CARVIEW |
Select Language
HTTP/2 200
x-guploader-uploadid: AAwnv3LXaeDCITlCDMiGD_gl1A9662yQ5C-OMrd6yFVuwyqJ6P13tgE02L2NIn88tMUovyCt
x-goog-generation: 1760058448856839
x-goog-metageneration: 1
x-goog-stored-content-encoding: identity
x-goog-stored-content-length: 140717
x-goog-meta-goog-reserved-file-mtime: 1760056825
x-goog-hash: crc32c=ZeYYxA==, md5=Lz86yu7/PU4HYZwU1qTVng==
x-goog-storage-class: STANDARD
accept-ranges: none
expires: Sun, 12 Oct 2025 17:54:31 GMT
cache-control: public, max-age=3600
last-modified: Fri, 10 Oct 2025 01:07:28 GMT
etag: W/"2f3f3acaeeff3d4e07619c14d6a4d59e"
content-type: text/html
age: 0
alt-svc: h3=":443"; ma=2592000,h3-29=":443"; ma=2592000
alt-svc: clear
referrer-policy: strict-origin-when-cross-origin
x-content-type-options: nosniff
strict-transport-security: max-age=63072000
content-security-policy: default-src 'self'; script-src 'report-sample' 'self' 'wasm-unsafe-eval' https://www.google-analytics.com/analytics.js https://www.googletagmanager.com/gtag/js assets.codepen.io production-assets.codepen.io https://js.stripe.com 'sha256-XNBp89FG76amD8BqrJzyflxOF9PaWPqPqvJfKZPCv7M=' 'sha256-YCNoU9DNiinACbd8n6UPyB/8vj0kXvhkOni9/06SuYw=' 'sha256-PZjP7OR6mBEtnvXIZfCZ5PuOlxoDF1LDZL8aj8c42rw='; script-src-elem 'report-sample' 'self' 'wasm-unsafe-eval' https://www.google-analytics.com/analytics.js https://www.googletagmanager.com/gtag/js assets.codepen.io production-assets.codepen.io https://js.stripe.com 'sha256-XNBp89FG76amD8BqrJzyflxOF9PaWPqPqvJfKZPCv7M=' 'sha256-YCNoU9DNiinACbd8n6UPyB/8vj0kXvhkOni9/06SuYw=' 'sha256-PZjP7OR6mBEtnvXIZfCZ5PuOlxoDF1LDZL8aj8c42rw='; style-src 'report-sample' 'self' 'unsafe-inline'; object-src 'none'; base-uri 'self'; connect-src 'self' developer.allizom.org bcd.developer.allizom.org bcd.developer.mozilla.org updates.developer.allizom.org updates.developer.mozilla.org https://*.google-analytics.com https://*.analytics.google.com https://*.googletagmanager.com https://incoming.telemetry.mozilla.org https://observatory-api.mdn.allizom.net https://observatory-api.mdn.mozilla.net https://api.github.com/search/issues stats.g.doubleclick.net https://api.stripe.com; font-src 'self'; frame-src 'self' interactive-examples.mdn.mozilla.net interactive-examples.mdn.allizom.net mdn.github.io live-samples.mdn.mozilla.net live-samples.mdn.allizom.net *.mdnplay.dev *.mdnyalp.dev *.play.test.mdn.allizom.net https://v2.scrimba.com https://scrimba.com jsfiddle.net www.youtube-nocookie.com codepen.io survey.alchemer.com https://js.stripe.com; img-src 'self' data: *.githubusercontent.com *.googleusercontent.com *.gravatar.com mozillausercontent.com firefoxusercontent.com profile.stage.mozaws.net profile.accounts.firefox.com developer.mozilla.org mdn.dev interactive-examples.mdn.mozilla.net interactive-examples.mdn.allizom.net wikipedia.org upload.wikimedia.org https://mdn.github.io/shared-assets/ https://mdn.dev/ https://*.google-analytics.com https://*.googletagmanager.com www.gstatic.com; manifest-src 'self'; media-src 'self' archive.org videos.cdn.mozilla.net https://mdn.github.io/shared-assets/; child-src 'self'; worker-src 'self';
x-frame-options: DENY
origin-trial: AxVILwizhbMjxFeHOn1P3R8niO1RJY/smaK4B4d1rLzc1gTaxtXMSaTi+FoigYgCw40uFRDwFcEAeqDR+vVLOW4AAABfeyJvcmlnaW4iOiJodHRwczovL2RldmVsb3Blci5tb3ppbGxhLm9yZyIsImZlYXR1cmUiOiJQcml2YXRlQXR0cmlidXRpb25WMiIsImV4cGlyeSI6MTc0MjA3OTYwMH0=
x-cloud-trace-context: e8ae57f23b097f39db14e1914c315c71
date: Sun, 12 Oct 2025 16:54:31 GMT
server: Google Frontend
via: 1.1 google
vary: Accept-Encoding
content-encoding: gzip
x-cache: miss
Left shift - WebAssembly | MDN
Toggle sidebar
Left shift
The shl
instructions, short for shift-left, are used for performing a bitwise left-shift, similar to the <<
operator in other languages.
Try it
(module
(func (export "shift_left") (param $num i32) (param $by i32) (result i32)
;; load the number to shift and the by how many spots
local.get $num
local.get $by
;; shift and return the result
i32.shl
)
)
const url = "{%wasm-url%}";
await WebAssembly.instantiateStreaming(fetch(url), { console }).then(
(result) => {
const shift_left = result.instance.exports.shift_left;
const res = shift_left(0b11100000_00000000_00000000_00000000, 1);
console.log(numToBin(res));
// Expected output: "11000000_00000000_00000000_00000000"
},
);
function numToBin(num) {
return (num >>> 0)
.toString(2)
.padStart(32, "0")
.match(/.{1,8}/g)
.join("_");
}
Syntax
wat
;; load two numbers onto the stack
i32.const 7 ;; 00000111
i32.const 1 ;; left shift one spot
;; perform a bitwise left-shift
i32.shl
;; the top item on the stack will now be 14 (00001110)
Instruction | Binary opcode |
---|---|
i32.shl |
0x74 |
i64.shl |
0x86 |