1 //===-- MipsExpandPseudo.cpp - Expand Pseudo Instructions ----------------===//
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 // This pass expands pseudo instructions into target instructions after register
11 // allocation but before post-RA scheduling.
12 //
13 //===----------------------------------------------------------------------===//
14
15 #define DEBUG_TYPE "mips-expand-pseudo"
16
17 #include "Mips.h"
18 #include "MipsTargetMachine.h"
19 #include "llvm/CodeGen/MachineFunctionPass.h"
20 #include "llvm/CodeGen/MachineInstrBuilder.h"
21 #include "llvm/Target/TargetInstrInfo.h"
22 #include "llvm/ADT/Statistic.h"
23
24 using namespace llvm;
25
26 namespace {
27 struct MipsExpandPseudo : public MachineFunctionPass {
28
29 TargetMachine &TM;
30 const TargetInstrInfo *TII;
31
32 static char ID;
MipsExpandPseudo__anonf12da0fd0111::MipsExpandPseudo33 MipsExpandPseudo(TargetMachine &tm)
34 : MachineFunctionPass(ID), TM(tm), TII(tm.getInstrInfo()) { }
35
getPassName__anonf12da0fd0111::MipsExpandPseudo36 virtual const char *getPassName() const {
37 return "Mips PseudoInstrs Expansion";
38 }
39
40 bool runOnMachineFunction(MachineFunction &F);
41 bool runOnMachineBasicBlock(MachineBasicBlock &MBB);
42
43 private:
44 void ExpandBuildPairF64(MachineBasicBlock&, MachineBasicBlock::iterator);
45 void ExpandExtractElementF64(MachineBasicBlock&,
46 MachineBasicBlock::iterator);
47 };
48 char MipsExpandPseudo::ID = 0;
49 } // end of anonymous namespace
50
runOnMachineFunction(MachineFunction & F)51 bool MipsExpandPseudo::runOnMachineFunction(MachineFunction& F) {
52 bool Changed = false;
53
54 for (MachineFunction::iterator I = F.begin(); I != F.end(); ++I)
55 Changed |= runOnMachineBasicBlock(*I);
56
57 return Changed;
58 }
59
runOnMachineBasicBlock(MachineBasicBlock & MBB)60 bool MipsExpandPseudo::runOnMachineBasicBlock(MachineBasicBlock& MBB) {
61
62 bool Changed = false;
63 for (MachineBasicBlock::iterator I = MBB.begin(); I != MBB.end();) {
64 const MCInstrDesc& MCid = I->getDesc();
65
66 switch(MCid.getOpcode()) {
67 default:
68 ++I;
69 continue;
70 case Mips::SETGP2:
71 // Convert "setgp2 $globalreg, $t9" to "addu $globalreg, $v0, $t9"
72 BuildMI(MBB, I, I->getDebugLoc(), TII->get(Mips::ADDu),
73 I->getOperand(0).getReg())
74 .addReg(Mips::V0).addReg(I->getOperand(1).getReg());
75 break;
76 case Mips::BuildPairF64:
77 ExpandBuildPairF64(MBB, I);
78 break;
79 case Mips::ExtractElementF64:
80 ExpandExtractElementF64(MBB, I);
81 break;
82 }
83
84 // delete original instr
85 MBB.erase(I++);
86 Changed = true;
87 }
88
89 return Changed;
90 }
91
ExpandBuildPairF64(MachineBasicBlock & MBB,MachineBasicBlock::iterator I)92 void MipsExpandPseudo::ExpandBuildPairF64(MachineBasicBlock& MBB,
93 MachineBasicBlock::iterator I) {
94 unsigned DstReg = I->getOperand(0).getReg();
95 unsigned LoReg = I->getOperand(1).getReg(), HiReg = I->getOperand(2).getReg();
96 const MCInstrDesc& Mtc1Tdd = TII->get(Mips::MTC1);
97 DebugLoc dl = I->getDebugLoc();
98 const uint16_t* SubReg =
99 TM.getRegisterInfo()->getSubRegisters(DstReg);
100
101 // mtc1 Lo, $fp
102 // mtc1 Hi, $fp + 1
103 BuildMI(MBB, I, dl, Mtc1Tdd, *SubReg).addReg(LoReg);
104 BuildMI(MBB, I, dl, Mtc1Tdd, *(SubReg + 1)).addReg(HiReg);
105 }
106
ExpandExtractElementF64(MachineBasicBlock & MBB,MachineBasicBlock::iterator I)107 void MipsExpandPseudo::ExpandExtractElementF64(MachineBasicBlock& MBB,
108 MachineBasicBlock::iterator I) {
109 unsigned DstReg = I->getOperand(0).getReg();
110 unsigned SrcReg = I->getOperand(1).getReg();
111 unsigned N = I->getOperand(2).getImm();
112 const MCInstrDesc& Mfc1Tdd = TII->get(Mips::MFC1);
113 DebugLoc dl = I->getDebugLoc();
114 const uint16_t* SubReg = TM.getRegisterInfo()->getSubRegisters(SrcReg);
115
116 BuildMI(MBB, I, dl, Mfc1Tdd, DstReg).addReg(*(SubReg + N));
117 }
118
119 /// createMipsMipsExpandPseudoPass - Returns a pass that expands pseudo
120 /// instrs into real instrs
createMipsExpandPseudoPass(MipsTargetMachine & tm)121 FunctionPass *llvm::createMipsExpandPseudoPass(MipsTargetMachine &tm) {
122 return new MipsExpandPseudo(tm);
123 }
124