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.

(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

InstructionBinary formatExample text => binaryf32x4.demote_f64x2_zero0xfd 94:u32f32x4.demote_f64x2_zero => 0xfd 0x5e

Specifications

Browser compatibility