1 //===- AMDGPUMCInstLower.cpp - Lower AMDGPU MachineInstr to an MCInst -----===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 /// \file
11 /// \brief Code to lower AMDGPU MachineInstrs to their corresponding MCInst.
12 //
13 //===----------------------------------------------------------------------===//
14 //
15
16 #include "AMDGPUMCInstLower.h"
17 #include "AMDGPUAsmPrinter.h"
18 #include "AMDGPUSubtarget.h"
19 #include "AMDGPUTargetMachine.h"
20 #include "InstPrinter/AMDGPUInstPrinter.h"
21 #include "SIInstrInfo.h"
22 #include "llvm/CodeGen/MachineBasicBlock.h"
23 #include "llvm/CodeGen/MachineInstr.h"
24 #include "llvm/IR/Constants.h"
25 #include "llvm/IR/Function.h"
26 #include "llvm/IR/GlobalVariable.h"
27 #include "llvm/MC/MCCodeEmitter.h"
28 #include "llvm/MC/MCContext.h"
29 #include "llvm/MC/MCExpr.h"
30 #include "llvm/MC/MCInst.h"
31 #include "llvm/MC/MCObjectStreamer.h"
32 #include "llvm/MC/MCStreamer.h"
33 #include "llvm/Support/ErrorHandling.h"
34 #include "llvm/Support/Format.h"
35 #include <algorithm>
36
37 using namespace llvm;
38
AMDGPUMCInstLower(MCContext & ctx,const AMDGPUSubtarget & st)39 AMDGPUMCInstLower::AMDGPUMCInstLower(MCContext &ctx, const AMDGPUSubtarget &st):
40 Ctx(ctx), ST(st) { }
41
getVariantKind(unsigned MOFlags)42 static MCSymbolRefExpr::VariantKind getVariantKind(unsigned MOFlags) {
43 switch (MOFlags) {
44 default: return MCSymbolRefExpr::VK_None;
45 case SIInstrInfo::MO_GOTPCREL: return MCSymbolRefExpr::VK_GOTPCREL;
46 }
47 }
48
lower(const MachineInstr * MI,MCInst & OutMI) const49 void AMDGPUMCInstLower::lower(const MachineInstr *MI, MCInst &OutMI) const {
50
51 int MCOpcode = ST.getInstrInfo()->pseudoToMCOpcode(MI->getOpcode());
52
53 if (MCOpcode == -1) {
54 LLVMContext &C = MI->getParent()->getParent()->getFunction()->getContext();
55 C.emitError("AMDGPUMCInstLower::lower - Pseudo instruction doesn't have "
56 "a target-specific version: " + Twine(MI->getOpcode()));
57 }
58
59 OutMI.setOpcode(MCOpcode);
60
61 for (const MachineOperand &MO : MI->explicit_operands()) {
62 MCOperand MCOp;
63 switch (MO.getType()) {
64 default:
65 llvm_unreachable("unknown operand type");
66 case MachineOperand::MO_Immediate:
67 MCOp = MCOperand::createImm(MO.getImm());
68 break;
69 case MachineOperand::MO_Register:
70 MCOp = MCOperand::createReg(AMDGPU::getMCReg(MO.getReg(), ST));
71 break;
72 case MachineOperand::MO_MachineBasicBlock:
73 MCOp = MCOperand::createExpr(MCSymbolRefExpr::create(
74 MO.getMBB()->getSymbol(), Ctx));
75 break;
76 case MachineOperand::MO_GlobalAddress: {
77 const GlobalValue *GV = MO.getGlobal();
78 MCSymbol *Sym = Ctx.getOrCreateSymbol(StringRef(GV->getName()));
79 const MCExpr *SymExpr =
80 MCSymbolRefExpr::create(Sym, getVariantKind(MO.getTargetFlags()),Ctx);
81 const MCExpr *Expr = MCBinaryExpr::createAdd(SymExpr,
82 MCConstantExpr::create(MO.getOffset(), Ctx), Ctx);
83 MCOp = MCOperand::createExpr(Expr);
84 break;
85 }
86 case MachineOperand::MO_ExternalSymbol: {
87 MCSymbol *Sym = Ctx.getOrCreateSymbol(StringRef(MO.getSymbolName()));
88 Sym->setExternal(true);
89 const MCSymbolRefExpr *Expr = MCSymbolRefExpr::create(Sym, Ctx);
90 MCOp = MCOperand::createExpr(Expr);
91 break;
92 }
93 }
94 OutMI.addOperand(MCOp);
95 }
96 }
97
EmitInstruction(const MachineInstr * MI)98 void AMDGPUAsmPrinter::EmitInstruction(const MachineInstr *MI) {
99 const AMDGPUSubtarget &STI = MF->getSubtarget<AMDGPUSubtarget>();
100 AMDGPUMCInstLower MCInstLowering(OutContext, STI);
101
102 StringRef Err;
103 if (!STI.getInstrInfo()->verifyInstruction(*MI, Err)) {
104 LLVMContext &C = MI->getParent()->getParent()->getFunction()->getContext();
105 C.emitError("Illegal instruction detected: " + Err);
106 MI->dump();
107 }
108
109 if (MI->isBundle()) {
110 const MachineBasicBlock *MBB = MI->getParent();
111 MachineBasicBlock::const_instr_iterator I = ++MI->getIterator();
112 while (I != MBB->instr_end() && I->isInsideBundle()) {
113 EmitInstruction(&*I);
114 ++I;
115 }
116 } else {
117 // We don't want SI_MASK_BRANCH/SI_RETURN encoded. They are placeholder
118 // terminator instructions and should only be printed as comments.
119 if (MI->getOpcode() == AMDGPU::SI_MASK_BRANCH) {
120 if (isVerbose()) {
121 SmallVector<char, 16> BBStr;
122 raw_svector_ostream Str(BBStr);
123
124 const MachineBasicBlock *MBB = MI->getOperand(0).getMBB();
125 const MCSymbolRefExpr *Expr
126 = MCSymbolRefExpr::create(MBB->getSymbol(), OutContext);
127 Expr->print(Str, MAI);
128 OutStreamer->emitRawComment(" mask branch " + BBStr);
129 }
130
131 return;
132 }
133
134 if (MI->getOpcode() == AMDGPU::SI_RETURN) {
135 if (isVerbose())
136 OutStreamer->emitRawComment(" return");
137 return;
138 }
139
140 MCInst TmpInst;
141 MCInstLowering.lower(MI, TmpInst);
142 EmitToStreamer(*OutStreamer, TmpInst);
143
144 if (STI.dumpCode()) {
145 // Disassemble instruction/operands to text.
146 DisasmLines.resize(DisasmLines.size() + 1);
147 std::string &DisasmLine = DisasmLines.back();
148 raw_string_ostream DisasmStream(DisasmLine);
149
150 AMDGPUInstPrinter InstPrinter(*TM.getMCAsmInfo(),
151 *STI.getInstrInfo(),
152 *STI.getRegisterInfo());
153 InstPrinter.printInst(&TmpInst, DisasmStream, StringRef(), STI);
154
155 // Disassemble instruction/operands to hex representation.
156 SmallVector<MCFixup, 4> Fixups;
157 SmallVector<char, 16> CodeBytes;
158 raw_svector_ostream CodeStream(CodeBytes);
159
160 auto &ObjStreamer = static_cast<MCObjectStreamer&>(*OutStreamer);
161 MCCodeEmitter &InstEmitter = ObjStreamer.getAssembler().getEmitter();
162 InstEmitter.encodeInstruction(TmpInst, CodeStream, Fixups,
163 MF->getSubtarget<MCSubtargetInfo>());
164 HexLines.resize(HexLines.size() + 1);
165 std::string &HexLine = HexLines.back();
166 raw_string_ostream HexStream(HexLine);
167
168 for (size_t i = 0; i < CodeBytes.size(); i += 4) {
169 unsigned int CodeDWord = *(unsigned int *)&CodeBytes[i];
170 HexStream << format("%s%08X", (i > 0 ? " " : ""), CodeDWord);
171 }
172
173 DisasmStream.flush();
174 DisasmLineMaxLen = std::max(DisasmLineMaxLen, DisasmLine.size());
175 }
176 }
177 }
178