1 //===- X86RegisterInfo.cpp - X86 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 X86 implementation of the MRegisterInfo class. This
11 // file is responsible for the frame pointer elimination optimization on X86.
13 //===----------------------------------------------------------------------===//
16 #include "X86RegisterInfo.h"
17 #include "X86InstrBuilder.h"
18 #include "llvm/Constants.h"
19 #include "llvm/Type.h"
20 #include "llvm/CodeGen/ValueTypes.h"
21 #include "llvm/CodeGen/MachineInstrBuilder.h"
22 #include "llvm/CodeGen/MachineFunction.h"
23 #include "llvm/CodeGen/MachineFrameInfo.h"
24 #include "llvm/Target/TargetFrameInfo.h"
25 #include "llvm/Target/TargetMachine.h"
26 #include "llvm/Target/TargetOptions.h"
27 #include "Support/CommandLine.h"
28 #include "Support/STLExtras.h"
35 NoFusing("disable-spill-fusing",
36 cl::desc("Disable fusing of spill code into instructions"));
38 PrintFailedFusing("print-failed-fuse-candidates",
39 cl::desc("Print instructions that the allocator wants to"
40 " fuse, but the X86 backend currently can't"),
44 X86RegisterInfo::X86RegisterInfo()
45 : X86GenRegisterInfo(X86::ADJCALLSTACKDOWN, X86::ADJCALLSTACKUP) {}
47 static unsigned getIdx(unsigned SpillSize) {
49 default: assert(0 && "Invalid data size!");
57 void X86RegisterInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
58 MachineBasicBlock::iterator MI,
59 unsigned SrcReg, int FrameIdx) const {
60 static const unsigned Opcode[] =
61 { X86::MOV8mr, X86::MOV16mr, X86::MOV32mr, X86::FSTP80m };
62 unsigned Idx = getIdx(getSpillSize(SrcReg));
63 addFrameReference(BuildMI(MBB, MI, Opcode[Idx], 5), FrameIdx).addReg(SrcReg);
66 void X86RegisterInfo::loadRegFromStackSlot(MachineBasicBlock &MBB,
67 MachineBasicBlock::iterator MI,
68 unsigned DestReg, int FrameIdx)const{
69 static const unsigned Opcode[] =
70 { X86::MOV8rm, X86::MOV16rm, X86::MOV32rm, X86::FLD80m };
71 unsigned Idx = getIdx(getSpillSize(DestReg));
72 addFrameReference(BuildMI(MBB, MI, Opcode[Idx], 4, DestReg), FrameIdx);
75 void X86RegisterInfo::copyRegToReg(MachineBasicBlock &MBB,
76 MachineBasicBlock::iterator MI,
77 unsigned DestReg, unsigned SrcReg,
78 const TargetRegisterClass *RC) const {
79 static const unsigned Opcode[] =
80 { X86::MOV8rr, X86::MOV16rr, X86::MOV32rr, X86::FpMOV };
81 BuildMI(MBB, MI, Opcode[getIdx(RC->getSize()*8)], 1, DestReg).addReg(SrcReg);
84 static MachineInstr *MakeMInst(unsigned Opcode, unsigned FrameIndex,
86 return addFrameReference(BuildMI(Opcode, 4), FrameIndex);
89 static MachineInstr *MakeMRInst(unsigned Opcode, unsigned FrameIndex,
91 return addFrameReference(BuildMI(Opcode, 5), FrameIndex)
92 .addReg(MI->getOperand(1).getReg());
95 static MachineInstr *MakeMRIInst(unsigned Opcode, unsigned FrameIndex,
97 return addFrameReference(BuildMI(Opcode, 6), FrameIndex)
98 .addReg(MI->getOperand(1).getReg())
99 .addZImm(MI->getOperand(2).getImmedValue());
102 static MachineInstr *MakeMIInst(unsigned Opcode, unsigned FrameIndex,
104 if (MI->getOperand(1).isImmediate())
105 return addFrameReference(BuildMI(Opcode, 5), FrameIndex)
106 .addZImm(MI->getOperand(1).getImmedValue());
107 else if (MI->getOperand(1).isGlobalAddress())
108 return addFrameReference(BuildMI(Opcode, 5), FrameIndex)
109 .addGlobalAddress(MI->getOperand(1).getGlobal());
110 assert(0 && "Unknown operand for MakeMI!");
114 static MachineInstr *MakeRMInst(unsigned Opcode, unsigned FrameIndex,
116 const MachineOperand& op = MI->getOperand(0);
117 return addFrameReference(BuildMI(Opcode, 5, op.getReg(), op.getUseType()),
121 static MachineInstr *MakeRMIInst(unsigned Opcode, unsigned FrameIndex,
123 const MachineOperand& op = MI->getOperand(0);
124 return addFrameReference(BuildMI(Opcode, 6, op.getReg(), op.getUseType()),
125 FrameIndex).addZImm(MI->getOperand(2).getImmedValue());
129 MachineInstr* X86RegisterInfo::foldMemoryOperand(MachineInstr* MI,
131 int FrameIndex) const {
132 if (NoFusing) return NULL;
134 /// FIXME: This should obviously be autogenerated by tablegen when patterns
136 MachineBasicBlock& MBB = *MI->getParent();
138 switch(MI->getOpcode()) {
139 case X86::XCHG8rr: return MakeMRInst(X86::XCHG8mr ,FrameIndex, MI);
140 case X86::XCHG16rr: return MakeMRInst(X86::XCHG16mr,FrameIndex, MI);
141 case X86::XCHG32rr: return MakeMRInst(X86::XCHG32mr,FrameIndex, MI);
142 case X86::MOV8rr: return MakeMRInst(X86::MOV8mr , FrameIndex, MI);
143 case X86::MOV16rr: return MakeMRInst(X86::MOV16mr, FrameIndex, MI);
144 case X86::MOV32rr: return MakeMRInst(X86::MOV32mr, FrameIndex, MI);
145 case X86::MOV8ri: return MakeMIInst(X86::MOV8mi , FrameIndex, MI);
146 case X86::MOV16ri: return MakeMIInst(X86::MOV16mi, FrameIndex, MI);
147 case X86::MOV32ri: return MakeMIInst(X86::MOV32mi, FrameIndex, MI);
148 case X86::MUL8r: return MakeMInst( X86::MUL8m , FrameIndex, MI);
149 case X86::MUL16r: return MakeMInst( X86::MUL16m, FrameIndex, MI);
150 case X86::MUL32r: return MakeMInst( X86::MUL32m, FrameIndex, MI);
151 case X86::DIV8r: return MakeMInst( X86::DIV8m , FrameIndex, MI);
152 case X86::DIV16r: return MakeMInst( X86::DIV16m, FrameIndex, MI);
153 case X86::DIV32r: return MakeMInst( X86::DIV32m, FrameIndex, MI);
154 case X86::IDIV8r: return MakeMInst( X86::IDIV8m , FrameIndex, MI);
155 case X86::IDIV16r: return MakeMInst( X86::IDIV16m, FrameIndex, MI);
156 case X86::IDIV32r: return MakeMInst( X86::IDIV32m, FrameIndex, MI);
157 case X86::NEG8r: return MakeMInst( X86::NEG8m , FrameIndex, MI);
158 case X86::NEG16r: return MakeMInst( X86::NEG16m, FrameIndex, MI);
159 case X86::NEG32r: return MakeMInst( X86::NEG32m, FrameIndex, MI);
160 case X86::NOT8r: return MakeMInst( X86::NOT8m , FrameIndex, MI);
161 case X86::NOT16r: return MakeMInst( X86::NOT16m, FrameIndex, MI);
162 case X86::NOT32r: return MakeMInst( X86::NOT32m, FrameIndex, MI);
163 case X86::INC8r: return MakeMInst( X86::INC8m , FrameIndex, MI);
164 case X86::INC16r: return MakeMInst( X86::INC16m, FrameIndex, MI);
165 case X86::INC32r: return MakeMInst( X86::INC32m, FrameIndex, MI);
166 case X86::DEC8r: return MakeMInst( X86::DEC8m , FrameIndex, MI);
167 case X86::DEC16r: return MakeMInst( X86::DEC16m, FrameIndex, MI);
168 case X86::DEC32r: return MakeMInst( X86::DEC32m, FrameIndex, MI);
169 case X86::ADD8rr: return MakeMRInst(X86::ADD8mr , FrameIndex, MI);
170 case X86::ADD16rr: return MakeMRInst(X86::ADD16mr, FrameIndex, MI);
171 case X86::ADD32rr: return MakeMRInst(X86::ADD32mr, FrameIndex, MI);
172 case X86::ADC32rr: return MakeMRInst(X86::ADC32mr, FrameIndex, MI);
173 case X86::ADC32ri: return MakeMIInst(X86::ADC32mi, FrameIndex, MI);
174 case X86::ADD8ri: return MakeMIInst(X86::ADD8mi , FrameIndex, MI);
175 case X86::ADD16ri: return MakeMIInst(X86::ADD16mi, FrameIndex, MI);
176 case X86::ADD32ri: return MakeMIInst(X86::ADD32mi, FrameIndex, MI);
177 case X86::SUB8rr: return MakeMRInst(X86::SUB8mr , FrameIndex, MI);
178 case X86::SUB16rr: return MakeMRInst(X86::SUB16mr, FrameIndex, MI);
179 case X86::SUB32rr: return MakeMRInst(X86::SUB32mr, FrameIndex, MI);
180 case X86::SBB32rr: return MakeMRInst(X86::SBB32mr, FrameIndex, MI);
181 case X86::SBB32ri: return MakeMIInst(X86::SBB32mi, FrameIndex, MI);
182 case X86::SUB8ri: return MakeMIInst(X86::SUB8mi , FrameIndex, MI);
183 case X86::SUB16ri: return MakeMIInst(X86::SUB16mi, FrameIndex, MI);
184 case X86::SUB32ri: return MakeMIInst(X86::SUB32mi, FrameIndex, MI);
185 case X86::AND8rr: return MakeMRInst(X86::AND8mr , FrameIndex, MI);
186 case X86::AND16rr: return MakeMRInst(X86::AND16mr, FrameIndex, MI);
187 case X86::AND32rr: return MakeMRInst(X86::AND32mr, FrameIndex, MI);
188 case X86::AND8ri: return MakeMIInst(X86::AND8mi , FrameIndex, MI);
189 case X86::AND16ri: return MakeMIInst(X86::AND16mi, FrameIndex, MI);
190 case X86::AND32ri: return MakeMIInst(X86::AND32mi, FrameIndex, MI);
191 case X86::OR8rr: return MakeMRInst(X86::OR8mr , FrameIndex, MI);
192 case X86::OR16rr: return MakeMRInst(X86::OR16mr, FrameIndex, MI);
193 case X86::OR32rr: return MakeMRInst(X86::OR32mr, FrameIndex, MI);
194 case X86::OR8ri: return MakeMIInst(X86::OR8mi , FrameIndex, MI);
195 case X86::OR16ri: return MakeMIInst(X86::OR16mi, FrameIndex, MI);
196 case X86::OR32ri: return MakeMIInst(X86::OR32mi, FrameIndex, MI);
197 case X86::XOR8rr: return MakeMRInst(X86::XOR8mr , FrameIndex, MI);
198 case X86::XOR16rr: return MakeMRInst(X86::XOR16mr, FrameIndex, MI);
199 case X86::XOR32rr: return MakeMRInst(X86::XOR32mr, FrameIndex, MI);
200 case X86::XOR8ri: return MakeMIInst(X86::XOR8mi , FrameIndex, MI);
201 case X86::XOR16ri: return MakeMIInst(X86::XOR16mi, FrameIndex, MI);
202 case X86::XOR32ri: return MakeMIInst(X86::XOR32mi, FrameIndex, MI);
203 case X86::SHL8rCL: return MakeMInst( X86::SHL8mCL ,FrameIndex, MI);
204 case X86::SHL16rCL: return MakeMInst( X86::SHL16mCL,FrameIndex, MI);
205 case X86::SHL32rCL: return MakeMInst( X86::SHL32mCL,FrameIndex, MI);
206 case X86::SHL8ri: return MakeMIInst(X86::SHL8mi , FrameIndex, MI);
207 case X86::SHL16ri: return MakeMIInst(X86::SHL16mi, FrameIndex, MI);
208 case X86::SHL32ri: return MakeMIInst(X86::SHL32mi, FrameIndex, MI);
209 case X86::SHR8rCL: return MakeMInst( X86::SHR8mCL ,FrameIndex, MI);
210 case X86::SHR16rCL: return MakeMInst( X86::SHR16mCL,FrameIndex, MI);
211 case X86::SHR32rCL: return MakeMInst( X86::SHR32mCL,FrameIndex, MI);
212 case X86::SHR8ri: return MakeMIInst(X86::SHR8mi , FrameIndex, MI);
213 case X86::SHR16ri: return MakeMIInst(X86::SHR16mi, FrameIndex, MI);
214 case X86::SHR32ri: return MakeMIInst(X86::SHR32mi, FrameIndex, MI);
215 case X86::SAR8rCL: return MakeMInst( X86::SAR8mCL ,FrameIndex, MI);
216 case X86::SAR16rCL: return MakeMInst( X86::SAR16mCL,FrameIndex, MI);
217 case X86::SAR32rCL: return MakeMInst( X86::SAR32mCL,FrameIndex, MI);
218 case X86::SAR8ri: return MakeMIInst(X86::SAR8mi , FrameIndex, MI);
219 case X86::SAR16ri: return MakeMIInst(X86::SAR16mi, FrameIndex, MI);
220 case X86::SAR32ri: return MakeMIInst(X86::SAR32mi, FrameIndex, MI);
221 case X86::SHLD32rrCL:return MakeMRInst( X86::SHLD32mrCL,FrameIndex, MI);
222 case X86::SHLD32rri8:return MakeMRIInst(X86::SHLD32mri8,FrameIndex, MI);
223 case X86::SHRD32rrCL:return MakeMRInst( X86::SHRD32mrCL,FrameIndex, MI);
224 case X86::SHRD32rri8:return MakeMRIInst(X86::SHRD32mri8,FrameIndex, MI);
225 case X86::SETBr: return MakeMInst( X86::SETBm, FrameIndex, MI);
226 case X86::SETAEr: return MakeMInst( X86::SETAEm, FrameIndex, MI);
227 case X86::SETEr: return MakeMInst( X86::SETEm, FrameIndex, MI);
228 case X86::SETNEr: return MakeMInst( X86::SETNEm, FrameIndex, MI);
229 case X86::SETBEr: return MakeMInst( X86::SETBEm, FrameIndex, MI);
230 case X86::SETAr: return MakeMInst( X86::SETAm, FrameIndex, MI);
231 case X86::SETSr: return MakeMInst( X86::SETSm, FrameIndex, MI);
232 case X86::SETNSr: return MakeMInst( X86::SETNSm, FrameIndex, MI);
233 case X86::SETPr: return MakeMInst( X86::SETPm, FrameIndex, MI);
234 case X86::SETLr: return MakeMInst( X86::SETLm, FrameIndex, MI);
235 case X86::SETGEr: return MakeMInst( X86::SETGEm, FrameIndex, MI);
236 case X86::SETLEr: return MakeMInst( X86::SETLEm, FrameIndex, MI);
237 case X86::SETGr: return MakeMInst( X86::SETGm, FrameIndex, MI);
238 case X86::TEST8rr: return MakeMRInst(X86::TEST8mr ,FrameIndex, MI);
239 case X86::TEST16rr: return MakeMRInst(X86::TEST16mr,FrameIndex, MI);
240 case X86::TEST32rr: return MakeMRInst(X86::TEST32mr,FrameIndex, MI);
241 case X86::TEST8ri: return MakeMIInst(X86::TEST8mi ,FrameIndex, MI);
242 case X86::TEST16ri: return MakeMIInst(X86::TEST16mi,FrameIndex, MI);
243 case X86::TEST32ri: return MakeMIInst(X86::TEST32mi,FrameIndex, MI);
244 case X86::CMP8rr: return MakeMRInst(X86::CMP8mr , FrameIndex, MI);
245 case X86::CMP16rr: return MakeMRInst(X86::CMP16mr, FrameIndex, MI);
246 case X86::CMP32rr: return MakeMRInst(X86::CMP32mr, FrameIndex, MI);
247 case X86::CMP8ri: return MakeMIInst(X86::CMP8mi , FrameIndex, MI);
248 case X86::CMP16ri: return MakeMIInst(X86::CMP16mi, FrameIndex, MI);
249 case X86::CMP32ri: return MakeMIInst(X86::CMP32mi, FrameIndex, MI);
252 switch(MI->getOpcode()) {
253 case X86::XCHG8rr: return MakeRMInst(X86::XCHG8rm ,FrameIndex, MI);
254 case X86::XCHG16rr: return MakeRMInst(X86::XCHG16rm,FrameIndex, MI);
255 case X86::XCHG32rr: return MakeRMInst(X86::XCHG32rm,FrameIndex, MI);
256 case X86::MOV8rr: return MakeRMInst(X86::MOV8rm , FrameIndex, MI);
257 case X86::MOV16rr: return MakeRMInst(X86::MOV16rm, FrameIndex, MI);
258 case X86::MOV32rr: return MakeRMInst(X86::MOV32rm, FrameIndex, MI);
259 case X86::CMOVB16rr: return MakeRMInst(X86::CMOVB16rm , FrameIndex, MI);
260 case X86::CMOVB32rr: return MakeRMInst(X86::CMOVB32rm , FrameIndex, MI);
261 case X86::CMOVAE16rr: return MakeRMInst(X86::CMOVAE16rm , FrameIndex, MI);
262 case X86::CMOVAE32rr: return MakeRMInst(X86::CMOVAE32rm , FrameIndex, MI);
263 case X86::CMOVE16rr: return MakeRMInst(X86::CMOVE16rm , FrameIndex, MI);
264 case X86::CMOVE32rr: return MakeRMInst(X86::CMOVE32rm , FrameIndex, MI);
265 case X86::CMOVNE16rr:return MakeRMInst(X86::CMOVNE16rm, FrameIndex, MI);
266 case X86::CMOVNE32rr:return MakeRMInst(X86::CMOVNE32rm, FrameIndex, MI);
267 case X86::CMOVBE16rr:return MakeRMInst(X86::CMOVBE16rm, FrameIndex, MI);
268 case X86::CMOVBE32rr:return MakeRMInst(X86::CMOVBE32rm, FrameIndex, MI);
269 case X86::CMOVA16rr:return MakeRMInst(X86::CMOVA16rm, FrameIndex, MI);
270 case X86::CMOVA32rr:return MakeRMInst(X86::CMOVA32rm, FrameIndex, MI);
271 case X86::CMOVS16rr: return MakeRMInst(X86::CMOVS16rm , FrameIndex, MI);
272 case X86::CMOVS32rr: return MakeRMInst(X86::CMOVS32rm , FrameIndex, MI);
273 case X86::CMOVNS16rr: return MakeRMInst(X86::CMOVNS16rm , FrameIndex, MI);
274 case X86::CMOVNS32rr: return MakeRMInst(X86::CMOVNS32rm , FrameIndex, MI);
275 case X86::CMOVL16rr: return MakeRMInst(X86::CMOVL16rm , FrameIndex, MI);
276 case X86::CMOVL32rr: return MakeRMInst(X86::CMOVL32rm , FrameIndex, MI);
277 case X86::CMOVGE16rr: return MakeRMInst(X86::CMOVGE16rm , FrameIndex, MI);
278 case X86::CMOVGE32rr: return MakeRMInst(X86::CMOVGE32rm , FrameIndex, MI);
279 case X86::CMOVLE16rr: return MakeRMInst(X86::CMOVLE16rm , FrameIndex, MI);
280 case X86::CMOVLE32rr: return MakeRMInst(X86::CMOVLE32rm , FrameIndex, MI);
281 case X86::CMOVG16rr: return MakeRMInst(X86::CMOVG16rm , FrameIndex, MI);
282 case X86::CMOVG32rr: return MakeRMInst(X86::CMOVG32rm , FrameIndex, MI);
283 case X86::ADD8rr: return MakeRMInst(X86::ADD8rm , FrameIndex, MI);
284 case X86::ADD16rr: return MakeRMInst(X86::ADD16rm, FrameIndex, MI);
285 case X86::ADD32rr: return MakeRMInst(X86::ADD32rm, FrameIndex, MI);
286 case X86::ADC32rr: return MakeRMInst(X86::ADC32rm, FrameIndex, MI);
287 case X86::SUB8rr: return MakeRMInst(X86::SUB8rm , FrameIndex, MI);
288 case X86::SUB16rr: return MakeRMInst(X86::SUB16rm, FrameIndex, MI);
289 case X86::SUB32rr: return MakeRMInst(X86::SUB32rm, FrameIndex, MI);
290 case X86::SBB32rr: return MakeRMInst(X86::SBB32rm, FrameIndex, MI);
291 case X86::AND8rr: return MakeRMInst(X86::AND8rm , FrameIndex, MI);
292 case X86::AND16rr: return MakeRMInst(X86::AND16rm, FrameIndex, MI);
293 case X86::AND32rr: return MakeRMInst(X86::AND32rm, FrameIndex, MI);
294 case X86::OR8rr: return MakeRMInst(X86::OR8rm , FrameIndex, MI);
295 case X86::OR16rr: return MakeRMInst(X86::OR16rm, FrameIndex, MI);
296 case X86::OR32rr: return MakeRMInst(X86::OR32rm, FrameIndex, MI);
297 case X86::XOR8rr: return MakeRMInst(X86::XOR8rm , FrameIndex, MI);
298 case X86::XOR16rr: return MakeRMInst(X86::XOR16rm, FrameIndex, MI);
299 case X86::XOR32rr: return MakeRMInst(X86::XOR32rm, FrameIndex, MI);
300 case X86::TEST8rr: return MakeRMInst(X86::TEST8rm ,FrameIndex, MI);
301 case X86::TEST16rr: return MakeRMInst(X86::TEST16rm,FrameIndex, MI);
302 case X86::TEST32rr: return MakeRMInst(X86::TEST32rm,FrameIndex, MI);
303 case X86::IMUL16rr: return MakeRMInst(X86::IMUL16rm,FrameIndex, MI);
304 case X86::IMUL32rr: return MakeRMInst(X86::IMUL32rm,FrameIndex, MI);
305 case X86::IMUL16rri: return MakeRMIInst(X86::IMUL16rmi, FrameIndex, MI);
306 case X86::IMUL32rri: return MakeRMIInst(X86::IMUL32rmi, FrameIndex, MI);
307 case X86::CMP8rr: return MakeRMInst(X86::CMP8rm , FrameIndex, MI);
308 case X86::CMP16rr: return MakeRMInst(X86::CMP16rm, FrameIndex, MI);
309 case X86::CMP32rr: return MakeRMInst(X86::CMP32rm, FrameIndex, MI);
310 case X86::MOVSX16rr8:return MakeRMInst(X86::MOVSX16rm8 , FrameIndex, MI);
311 case X86::MOVSX32rr8:return MakeRMInst(X86::MOVSX32rm8, FrameIndex, MI);
312 case X86::MOVSX32rr16:return MakeRMInst(X86::MOVSX32rm16, FrameIndex, MI);
313 case X86::MOVZX16rr8:return MakeRMInst(X86::MOVZX16rm8 , FrameIndex, MI);
314 case X86::MOVZX32rr8: return MakeRMInst(X86::MOVZX32rm8, FrameIndex, MI);
315 case X86::MOVZX32rr16:return MakeRMInst(X86::MOVZX32rm16, FrameIndex, MI);
318 if (PrintFailedFusing)
319 std::cerr << "We failed to fuse: " << *MI;
323 //===----------------------------------------------------------------------===//
324 // Stack Frame Processing methods
325 //===----------------------------------------------------------------------===//
327 // hasFP - Return true if the specified function should have a dedicated frame
328 // pointer register. This is true if the function has variable sized allocas or
329 // if frame pointer elimination is disabled.
331 static bool hasFP(MachineFunction &MF) {
332 return NoFramePointerElim || MF.getFrameInfo()->hasVarSizedObjects();
335 void X86RegisterInfo::
336 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
337 MachineBasicBlock::iterator I) const {
339 // If we have a frame pointer, turn the adjcallstackup instruction into a
340 // 'sub ESP, <amt>' and the adjcallstackdown instruction into 'add ESP,
342 MachineInstr *Old = I;
343 unsigned Amount = Old->getOperand(0).getImmedValue();
345 // We need to keep the stack aligned properly. To do this, we round the
346 // amount of space needed for the outgoing arguments up to the next
347 // alignment boundary.
348 unsigned Align = MF.getTarget().getFrameInfo()->getStackAlignment();
349 Amount = (Amount+Align-1)/Align*Align;
352 if (Old->getOpcode() == X86::ADJCALLSTACKDOWN) {
353 New=BuildMI(X86::SUB32ri, 1, X86::ESP, MachineOperand::UseAndDef)
356 assert(Old->getOpcode() == X86::ADJCALLSTACKUP);
357 New=BuildMI(X86::ADD32ri, 1, X86::ESP, MachineOperand::UseAndDef)
361 // Replace the pseudo instruction with a new instruction...
369 void X86RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II) const{
371 MachineInstr &MI = *II;
372 MachineFunction &MF = *MI.getParent()->getParent();
373 while (!MI.getOperand(i).isFrameIndex()) {
375 assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
378 int FrameIndex = MI.getOperand(i).getFrameIndex();
380 // This must be part of a four operand memory reference. Replace the
381 // FrameIndex with base register with EBP. Add add an offset to the offset.
382 MI.SetMachineOperandReg(i, hasFP(MF) ? X86::EBP : X86::ESP);
384 // Now add the frame object offset to the offset from EBP.
385 int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex) +
386 MI.getOperand(i+3).getImmedValue()+4;
389 Offset += MF.getFrameInfo()->getStackSize();
391 Offset += 4; // Skip the saved EBP
393 MI.SetMachineOperandConst(i+3, MachineOperand::MO_SignExtendedImmed, Offset);
397 X86RegisterInfo::processFunctionBeforeFrameFinalized(MachineFunction &MF) const{
399 // Create a frame entry for the EBP register that must be saved.
400 int FrameIdx = MF.getFrameInfo()->CreateFixedObject(4, -8);
401 assert(FrameIdx == MF.getFrameInfo()->getObjectIndexBegin() &&
402 "Slot for EBP register must be last in order to be found!");
406 void X86RegisterInfo::emitPrologue(MachineFunction &MF) const {
407 MachineBasicBlock &MBB = MF.front(); // Prolog goes in entry BB
408 MachineBasicBlock::iterator MBBI = MBB.begin();
409 MachineFrameInfo *MFI = MF.getFrameInfo();
412 // Get the number of bytes to allocate from the FrameInfo
413 unsigned NumBytes = MFI->getStackSize();
415 // Get the offset of the stack slot for the EBP register... which is
416 // guaranteed to be the last slot by processFunctionBeforeFrameFinalized.
417 int EBPOffset = MFI->getObjectOffset(MFI->getObjectIndexBegin())+4;
419 if (NumBytes) { // adjust stack pointer: ESP -= numbytes
420 MI= BuildMI(X86::SUB32ri, 1, X86::ESP, MachineOperand::UseAndDef)
422 MBB.insert(MBBI, MI);
425 // Save EBP into the appropriate stack slot...
426 MI = addRegOffset(BuildMI(X86::MOV32mr, 5), // mov [ESP-<offset>], EBP
427 X86::ESP, EBPOffset+NumBytes).addReg(X86::EBP);
428 MBB.insert(MBBI, MI);
430 // Update EBP with the new base value...
431 if (NumBytes == 4) // mov EBP, ESP
432 MI = BuildMI(X86::MOV32rr, 2, X86::EBP).addReg(X86::ESP);
433 else // lea EBP, [ESP+StackSize]
434 MI = addRegOffset(BuildMI(X86::LEA32r, 5, X86::EBP), X86::ESP,NumBytes-4);
436 MBB.insert(MBBI, MI);
439 if (MFI->hasCalls()) {
440 // When we have no frame pointer, we reserve argument space for call sites
441 // in the function immediately on entry to the current function. This
442 // eliminates the need for add/sub ESP brackets around call sites.
444 NumBytes += MFI->getMaxCallFrameSize();
446 // Round the size to a multiple of the alignment (don't forget the 4 byte
448 unsigned Align = MF.getTarget().getFrameInfo()->getStackAlignment();
449 NumBytes = ((NumBytes+4)+Align-1)/Align*Align - 4;
452 // Update frame info to pretend that this is part of the stack...
453 MFI->setStackSize(NumBytes);
456 // adjust stack pointer: ESP -= numbytes
457 MI= BuildMI(X86::SUB32ri, 1, X86::ESP, MachineOperand::UseAndDef)
459 MBB.insert(MBBI, MI);
464 void X86RegisterInfo::emitEpilogue(MachineFunction &MF,
465 MachineBasicBlock &MBB) const {
466 const MachineFrameInfo *MFI = MF.getFrameInfo();
467 MachineBasicBlock::iterator MBBI = prior(MBB.end());
469 assert(MBBI->getOpcode() == X86::RET &&
470 "Can only insert epilog into returning blocks");
473 // Get the offset of the stack slot for the EBP register... which is
474 // guaranteed to be the last slot by processFunctionBeforeFrameFinalized.
475 int EBPOffset = MFI->getObjectOffset(MFI->getObjectIndexEnd()-1)+4;
478 MI = BuildMI(X86::MOV32rr, 1,X86::ESP).addReg(X86::EBP);
479 MBB.insert(MBBI, MI);
482 MI = BuildMI(X86::POP32r, 0, X86::EBP);
483 MBB.insert(MBBI, MI);
485 // Get the number of bytes allocated from the FrameInfo...
486 unsigned NumBytes = MFI->getStackSize();
488 if (NumBytes) { // adjust stack pointer back: ESP += numbytes
489 MI =BuildMI(X86::ADD32ri, 1, X86::ESP, MachineOperand::UseAndDef)
491 MBB.insert(MBBI, MI);
496 #include "X86GenRegisterInfo.inc"
498 const TargetRegisterClass*
499 X86RegisterInfo::getRegClassForType(const Type* Ty) const {
500 switch (Ty->getTypeID()) {
502 case Type::ULongTyID: assert(0 && "Long values can't fit in registers!");
503 default: assert(0 && "Invalid type to getClass!");
505 case Type::SByteTyID:
506 case Type::UByteTyID: return &R8Instance;
507 case Type::ShortTyID:
508 case Type::UShortTyID: return &R16Instance;
511 case Type::PointerTyID: return &R32Instance;
513 case Type::FloatTyID:
514 case Type::DoubleTyID: return &RFPInstance;