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some simd

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This commit is contained in:
Ryan Oldenburg 2022-05-25 20:56:54 -05:00
parent 7ca2d51a9b
commit 4dc81592f6
1 changed files with 16 additions and 2 deletions
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18
src/pixie/fileformats/jpeg.nim
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@ -1,6 +1,9 @@
import pixie/common, pixie/images, pixie/masks, sequtils, strutils, chroma,
std/decls, flatty/binny
when defined(amd64) and not defined(pixieNoSimd):
import nimsimd/sse2
# This JPEG decoder is loosely based on stb_image which is public domain.
# JPEG is a complex format, this decoder only supports the most common features:
@ -887,8 +890,19 @@ proc quantizationAndIDCTPass(state: var DecoderState) =
for column in 0 ..< h:
for row in 0 ..< w:
var data {.byaddr.} = state.components[comp].blocks[row][column]
for i in 0 ..< 64:
data[i] = cast[int16](data[i] * state.quantizationTables[qTableId][i].int32)
when defined(amd64) and not defined(pixieNoSimd):
for i in 0 ..< 8: # 8 per pass
var q = mm_loadu_si128(state.quantizationTables[qTableId][i * 8].addr)
q = mm_unpacklo_epi8(q, mm_setzero_si128())
var v = mm_loadu_si128(data[i * 8].addr)
mm_storeu_si128(data[i * 8].addr, mm_mullo_epi16(v, q))
else:
for i in 0 ..< 64:
data[i] = cast[int16](
data[i] * state.quantizationTables[qTableId][i].int32
)
state.components[comp].idctBlock(
state.components[comp].widthStride * column * 8 + row * 8,
data