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Intrinsics

The compiler synthesises a small set of runtime intrinsic functions on demand: if a compiled module has an unresolved relocation to one of these names, and the user did not define a function with the same name, the driver appends a hand-written x86-64 implementation to the program before linking.

All print intrinsics carry the @io effect, so any function that calls one (directly or transitively) must itself be annotated @io. A pure function that calls print_i32 is a type error; see Effects (@io) for the propagation rules.

@io fn print_i32(x: i32) -> i32

Writes x to stdout as a base-10 signed integer, followed by a newline. Returns x unchanged so the call can sit in expression position (let y = print_i32(compute()) + 1).

Implementation: an inlined decimal-formatter and a Linux write(2) syscall (no libc).

Source: internal/backend/cpu/x86/runtime.go, BuildPrintI32 (registered via IsPrintBuiltin).

@io fn print_f32(x: f32) -> f32

Writes x to stdout as a fixed-point decimal with six fractional digits, followed by a newline. Returns x unchanged.

Caveats: no NaN/Inf handling, no scientific notation, no trailing-zero trim. This is a debug/tracing intrinsic, not a production printer.

@io fn print_str(s: string) -> string

Writes the bytes of s to stdout verbatim. No trailing newline. Returns s unchanged.

Adding a new intrinsic​

The pattern is fixed. To add print_i64:

  1. Implement Build_print_i64() in internal/backend/cpu/x86/runtime.go.
  2. Add the name to IsPrintBuiltin so the symbol is recognised as a runtime intrinsic and not a missing user function.
  3. Add a case "print_i64": in appendRuntimeFns in cmd/esquec/main.go to emit the body when needed.
  4. Update the type checker to accept print_i64 as a name with the appropriate signature (today these are special-cased; once the stdlib package exists they will live there).

There is no other place to touch; the linker picks up the new symbol automatically.

What is not an intrinsic​

  • +/, */, …: parsed as operators, lowered in CEIR/MIR, codegen'd by the SIMD reduction path. Not intrinsics.
  • tabulate, scan, iterate_until, each, iterate: parsed specially in the parser; lowered in CEIR. Not intrinsics.
  • as: parsed as a postfix operator; lowered to MIR cast ops.