1 //===---------- PPCTLSDynamicCall.cpp - TLS Dynamic Call Fixup ------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This pass expands ADDItls{ld,gd}LADDR[32] machine instructions into
11 // separate ADDItls[gd]L[32] and GETtlsADDR[32] instructions, both of
12 // which define GPR3. A copy is added from GPR3 to the target virtual
13 // register of the original instruction. The GETtlsADDR[32] is really
14 // a call instruction, so its target register is constrained to be GPR3.
15 // This is not true of ADDItls[gd]L[32], but there is a legacy linker
16 // optimization bug that requires the target register of the addi of
17 // a local- or general-dynamic TLS access sequence to be GPR3.
19 // This is done in a late pass so that TLS variable accesses can be
20 // fully commoned by MachineCSE.
22 //===----------------------------------------------------------------------===//
24 #include "PPCInstrInfo.h"
26 #include "PPCInstrBuilder.h"
27 #include "PPCTargetMachine.h"
28 #include "llvm/CodeGen/LiveIntervalAnalysis.h"
29 #include "llvm/CodeGen/MachineFunctionPass.h"
30 #include "llvm/CodeGen/MachineInstrBuilder.h"
31 #include "llvm/Support/Debug.h"
32 #include "llvm/Support/raw_ostream.h"
36 #define DEBUG_TYPE "ppc-tls-dynamic-call"
39 void initializePPCTLSDynamicCallPass(PassRegistry&);
43 struct PPCTLSDynamicCall : public MachineFunctionPass {
45 PPCTLSDynamicCall() : MachineFunctionPass(ID) {
46 initializePPCTLSDynamicCallPass(*PassRegistry::getPassRegistry());
49 const PPCInstrInfo *TII;
53 bool processBlock(MachineBasicBlock &MBB) {
55 bool Is64Bit = MBB.getParent()->getSubtarget<PPCSubtarget>().isPPC64();
57 for (MachineBasicBlock::iterator I = MBB.begin(), IE = MBB.end();
61 if (MI->getOpcode() != PPC::ADDItlsgdLADDR &&
62 MI->getOpcode() != PPC::ADDItlsldLADDR &&
63 MI->getOpcode() != PPC::ADDItlsgdLADDR32 &&
64 MI->getOpcode() != PPC::ADDItlsldLADDR32)
67 DEBUG(dbgs() << "TLS Dynamic Call Fixup:\n " << *MI;);
69 unsigned OutReg = MI->getOperand(0).getReg();
70 unsigned InReg = MI->getOperand(1).getReg();
71 DebugLoc DL = MI->getDebugLoc();
72 unsigned GPR3 = Is64Bit ? PPC::X3 : PPC::R3;
74 SmallVector<unsigned, 4> OrigRegs;
75 OrigRegs.push_back(OutReg);
76 OrigRegs.push_back(InReg);
77 OrigRegs.push_back(GPR3);
79 switch (MI->getOpcode()) {
81 llvm_unreachable("Opcode inconsistency error");
82 case PPC::ADDItlsgdLADDR:
83 Opc1 = PPC::ADDItlsgdL;
84 Opc2 = PPC::GETtlsADDR;
86 case PPC::ADDItlsldLADDR:
87 Opc1 = PPC::ADDItlsldL;
88 Opc2 = PPC::GETtlsldADDR;
90 case PPC::ADDItlsgdLADDR32:
91 Opc1 = PPC::ADDItlsgdL32;
92 Opc2 = PPC::GETtlsADDR32;
94 case PPC::ADDItlsldLADDR32:
95 Opc1 = PPC::ADDItlsldL32;
96 Opc2 = PPC::GETtlsldADDR32;
100 // Expand into two ops built prior to the existing instruction.
101 MachineInstr *Addi = BuildMI(MBB, I, DL, TII->get(Opc1), GPR3)
103 Addi->addOperand(MI->getOperand(2));
105 // The ADDItls* instruction is the first instruction in the
107 MachineBasicBlock::iterator First = I;
110 MachineInstr *Call = (BuildMI(MBB, I, DL, TII->get(Opc2), GPR3)
112 Call->addOperand(MI->getOperand(3));
114 BuildMI(MBB, I, DL, TII->get(TargetOpcode::COPY), OutReg)
117 // The COPY is the last instruction in the repair range.
118 MachineBasicBlock::iterator Last = I;
121 // Move past the original instruction and remove it.
123 MI->removeFromParent();
125 // Repair the live intervals.
126 LIS->repairIntervalsInRange(&MBB, First, Last, OrigRegs);
134 bool runOnMachineFunction(MachineFunction &MF) override {
135 TII = MF.getSubtarget<PPCSubtarget>().getInstrInfo();
136 LIS = &getAnalysis<LiveIntervals>();
138 bool Changed = false;
140 for (MachineFunction::iterator I = MF.begin(); I != MF.end();) {
141 MachineBasicBlock &B = *I++;
149 void getAnalysisUsage(AnalysisUsage &AU) const override {
150 AU.addRequired<LiveIntervals>();
151 AU.addPreserved<LiveIntervals>();
152 AU.addRequired<SlotIndexes>();
153 AU.addPreserved<SlotIndexes>();
154 MachineFunctionPass::getAnalysisUsage(AU);
159 INITIALIZE_PASS_BEGIN(PPCTLSDynamicCall, DEBUG_TYPE,
160 "PowerPC TLS Dynamic Call Fixup", false, false)
161 INITIALIZE_PASS_DEPENDENCY(LiveIntervals)
162 INITIALIZE_PASS_DEPENDENCY(SlotIndexes)
163 INITIALIZE_PASS_END(PPCTLSDynamicCall, DEBUG_TYPE,
164 "PowerPC TLS Dynamic Call Fixup", false, false)
166 char PPCTLSDynamicCall::ID = 0;
168 llvm::createPPCTLSDynamicCallPass() { return new PPCTLSDynamicCall(); }