From f82e90b1b619d6a3aa701b6d755b3f5dcf7e1191 Mon Sep 17 00:00:00 2001
From: ChrisRackauckas <me@chrisrackauckas.com>
Date: Mon, 29 Dec 2025 14:21:12 -0500
Subject: [PATCH] Add PrecompileTools workload to reduce time-to-first-X
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This PR adds PrecompileTools to precompile common code paths, dramatically
reducing the time-to-first-X (TTFX) for key operations while maintaining
roughly the same startup time.

## Changes

- Add PrecompileTools as a dependency
- Add src/precompilation.jl with @compile_workload that covers:
  - POD with matrix input + SVD
  - POD with Vector{Vector} input + TSVD
  - POD with RSVD algorithm
  - deim_interpolation_indices

## Timing Improvements

| Operation | Before | After | Speedup |
|-----------|--------|-------|---------|
| reduce!(pod, SVD()) [Vector{Vector}] | 1.072s | 0.024s | 44x |
| reduce!(pod, TSVD()) | 1.989s | 0.020s | 100x |
| reduce!(pod, RSVD()) | 0.257s | 0.021s | 12x |
| reduce!(pod, SVD()) [Matrix] | 0.034s | 0.001s | 34x |
| deim_interpolation_indices() | 1.643s | 0.0s | instant |

Startup time remains similar (~8s).

No invalidations were found originating from ModelOrderReduction itself;
all invalidations come from upstream dependencies.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
---
 Project.toml               |  2 ++
 src/ModelOrderReduction.jl |  2 ++
 src/precompilation.jl      | 25 +++++++++++++++++++++++++
 3 files changed, 29 insertions(+)
 create mode 100644 src/precompilation.jl

diff --git a/Project.toml b/Project.toml
index 290d744..dd3dfe4 100644
--- a/Project.toml
+++ b/Project.toml
@@ -7,6 +7,7 @@ version = "0.1.3"
 DocStringExtensions = "ffbed154-4ef7-542d-bbb7-c09d3a79fcae"
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 ModelingToolkit = "961ee093-0014-501f-94e3-6117800e7a78"
+PrecompileTools = "aea7be01-6a6a-4083-8856-8a6e6704d82a"
 RandomizedLinAlg = "0448d7d9-159c-5637-8537-fd72090fea46"
 Setfield = "efcf1570-3423-57d1-acb7-fd33fddbac46"
 SparseArrays = "2f01184e-e22b-5df5-ae63-d93ebab69eaf"
@@ -16,6 +17,7 @@ TSVD = "9449cd9e-2762-5aa3-a617-5413e99d722e"
 DocStringExtensions = "0.8, 0.9"
 LinearAlgebra = "1"
 ModelingToolkit = "10"
+PrecompileTools = "1"
 RandomizedLinAlg = "0.1"
 Setfield = "0.8, 1"
 SparseArrays = "1"
diff --git a/src/ModelOrderReduction.jl b/src/ModelOrderReduction.jl
index 9691054..d4e0d61 100644
--- a/src/ModelOrderReduction.jl
+++ b/src/ModelOrderReduction.jl
@@ -19,4 +19,6 @@ export POD, reduce!
 include("deim.jl")
 export deim
 
+include("precompilation.jl")
+
 end
diff --git a/src/precompilation.jl b/src/precompilation.jl
new file mode 100644
index 0000000..7d5eeff
--- /dev/null
+++ b/src/precompilation.jl
@@ -0,0 +1,25 @@
+using PrecompileTools
+
+@setup_workload begin
+    using LinearAlgebra: qr
+
+    @compile_workload begin
+        # Precompile POD with matrix input (most common use case)
+        mat_snapshots = randn(20, 10)
+        pod_mat = POD(mat_snapshots, 3)
+        reduce!(pod_mat, SVD())
+
+        # Precompile POD with Vector{Vector} input
+        vec_snapshots = [randn(20) for _ in 1:10]
+        pod_vec = POD(vec_snapshots, 3)
+        reduce!(pod_vec, TSVD())
+
+        # Precompile RSVD algorithm
+        pod_rsvd = POD(mat_snapshots, 3)
+        reduce!(pod_rsvd, RSVD(2))
+
+        # Precompile deim_interpolation_indices
+        basis = Matrix(qr(randn(20, 5)).Q)
+        deim_interpolation_indices(basis)
+    end
+end