load：Wasm 文字指令

(module

  (memory $memory 1)
  (export "memory" (memory $memory))

  (func (export "load_first_item_in_mem") (param $num i32) (result i32)
    i32.const 0

    ;; load first item in memory and return the result
    i32.load
  )

)

const url = "{%wasm-url%}";
const result = await WebAssembly.instantiateStreaming(fetch(url));
const load_first_item_in_mem = result.instance.exports.load_first_item_in_mem;
const memory = result.instance.exports.memory;

const dataView = new DataView(memory.buffer);
// Store 30 at the beginning of memory
dataView.setUint32(0, 30, true);

console.log(load_first_item_in_mem(100));
// Expected output: 30

;; Load from default memory at offset specified by value on top of stack
i32.const 0 ;; Stack variable containing memory offset (0) of number to be loaded.
i32.load    ;; Load from specified offset in default memory

;; Load from same location using an S-function
(i32.load (i32.const 0))

;; Load from memory specified by index
i32.const 0 ;; offset in memory to load from (0)
i32.load (memory 1) ;; load from memory index 1

;; Load from memory specified by name
i32.const 1  ;; offset in memory to load from (1)
i32.load (memory $memory1) ;; load from named memory $memory1

;; Load from memory specified by name using an S-function
(i32.load (memory $memory1) (i32.const 0))

(module
  ;; Define memory named $memory and export
  (memory $memory 1)  ;; First memory declared is default, with index 0
  (export "memory" (memory $memory))

  ;; Exported function to load first item in default memory
  (func (export "load_first_item_in_mem") (param $num i32) (result i32)
    ;; load 0-offset item in memory and return the result
    i32.const 0
    i32.load
  )
)

// await on the specified .wasm file to be fetched and loaded
const result = await WebAssembly.instantiateStreaming(
  fetch("load_single.wasm"),
);

// Get the exported function that we will call below
const load_first_item_in_mem = result.instance.exports.load_first_item_in_mem;

// Get the exported memory and store 30 at the 0 offset
const memory = result.instance.exports.memory;
const dataView = new DataView(memory.buffer);
dataView.setUint32(0, 30, true);

// Log the result of calling the exported Wasm function
console.log(load_first_item_in_mem(100)); // 30

(module
  ;; Define memory for the module
  (memory $memory0 1)  ;; First (default) memory with memory index 0 (and 1 page)
  (memory $memory1 1)  ;; Second memory with index 1, named $memory1
  (export "memory" (memory $memory1))  ;; Export $memory1

  ;; Exported function to load first item in default memory
  (func (export "load_first_item_in_mem") (param $num i32) (result i32)
    ;; load 0-offset item in memory index 1 and return the result
    i32.const 0
    i32.load (memory 1)
  )
)

i32.const 0
i32.load (memory $memory1)  ;; referencing memory by name

;; Using S-functions
(i32.load (memory 1) (i32.const 0))  ;; reference memory by index
(i32.load (memory $memory1) (i32.const 0)) ;; reference memory by name

i32.const 0
i32.load (memory 0)  ;; referencing memory by index

;; Using S-functions
(i32.load (i32.const 0))
(i32.load (memory 0) (i32.const 0))  ;; reference memory by index
(i32.load (memory $memory0) (i32.const 0)) ;; reference memory by name