demote_f64x2_zero: Wasm SIMD conversion instruction

The demote_f64x2_zero SIMD conversion instruction converts the lanes of a v128 f64x2 value interpretation into an f32x4 value interpretation. The two higher lanes of the result are initialized to zero.

Try it

(module
  (import "console" "log" (func $log (param f32)))
  (func $main
    v128.const f64x2 0x3 0x3a

    f32x4.demote_f64x2_zero
    f32x4.extract_lane 1
    call $log ;; log the result
  )
  (start $main)
)

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

Syntax

value_type.demote_f64x2_zero

value_type

The type of value the instruction is being run on. The following v128 value interpretations support demote_f64x2_zero:

• f32x4

demote_f64x2_zero

The demote_f64x2_zero instruction. Must always be included after the value_type and a period (.).

Type

[input] -> [output]

input

The input v128 f64x2 value interpretation.

output

The output v128 f32x4 value interpretation.

Binary encoding

Specifications

• WebAssembly Core Specification