commit 9692529844bfc1cc3657618990e2340ba474c676 parent abc984dc65f0df9bd958c0bc8f390c68e660f710 Author: Jared Tobin <jared@jtobin.io> Date: Tue, 21 Jan 2025 21:44:58 +0400 lib: performance tuning Minimizing bytes written by builders when padding yields a few nanoseconds worth of performance gain. I've only optimized the strict case, as the lazy bytestring case would presumably gain less from this kind of optimisation. Diffstat:
| M | lib/Crypto/Hash/SHA256.hs | | | 82 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++------ |
1 file changed, 76 insertions(+), 6 deletions(-)
diff --git a/lib/Crypto/Hash/SHA256.hs b/lib/Crypto/Hash/SHA256.hs @@ -105,16 +105,86 @@ unsafe_parseWsPair (BI.BS x l) = -- k such that (l + 1 + k) mod 64 = 56 sol :: Word64 -> Word64 sol l = - let r = 56 - fi l `mod` 64 - 1 :: Integer -- fi prevents underflow + let r = 56 - fi l `rem` 64 - 1 :: Integer -- fi prevents underflow in fi (if r < 0 then r + 64 else r) -- RFC 6234 4.1 (strict) pad :: BS.ByteString -> BS.ByteString -pad m@(BI.PS _ _ (fi -> l)) = BL.toStrict . BSB.toLazyByteString $ padded where - padded = BSB.byteString m <> fill (sol l) (BSB.word8 0x80) - fill j !acc - | j == 0 = acc <> BSB.word64BE (l * 8) - | otherwise = fill (pred j) (acc <> BSB.word8 0x00) +pad m@(BI.PS _ _ (fi -> l)) = + BL.toStrict . BE.toLazyByteStringWith + (BE.safeStrategy 128 BE.smallChunkSize) mempty $ padded + where + padded = BSB.byteString m + <> fill (sol l) (BSB.word8 0x80) + <> BSB.word64BE (l * 8) + + fill j !acc + | j `rem` 8 == 0 = + loop64 j acc + | (j - 7) `rem` 8 == 0 = + loop64 (j - 7) acc + <> BSB.word32BE 0x00 + <> BSB.word16BE 0x00 + <> BSB.word8 0x00 + | (j - 6) `rem` 8 == 0 = + loop64 (j - 6) acc + <> BSB.word32BE 0x00 + <> BSB.word16BE 0x00 + | (j - 5) `rem` 8 == 0 = + loop64 (j - 5) acc + <> BSB.word32BE 0x00 + <> BSB.word8 0x00 + | (j - 4) `rem` 8 == 0 = + loop64 (j - 4) acc + <> BSB.word32BE 0x00 + | (j - 3) `rem` 8 == 0 = + loop64 (j - 3) acc + <> BSB.word16BE 0x00 + <> BSB.word8 0x00 + | (j - 2) `rem` 8 == 0 = + loop64 (j - 2) acc + <> BSB.word16BE 0x00 + | (j - 1) `rem` 8 == 0 = + loop64 (j - 1) acc + <> BSB.word8 0x00 + + | j `rem` 4 == 0 = + loop32 j acc + | (j - 3) `rem` 4 == 0 = + loop32 (j - 3) acc + <> BSB.word16BE 0x00 + <> BSB.word8 0x00 + | (j - 2) `rem` 4 == 0 = + loop32 (j - 2) acc + <> BSB.word16BE 0x00 + | (j - 1) `rem` 4 == 0 = + loop32 (j - 1) acc + <> BSB.word8 0x00 + + | j `rem` 2 == 0 = + loop16 j acc + | (j - 1) `rem` 2 == 0 = + loop16 (j - 1) acc + <> BSB.word8 0x00 + + | otherwise = + loop8 j acc + + loop64 j !acc + | j == 0 = acc + | otherwise = loop64 (j - 8) (acc <> BSB.word64BE 0x00) + + loop32 j !acc + | j == 0 = acc + | otherwise = loop32 (j - 4) (acc <> BSB.word32BE 0x00) + + loop16 j !acc + | j == 0 = acc + | otherwise = loop16 (j - 2) (acc <> BSB.word16BE 0x00) + + loop8 j !acc + | j == 0 = acc + | otherwise = loop8 (pred j) (acc <> BSB.word8 0x00) -- RFC 6234 4.1 (lazy) pad_lazy :: BL.ByteString -> BL.ByteString