extract_lane_u: Wasm SIMD extract instruction

The extract_lane_u SIMD extract instruction extracts the value contained within the specified lane of a v128 value interpretation as an unsigned integer.

Try it

(module
  (import "console" "log" (func $log (param i32)))
  (func $main
    ;; load a SIMD value onto the stack
    (v128.const i16x8 1 0 -2 -1 -4 -2 -2 3)

    i16x8.extract_lane_u 6 ;; Extract a scalar value from the result
    call $log ;; log the result
  )
  (start $main)
)

WebAssembly.instantiateStreaming(fetch("{%wasm-url%}"), { console });

Syntax

value_type.extract_lane_u

value_type

The type of value the instruction is being run on. The following v128 value interpretations support extract_lane_u:

• i8x16
• i16x8

extract_lane_u

The extract_lane_u instruction. Must always be included after the value_type and a period (.).

Type

[input, lane] -> [output]

input

The v128 value interpretation you want to extract a lane from.

lane

The index of the lane whose value you wish to extract, for example 0.

output

The value extracted from the lane.

Binary encoding

Specifications

• WebAssembly Core Specification

See also

• extract_lane