1 //===-------------- PPCVSXCopy.cpp - VSX Copy Legalization ----------------===//
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 // A pass which deals with the complexity of generating legal VSX register
11 // copies to/from register classes which partially overlap with the VSX
14 //===----------------------------------------------------------------------===//
16 #include "PPCInstrInfo.h"
17 #include "MCTargetDesc/PPCPredicates.h"
19 #include "PPCHazardRecognizers.h"
20 #include "PPCInstrBuilder.h"
21 #include "PPCMachineFunctionInfo.h"
22 #include "PPCTargetMachine.h"
23 #include "llvm/ADT/STLExtras.h"
24 #include "llvm/ADT/Statistic.h"
25 #include "llvm/CodeGen/MachineFrameInfo.h"
26 #include "llvm/CodeGen/MachineFunctionPass.h"
27 #include "llvm/CodeGen/MachineInstrBuilder.h"
28 #include "llvm/CodeGen/MachineMemOperand.h"
29 #include "llvm/CodeGen/MachineRegisterInfo.h"
30 #include "llvm/MC/MCAsmInfo.h"
31 #include "llvm/Support/CommandLine.h"
32 #include "llvm/Support/Debug.h"
33 #include "llvm/Support/ErrorHandling.h"
34 #include "llvm/Support/TargetRegistry.h"
35 #include "llvm/Support/raw_ostream.h"
39 #define DEBUG_TYPE "ppc-vsx-copy"
42 void initializePPCVSXCopyPass(PassRegistry&);
46 // PPCVSXCopy pass - For copies between VSX registers and non-VSX registers
47 // (Altivec and scalar floating-point registers), we need to transform the
48 // copies into subregister copies with other restrictions.
49 struct PPCVSXCopy : public MachineFunctionPass {
51 PPCVSXCopy() : MachineFunctionPass(ID) {
52 initializePPCVSXCopyPass(*PassRegistry::getPassRegistry());
55 const TargetInstrInfo *TII;
57 bool IsRegInClass(unsigned Reg, const TargetRegisterClass *RC,
58 MachineRegisterInfo &MRI) {
59 if (TargetRegisterInfo::isVirtualRegister(Reg)) {
60 return RC->hasSubClassEq(MRI.getRegClass(Reg));
61 } else if (RC->contains(Reg)) {
68 bool IsVSReg(unsigned Reg, MachineRegisterInfo &MRI) {
69 return IsRegInClass(Reg, &PPC::VSRCRegClass, MRI);
72 bool IsVRReg(unsigned Reg, MachineRegisterInfo &MRI) {
73 return IsRegInClass(Reg, &PPC::VRRCRegClass, MRI);
76 bool IsF8Reg(unsigned Reg, MachineRegisterInfo &MRI) {
77 return IsRegInClass(Reg, &PPC::F8RCRegClass, MRI);
80 bool IsVSFReg(unsigned Reg, MachineRegisterInfo &MRI) {
81 return IsRegInClass(Reg, &PPC::VSFRCRegClass, MRI);
85 bool processBlock(MachineBasicBlock &MBB) {
88 MachineRegisterInfo &MRI = MBB.getParent()->getRegInfo();
89 for (MachineBasicBlock::iterator I = MBB.begin(), IE = MBB.end();
92 if (!MI->isFullCopy())
95 MachineOperand &DstMO = MI->getOperand(0);
96 MachineOperand &SrcMO = MI->getOperand(1);
98 if ( IsVSReg(DstMO.getReg(), MRI) &&
99 !IsVSReg(SrcMO.getReg(), MRI)) {
100 // This is a copy *to* a VSX register from a non-VSX register.
103 const TargetRegisterClass *SrcRC =
104 IsVRReg(SrcMO.getReg(), MRI) ? &PPC::VSHRCRegClass :
106 assert((IsF8Reg(SrcMO.getReg(), MRI) ||
107 IsVRReg(SrcMO.getReg(), MRI) ||
108 IsVSFReg(SrcMO.getReg(), MRI)) &&
109 "Unknown source for a VSX copy");
111 unsigned NewVReg = MRI.createVirtualRegister(SrcRC);
112 BuildMI(MBB, MI, MI->getDebugLoc(),
113 TII->get(TargetOpcode::SUBREG_TO_REG), NewVReg)
114 .addImm(1) // add 1, not 0, because there is no implicit clearing
117 .addImm(IsVRReg(SrcMO.getReg(), MRI) ? PPC::sub_128 :
120 // The source of the original copy is now the new virtual register.
121 SrcMO.setReg(NewVReg);
122 } else if (!IsVSReg(DstMO.getReg(), MRI) &&
123 IsVSReg(SrcMO.getReg(), MRI)) {
124 // This is a copy *from* a VSX register to a non-VSX register.
127 const TargetRegisterClass *DstRC =
128 IsVRReg(DstMO.getReg(), MRI) ? &PPC::VSHRCRegClass :
130 assert((IsF8Reg(DstMO.getReg(), MRI) ||
131 IsVSFReg(DstMO.getReg(), MRI) ||
132 IsVRReg(DstMO.getReg(), MRI)) &&
133 "Unknown destination for a VSX copy");
135 // Copy the VSX value into a new VSX register of the correct subclass.
136 unsigned NewVReg = MRI.createVirtualRegister(DstRC);
137 BuildMI(MBB, MI, MI->getDebugLoc(),
138 TII->get(TargetOpcode::COPY), NewVReg)
141 // Transform the original copy into a subregister extraction copy.
142 SrcMO.setReg(NewVReg);
143 SrcMO.setSubReg(IsVRReg(DstMO.getReg(), MRI) ? PPC::sub_128 :
152 bool runOnMachineFunction(MachineFunction &MF) override {
153 // If we don't have VSX on the subtarget, don't do anything.
154 const PPCSubtarget &STI = MF.getSubtarget<PPCSubtarget>();
157 TII = STI.getInstrInfo();
159 bool Changed = false;
161 for (MachineFunction::iterator I = MF.begin(); I != MF.end();) {
162 MachineBasicBlock &B = *I++;
170 void getAnalysisUsage(AnalysisUsage &AU) const override {
171 MachineFunctionPass::getAnalysisUsage(AU);
176 INITIALIZE_PASS(PPCVSXCopy, DEBUG_TYPE,
177 "PowerPC VSX Copy Legalization", false, false)
179 char PPCVSXCopy::ID = 0;
181 llvm::createPPCVSXCopyPass() { return new PPCVSXCopy(); }