store64_lane: Wasm SIMD load/store instruction
The store64_lane SIMD load/store instruction stores a specified lane of a v128 i64x2 value interpretation at a given memory address.
Try it
(module
(import "console" "log" (func $log (param i64)))
(memory $memory 1)
(func $main
i32.const 0
v128.const i64x2 8000001 16000001
v128.store64_lane 1
i32.const 0
v128.load
i64x2.extract_lane 0
call $log
)
(start $main)
)
WebAssembly.instantiateStreaming(fetch("{%wasm-url%}"), { console });
Syntax
;; Common usage v128.store64_lane lane_idx ;; With optional immediate operands v128.store64_lane mem_idx offset=int align=int lane_idx
v128.store64_lane-
The
v128.store64_laneinstruction. mem_idxOptional-
An integer representing the memory index, in cases where the module uses multiple memories. The default is
0. offset=intOptional-
An integer representing a constant number of bytes to add to the address before storing. The default is
0. align=intOptional-
An integer representing a hint to the Wasm engine about what alignment to expect for the final address. The minimum value is
1and the default and maximum value is8. Analignvalue has to be a power of2. lane_idx-
The index of the lane whose value you want to store.
Type
[memory_address, input] -> []
memory_address-
An integer representing the memory address to store the
inputat. input-
The
v128type from which to extract a lane value to store.
Binary encoding
| Instruction | Binary format | Example text => binary |
|---|---|---|
v128.store64_lane |
0xfd 91:u32 mem_idx:u8 offset:u32 align:u32 l:laneidx |
v128.store64_lane 0 offset=0 align=8 1 => 0xfd 0x5b 0x03 0x00 0x01 |
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 for example, align=1 is equivalent to 0x00 (2^0), while align=8 is equivalent to 0x03 (2^3).