mirror of
https://github.com/opencv/opencv.git
synced 2024-12-13 16:09:23 +08:00
394 lines
17 KiB
C
394 lines
17 KiB
C
/*
|
|
* jdct.h
|
|
*
|
|
* Copyright (C) 1994-1996, Thomas G. Lane.
|
|
* This file is part of the Independent JPEG Group's software.
|
|
* For conditions of distribution and use, see the accompanying README file.
|
|
*
|
|
* This include file contains common declarations for the forward and
|
|
* inverse DCT modules. These declarations are private to the DCT managers
|
|
* (jcdctmgr.c, jddctmgr.c) and the individual DCT algorithms.
|
|
* The individual DCT algorithms are kept in separate files to ease
|
|
* machine-dependent tuning (e.g., assembly coding).
|
|
*/
|
|
|
|
|
|
/*
|
|
* A forward DCT routine is given a pointer to an input sample array and
|
|
* a pointer to a work area of type DCTELEM[]; the DCT is to be performed
|
|
* in-place in that buffer. Type DCTELEM is int for 8-bit samples, INT32
|
|
* for 12-bit samples. (NOTE: Floating-point DCT implementations use an
|
|
* array of type FAST_FLOAT, instead.)
|
|
* The input data is to be fetched from the sample array starting at a
|
|
* specified column. (Any row offset needed will be applied to the array
|
|
* pointer before it is passed to the FDCT code.)
|
|
* Note that the number of samples fetched by the FDCT routine is
|
|
* DCT_h_scaled_size * DCT_v_scaled_size.
|
|
* The DCT outputs are returned scaled up by a factor of 8; they therefore
|
|
* have a range of +-8K for 8-bit data, +-128K for 12-bit data. This
|
|
* convention improves accuracy in integer implementations and saves some
|
|
* work in floating-point ones.
|
|
* Quantization of the output coefficients is done by jcdctmgr.c.
|
|
*/
|
|
|
|
#if BITS_IN_JSAMPLE == 8
|
|
typedef int DCTELEM; /* 16 or 32 bits is fine */
|
|
#else
|
|
typedef INT32 DCTELEM; /* must have 32 bits */
|
|
#endif
|
|
|
|
typedef JMETHOD(void, forward_DCT_method_ptr, (DCTELEM * data,
|
|
JSAMPARRAY sample_data,
|
|
JDIMENSION start_col));
|
|
typedef JMETHOD(void, float_DCT_method_ptr, (FAST_FLOAT * data,
|
|
JSAMPARRAY sample_data,
|
|
JDIMENSION start_col));
|
|
|
|
|
|
/*
|
|
* An inverse DCT routine is given a pointer to the input JBLOCK and a pointer
|
|
* to an output sample array. The routine must dequantize the input data as
|
|
* well as perform the IDCT; for dequantization, it uses the multiplier table
|
|
* pointed to by compptr->dct_table. The output data is to be placed into the
|
|
* sample array starting at a specified column. (Any row offset needed will
|
|
* be applied to the array pointer before it is passed to the IDCT code.)
|
|
* Note that the number of samples emitted by the IDCT routine is
|
|
* DCT_h_scaled_size * DCT_v_scaled_size.
|
|
*/
|
|
|
|
/* typedef inverse_DCT_method_ptr is declared in jpegint.h */
|
|
|
|
/*
|
|
* Each IDCT routine has its own ideas about the best dct_table element type.
|
|
*/
|
|
|
|
typedef MULTIPLIER ISLOW_MULT_TYPE; /* short or int, whichever is faster */
|
|
#if BITS_IN_JSAMPLE == 8
|
|
typedef MULTIPLIER IFAST_MULT_TYPE; /* 16 bits is OK, use short if faster */
|
|
#define IFAST_SCALE_BITS 2 /* fractional bits in scale factors */
|
|
#else
|
|
typedef INT32 IFAST_MULT_TYPE; /* need 32 bits for scaled quantizers */
|
|
#define IFAST_SCALE_BITS 13 /* fractional bits in scale factors */
|
|
#endif
|
|
typedef FAST_FLOAT FLOAT_MULT_TYPE; /* preferred floating type */
|
|
|
|
|
|
/*
|
|
* 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. See the comments with
|
|
* prepare_range_limit_table (in jdmaster.c) for more info.
|
|
*/
|
|
|
|
#define IDCT_range_limit(cinfo) ((cinfo)->sample_range_limit + CENTERJSAMPLE)
|
|
|
|
#define RANGE_MASK (MAXJSAMPLE * 4 + 3) /* 2 bits wider than legal samples */
|
|
|
|
|
|
/* Short forms of external names for systems with brain-damaged linkers. */
|
|
|
|
#ifdef NEED_SHORT_EXTERNAL_NAMES
|
|
#define jpeg_fdct_islow jFDislow
|
|
#define jpeg_fdct_ifast jFDifast
|
|
#define jpeg_fdct_float jFDfloat
|
|
#define jpeg_fdct_7x7 jFD7x7
|
|
#define jpeg_fdct_6x6 jFD6x6
|
|
#define jpeg_fdct_5x5 jFD5x5
|
|
#define jpeg_fdct_4x4 jFD4x4
|
|
#define jpeg_fdct_3x3 jFD3x3
|
|
#define jpeg_fdct_2x2 jFD2x2
|
|
#define jpeg_fdct_1x1 jFD1x1
|
|
#define jpeg_fdct_9x9 jFD9x9
|
|
#define jpeg_fdct_10x10 jFD10x10
|
|
#define jpeg_fdct_11x11 jFD11x11
|
|
#define jpeg_fdct_12x12 jFD12x12
|
|
#define jpeg_fdct_13x13 jFD13x13
|
|
#define jpeg_fdct_14x14 jFD14x14
|
|
#define jpeg_fdct_15x15 jFD15x15
|
|
#define jpeg_fdct_16x16 jFD16x16
|
|
#define jpeg_fdct_16x8 jFD16x8
|
|
#define jpeg_fdct_14x7 jFD14x7
|
|
#define jpeg_fdct_12x6 jFD12x6
|
|
#define jpeg_fdct_10x5 jFD10x5
|
|
#define jpeg_fdct_8x4 jFD8x4
|
|
#define jpeg_fdct_6x3 jFD6x3
|
|
#define jpeg_fdct_4x2 jFD4x2
|
|
#define jpeg_fdct_2x1 jFD2x1
|
|
#define jpeg_fdct_8x16 jFD8x16
|
|
#define jpeg_fdct_7x14 jFD7x14
|
|
#define jpeg_fdct_6x12 jFD6x12
|
|
#define jpeg_fdct_5x10 jFD5x10
|
|
#define jpeg_fdct_4x8 jFD4x8
|
|
#define jpeg_fdct_3x6 jFD3x6
|
|
#define jpeg_fdct_2x4 jFD2x4
|
|
#define jpeg_fdct_1x2 jFD1x2
|
|
#define jpeg_idct_islow jRDislow
|
|
#define jpeg_idct_ifast jRDifast
|
|
#define jpeg_idct_float jRDfloat
|
|
#define jpeg_idct_7x7 jRD7x7
|
|
#define jpeg_idct_6x6 jRD6x6
|
|
#define jpeg_idct_5x5 jRD5x5
|
|
#define jpeg_idct_4x4 jRD4x4
|
|
#define jpeg_idct_3x3 jRD3x3
|
|
#define jpeg_idct_2x2 jRD2x2
|
|
#define jpeg_idct_1x1 jRD1x1
|
|
#define jpeg_idct_9x9 jRD9x9
|
|
#define jpeg_idct_10x10 jRD10x10
|
|
#define jpeg_idct_11x11 jRD11x11
|
|
#define jpeg_idct_12x12 jRD12x12
|
|
#define jpeg_idct_13x13 jRD13x13
|
|
#define jpeg_idct_14x14 jRD14x14
|
|
#define jpeg_idct_15x15 jRD15x15
|
|
#define jpeg_idct_16x16 jRD16x16
|
|
#define jpeg_idct_16x8 jRD16x8
|
|
#define jpeg_idct_14x7 jRD14x7
|
|
#define jpeg_idct_12x6 jRD12x6
|
|
#define jpeg_idct_10x5 jRD10x5
|
|
#define jpeg_idct_8x4 jRD8x4
|
|
#define jpeg_idct_6x3 jRD6x3
|
|
#define jpeg_idct_4x2 jRD4x2
|
|
#define jpeg_idct_2x1 jRD2x1
|
|
#define jpeg_idct_8x16 jRD8x16
|
|
#define jpeg_idct_7x14 jRD7x14
|
|
#define jpeg_idct_6x12 jRD6x12
|
|
#define jpeg_idct_5x10 jRD5x10
|
|
#define jpeg_idct_4x8 jRD4x8
|
|
#define jpeg_idct_3x6 jRD3x8
|
|
#define jpeg_idct_2x4 jRD2x4
|
|
#define jpeg_idct_1x2 jRD1x2
|
|
#endif /* NEED_SHORT_EXTERNAL_NAMES */
|
|
|
|
/* Extern declarations for the forward and inverse DCT routines. */
|
|
|
|
EXTERN(void) jpeg_fdct_islow
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_ifast
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_float
|
|
JPP((FAST_FLOAT * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_7x7
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_6x6
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_5x5
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_4x4
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_3x3
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_2x2
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_1x1
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_9x9
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_10x10
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_11x11
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_12x12
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_13x13
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_14x14
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_15x15
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_16x16
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_16x8
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_14x7
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_12x6
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_10x5
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_8x4
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_6x3
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_4x2
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_2x1
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_8x16
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_7x14
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_6x12
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_5x10
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_4x8
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_3x6
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_2x4
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
EXTERN(void) jpeg_fdct_1x2
|
|
JPP((DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col));
|
|
|
|
EXTERN(void) jpeg_idct_islow
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_ifast
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_float
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_7x7
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_6x6
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_5x5
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_4x4
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_3x3
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_2x2
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_1x1
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_9x9
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_10x10
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_11x11
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_12x12
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_13x13
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_14x14
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_15x15
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_16x16
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_16x8
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_14x7
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_12x6
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_10x5
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_8x4
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_6x3
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_4x2
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_2x1
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_8x16
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_7x14
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_6x12
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_5x10
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_4x8
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_3x6
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_2x4
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
EXTERN(void) jpeg_idct_1x2
|
|
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
|
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
|
|
|
|
|
/*
|
|
* Macros for handling fixed-point arithmetic; these are used by many
|
|
* but not all of the DCT/IDCT modules.
|
|
*
|
|
* All values are expected to be of type INT32.
|
|
* Fractional constants are scaled left by CONST_BITS bits.
|
|
* CONST_BITS is defined within each module using these macros,
|
|
* and may differ from one module to the next.
|
|
*/
|
|
|
|
#define ONE ((INT32) 1)
|
|
#define CONST_SCALE (ONE << CONST_BITS)
|
|
|
|
/* Convert a positive real constant to an integer scaled by CONST_SCALE.
|
|
* Caution: some C compilers fail to reduce "FIX(constant)" at compile time,
|
|
* thus causing a lot of useless floating-point operations at run time.
|
|
*/
|
|
|
|
#define FIX(x) ((INT32) ((x) * CONST_SCALE + 0.5))
|
|
|
|
/* Descale and correctly round an INT32 value that's scaled by N bits.
|
|
* We assume RIGHT_SHIFT rounds towards minus infinity, so adding
|
|
* the fudge factor is correct for either sign of X.
|
|
*/
|
|
|
|
#define DESCALE(x,n) RIGHT_SHIFT((x) + (ONE << ((n)-1)), n)
|
|
|
|
/* Multiply an INT32 variable by an INT32 constant to yield an INT32 result.
|
|
* This macro is used only when the two inputs will actually be no more than
|
|
* 16 bits wide, so that a 16x16->32 bit multiply can be used instead of a
|
|
* full 32x32 multiply. This provides a useful speedup on many machines.
|
|
* Unfortunately there is no way to specify a 16x16->32 multiply portably
|
|
* in C, but some C compilers will do the right thing if you provide the
|
|
* correct combination of casts.
|
|
*/
|
|
|
|
#ifdef SHORTxSHORT_32 /* may work if 'int' is 32 bits */
|
|
#define MULTIPLY16C16(var,const) (((INT16) (var)) * ((INT16) (const)))
|
|
#endif
|
|
#ifdef SHORTxLCONST_32 /* known to work with Microsoft C 6.0 */
|
|
#define MULTIPLY16C16(var,const) (((INT16) (var)) * ((INT32) (const)))
|
|
#endif
|
|
|
|
#ifndef MULTIPLY16C16 /* default definition */
|
|
#define MULTIPLY16C16(var,const) ((var) * (const))
|
|
#endif
|
|
|
|
/* Same except both inputs are variables. */
|
|
|
|
#ifdef SHORTxSHORT_32 /* may work if 'int' is 32 bits */
|
|
#define MULTIPLY16V16(var1,var2) (((INT16) (var1)) * ((INT16) (var2)))
|
|
#endif
|
|
|
|
#ifndef MULTIPLY16V16 /* default definition */
|
|
#define MULTIPLY16V16(var1,var2) ((var1) * (var2))
|
|
#endif
|