Issues found PVS studio static analyzer #169959
Description
Hi! I found several issues in LLVM code using static analyzer tool PVS-studio. I hope this will be helpful. Full descriptions in the article: https://pvs-studio.com/en/blog/posts/cpp/1318/
- Issues found PVS studio static analyzer. PPCISelLowering.cpp #170115
The PVS-Studio warning: V501 There are identical sub-expressions to the left and to the right of the '==' operator: PeekArg.getValNo() == PeekArg.getValNo() PPCISelLowering.cpp 7865 - Issues found PVS studio static analyzer. LVCodeViewReader.cpp #170117
The PVS-Studio warning: V519 The 'FeaturesValue' variable is assigned values twice successively. Perhaps this is a mistake. Check lines: 1190, 1192. LVCodeViewReader.cpp 1192 - Issues found PVS studio static analyzer. RISCVCustomBehaviour.cpp #170118
The PVS-Studio warning: V609 Divide by zero. Denominator range [0..255]. RISCVCustomBehaviour.cpp 268 - Issues found PVS studio static analyzer. VEISelDAGToDAG.cp #170119
The PVS-Studio warning: V779 Unreachable code detected. It is possible that an error is present. VEISelDAGToDAG.cpp 321 - Issues found PVS studio static analyzer. ARMBaseInstrInfo.cpp #170120
The PVS-Studio warnings: V560 a part of conditional expression is always false: Opc == ARM::MVE_VORR. ARMBaseInstrInfo.cpp 752 - Issues found PVS studio static analyzer. DwarfDebug.cpp 485 #170121
The PVS-Studio warning: V590 Consider inspecting this expression. The expression is excessive or contains a misprint. DwarfDebug.cpp 485 - Issues found PVS studio static analyzer. LoongArchAsmBackend.cpp #170122
The PVS-Studio warning: V547 Expression 'Value' is always false. LoongArchAsmBackend.cpp 139 - Issues found PVS studio static analyzer. HexagonMCChecker.cpp #170124
The PVS-Studio warning: V560 A part of conditional expression is always false: Defs.count(R) > 1. HexagonMCChecker.cpp 612 - Issues found PVS studio static analyzer. SystemZAsmPrinter.cpp #170125
The PVS-Studio warning: V547 Expression is always true. SystemZAsmPrinter.cpp 1324 - Issues found PVS studio static analyzer. LoopUnrollAndJam.cpp #170126
The PVS-Studio warning: V791 The initial value of the index in the nested loop equals 'I'. Perhaps, 'I + 1' should be used instead. LoopUnrollAndJam.cpp 793
I took the liberty of correcting some simple fragments myself:
#169958
- 1. Misprint in conditional.
The PVS-Studio warning: V501 There are identical sub-expressions '!Subtarget.hasZeroCycleRegMoveFPR64()' to the left and to the right of the '&&' operator. AArch64InstrInfo.cpp 5430 - 3. Array overrun is possible.
The PVS-Studio warning: V557 Array overrun is possible. The value of 'regIdx' index could reach 31. VEAsmParser.cpp 696 - 10. Excessive check.
The PVS-Studio warning: V547 Expression 'IsLeaf' is always false. PPCInstrInfo.cpp 419 - 11. Doubling the same check.
The PVS-Studio warning: V581 The conditional expressions of the 'if' statements situated alongside each other are identical. Check lines: 5820, 5823. PPCInstrInfo.cpp 5823 - 12. Wrong value in conditional.
The PVS-Studio warning: V547 Expression 'Opcode == Instruction::FDiv' is always false. GISelValueTracking.cpp 1451 - 14. Type issue in expression.
The PVS-Studio warning: V560 A part of conditional expression is always false: AVX10Ver >= 2. Host.cpp 2177 - 15. Excessive check.
The PVS-Studio warning: V547 Expression 'i != e' is always true. MachineFunction.cpp 1444 - 17. Excessive assignment.
The PVS-Studio warning: V1048 The 'FirstOp' variable was assigned the same value. MachineInstr.cpp 1995 - 18. Excessive check.
The PVS-Studio warning: V547 Expression 'AllSame' is always true. SimplifyCFG.cpp 1914 - 19. Excessive check.
The PVS-Studio warning: V547 Expression 'AbbrevDecl' is always true. LVDWARFReader.cpp 398