Bug Summary

File:llvm/lib/Target/PowerPC/PPCMachineFunctionInfo.cpp
Warning:line 186, column 37
The result of the left shift is undefined due to shifting by '32', which is greater or equal to the width of type 'uint32_t'

Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name PPCMachineFunctionInfo.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mframe-pointer=none -fmath-errno -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -ffunction-sections -fdata-sections -fcoverage-compilation-dir=/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/build-llvm/lib/Target/PowerPC -resource-dir /usr/lib/llvm-14/lib/clang/14.0.0 -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/build-llvm/lib/Target/PowerPC -I /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/llvm/lib/Target/PowerPC -I /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/build-llvm/include -I /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/llvm/include -D NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/x86_64-linux-gnu/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/backward -internal-isystem /usr/lib/llvm-14/lib/clang/14.0.0/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/build-llvm/lib/Target/PowerPC -fdebug-prefix-map=/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e=. -ferror-limit 19 -fvisibility hidden -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2021-09-04-040900-46481-1 -x c++ /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/llvm/lib/Target/PowerPC/PPCMachineFunctionInfo.cpp
1//===-- PPCMachineFunctionInfo.cpp - Private data used for PowerPC --------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "PPCMachineFunctionInfo.h"
10#include "llvm/ADT/Twine.h"
11#include "llvm/BinaryFormat/XCOFF.h"
12#include "llvm/IR/DataLayout.h"
13#include "llvm/MC/MCContext.h"
14#include "llvm/Support/CommandLine.h"
15
16using namespace llvm;
17static cl::opt<bool> PPCDisableNonVolatileCR(
18 "ppc-disable-non-volatile-cr",
19 cl::desc("Disable the use of non-volatile CR register fields"),
20 cl::init(false), cl::Hidden);
21
22void PPCFunctionInfo::anchor() {}
23PPCFunctionInfo::PPCFunctionInfo(const MachineFunction &MF)
24 : DisableNonVolatileCR(PPCDisableNonVolatileCR) {}
25
26MCSymbol *PPCFunctionInfo::getPICOffsetSymbol(MachineFunction &MF) const {
27 const DataLayout &DL = MF.getDataLayout();
28 return MF.getContext().getOrCreateSymbol(Twine(DL.getPrivateGlobalPrefix()) +
29 Twine(MF.getFunctionNumber()) +
30 "$poff");
31}
32
33MCSymbol *PPCFunctionInfo::getGlobalEPSymbol(MachineFunction &MF) const {
34 const DataLayout &DL = MF.getDataLayout();
35 return MF.getContext().getOrCreateSymbol(Twine(DL.getPrivateGlobalPrefix()) +
36 "func_gep" +
37 Twine(MF.getFunctionNumber()));
38}
39
40MCSymbol *PPCFunctionInfo::getLocalEPSymbol(MachineFunction &MF) const {
41 const DataLayout &DL = MF.getDataLayout();
42 return MF.getContext().getOrCreateSymbol(Twine(DL.getPrivateGlobalPrefix()) +
43 "func_lep" +
44 Twine(MF.getFunctionNumber()));
45}
46
47MCSymbol *PPCFunctionInfo::getTOCOffsetSymbol(MachineFunction &MF) const {
48 const DataLayout &DL = MF.getDataLayout();
49 return MF.getContext().getOrCreateSymbol(Twine(DL.getPrivateGlobalPrefix()) +
50 "func_toc" +
51 Twine(MF.getFunctionNumber()));
52}
53
54bool PPCFunctionInfo::isLiveInSExt(Register VReg) const {
55 for (const std::pair<Register, ISD::ArgFlagsTy> &LiveIn : LiveInAttrs)
56 if (LiveIn.first == VReg)
57 return LiveIn.second.isSExt();
58 return false;
59}
60
61bool PPCFunctionInfo::isLiveInZExt(Register VReg) const {
62 for (const std::pair<Register, ISD::ArgFlagsTy> &LiveIn : LiveInAttrs)
63 if (LiveIn.first == VReg)
64 return LiveIn.second.isZExt();
65 return false;
66}
67
68void PPCFunctionInfo::appendParameterType(ParamType Type) {
69
70 ParamtersType.push_back(Type);
71 switch (Type) {
72 case FixedType:
73 ++FixedParmsNum;
74 return;
75 case ShortFloatingPoint:
76 case LongFloatingPoint:
77 ++FloatingParmsNum;
78 return;
79 case VectorChar:
80 case VectorShort:
81 case VectorInt:
82 case VectorFloat:
83 ++VectorParmsNum;
84 return;
85 }
86 llvm_unreachable("Error ParamType type.")__builtin_unreachable();
87}
88
89uint32_t PPCFunctionInfo::getVecExtParmsType() const {
90
91 uint32_t VectExtParamInfo = 0;
92 unsigned ShiftBits = 32 - XCOFF::TracebackTable::WidthOfParamType;
93 int Bits = 0;
94
95 if (!hasVectorParms())
96 return 0;
97
98 for (const auto &Elt : ParamtersType) {
99 switch (Elt) {
100 case VectorChar:
101 VectExtParamInfo <<= XCOFF::TracebackTable::WidthOfParamType;
102 VectExtParamInfo |=
103 XCOFF::TracebackTable::ParmTypeIsVectorCharBit >> ShiftBits;
104 Bits += XCOFF::TracebackTable::WidthOfParamType;
105 break;
106 case VectorShort:
107 VectExtParamInfo <<= XCOFF::TracebackTable::WidthOfParamType;
108 VectExtParamInfo |=
109 XCOFF::TracebackTable::ParmTypeIsVectorShortBit >> ShiftBits;
110 Bits += XCOFF::TracebackTable::WidthOfParamType;
111 break;
112 case VectorInt:
113 VectExtParamInfo <<= XCOFF::TracebackTable::WidthOfParamType;
114 VectExtParamInfo |=
115 XCOFF::TracebackTable::ParmTypeIsVectorIntBit >> ShiftBits;
116 Bits += XCOFF::TracebackTable::WidthOfParamType;
117 break;
118 case VectorFloat:
119 VectExtParamInfo <<= XCOFF::TracebackTable::WidthOfParamType;
120 VectExtParamInfo |=
121 XCOFF::TracebackTable::ParmTypeIsVectorFloatBit >> ShiftBits;
122 Bits += XCOFF::TracebackTable::WidthOfParamType;
123 break;
124 default:
125 break;
126 }
127
128 // There are only 32bits in the VectExtParamInfo.
129 if (Bits >= 32)
130 break;
131 }
132 return Bits < 32 ? VectExtParamInfo << (32 - Bits) : VectExtParamInfo;
133}
134
135uint32_t PPCFunctionInfo::getParmsType() const {
136 uint32_t ParamsTypeInfo = 0;
137 unsigned ShiftBits = 32 - XCOFF::TracebackTable::WidthOfParamType;
138
139 int Bits = 0;
140 for (const auto &Elt : ParamtersType) {
1
Assuming '__begin1' is equal to '__end1'
141
142 if (Bits > 31 || (Bits > 30 && (Elt != FixedType || hasVectorParms())))
143 break;
144
145 switch (Elt) {
146 case FixedType:
147 if (hasVectorParms()) {
148 //'00' ==> fixed parameter if HasVectorParms is true.
149 ParamsTypeInfo <<= XCOFF::TracebackTable::WidthOfParamType;
150 ParamsTypeInfo |=
151 XCOFF::TracebackTable::ParmTypeIsFixedBits >> ShiftBits;
152 Bits += XCOFF::TracebackTable::WidthOfParamType;
153 } else {
154 //'0' ==> fixed parameter if HasVectorParms is false.
155 ParamsTypeInfo <<= 1;
156 ++Bits;
157 }
158 break;
159 case ShortFloatingPoint:
160 // '10'b => floating point short parameter.
161 ParamsTypeInfo <<= XCOFF::TracebackTable::WidthOfParamType;
162 ParamsTypeInfo |=
163 XCOFF::TracebackTable::ParmTypeIsFloatingBits >> ShiftBits;
164 Bits += XCOFF::TracebackTable::WidthOfParamType;
165 break;
166 case LongFloatingPoint:
167 // '11'b => floating point long parameter.
168 ParamsTypeInfo <<= XCOFF::TracebackTable::WidthOfParamType;
169 ParamsTypeInfo |=
170 XCOFF::TracebackTable::ParmTypeIsDoubleBits >> ShiftBits;
171 Bits += XCOFF::TracebackTable::WidthOfParamType;
172 break;
173 case VectorChar:
174 case VectorShort:
175 case VectorInt:
176 case VectorFloat:
177 // '01' ==> vector parameter
178 ParamsTypeInfo <<= XCOFF::TracebackTable::WidthOfParamType;
179 ParamsTypeInfo |=
180 XCOFF::TracebackTable::ParmTypeIsVectorBits >> ShiftBits;
181 Bits += XCOFF::TracebackTable::WidthOfParamType;
182 break;
183 }
184 }
185
186 return Bits
1.1
'Bits' is < 32
< 32 ? ParamsTypeInfo << (32 - Bits) : ParamsTypeInfo;
2
'?' condition is true
3
The result of the left shift is undefined due to shifting by '32', which is greater or equal to the width of type 'uint32_t'
187}