ensureballast-contparams.js

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// |jit-test| skip-if: !wasmStackSwitchingEnabled()

// Regression test: Ion MIR emitters for cont params/results and suspend tag

// results omitted mirGen().ensureBallast() in per-value loops. With a large

// number of values, this exhausts the LifoAlloc ballast and trips an

// infallible-allocation assertion in debug builds.

const N = 500;

const types = new Array(N).fill("i64").join(" ");

const pushes = "(i64.const 0) ".repeat(N);

const drops = "drop ".repeat(N);

// Case 1: cont type with many params — triggers the emitResume args loop

// (MWasmStoreStackResult per arg, no ensureBallast).

wasmEvalText(`(module

  (type $ft (func (param ${types})))

  (type $ct (cont $ft))

  (func $f (type $ft))

  (elem declare func $f)

  (func

    ${pushes}

    ref.func $f

    cont.new $ct

    resume $ct))`);

// Case 2: cont type with many results — triggers the emitResume results loop

// (MWasmStackResult per result, no ensureBallast).

wasmEvalText(`(module

  (type $ft (func (result ${types})))

  (type $ct (cont $ft))

  (func $f (type $ft) ${pushes})

  (elem declare func $f)

  (func

    ref.func $f

    cont.new $ct

    resume $ct

    ${drops}))`);

// Case 3: tag with many results (matching cont params) — triggers the

// emitSuspend tag-results loop (MWasmStackResult per tag result, no

// ensureBallast). $f ignores its N params (in locals) and suspends, then drops

// the N tag results delivered by the resumer.

wasmEvalText(`(module

  (type $ft (func (param ${types})))

  (type $ct (cont $ft))

  (tag $tag (result ${types}))

  (func $f (type $ft)

    suspend $tag

    ${drops})

  (elem declare func $f)

  (func

    (local $k (ref null $ct))

    (block $on_tag (result (ref $ct))

      ${pushes}

      ref.func $f

      cont.new $ct

      resume $ct (on $tag 0)

      unreachable)

    local.set $k

    ${pushes}

    local.get $k

    resume $ct))`);