/Users/buildslave/jenkins/sharedspace/clang-stage2-coverage-R@2/llvm/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp
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1 | | //==- llvm/CodeGen/SelectionDAGAddressAnalysis.cpp - DAG Address Analysis --==// |
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 | | #include "llvm/CodeGen/SelectionDAGAddressAnalysis.h" |
11 | | #include "llvm/CodeGen/ISDOpcodes.h" |
12 | | #include "llvm/CodeGen/MachineFrameInfo.h" |
13 | | #include "llvm/CodeGen/MachineFunction.h" |
14 | | #include "llvm/CodeGen/SelectionDAG.h" |
15 | | #include "llvm/CodeGen/SelectionDAGNodes.h" |
16 | | #include "llvm/Support/Casting.h" |
17 | | #include "llvm/Target/TargetLowering.h" |
18 | | #include <cstdint> |
19 | | |
20 | | using namespace llvm; |
21 | | |
22 | | bool BaseIndexOffset::equalBaseIndex(BaseIndexOffset &Other, |
23 | 69.4M | const SelectionDAG &DAG, int64_t &Off) { |
24 | 69.4M | // Initial Offset difference. |
25 | 69.4M | Off = Other.Offset - Offset; |
26 | 69.4M | |
27 | 69.4M | if ((Other.Index == Index) && 69.4M (Other.IsIndexSignExt == IsIndexSignExt)67.3M ) { |
28 | 67.3M | // Trivial match. |
29 | 67.3M | if (Other.Base == Base) |
30 | 62.9M | return true; |
31 | 4.48M | |
32 | 4.48M | // Match GlobalAddresses |
33 | 4.48M | if (auto *4.48M A4.48M = dyn_cast<GlobalAddressSDNode>(Base)) |
34 | 679k | if (auto *679k B679k = dyn_cast<GlobalAddressSDNode>(Other.Base)) |
35 | 404k | if (404k A->getGlobal() == B->getGlobal()404k ) { |
36 | 5.65k | Off += B->getOffset() - A->getOffset(); |
37 | 5.65k | return true; |
38 | 5.65k | } |
39 | 4.47M | |
40 | 4.47M | const MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo(); |
41 | 4.47M | |
42 | 4.47M | // Match non-equal FrameIndexes - If both frame indices are fixed |
43 | 4.47M | // we know their relative offsets and can compare them. Otherwise |
44 | 4.47M | // we must be conservative. |
45 | 4.47M | if (auto *A = dyn_cast<FrameIndexSDNode>(Base)) |
46 | 867k | if (auto *867k B867k = dyn_cast<FrameIndexSDNode>(Other.Base)) |
47 | 108k | if (108k MFI.isFixedObjectIndex(A->getIndex()) && |
48 | 108k | MFI.isFixedObjectIndex(B->getIndex())19.7k ) { |
49 | 19.4k | Off += MFI.getObjectOffset(B->getIndex()) - |
50 | 19.4k | MFI.getObjectOffset(A->getIndex()); |
51 | 19.4k | return true; |
52 | 19.4k | } |
53 | 6.49M | } |
54 | 6.49M | return false; |
55 | 6.49M | } |
56 | | |
57 | | /// Parses tree in Ptr for base, index, offset addresses. |
58 | 116M | BaseIndexOffset BaseIndexOffset::match(SDValue Ptr, const SelectionDAG &DAG) { |
59 | 116M | // (((B + I*M) + c)) + c ... |
60 | 116M | SDValue Base = DAG.getTargetLoweringInfo().unwrapAddress(Ptr); |
61 | 116M | SDValue Index = SDValue(); |
62 | 116M | int64_t Offset = 0; |
63 | 116M | bool IsIndexSignExt = false; |
64 | 116M | |
65 | 116M | // Consume constant adds & ors with appropriate masking. |
66 | 279M | while (Base->getOpcode() == ISD::ADD || 279M Base->getOpcode() == ISD::OR111M ) { |
67 | 168M | if (auto *C168M = dyn_cast<ConstantSDNode>(Base->getOperand(1))) { |
68 | 163M | // Only consider ORs which act as adds. |
69 | 163M | if (Base->getOpcode() == ISD::OR && |
70 | 370k | !DAG.MaskedValueIsZero(Base->getOperand(0), C->getAPIntValue())) |
71 | 0 | break; |
72 | 163M | Offset += C->getSExtValue(); |
73 | 163M | Base = Base->getOperand(0); |
74 | 163M | continue; |
75 | 163M | } |
76 | 5.08M | break; |
77 | 5.08M | } |
78 | 116M | |
79 | 116M | if (Base->getOpcode() == ISD::ADD116M ) { |
80 | 5.05M | // TODO: The following code appears to be needless as it just |
81 | 5.05M | // bails on some Ptrs early, reducing the cases where we |
82 | 5.05M | // find equivalence. We should be able to remove this. |
83 | 5.05M | // Inside a loop the current BASE pointer is calculated using an ADD and a |
84 | 5.05M | // MUL instruction. In this case Base is the actual BASE pointer. |
85 | 5.05M | // (i64 add (i64 %array_ptr) |
86 | 5.05M | // (i64 mul (i64 %induction_var) |
87 | 5.05M | // (i64 %element_size))) |
88 | 5.05M | if (Base->getOperand(1)->getOpcode() == ISD::MUL) |
89 | 699k | return BaseIndexOffset(Base, Index, Offset, IsIndexSignExt); |
90 | 4.35M | |
91 | 4.35M | // Look at Base + Index + Offset cases. |
92 | 4.35M | Index = Base->getOperand(1); |
93 | 4.35M | SDValue PotentialBase = Base->getOperand(0); |
94 | 4.35M | |
95 | 4.35M | // Skip signextends. |
96 | 4.35M | if (Index->getOpcode() == ISD::SIGN_EXTEND4.35M ) { |
97 | 107k | Index = Index->getOperand(0); |
98 | 107k | IsIndexSignExt = true; |
99 | 107k | } |
100 | 4.35M | |
101 | 4.35M | // Check if Index Offset pattern |
102 | 4.35M | if (Index->getOpcode() != ISD::ADD || |
103 | 46.2k | !isa<ConstantSDNode>(Index->getOperand(1))) |
104 | 4.32M | return BaseIndexOffset(PotentialBase, Index, Offset, IsIndexSignExt); |
105 | 37.5k | |
106 | 37.5k | Offset += cast<ConstantSDNode>(Index->getOperand(1))->getSExtValue(); |
107 | 37.5k | Index = Index->getOperand(0); |
108 | 37.5k | if (Index->getOpcode() == ISD::SIGN_EXTEND37.5k ) { |
109 | 6.34k | Index = Index->getOperand(0); |
110 | 6.34k | IsIndexSignExt = true; |
111 | 6.34k | } else |
112 | 31.1k | IsIndexSignExt = false; |
113 | 5.05M | Base = PotentialBase; |
114 | 5.05M | } |
115 | 110M | return BaseIndexOffset(Base, Index, Offset, IsIndexSignExt); |
116 | 116M | } |