convert_low_i32x4_u: Wasm SIMD conversion instruction

The convert_low_i32x4_u SIMD conversion instruction converts the first two lanes of an unsigned v128 i32x4 value interpretation into an f64x2 value interpretation.

Try it

(module
  (import "console" "log" (func $log (param f64)))
  (func $main
    v128.const i32x4 0x3 0x3a 0xa9 0xff

    f64x2.convert_low_i32x4_u
    f64x2.extract_lane 1
    call $log ;; log the result
  )
  (start $main)
)
WebAssembly.instantiateStreaming(fetch("{%wasm-url%}"), { console });

Syntax

value_type.convert_low_i32x4_u
value_type

The type of value the instruction is being run on. The following v128 value interpretations support convert_low_i32x4_u:

  • f64x2
convert_low_i32x4_u

The convert_low_i32x4_u instruction. Must always be included after the value_type and a period (.).

Type

[input] -> [output]
input

The input v128 i32x4 value interpretation.

output

The output v128 f64x2 value interpretation. The first two values of the input i32x4 are included in the output f64x2.

Binary encoding

Instruction Binary format Example text => binary
f64x2.convert_low_i32x4_u 0xfd 255:u32 f64x2.convert_low_i32x4_u => 0xfd 0xff 0x01

Specifications

This feature does not appear to be defined in any specification.

Browser compatibility

See also