Lexicon Entry
PHI Node
An SSA construct that selects a value based on which predecessor basic block control flow came from. Necessary because in SSA form each variable has exactly one definition.
Related Knowledge & Cross-References
Guide
LLVM IR Tutorial: The Hidden Language Between Your C Code and Assembly
Master LLVM IR in this hands-on tutorial. Learn SSA form, basic blocks, and PHI nodes with real Clang output and Godbolt examples — from C to IR to x86-64 and ARM64.