AMDGPUMCInstLower.cpp revision 249259 
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 "R600InstrInfo.h"
19#include "llvm/CodeGen/MachineBasicBlock.h"
20#include "llvm/CodeGen/MachineInstr.h"
21#include "llvm/IR/Constants.h"
22#include "llvm/MC/MCExpr.h"
23#include "llvm/MC/MCInst.h"
24#include "llvm/MC/MCStreamer.h"
25#include "llvm/Support/ErrorHandling.h"
26
27using namespace llvm;
28
29AMDGPUMCInstLower::AMDGPUMCInstLower(MCContext &ctx):
30  Ctx(ctx)
31{ }
32
33void AMDGPUMCInstLower::lower(const MachineInstr *MI, MCInst &OutMI) const {
34  OutMI.setOpcode(MI->getOpcode());
35
36  for (unsigned i = 0, e = MI->getNumExplicitOperands(); i != e; ++i) {
37    const MachineOperand &MO = MI->getOperand(i);
38
39    MCOperand MCOp;
40    switch (MO.getType()) {
41    default:
42      llvm_unreachable("unknown operand type");
43    case MachineOperand::MO_FPImmediate: {
44      const APFloat &FloatValue = MO.getFPImm()->getValueAPF();
45      assert(&FloatValue.getSemantics() == &APFloat::IEEEsingle &&
46             "Only floating point immediates are supported at the moment.");
47      MCOp = MCOperand::CreateFPImm(FloatValue.convertToFloat());
48      break;
49    }
50    case MachineOperand::MO_Immediate:
51      MCOp = MCOperand::CreateImm(MO.getImm());
52      break;
53    case MachineOperand::MO_Register:
54      MCOp = MCOperand::CreateReg(MO.getReg());
55      break;
56    case MachineOperand::MO_MachineBasicBlock:
57      MCOp = MCOperand::CreateExpr(MCSymbolRefExpr::Create(
58                                   MO.getMBB()->getSymbol(), Ctx));
59    }
60    OutMI.addOperand(MCOp);
61  }
62}
63
64void AMDGPUAsmPrinter::EmitInstruction(const MachineInstr *MI) {
65  AMDGPUMCInstLower MCInstLowering(OutContext);
66
67  if (MI->isBundle()) {
68    const MachineBasicBlock *MBB = MI->getParent();
69    MachineBasicBlock::const_instr_iterator I = MI;
70    ++I;
71    while (I != MBB->end() && I->isInsideBundle()) {
72      MCInst MCBundleInst;
73      const MachineInstr *BundledInst = I;
74      MCInstLowering.lower(BundledInst, MCBundleInst);
75      OutStreamer.EmitInstruction(MCBundleInst);
76      ++I;
77    }
78  } else {
79    MCInst TmpInst;
80    MCInstLowering.lower(MI, TmpInst);
81    OutStreamer.EmitInstruction(TmpInst);
82  }
83}
84