SinCosLUT.jl

Fast SIMD sine/cosine by register-resident table lookup. Each sin/cos is a single hardware byte/word/dword permute over a table held entirely in vector registers — no multiplies, no memory gathers, and (unlike floating-point range reduction) no input range limit: the phase wraps for free via a bit-mask.

It is a deliberately low-precision, very high-throughput technique, built for GNSS carrier generation and bit-wise software correlators. If you need more than a few bits of accuracy, reach for a polynomial approximation instead (FixedPointSinCosApproximations.jl or FastSinCos.jl); see Choosing a package and Benchmarks.

Installation

using Pkg
Pkg.add("SinCosLUT")

The speed/precision trade

Pick the output element type to trade precision for speed. A 512-bit register holds 64×Int8 but only 32×Int16 / 16×Int32, so wider elements give more amplitude bits but fewer table entries (coarser phase) and fewer lanes (lower throughput):

Quick start

The examples on this page (and throughout the docs) are executed when the manual is built, against the current source — if the API changes under them, the build fails, so they cannot go stale.

using SinCosLUT

# 64-entry Int8 table (6-bit phase, full Int8 amplitude)
tbl = SinCosTable(Int8; steps = 64)

sins = zeros(Int8, 8)
coss = zeros(Int8, 8)

# Carrier of 0.05 cycles/sample, drift-free integer phase:
generate_carrier!(sins, coss, tbl, 0.05)
sins

8-element Vector{Int8}:
   0
  37
  71
  98
 117
 127
 122
 106

coss

8-element Vector{Int8}:
 127
 122
 106
  81
  49
   0
 -37
 -71

From here:

• Usage guide — carrier generation, frequency forms, initial phase, amplitude precision, backends, arbitrary-index lookup, and the 1-bit carrier.
• Fused, array-free generation — the allocation-free carrier_engine for fusing sin/cos straight into a correlation loop.
• Accuracy & drift-free phase — what the quantisation buys you and why the phase never drifts.
• Benchmarks — throughput and accuracy against the polynomial packages.
• API reference — every exported function.