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 //===----------------------------------------------------------------------===//
17 #include "MCTargetDesc/PPCPredicates.h"
18 #include "PPCHazardRecognizers.h"
19 #include "PPCInstrBuilder.h"
20 #include "PPCInstrInfo.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/Debug.h"
32 #include "llvm/Support/ErrorHandling.h"
33 #include "llvm/Support/TargetRegistry.h"
34 #include "llvm/Support/raw_ostream.h"
38 #define DEBUG_TYPE "ppc-vsx-copy"
41 void initializePPCVSXCopyPass(PassRegistry&);
45 // PPCVSXCopy pass - For copies between VSX registers and non-VSX registers
46 // (Altivec and scalar floating-point registers), we need to transform the
47 // copies into subregister copies with other restrictions.
48 struct PPCVSXCopy : public MachineFunctionPass {
50 PPCVSXCopy() : MachineFunctionPass(ID) {
51 initializePPCVSXCopyPass(*PassRegistry::getPassRegistry());
54 const TargetInstrInfo *TII;
56 bool IsRegInClass(unsigned Reg, const TargetRegisterClass *RC,
57 MachineRegisterInfo &MRI) {
58 if (TargetRegisterInfo::isVirtualRegister(Reg)) {
59 return RC->hasSubClassEq(MRI.getRegClass(Reg));
60 } else if (RC->contains(Reg)) {
67 bool IsVSReg(unsigned Reg, MachineRegisterInfo &MRI) {
68 return IsRegInClass(Reg, &PPC::VSRCRegClass, MRI);
71 bool IsVRReg(unsigned Reg, MachineRegisterInfo &MRI) {
72 return IsRegInClass(Reg, &PPC::VRRCRegClass, MRI);
75 bool IsF8Reg(unsigned Reg, MachineRegisterInfo &MRI) {
76 return IsRegInClass(Reg, &PPC::F8RCRegClass, MRI);
79 bool IsVSFReg(unsigned Reg, MachineRegisterInfo &MRI) {
80 return IsRegInClass(Reg, &PPC::VSFRCRegClass, MRI);
83 bool IsVSSReg(unsigned Reg, MachineRegisterInfo &MRI) {
84 return IsRegInClass(Reg, &PPC::VSSRCRegClass, MRI);
88 bool processBlock(MachineBasicBlock &MBB) {
91 MachineRegisterInfo &MRI = MBB.getParent()->getRegInfo();
92 for (MachineBasicBlock::iterator I = MBB.begin(), IE = MBB.end();
95 if (!MI->isFullCopy())
98 MachineOperand &DstMO = MI->getOperand(0);
99 MachineOperand &SrcMO = MI->getOperand(1);
101 if ( IsVSReg(DstMO.getReg(), MRI) &&
102 !IsVSReg(SrcMO.getReg(), MRI)) {
103 // This is a copy *to* a VSX register from a non-VSX register.
106 const TargetRegisterClass *SrcRC =
107 IsVRReg(SrcMO.getReg(), MRI) ? &PPC::VSHRCRegClass :
109 assert((IsF8Reg(SrcMO.getReg(), MRI) ||
110 IsVRReg(SrcMO.getReg(), MRI) ||
111 IsVSSReg(SrcMO.getReg(), MRI) ||
112 IsVSFReg(SrcMO.getReg(), MRI)) &&
113 "Unknown source for a VSX copy");
115 unsigned NewVReg = MRI.createVirtualRegister(SrcRC);
116 BuildMI(MBB, MI, MI->getDebugLoc(),
117 TII->get(TargetOpcode::SUBREG_TO_REG), NewVReg)
118 .addImm(1) // add 1, not 0, because there is no implicit clearing
121 .addImm(IsVRReg(SrcMO.getReg(), MRI) ? PPC::sub_128 :
124 // The source of the original copy is now the new virtual register.
125 SrcMO.setReg(NewVReg);
126 } else if (!IsVSReg(DstMO.getReg(), MRI) &&
127 IsVSReg(SrcMO.getReg(), MRI)) {
128 // This is a copy *from* a VSX register to a non-VSX register.
131 const TargetRegisterClass *DstRC =
132 IsVRReg(DstMO.getReg(), MRI) ? &PPC::VSHRCRegClass :
134 assert((IsF8Reg(DstMO.getReg(), MRI) ||
135 IsVSFReg(DstMO.getReg(), MRI) ||
136 IsVSSReg(DstMO.getReg(), MRI) ||
137 IsVRReg(DstMO.getReg(), MRI)) &&
138 "Unknown destination for a VSX copy");
140 // Copy the VSX value into a new VSX register of the correct subclass.
141 unsigned NewVReg = MRI.createVirtualRegister(DstRC);
142 BuildMI(MBB, MI, MI->getDebugLoc(),
143 TII->get(TargetOpcode::COPY), NewVReg)
146 // Transform the original copy into a subregister extraction copy.
147 SrcMO.setReg(NewVReg);
148 SrcMO.setSubReg(IsVRReg(DstMO.getReg(), MRI) ? PPC::sub_128 :
157 bool runOnMachineFunction(MachineFunction &MF) override {
158 // If we don't have VSX on the subtarget, don't do anything.
159 const PPCSubtarget &STI = MF.getSubtarget<PPCSubtarget>();
162 TII = STI.getInstrInfo();
164 bool Changed = false;
166 for (MachineFunction::iterator I = MF.begin(); I != MF.end();) {
167 MachineBasicBlock &B = *I++;
175 void getAnalysisUsage(AnalysisUsage &AU) const override {
176 MachineFunctionPass::getAnalysisUsage(AU);
181 INITIALIZE_PASS(PPCVSXCopy, DEBUG_TYPE,
182 "PowerPC VSX Copy Legalization", false, false)
184 char PPCVSXCopy::ID = 0;
186 llvm::createPPCVSXCopyPass() { return new PPCVSXCopy(); }