1 //===- MC/MCRegisterInfo.cpp - Target Register Description ----------------===//
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 file implements MCRegisterInfo functions.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #include "llvm/MC/MCRegisterInfo.h"
15 #include "llvm/ADT/DenseMap.h"
16 #include "llvm/ADT/Twine.h"
17 #include "llvm/Support/ErrorHandling.h"
18 #include <algorithm>
19 #include <cassert>
20 #include <cstdint>
21
22 using namespace llvm;
23
getMatchingSuperReg(unsigned Reg,unsigned SubIdx,const MCRegisterClass * RC) const24 unsigned MCRegisterInfo::getMatchingSuperReg(unsigned Reg, unsigned SubIdx,
25 const MCRegisterClass *RC) const {
26 for (MCSuperRegIterator Supers(Reg, this); Supers.isValid(); ++Supers)
27 if (RC->contains(*Supers) && Reg == getSubReg(*Supers, SubIdx))
28 return *Supers;
29 return 0;
30 }
31
getSubReg(unsigned Reg,unsigned Idx) const32 unsigned MCRegisterInfo::getSubReg(unsigned Reg, unsigned Idx) const {
33 assert(Idx && Idx < getNumSubRegIndices() &&
34 "This is not a subregister index");
35 // Get a pointer to the corresponding SubRegIndices list. This list has the
36 // name of each sub-register in the same order as MCSubRegIterator.
37 const uint16_t *SRI = SubRegIndices + get(Reg).SubRegIndices;
38 for (MCSubRegIterator Subs(Reg, this); Subs.isValid(); ++Subs, ++SRI)
39 if (*SRI == Idx)
40 return *Subs;
41 return 0;
42 }
43
getSubRegIndex(unsigned Reg,unsigned SubReg) const44 unsigned MCRegisterInfo::getSubRegIndex(unsigned Reg, unsigned SubReg) const {
45 assert(SubReg && SubReg < getNumRegs() && "This is not a register");
46 // Get a pointer to the corresponding SubRegIndices list. This list has the
47 // name of each sub-register in the same order as MCSubRegIterator.
48 const uint16_t *SRI = SubRegIndices + get(Reg).SubRegIndices;
49 for (MCSubRegIterator Subs(Reg, this); Subs.isValid(); ++Subs, ++SRI)
50 if (*Subs == SubReg)
51 return *SRI;
52 return 0;
53 }
54
getSubRegIdxSize(unsigned Idx) const55 unsigned MCRegisterInfo::getSubRegIdxSize(unsigned Idx) const {
56 assert(Idx && Idx < getNumSubRegIndices() &&
57 "This is not a subregister index");
58 return SubRegIdxRanges[Idx].Size;
59 }
60
getSubRegIdxOffset(unsigned Idx) const61 unsigned MCRegisterInfo::getSubRegIdxOffset(unsigned Idx) const {
62 assert(Idx && Idx < getNumSubRegIndices() &&
63 "This is not a subregister index");
64 return SubRegIdxRanges[Idx].Offset;
65 }
66
getDwarfRegNum(unsigned RegNum,bool isEH) const67 int MCRegisterInfo::getDwarfRegNum(unsigned RegNum, bool isEH) const {
68 const DwarfLLVMRegPair *M = isEH ? EHL2DwarfRegs : L2DwarfRegs;
69 unsigned Size = isEH ? EHL2DwarfRegsSize : L2DwarfRegsSize;
70
71 if (!M)
72 return -1;
73 DwarfLLVMRegPair Key = { RegNum, 0 };
74 const DwarfLLVMRegPair *I = std::lower_bound(M, M+Size, Key);
75 if (I == M+Size || I->FromReg != RegNum)
76 return -1;
77 return I->ToReg;
78 }
79
getLLVMRegNum(unsigned RegNum,bool isEH) const80 int MCRegisterInfo::getLLVMRegNum(unsigned RegNum, bool isEH) const {
81 const DwarfLLVMRegPair *M = isEH ? EHDwarf2LRegs : Dwarf2LRegs;
82 unsigned Size = isEH ? EHDwarf2LRegsSize : Dwarf2LRegsSize;
83
84 if (!M)
85 return -1;
86 DwarfLLVMRegPair Key = { RegNum, 0 };
87 const DwarfLLVMRegPair *I = std::lower_bound(M, M+Size, Key);
88 assert(I != M+Size && I->FromReg == RegNum && "Invalid RegNum");
89 return I->ToReg;
90 }
91
getLLVMRegNumFromEH(unsigned RegNum) const92 int MCRegisterInfo::getLLVMRegNumFromEH(unsigned RegNum) const {
93 const DwarfLLVMRegPair *M = EHDwarf2LRegs;
94 unsigned Size = EHDwarf2LRegsSize;
95
96 if (!M)
97 return -1;
98 DwarfLLVMRegPair Key = { RegNum, 0 };
99 const DwarfLLVMRegPair *I = std::lower_bound(M, M+Size, Key);
100 if (I == M+Size || I->FromReg != RegNum)
101 return -1;
102 return I->ToReg;
103 }
104
getDwarfRegNumFromDwarfEHRegNum(unsigned RegNum) const105 int MCRegisterInfo::getDwarfRegNumFromDwarfEHRegNum(unsigned RegNum) const {
106 // On ELF platforms, DWARF EH register numbers are the same as DWARF
107 // other register numbers. On Darwin x86, they differ and so need to be
108 // mapped. The .cfi_* directives accept integer literals as well as
109 // register names and should generate exactly what the assembly code
110 // asked for, so there might be DWARF/EH register numbers that don't have
111 // a corresponding LLVM register number at all. So if we can't map the
112 // EH register number to an LLVM register number, assume it's just a
113 // valid DWARF register number as is.
114 int LRegNum = getLLVMRegNumFromEH(RegNum);
115 if (LRegNum != -1)
116 return getDwarfRegNum(LRegNum, false);
117 return RegNum;
118 }
119
getSEHRegNum(unsigned RegNum) const120 int MCRegisterInfo::getSEHRegNum(unsigned RegNum) const {
121 const DenseMap<unsigned, int>::const_iterator I = L2SEHRegs.find(RegNum);
122 if (I == L2SEHRegs.end()) return (int)RegNum;
123 return I->second;
124 }
125
getCodeViewRegNum(unsigned RegNum) const126 int MCRegisterInfo::getCodeViewRegNum(unsigned RegNum) const {
127 if (L2CVRegs.empty())
128 report_fatal_error("target does not implement codeview register mapping");
129 const DenseMap<unsigned, int>::const_iterator I = L2CVRegs.find(RegNum);
130 if (I == L2CVRegs.end())
131 report_fatal_error("unknown codeview register " + (RegNum < getNumRegs()
132 ? getName(RegNum)
133 : Twine(RegNum)));
134 return I->second;
135 }
136