pmin: Wasm SIMD arithmetic instruction
The pmin instruction compares two v128 floating point value interpretations and returns a new interpretation with each output lane set to the smaller of the corresponding input lanes. It is defined as b < a ? b : a, meaning that NaN in the first operand propagates to the output but NaN in the second operand does not — unlike min, which propagates NaN from either operand.
Try it
(module
(import "console" "log" (func $log (param f32)))
(func $main
;; load two v128 f32x4s onto the stack
v128.const f32x4 52.6 101.2 78.0 9.9
v128.const f32x4 51.9 102.0 78.1 -0.9
;; return a f32x4 containing the smallest values from each input lane
f32x4.pmin
f32x4.extract_lane 3 ;; Extract a single lane
call $log ;; log the result
)
(start $main)
)
const url = "{%wasm-url%}";
await WebAssembly.instantiateStreaming(fetch(url), { console });
Syntax
value_type.pmin
value_type-
The type of value the instruction is being run on. The following types support
pmin:f32x4f64x2
pmin-
The
pmininstruction. Must always be included after thevalue_typeand a period (.).
Type
[input1, input2] -> [output]
Binary encoding
| Instruction | Binary format | Example text => binary |
|---|---|---|
f32x4.pmin |
0xfd 234:u32 |
f32x4.pmin => 0xfd 0xea 0x01 |
f64x2.pmin |
0xfd 246:u32 |
f64x2.pmin => 0xfd 0xf6 0x01 |