rampitec wrote: > > Hi @rampitec > > With UBSan built binaries the MC/AMDGPU/literals.s testcase fails and > > triggers UB like > > ``` > > 07:33:04 ../lib/Target/AMDGPU/AsmParser/AMDGPUAsmParser.cpp:2246:59: > > runtime error: left shift of negative value -54321 > > 07:33:04 SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior > > ../lib/Target/AMDGPU/AsmParser/AMDGPUAsmParser.cpp:2246:59 > > ``` > > > > > > It's this new shift that it complains on: > > ``` > > Val = AMDGPU::isSISrcFPOperand(InstDesc, OpNum) ? Val << 32 : > > Lo_32(Val); > > ``` > > I am happy to fix it, but I do not understand how a LEFT shift can be a UB? > Low bits will be zero, right? High bits will be disposed. I really do not > understand.
Building ubsan now... https://github.com/llvm/llvm-project/pull/68740 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
