le: Wasm text instruction - Content

The le instructions, short for less or equal, check if a number is less than or equal to another number. If the first number is less than or equal to the second number equal 1 will be pushed on to the stack, otherwise 0 will be pushed on to the stack.

The integer types have separate less or equal instructions for signed (le_s) and unsigned (le_u) numbers.

wat

(module
  (import "env" "log_bool" (func $log_bool (param i32)))
  (func $main
    ;; load `10` and `2` onto the stack
    i32.const 10
    i32.const 2

    i32.le_u ;; check if `10` is  less than or equal to '2'
    call $log_bool ;; log the result
  )
  (start $main)
)

const url = "{%wasm-url%}";

function log_bool(value) {
  console.log(Boolean(value));
  // Expected output: false
}

await WebAssembly.instantiateStreaming(fetch(url), {
  env: { log_bool },
});

Syntax

wat

;; load 2 numbers on to the stack
local.get $num
i32.const 2

;; check if $num is less than or equal to '2'
i32.le_u

;; if $num is less than or equal to the `2`, `1` will be pushed on to the stack,
;; otherwise `0` will be pushed on to the stack.

Instruction	Binary opcode
`i32.le_s`	`0x4C`
`i32.le_u`	`0x4D`
`i64.le_s`	`0x57`
`i64.le_u`	`0x58`
`f32.le`	`0x5F`
`f64.le`	`0x65`