
119 void AlphaRegisterInfo::
120 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
121 MachineBasicBlock::iterator I) const {
123 // If we have a frame pointer, turn the adjcallstackup instruction into a
124 // 'sub ESP, <amt>' and the adjcallstackdown instruction into 'add ESP,
126 MachineInstr *Old = I;
127 unsigned Amount = Old->getOperand(0).getImmedValue();
129 // We need to keep the stack aligned properly. To do this, we round the
130 // amount of space needed for the outgoing arguments up to the next
131 // alignment boundary.
132 unsigned Align = MF.getTarget().getFrameInfo()->getStackAlignment();
133 Amount = (Amount+Align-1)/Align*Align;
136 if (Old->getOpcode() == Alpha::ADJUSTSTACKDOWN) {
137 New=BuildMI(Alpha::LDA, 2, Alpha::R30)
138 .addImm(-Amount).addReg(Alpha::R30);
140 assert(Old->getOpcode() == Alpha::ADJUSTSTACKUP);
141 New=BuildMI(Alpha::LDA, 2, Alpha::R30)
142 .addImm(Amount).addReg(Alpha::R30);
145 // Replace the pseudo instruction with a new instruction...
153 //Alpha has a slightly funny stack:
156 //fixed locals (and spills, callee saved, etc)
162 AlphaRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II) const {
164 MachineInstr &MI = *II;
165 MachineBasicBlock &MBB = *MI.getParent();
166 MachineFunction &MF = *MBB.getParent();
169 while (!MI.getOperand(i).isFrameIndex()) {
171 assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
174 int FrameIndex = MI.getOperand(i).getFrameIndex();
176 // Add the base register of R30 (SP) or R15 (FP).
177 MI.SetMachineOperandReg(i + 1, FP ? Alpha::R15 : Alpha::R30);
179 // Now add the frame object offset to the offset from the virtual frame index.
180 int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex);
182 DEBUG(std::cerr << "FI: " << FrameIndex << " Offset: " << Offset << "\n");
184 Offset += MF.getFrameInfo()->getStackSize();
186 DEBUG(std::cerr << "Corrected Offset " << Offset <<
187 " for stack size: " << MF.getFrameInfo()->getStackSize() << "\n");
189 if (Offset > IMM_HIGH || Offset < IMM_LOW) {
190 //so in this case, we need to use a temporary register, and move the original
193 MI.SetMachineOperandReg(i + 1, Alpha::R28);
194 MI.SetMachineOperandConst(i, MachineOperand::MO_SignExtendedImmed,
197 MachineInstr* nMI=BuildMI(Alpha::LDAH, 2, Alpha::R28)
198 .addImm(getUpper16(Offset)).addReg(FP ? Alpha::R15 : Alpha::R30);
199 MBB.insert(--II, nMI);
201 MI.SetMachineOperandConst(i, MachineOperand::MO_SignExtendedImmed, Offset);
206 void AlphaRegisterInfo::emitPrologue(MachineFunction &MF) const {
207 MachineBasicBlock &MBB = MF.front(); // Prolog goes in entry BB
208 MachineBasicBlock::iterator MBBI = MBB.begin();
209 MachineFrameInfo *MFI = MF.getFrameInfo();
214 MI = BuildMI(Alpha::LDGP, 0);
215 MBB.insert(MBBI, MI);
217 // Get the number of bytes to allocate from the FrameInfo
218 long NumBytes = MFI->getStackSize();
220 if (MFI->hasCalls() && !FP) {
221 // We reserve argument space for call sites in the function immediately on
222 // entry to the current function. This eliminates the need for add/sub
223 // brackets around call sites.
224 //If there is a frame pointer, then we don't do this
225 NumBytes += MFI->getMaxCallFrameSize();
226 DEBUG(std::cerr << "Added " << MFI->getMaxCallFrameSize()
227 << " to the stack due to calls\n");
231 NumBytes += 8; //reserve space for the old FP
233 // Do we need to allocate space on the stack?
234 if (NumBytes == 0) return;
236 // Update frame info to pretend that this is part of the stack...
237 MFI->setStackSize(NumBytes);
239 // adjust stack pointer: r30 -= numbytes
240 NumBytes = -NumBytes;
241 if (NumBytes >= IMM_LOW) {
242 MI=BuildMI(Alpha::LDA, 2, Alpha::R30).addImm(NumBytes).addReg(Alpha::R30);
243 MBB.insert(MBBI, MI);
244 } else if (getUpper16(NumBytes) >= IMM_LOW) {
245 MI=BuildMI(Alpha::LDAH, 2, Alpha::R30).addImm(getUpper16(NumBytes)).addReg(Alpha::R30);
246 MBB.insert(MBBI, MI);
247 MI=BuildMI(Alpha::LDA, 2, Alpha::R30).addImm(getLower16(NumBytes)).addReg(Alpha::R30);
248 MBB.insert(MBBI, MI);
250 std::cerr << "Too big a stack frame at " << NumBytes << "\n";
254 //now if we need to, save the old FP and set the new
257 MI=BuildMI(Alpha::STQ, 3).addReg(Alpha::R15).addImm(0).addReg(Alpha::R30);
258 MBB.insert(MBBI, MI);
259 //this must be the last instr in the prolog
260 MI=BuildMI(Alpha::BIS, 2, Alpha::R15).addReg(Alpha::R30).addReg(Alpha::R30);
261 MBB.insert(MBBI, MI);
266 void AlphaRegisterInfo::emitEpilogue(MachineFunction &MF,
267 MachineBasicBlock &MBB) const {
268 const MachineFrameInfo *MFI = MF.getFrameInfo();
269 MachineBasicBlock::iterator MBBI = prior(MBB.end());
271 assert((MBBI->getOpcode() == Alpha::RET || MBBI->getOpcode() == Alpha::RETURN) &&
272 "Can only insert epilog into returning blocks");
276 // Get the number of bytes allocated from the FrameInfo...
277 long NumBytes = MFI->getStackSize();
279 //now if we need to, restore the old FP
282 //copy the FP into the SP (discards allocas)
283 MI=BuildMI(Alpha::BIS, 2, Alpha::R30).addReg(Alpha::R15).addReg(Alpha::R15);
284 MBB.insert(MBBI, MI);
286 MI=BuildMI(Alpha::LDQ, 2, Alpha::R15).addImm(0).addReg(Alpha::R15);
287 MBB.insert(MBBI, MI);
292 if (NumBytes <= IMM_HIGH) {
293 MI=BuildMI(Alpha::LDA, 2, Alpha::R30).addImm(NumBytes).addReg(Alpha::R30);
294 MBB.insert(MBBI, MI);
295 } else if (getUpper16(NumBytes) <= IMM_HIGH) {
296 MI=BuildMI(Alpha::LDAH, 2, Alpha::R30).addImm(getUpper16(NumBytes)).addReg(Alpha::R30);
297 MBB.insert(MBBI, MI);
298 MI=BuildMI(Alpha::LDA, 2, Alpha::R30).addImm(getLower16(NumBytes)).addReg(Alpha::R30);
299 MBB.insert(MBBI, MI);
301 std::cerr << "Too big a stack frame at " << NumBytes << "\n";
307 #include "AlphaGenRegisterInfo.inc"
309 const TargetRegisterClass*
310 AlphaRegisterInfo::getRegClassForType(const Type* Ty) const {
311 switch (Ty->getTypeID()) {
312 default: assert(0 && "Invalid type to getClass!");
314 case Type::SByteTyID:
315 case Type::UByteTyID:
316 case Type::ShortTyID:
317 case Type::UShortTyID:
320 case Type::PointerTyID:
322 case Type::ULongTyID: return &GPRCInstance;
324 case Type::FloatTyID:
325 case Type::DoubleTyID: return &FPRCInstance;
329 std::string AlphaRegisterInfo::getPrettyName(unsigned reg)
331 std::string s(RegisterDescriptors[reg].Name);