The extadd_pairwise_i8x16_s SIMD arithmetic instruction adds each adjacent pair of lanes of a signed v128 i8x16 value interpretation, outputting the results into an i16x8 value interpretation.

(module
  (import "console" "log" (func $log (param i32)))
  (func $main
    v128.const i8x16 2 4 2 4 2 4 2 4 2 4 2 4 2 4 2 4

    i16x8.extadd_pairwise_i8x16_s
    i16x8.extract_lane_s 7
    call $log ;; log the result
  )
  (start $main)
)

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

In the above example, each adjacent pair of lanes contains the values 2 and 4. The extadd_pairwise_i8x16_s instruction adds each pair together, resulting in the 8 lanes of the output i16x8 value all containing the value 6.

Syntax

i16x8.extadd_pairwise_i8x16_s

• i16x8.extadd_pairwise_i8x16_s

  • : The i16x8.extadd_pairwise_i8x16_s instruction.

Type

[input] -> [output]

• input

  • : The input v128 i8x16 value interpretation.

  output

  • : The output v128 i16x8 value interpretation.

Binary encoding

InstructionBinary formatExample text => binaryi16x8.extadd_pairwise_i8x16_s0xfd 124:u32i16x8.extadd_pairwise_i8x16_s => 0xfd 0x7c

Specifications

Browser compatibility