microtime() — internals

microtime() — internals

Where it lives

• Signature: src/builtins/system/microtime.rs
• Lowering: src/codegen/lower_inst/builtins/system.rs:111 (lower_microtime)
• Function symbol: lower_microtime()

Lowering notes

• Lowers microtime() / microtime(true) / microtime(false) / microtime($flag).
• Dispatch is driven by the arg-aware result type set in ir_lower (see
• call_return_type_for_args and the microtime fallback in call_return_type):
• Float (literal true) calls the existing __rt_microtime float helper; Str
• (omitted / literal false) calls __rt_microtime_str, which builds the
• “0.NNNNNNNN sec” string on the stack and persists it; Mixed (non-literal flag)
• marshals the flag and calls __rt_microtime_mixed, which branches at runtime and
• boxes either the string or the float.

Runtime helpers

The following runtime helpers are referenced:

• __rt_microtime
• __rt_microtime_mixed
• __rt_microtime_str

Signature summary

function microtime(bool $as_float = false): mixed

What the type checker enforces

• Arity: takes 0–1 arguments (1 optional).

Eval interpreter (magician)

• Declaration: crates/elephc-magician/src/interpreter/builtins/time/microtime.rs (eval_builtin!)
• Dispatch hooks: direct, values

Cross-references

• User reference for microtime()