load8_splat: Wasm SIMD load instruction

Try it

(module
  (import "console" "log" (func $log (param i32)))
  (memory $memory 1)
  (data (i32.const 0) "\01\02\03\04\05\06\07\08\09\0a\0b\0c\0d\0e\0f\00\01\02\03")
  (func $main
    i32.const 1
    v128.load8_splat
    i8x16.extract_lane_s 15
    call $log
  )
  (start $main)
)

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

Syntax

;; Common usage
v128.load8_splat

;; With optional immediates
v128.load8_splat memidx offset=int align=int

v128.load8_splat: The v128.load8_splat instruction.
memidx Optional: An integer representing the memory index, in cases where the module uses multiple memories. The default is 0.
offset=int Optional: An integer representing a constant number of bytes to add to the memory address before loading. The default is 0.
align=int Optional: An integer representing a hint to the Wasm engine about what alignment to expect for the final address. The minimum, default, and maximum value is 1.

Type

[memory_address] -> [output]

memory_address: An integer representing the memory address to load from.
output: The output v128 type i8x16 value interpretation.

Binary encoding

Instruction	Binary format	Example text => binary
`v128.load8_splat`	`0xFD 7:u32 memidx:u8 offset:u32 align:u32`	`v128.load8_splat 0 offset=0 align=1` => `0xfd 0x07 0x00 0x00`

Note: While Wasm text format specifies the literal align value, the binary equivalent represents the exponent of the formula 2^x used to calculate the alignment. So align=1 is equivalent to 0x00 (2^0).