1;
2; jdct.inc - private declarations for forward & reverse DCT subsystems
3;
4; Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
5;
6; Based on
7; x86 SIMD extension for IJG JPEG library
8; Copyright (C) 1999-2006, MIYASAKA Masaru.
9; For conditions of distribution and use, see copyright notice in jsimdext.inc
10;
11; [TAB8]
12
13; Each IDCT routine is responsible for range-limiting its results and
14; converting them to unsigned form (0..MAXJSAMPLE).  The raw outputs could
15; be quite far out of range if the input data is corrupt, so a bulletproof
16; range-limiting step is required.  We use a mask-and-table-lookup method
17; to do the combined operations quickly.
18;
19%define RANGE_MASK  (MAXJSAMPLE * 4 + 3)  ; 2 bits wider than legal samples
20
21%define ROW(n,b,s)              ((b)+(n)*(s))
22%define COL(n,b,s)              ((b)+(n)*(s)*DCTSIZE)
23
24%define DWBLOCK(m,n,b,s)        ((b)+(m)*DCTSIZE*(s)+(n)*SIZEOF_DWORD)
25%define MMBLOCK(m,n,b,s)        ((b)+(m)*DCTSIZE*(s)+(n)*SIZEOF_MMWORD)
26%define XMMBLOCK(m,n,b,s)       ((b)+(m)*DCTSIZE*(s)+(n)*SIZEOF_XMMWORD)
27
28; --------------------------------------------------------------------------
29