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#ifndef lint
static char rcsid[] = "$Header: /usr/people/sam/tiff/libtiff/RCS/tif_machdep.c,v 1.6 93/08/25 09:29:25 sam Exp $";
#endif
/*
* Copyright (c) 1992 Sam Leffler
* Copyright (c) 1992 Silicon Graphics, Inc.
*
* Permission to use, copy, modify, distribute, and sell this software and
* its documentation for any purpose is hereby granted without fee, provided
* that (i) the above copyright notices and this permission notice appear in
* all copies of the software and related documentation, and (ii) the names of
* Sam Leffler and Silicon Graphics may not be used in any advertising or
* publicity relating to the software without the specific, prior written
* permission of Sam Leffler and Silicon Graphics.
*
* THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
* EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
* WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
*
* IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
* ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
* OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
* WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
* LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
* OF THIS SOFTWARE.
*/
/*
* TIFF Library Machine Dependent Routines.
*/
#include "tiffiop.h"
#ifdef tahoe
typedef struct ieeedouble {
u_long sign : 1,
exp : 11,
mant : 20;
u_long mant2;
} ieeedouble;
typedef struct ieeefloat {
u_long sign : 1,
exp : 8,
mant : 23;
} ieeefloat;
typedef struct {
u_long sign : 1,
exp : 8,
mant : 23;
u_long mant2;
} nativedouble;
typedef struct {
u_long sign : 1,
exp : 8,
mant : 23;
} nativefloat;
/*
* Beware, over/under-flow in conversions will
* result in garbage values -- handling it would
* require a subroutine call or lots more code.
*/
#define NATIVE2IEEEFLOAT(fp) { \
if ((fp)->native.exp) \
(fp)->ieee.exp = (fp)->native.exp - 129 + 127; /* alter bias */\
}
#define IEEEFLOAT2NATIVE(fp) { \
if ((fp)->ieee.exp) \
(fp)->native.exp = (fp)->ieee.exp - 127 + 129; /* alter bias */\
}
#define IEEEDOUBLE2NATIVE(dp) { \
if ((dp)->native.exp = (dp)->ieee.exp) \
(dp)->native.exp += -1023 + 129; \
(dp)->native.mant = ((dp)->ieee.mant<<3)|((dp)->native.mant2>>29); \
(dp)->native.mant2 <<= 3; \
}
#endif /* tahoe */
#ifdef vax
typedef struct ieeedouble {
u_long mant : 20,
exp : 11,
sign : 1;
u_long mant2;
} ieeedouble;
typedef struct ieeefloat {
u_long mant : 23,
exp : 8,
sign : 1;
} ieeefloat;
typedef struct {
u_long mant1 : 7,
exp : 8,
sign : 1,
mant2 : 16;
u_long mant3;
} nativedouble;
typedef struct {
u_long mant1 : 7,
exp : 8,
sign : 1,
mant2 : 16;
} nativefloat;
/*
* Beware, these do not handle over/under-flow
* during conversion from ieee to native format.
*/
#define NATIVE2IEEEFLOAT(fp) { \
float_t t; \
if (t.ieee.exp = (fp)->native.exp) \
t.ieee.exp += -129 + 127; \
t.ieee.sign = (fp)->native.sign; \
t.ieee.mant = ((fp)->native.mant1<<16)|(fp)->native.mant2; \
*(fp) = t; \
}
#define IEEEFLOAT2NATIVE(fp) { \
float_t t; int v = (fp)->ieee.exp; \
if (v) v += -127 + 129; /* alter bias of exponent */\
t.native.exp = v; /* implicit truncation of exponent */\
t.native.sign = (fp)->ieee.sign; \
v = (fp)->ieee.mant; \
t.native.mant1 = v >> 16; \
t.native.mant2 = v;\
*(fp) = t; \
}
#define IEEEDOUBLE2NATIVE(dp) { \
double_t t; int v = (dp)->ieee.exp; \
if (v) v += -1023 + 1025; /* if can alter bias of exponent */\
t.native.exp = v; /* implicit truncation of exponent */\
v = (dp)->ieee.mant; \
t.native.sign = (dp)->ieee.sign; \
t.native.mant1 = v >> 16; \
t.native.mant2 = v;\
t.native.mant3 = (dp)->mant2; \
*(dp) = t; \
}
#endif /* vax */
#if !HAVE_IEEEFP
#if !defined(IEEEFLOAT2NATIVE) || !defined(NATIVE2IEEEFLOAT)
"Help, you've configured the library to not have IEEE floating point,\
but not defined how to convert between IEEE and native formats!"
#endif
/*
* These unions are used during floating point
* conversions. The above macros define the
* conversion operations.
*/
typedef union {
ieeedouble ieee;
nativedouble native;
char b[8];
double d;
} double_t;
typedef union {
ieeefloat ieee;
nativefloat native;
char b[4];
float f;
} float_t;
void
TIFFCvtIEEEFloatToNative(TIFF* tif, u_int n, float* f)
{
float_t *fp = (float_t *)f;
while (n-- > 0) {
IEEEFLOAT2NATIVE(fp);
fp++;
}
}
void
TIFFCvtNativeToIEEEFloat(TIFF* tif, u_int n, float* f)
{
float_t *fp = (float_t *)f;
while (n-- > 0) {
NATIVE2IEEEFLOAT(fp);
fp++;
}
}
#endif
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