SIMD

Construct

Method	Description
Simd4f.new(a, b, c, d)	Four explicit f32 lanes.
Simd4f.splat(x)	All four lanes set to x.
Simd4i.new(a, b, c, d)	Four explicit i32 lanes.
Simd4i.splat(x)	All four lanes set to x.

var v = Simd4f.new(1.0, 2.0, 3.0, 4.0)
var ones = Simd4f.splat(1.0)
var w = v + ones                    // (2, 3, 4, 5)
System.print(w)                     // Simd4f(2, 3, 4, 5)

Arithmetic & comparison

Real Wren operators land on both classes: +, -, *, / for arithmetic; <, <=, >, >=, ==, != for comparison. min and max are method-style.

var a = Simd4f.new(1, 2, 3, 4)
var b = Simd4f.new(2, 2, 2, 2)
System.print(a + b)                 // Simd4f(3, 4, 5, 6)
System.print(a * b)                 // Simd4f(2, 4, 6, 8)
System.print(a.min(b))              // Simd4f(1, 2, 2, 2)
System.print(a.max(b))              // Simd4f(2, 2, 3, 4)

Per-lane access

Method	Description
v[i]	Read lane i (0..3) as a Num.
v.replaceLane(i, x)	New vector with lane i set to x.

Lane indices are 0 (lowest) through 3 (highest). The class is immutable; mutations return a new vector.

Mask, bitmask, select

Comparisons return a Simd4i mask (-1 on true, 0 on false per lane).

Method	Description
mask.bitmask	Pack the MSB of each lane into bit i (lane 0 → bit 0).
mask.allTrue	true when every lane is non-zero.
mask.anyTrue	true when at least one lane is non-zero.
X.select(mask, onTrue, onFalse)	Per-lane: mask[i] ? onTrue[i] : onFalse[i]. Available on both Simd4f and Simd4i.

var ints = Simd4i.new(1, 5, 3, 7)
var mask = ints > Simd4i.splat(4)
System.print(mask.bitmask)          // 10   (binary 1010 — lanes 1 + 3)
System.print(mask.anyTrue)          // true

Load / store via typed arrays

Bridge between SIMD and packed memory through a typed array:

Method	Description
Simd4f.load(arr, offset)	Read 4 floats starting at offset from a Float32Array.
v.store(arr, offset)	Write 4 floats into a Float32Array starting at offset.
Simd4i.load · .store	Same, against Int32Array.

var buf = Float32Array.fromList([1, 2, 3, 4, 5, 6, 7, 8])
var lo  = Simd4f.load(buf, 0)        // (1, 2, 3, 4)
var hi  = Simd4f.load(buf, 4)        // (5, 6, 7, 8)
(lo + hi).store(buf, 0)              // buf is now (6, 8, 10, 12, 5, 6, 7, 8)