trunc_sat_f64x2_u_zero: Wasm SIMD conversion instruction

The trunc_sat_f64x2_u_zero SIMD conversion instruction performs a saturating conversion of the lanes of a v128 f64x2 value interpretation into an unsigned i32x4 value interpretation, clamping the output to the range allowed by the value type. The two higher lanes of the result are initialized to zero.

Try it

(module
  (import "console" "log" (func $log (param i32)))
  (func $main
    v128.const f64x2 1345400000.9 90000000000.5

    i32x4.trunc_sat_f64x2_u_zero
    i32x4.extract_lane 1
    call $log ;; log the result
  )
  (start $main)
)
WebAssembly.instantiateStreaming(fetch("{%wasm-url%}"), { console });

Saturation means that the output values are clamped to the upper and lower values allowed by the value interpretation. Allowed output values are 0 to 4,294,967,295 (the full range of an unsigned 32-bit integer). NaN values are converted to 0.

Syntax

value_type.trunc_sat_f64x2_u_zero
value_type

The type of value the instruction is being run on. The following v128 value interpretations support trunc_sat_f64x2_u_zero:

  • i32x4
trunc_sat_f64x2_u_zero

The trunc_sat_f64x2_u_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 i32x4 value interpretation.

Binary encoding

Instruction Binary format Example text => binary
i32x4.trunc_sat_f64x2_u_zero 0xfd 253:u32 i32x4.trunc_sat_f64x2_u_zero => 0xfd 0xfd 0x01

Specifications

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

Browser compatibility

See also