/* The loop optimizations' per-function state: counted loops, dense array
 * loops, byte windows and typed-array loop versioning, and the unaliased
 * local arrays they rely on. */
import { findUnaliasedLocalArrays } from "../../ir/array-length-stability.js";
import type { IrFunction, IrStmt } from "../../ir/ir.js";
import { findInitializedByteLoopBindings } from "./byte-windows.js";
import type { DenseArrayLoop } from "./dense-array-loops.js";
import type { LlEmitter } from "./emitter.js";

/** Sets the loop state for `fn` at the start of its emission; `numericFn`
 * is `fn` with its initializer bindings (emitFunction). */
export function beginFunctionLoops(
  emitter: LlEmitter,
  fn: IrFunction,
  numericFn: IrFunction,
): void {
  const loops = LOOPS.of(emitter);
  loops.unaliasedArrays = findUnaliasedLocalArrays(fn);
  loops.countedLoopsEnabled = emitter.debug === null && !fn.async && !fn.generator;
  loops.byteWindowsEnabled = loops.countedLoopsEnabled;
  loops.bytesLoopVersionsEnabled = loops.countedLoopsEnabled;
  loops.bytesLoopEntries = null;
  loops.bytesLoopFunction = fn;
  loops.denseLoopsEnabled = loops.countedLoopsEnabled;
  loops.denseLoop = null;
  loops.denseLoopEntries =
    loops.denseLoopsEnabled && numericFn.locals.some((l) => l.type.kind === "array")
      ? findInitializedByteLoopBindings(fn)
      : new Map();
  loops.byteWindowEntries =
    loops.byteWindowsEnabled && numericFn.locals.some((l) => l.type.kind === "bytes")
      ? findInitializedByteLoopBindings(fn)
      : new Map();
}