git.iko.soy/grenade
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Speed up im2col, vid2col.

Each point on the output is written to precisely once, so we don't need to initialise it or use an additive update modifier.

commitf04bfebfeef7e5e515295ecca57332f931b4823a authorHuw Campbell <huw.campbell@ambiata.com> dateMon 12 Dec 2016, 12:55 (10 years ago) parentbd881fa
1 file changed+4−4
compare with master
unifiedsplit
src/Grenade/Layers/Internal/Convolution.hs+4−4
src/Grenade/Layers/Internal/Convolution.hs+4−4
@@ -127,7 +127,7 @@ vid2colUnsafe kernelRows kernelColumns striderows stridecols vidrows vidcols dat
127127 numberOfPatches = length starts
128128 channels = length dataVid
129129
130− dataCol <- U.newMatrix 0 numberOfPatches (channels * kernelSize)
130+ dataCol <- U.newUndefinedMatrix U.RowMajor numberOfPatches (channels * kernelSize)
131131
132132 offsetC <- newSTRef 0
133133
@@ -140,7 +140,7 @@ vid2colUnsafe kernelRows kernelColumns striderows stridecols vidrows vidcols dat
140140 forM_ [startRow .. startRow + kernelRows -1] $ \kr ->
141141 forM_ [startCol .. startCol + kernelColumns -1] $ \kc -> do
142142 inputColumn <- readSTRef inputColumnRef
143− unsafeModifyMatrix dataCol inputRow (inputColumn + offsetC') (+ U.atM' dataIm kr kc)
143+ U.unsafeWriteMatrix dataCol inputRow (inputColumn + offsetC') (U.atM' dataIm kr kc)
144144 modifySTRef' inputColumnRef (+1)
145145 modifySTRef' inputRowRef (+1)
146146
@@ -154,7 +154,7 @@ im2colUnsafe kernelRows kernelColumns striderows stridecols dataIm = U.runSTMatr
154154 kernelSize = kernelRows * kernelColumns
155155 numberOfPatches = length starts
156156
157− dataCol <- U.newMatrix 0 numberOfPatches kernelSize
157+ dataCol <- U.newUndefinedMatrix U.RowMajor numberOfPatches kernelSize
158158
159159 inputRowRef <- newSTRef 0
160160 forM_ starts $ \(startRow, startCol) -> do
@@ -163,7 +163,7 @@ im2colUnsafe kernelRows kernelColumns striderows stridecols dataIm = U.runSTMatr
163163 forM_ [startRow .. startRow + kernelRows -1] $ \kr ->
164164 forM_ [startCol .. startCol + kernelColumns -1] $ \kc -> do
165165 inputColumn <- readSTRef inputColumnRef
166− unsafeModifyMatrix dataCol inputRow inputColumn (+ U.atM' dataIm kr kc)
166+ U.unsafeWriteMatrix dataCol inputRow inputColumn (U.atM' dataIm kr kc)
167167 modifySTRef' inputColumnRef (+1)
168168 modifySTRef' inputRowRef (+1)
169169