bolt3

commit b7bd940fe55541047bc12fd523880b924df8049e
parent f2031cfb310fda6bbe02150668e084cdabea0eca
Author: Jared Tobin <jared@jtobin.io>
Date:   Sun, 17 May 2026 18:52:59 -0230

bench: criterion + weigh entries for wNAF derive_* variants

Adds apostrophe-suffixed variants to both bench targets, alongside
their non-wNAF counterparts so the comparison is direct. Also adds
derive_per_commitment_point to the criterion suite (wasn't covered
before).

Results on M-series macOS, -O2:
  derive_pubkey:                148.7 us -> 45.4 us   (3.3x)
  derive_per_commitment_point:  141.2 us -> 37.7 us   (3.7x)

Weigh allocation matches non-wNAF once the precompute table is
forced before mainWith — without that, the one-time ~50 KB ctxArray
build gets billed to whichever apostrophe-suffixed entry happens to
touch tex first.

ppad-secp256k1 added to both bench targets' build-depends.

Diffstat:
M
bench/Main.hs
 | 
20
++++++++++++++++++++
M
bench/Weight.hs
 | 
23
++++++++++++++++++++++-
M
ppad-bolt3.cabal
 | 
2
++

3 files changed, 44 insertions(+), 1 deletion(-)
diff --git a/bench/Main.hs b/bench/Main.hs
@@ -3,6 +3,7 @@
 
 module Main where
 
+import qualified Crypto.Curve.Secp256k1 as S
 import Control.DeepSeq (NFData(..))
 import Criterion.Main
 import Data.Word (Word64)
@@ -11,6 +12,7 @@ import Lightning.Protocol.BOLT3
 import Lightning.Protocol.BOLT3.Types
   ( Pubkey(..), Point(..)
   , PaymentHash(..), PerCommitmentPoint(..)
+  , PerCommitmentSecret(..)
   , CommitmentNumber(..)
   )
 
@@ -163,11 +165,25 @@ instance NFData ValidationError where
   rnf NoOutputs = ()
   rnf (TooManyOutputs a) = rnf a
 
+-- | Precomputed wNAF context, built once and reused across the
+--   apostrophe-suffixed benches. NOINLINE keeps it from being
+--   re-created on every call site.
+tex :: S.Context
+tex = S.precompute
+{-# NOINLINE tex #-}
+
 main :: IO ()
 main = defaultMain [
     bgroup "key derivation" [
       bench "derive_pubkey" $
         whnf (derive_pubkey basepoint) perCommitmentPoint
+    , bench "derive_pubkey'" $
+        whnf (derive_pubkey' tex basepoint) perCommitmentPoint
+    , bench "derive_per_commitment_point" $
+        whnf derive_per_commitment_point samplePcs
+    , bench "derive_per_commitment_point'" $
+        whnf (derive_per_commitment_point' tex)
+          samplePcs
     , bench "derive_revocationpubkey" $
         whnf (derive_revocationpubkey revocationBasepoint) perCommitmentPoint
     ]
@@ -313,6 +329,10 @@ main = defaultMain [
        0xf9, 0x04, 0xf5, 0x50, 0x25, 0x3a, 0x0f, 0x3e, 0xf3, 0xf5, 0xaa,
        0x2f, 0xe6, 0x83, 0x8a, 0x95, 0xb2, 0x16, 0x69, 0x14, 0x68, 0xe2]
 
+    samplePcs :: PerCommitmentSecret
+    samplePcs =
+      PerCommitmentSecret (BS.replicate 32 0x01)
+
     -- Secret generation test data
     seed = BS.replicate 32 0xFF
 
diff --git a/bench/Weight.hs b/bench/Weight.hs
@@ -3,6 +3,7 @@
 
 module Main where
 
+import qualified Crypto.Curve.Secp256k1 as S
 import Control.DeepSeq (NFData(..))
 import qualified Data.ByteString as BS
 import Data.Word (Word32, Word64)
@@ -10,10 +11,17 @@ import Lightning.Protocol.BOLT3
 import Lightning.Protocol.BOLT3.Types
   ( Pubkey(..), Point(..)
   , PaymentHash(..), PerCommitmentPoint(..)
+  , PerCommitmentSecret(..)
   , CommitmentNumber(..)
   )
 import Weigh
 
+-- | Precomputed wNAF context; reused across every apostrophe-
+--   suffixed weigh entry.
+tex :: S.Context
+tex = S.precompute
+{-# NOINLINE tex #-}
+
 -- NFData instances for weigh
 -- (Satoshi, MilliSatoshi, Point, PaymentHash, PerCommitmentSecret
 -- derive NFData via ppad-bolt1)
@@ -165,11 +173,20 @@ instance NFData SecretStore where
   rnf ss = ss `seq` ()
 
 main :: IO ()
-main = mainWith $ do
+main = tex `seq` mainWith $ do
+  -- 'tex' is forced before mainWith so the one-time wNAF
+  -- precompute (~50 KB) doesn't get billed to whichever
+  -- apostrophe-suffixed func happens to evaluate it first.
   setColumns [Case, Allocated, GCs, Max]
 
   -- Key derivation allocations
   func "derive_pubkey" (derive_pubkey basepoint) perCommitmentPoint
+  func "derive_pubkey'"
+       (derive_pubkey' tex basepoint) perCommitmentPoint
+  func "derive_per_commitment_point"
+       derive_per_commitment_point samplePcs
+  func "derive_per_commitment_point'"
+       (derive_per_commitment_point' tex) samplePcs
   func "derive_revocationpubkey"
        (derive_revocationpubkey revocationBasepoint) perCommitmentPoint
 
@@ -306,6 +323,10 @@ main = mainWith $ do
        0xf9, 0x04, 0xf5, 0x50, 0x25, 0x3a, 0x0f, 0x3e, 0xf3, 0xf5, 0xaa,
        0x2f, 0xe6, 0x83, 0x8a, 0x95, 0xb2, 0x16, 0x69, 0x14, 0x68, 0xe2]
 
+    samplePcs :: PerCommitmentSecret
+    samplePcs =
+      PerCommitmentSecret (BS.replicate 32 0x01)
+
     -- Secret generation test data
     seed = BS.replicate 32 0xFF
 
diff --git a/ppad-bolt3.cabal b/ppad-bolt3.cabal
@@ -77,6 +77,7 @@ benchmark bolt3-bench
     , criterion
     , deepseq
     , ppad-bolt3
+    , ppad-secp256k1 >= 0.5.4 && < 0.6
 
 benchmark bolt3-weigh
   type:                exitcode-stdio-1.0
@@ -92,5 +93,6 @@ benchmark bolt3-weigh
     , bytestring
     , deepseq
     , ppad-bolt3
+    , ppad-secp256k1 >= 0.5.4 && < 0.6
     , weigh