How Go Generics Balance Performance with GC Shape Stenciling

GC shape stenciling in Go generics

I explored how Go implements generics using GC shape stenciling, a unique middle ground between Rust's full monomorphization and Java's type erasure. By grouping types based on their garbage collector shape, Go reduces binary size while maintaining high performance. This approach compiles shared function bodies for similar types, using hidden dictionaries to handle specific type details at runtime, effectively balancing compile time and execution speed.

"The main exception is method calls, which can't be fully resolved at compile time. They can also block inlining and make escape analysis more conservative, which can mean extra heap allocations."