1 //=== HexagonSplitConst32AndConst64.cpp - split CONST32/Const64 into HI/LO ===//
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 // When the compiler is invoked with no small data, for instance, with the -G0
11 // command line option, then all CONST32_* opcodes should be broken down into
12 // appropriate LO and HI instructions. This splitting is done by this pass.
13 // The only reason this is not done in the DAG lowering itself is that there
14 // is no simple way of getting the register allocator to allot the same hard
15 // register to the result of LO and HI instructions. This pass is always
16 // scheduled after register allocation.
17 //
18 //===----------------------------------------------------------------------===//
19
20 #include "HexagonMachineFunctionInfo.h"
21 #include "HexagonSubtarget.h"
22 #include "HexagonTargetMachine.h"
23 #include "HexagonTargetObjectFile.h"
24 #include "llvm/ADT/Statistic.h"
25 #include "llvm/CodeGen/LatencyPriorityQueue.h"
26 #include "llvm/CodeGen/MachineDominators.h"
27 #include "llvm/CodeGen/MachineFunctionPass.h"
28 #include "llvm/CodeGen/MachineInstrBuilder.h"
29 #include "llvm/CodeGen/MachineLoopInfo.h"
30 #include "llvm/CodeGen/MachineRegisterInfo.h"
31 #include "llvm/CodeGen/Passes.h"
32 #include "llvm/CodeGen/ScheduleDAGInstrs.h"
33 #include "llvm/CodeGen/ScheduleHazardRecognizer.h"
34 #include "llvm/CodeGen/SchedulerRegistry.h"
35 #include "llvm/Support/CommandLine.h"
36 #include "llvm/Support/Compiler.h"
37 #include "llvm/Support/Debug.h"
38 #include "llvm/Support/MathExtras.h"
39 #include "llvm/Target/TargetInstrInfo.h"
40 #include "llvm/Target/TargetMachine.h"
41 #include "llvm/Target/TargetRegisterInfo.h"
42 #include <map>
43
44 using namespace llvm;
45
46 #define DEBUG_TYPE "xfer"
47
48 namespace llvm {
49 FunctionPass *createHexagonSplitConst32AndConst64();
50 void initializeHexagonSplitConst32AndConst64Pass(PassRegistry&);
51 }
52
53 namespace {
54
55 class HexagonSplitConst32AndConst64 : public MachineFunctionPass {
56 public:
57 static char ID;
HexagonSplitConst32AndConst64()58 HexagonSplitConst32AndConst64() : MachineFunctionPass(ID) {}
59
getPassName() const60 const char *getPassName() const override {
61 return "Hexagon Split Const32s and Const64s";
62 }
63 bool runOnMachineFunction(MachineFunction &Fn) override;
64 };
65
66
67 char HexagonSplitConst32AndConst64::ID = 0;
68
69
runOnMachineFunction(MachineFunction & Fn)70 bool HexagonSplitConst32AndConst64::runOnMachineFunction(MachineFunction &Fn) {
71
72 const HexagonTargetObjectFile &TLOF =
73 *static_cast<const HexagonTargetObjectFile *>(
74 Fn.getTarget().getObjFileLowering());
75 if (TLOF.IsSmallDataEnabled())
76 return true;
77
78 const TargetInstrInfo *TII = Fn.getSubtarget().getInstrInfo();
79 const TargetRegisterInfo *TRI = Fn.getSubtarget().getRegisterInfo();
80
81 // Loop over all of the basic blocks
82 for (MachineFunction::iterator MBBb = Fn.begin(), MBBe = Fn.end();
83 MBBb != MBBe; ++MBBb) {
84 MachineBasicBlock *MBB = &*MBBb;
85 // Traverse the basic block
86 MachineBasicBlock::iterator MII = MBB->begin();
87 MachineBasicBlock::iterator MIE = MBB->end ();
88 while (MII != MIE) {
89 MachineInstr *MI = MII;
90 int Opc = MI->getOpcode();
91 if (Opc == Hexagon::CONST32_Int_Real &&
92 MI->getOperand(1).isBlockAddress()) {
93 int DestReg = MI->getOperand(0).getReg();
94 MachineOperand &Symbol = MI->getOperand (1);
95
96 BuildMI (*MBB, MII, MI->getDebugLoc(),
97 TII->get(Hexagon::LO), DestReg).addOperand(Symbol);
98 BuildMI (*MBB, MII, MI->getDebugLoc(),
99 TII->get(Hexagon::HI), DestReg).addOperand(Symbol);
100 // MBB->erase returns the iterator to the next instruction, which is the
101 // one we want to process next
102 MII = MBB->erase (MI);
103 continue;
104 }
105
106 else if (Opc == Hexagon::CONST32_Int_Real ||
107 Opc == Hexagon::CONST32_Float_Real) {
108 int DestReg = MI->getOperand(0).getReg();
109
110 // We have to convert an FP immediate into its corresponding integer
111 // representation
112 int64_t ImmValue;
113 if (Opc == Hexagon::CONST32_Float_Real) {
114 APFloat Val = MI->getOperand(1).getFPImm()->getValueAPF();
115 ImmValue = *Val.bitcastToAPInt().getRawData();
116 }
117 else
118 ImmValue = MI->getOperand(1).getImm();
119
120 BuildMI(*MBB, MII, MI->getDebugLoc(),
121 TII->get(Hexagon::A2_tfrsi), DestReg).addImm(ImmValue);
122 MII = MBB->erase (MI);
123 continue;
124 }
125 else if (Opc == Hexagon::CONST64_Int_Real ||
126 Opc == Hexagon::CONST64_Float_Real) {
127 int DestReg = MI->getOperand(0).getReg();
128
129 // We have to convert an FP immediate into its corresponding integer
130 // representation
131 int64_t ImmValue;
132 if (Opc == Hexagon::CONST64_Float_Real) {
133 APFloat Val = MI->getOperand(1).getFPImm()->getValueAPF();
134 ImmValue = *Val.bitcastToAPInt().getRawData();
135 }
136 else
137 ImmValue = MI->getOperand(1).getImm();
138
139 unsigned DestLo = TRI->getSubReg(DestReg, Hexagon::subreg_loreg);
140 unsigned DestHi = TRI->getSubReg(DestReg, Hexagon::subreg_hireg);
141
142 int32_t LowWord = (ImmValue & 0xFFFFFFFF);
143 int32_t HighWord = (ImmValue >> 32) & 0xFFFFFFFF;
144
145 BuildMI(*MBB, MII, MI->getDebugLoc(),
146 TII->get(Hexagon::A2_tfrsi), DestLo).addImm(LowWord);
147 BuildMI (*MBB, MII, MI->getDebugLoc(),
148 TII->get(Hexagon::A2_tfrsi), DestHi).addImm(HighWord);
149 MII = MBB->erase (MI);
150 continue;
151 }
152 ++MII;
153 }
154 }
155
156 return true;
157 }
158
159 }
160
161 //===----------------------------------------------------------------------===//
162 // Public Constructor Functions
163 //===----------------------------------------------------------------------===//
164
165 FunctionPass *
createHexagonSplitConst32AndConst64()166 llvm::createHexagonSplitConst32AndConst64() {
167 return new HexagonSplitConst32AndConst64();
168 }
169