Poison Value

A undefined behavior value that takes on every value at once. These are usually garbage values that are returned at undefined behavior.

Doing operations with poison values like dereferencing it, LLVM br, LLVM select, LLVM phi will also result in Undefined Behaviors

Examples that lead the poison values

• C signed overflow
• LLVM add nsw (adding no signed wrap)
• floating point operations marked with nnan and ninf
• LLVM GEP with out-of-bounds
• LLVM udiv without zero remainder like 5 / 2