LLVM: lib/Target/Mips/MipsAnalyzeImmediate.cpp Source File (original) (raw)
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12#include
13#include
14#include
15
16using namespace llvm;
17
19
20
21void MipsAnalyzeImmediate::AddInstr(InstSeqLs &SeqLs, const Inst &I) {
22
23 if (SeqLs.empty()) {
25 return;
26 }
27
28 for (auto &S : SeqLs)
29 S.push_back(I);
30}
31
32void MipsAnalyzeImmediate::GetInstSeqLsADDiu(uint64_t Imm, unsigned RemSize,
33 InstSeqLs &SeqLs) {
34 GetInstSeqLs((Imm + 0x8000ULL) & 0xffffffffffff0000ULL, RemSize, SeqLs);
35 AddInstr(SeqLs, Inst(ADDiu, Imm & 0xffffULL));
36}
37
38void MipsAnalyzeImmediate::GetInstSeqLsORi(uint64_t Imm, unsigned RemSize,
39 InstSeqLs &SeqLs) {
40 GetInstSeqLs(Imm & 0xffffffffffff0000ULL, RemSize, SeqLs);
41 AddInstr(SeqLs, Inst(ORi, Imm & 0xffffULL));
42}
43
44void MipsAnalyzeImmediate::GetInstSeqLsSLL(uint64_t Imm, unsigned RemSize,
45 InstSeqLs &SeqLs) {
47 GetInstSeqLs(Imm >> Shamt, RemSize - Shamt, SeqLs);
48 AddInstr(SeqLs, Inst(SLL, Shamt));
49}
50
51void MipsAnalyzeImmediate::GetInstSeqLs(uint64_t Imm, unsigned RemSize,
52 InstSeqLs &SeqLs) {
53 uint64_t MaskedImm = Imm & (0xffffffffffffffffULL >> (64 - Size));
54
55
56 if (!MaskedImm)
57 return;
58
59
60 if (RemSize <= 16) {
61 AddInstr(SeqLs, Inst(ADDiu, MaskedImm));
62 return;
63 }
64
65
66 if (!(Imm & 0xffff)) {
67 GetInstSeqLsSLL(Imm, RemSize, SeqLs);
68 return;
69 }
70
71 GetInstSeqLsADDiu(Imm, RemSize, SeqLs);
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73
74
75 if (Imm & 0x8000) {
76 InstSeqLs SeqLsORi;
77 GetInstSeqLsORi(Imm, RemSize, SeqLsORi);
78 SeqLs.append(std::make_move_iterator(SeqLsORi.begin()),
79 std::make_move_iterator(SeqLsORi.end()));
80 }
81}
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88
89void MipsAnalyzeImmediate::ReplaceADDiuSLLWithLUi(InstSeq &Seq) {
90
91
92 if ((Seq.size() < 2) || (Seq[0].Opc != ADDiu) ||
93 (Seq[1].Opc != SLL) || (Seq[1].ImmOpnd < 16))
94 return;
95
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98 int64_t ShiftedImm = (uint64_t)Imm << (Seq[1].ImmOpnd - 16);
99
101 return;
102
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104 Seq[0].Opc = LUi;
105 Seq[0].ImmOpnd = (unsigned)(ShiftedImm & 0xffff);
106 Seq.erase(Seq.begin() + 1);
107}
108
109void MipsAnalyzeImmediate::GetShortestSeq(InstSeqLs &SeqLs, InstSeq &Insts) {
111
112 unsigned ShortestLength = 8;
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115 ReplaceADDiuSLLWithLUi(*S);
116 assert(S->size() <= 7);
117
118 if (S->size() < ShortestLength) {
119 ShortestSeq = S;
120 ShortestLength = S->size();
121 }
122 }
123
124 Insts.clear();
125 Insts.append(ShortestSeq->begin(), ShortestSeq->end());
126}
127
130 bool LastInstrIsADDiu) {
131 this->Size = Size;
132
133 if (Size == 32) {
134 ADDiu = Mips::ADDiu;
135 ORi = Mips::ORi;
136 SLL = Mips::SLL;
137 LUi = Mips::LUi;
138 } else {
139 ADDiu = Mips::DADDiu;
140 ORi = Mips::ORi64;
141 SLL = Mips::DSLL;
142 LUi = Mips::LUi64;
143 }
144
145 InstSeqLs SeqLs;
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147
148 if (LastInstrIsADDiu | !Imm)
149 GetInstSeqLsADDiu(Imm, Size, SeqLs);
150 else
151 GetInstSeqLs(Imm, Size, SeqLs);
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154 GetShortestSeq(SeqLs, Insts);
155
156 return Insts;
157}
assert(UImm &&(UImm !=~static_cast< T >(0)) &&"Invalid immediate!")
void push_back(const T &Elt)
This is an optimization pass for GlobalISel generic memory operations.
constexpr bool isInt(int64_t x)
Checks if an integer fits into the given bit width.
int countr_zero(T Val)
Count number of 0's from the least significant bit to the most stopping at the first 1.
constexpr int64_t SignExtend64(uint64_t x)
Sign-extend the number in the bottom B bits of X to a 64-bit integer.