Add MMX SIMD implementation of computationally intensive routines.

git-svn-id: svn://svn.code.sf.net/p/libjpeg-turbo/code/trunk@17 632fc199-4ca6-4c93-a231-07263d6284db

1 files changed, 27 insertions, 0 deletions

diff --git a/simd/jdct.inc b/simd/jdct.inc
new file mode 100644
index 0000000..e53f66e
--- /dev/null
+++ b/simd/jdct.inc
@@ -0,0 +1,27 @@
+;
+; jdct.inc - private declarations for forward & reverse DCT subsystems
+;
+; Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
+;
+; Based on
+; x86 SIMD extension for IJG JPEG library
+; Copyright (C) 1999-2006, MIYASAKA Masaru.
+; For conditions of distribution and use, see copyright notice in jsimdext.inc
+;
+; [TAB8]
+
+; Each IDCT routine is responsible for range-limiting its results and
+; converting them to unsigned form (0..MAXJSAMPLE).  The raw outputs could
+; be quite far out of range if the input data is corrupt, so a bulletproof
+; range-limiting step is required.  We use a mask-and-table-lookup method
+; to do the combined operations quickly.
+;
+%define RANGE_MASK  (MAXJSAMPLE * 4 + 3)  ; 2 bits wider than legal samples
+
+%define ROW(n,b,s)		((b)+(n)*(s))
+%define COL(n,b,s)		((b)+(n)*(s)*DCTSIZE)
+
+%define DWBLOCK(m,n,b,s)	((b)+(m)*DCTSIZE*(s)+(n)*SIZEOF_DWORD)
+%define MMBLOCK(m,n,b,s)	((b)+(m)*DCTSIZE*(s)+(n)*SIZEOF_MMWORD)
+
+; --------------------------------------------------------------------------