simd/jdct.inc

;
; 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)
%define XMMBLOCK(m,n,b,s)       ((b)+(m)*DCTSIZE*(s)+(n)*SIZEOF_XMMWORD)

; --------------------------------------------------------------------------