+#include "wx/setup.h"
+#include <math.h>
+
+#if USE_APPLE_IEEE
+
+/*
+ * C O N V E R T T O I E E E E X T E N D E D
+ */
+
+/* Copyright (C) 1988-1991 Apple Computer, Inc.
+ * All rights reserved.
+ *
+ * Machine-independent I/O routines for IEEE floating-point numbers.
+ *
+ * NaN's and infinities are converted to HUGE_VAL or HUGE, which
+ * happens to be infinity on IEEE machines. Unfortunately, it is
+ * impossible to preserve NaN's in a machine-independent way.
+ * Infinities are, however, preserved on IEEE machines.
+ *
+ * These routines have been tested on the following machines:
+ * Apple Macintosh, MPW 3.1 C compiler
+ * Apple Macintosh, THINK C compiler
+ * Silicon Graphics IRIS, MIPS compiler
+ * Cray X/MP and Y/MP
+ * Digital Equipment VAX
+ *
+ *
+ * Implemented by Malcolm Slaney and Ken Turkowski.
+ *
+ * Malcolm Slaney contributions during 1988-1990 include big- and little-
+ * endian file I/O, conversion to and from Motorola's extended 80-bit
+ * floating-point format, and conversions to and from IEEE single-
+ * precision floating-point format.
+ *
+ * In 1991, Ken Turkowski implemented the conversions to and from
+ * IEEE double-precision format, added more precision to the extended
+ * conversions, and accommodated conversions involving +/- infinity,
+ * NaN's, and denormalized numbers.
+ */
+
+#ifndef HUGE_VAL
+#define HUGE_VAL HUGE
+#endif /*HUGE_VAL*/
+
+#define FloatToUnsigned(f) ((unsigned long) (((long) (f - 2147483648.0)) + 2147483647L) + 1)
+
+void ConvertToIeeeExtended(double num, unsigned char *bytes)
+{
+ int sign;
+ int expon;
+ double fMant, fsMant;
+ unsigned long hiMant, loMant;
+
+ if (num < 0) {
+ sign = 0x8000;
+ num *= -1;
+ } else {
+ sign = 0;
+ }
+
+ if (num == 0) {
+ expon = 0; hiMant = 0; loMant = 0;
+ }
+ else {
+ fMant = frexp(num, &expon);
+ if ((expon > 16384) || !(fMant < 1)) { /* Infinity or NaN */
+ expon = sign|0x7FFF; hiMant = 0; loMant = 0; /* infinity */
+ }
+ else { /* Finite */
+ expon += 16382;
+ if (expon < 0) { /* denormalized */
+ fMant = ldexp(fMant, expon);
+ expon = 0;
+ }
+ expon |= sign;
+ fMant = ldexp(fMant, 32);
+ fsMant = floor(fMant);
+ hiMant = FloatToUnsigned(fsMant);
+ fMant = ldexp(fMant - fsMant, 32);
+ fsMant = floor(fMant);
+ loMant = FloatToUnsigned(fsMant);
+ }
+ }
+
+ bytes[0] = expon >> 8;
+ bytes[1] = expon;
+ bytes[2] = hiMant >> 24;
+ bytes[3] = hiMant >> 16;
+ bytes[4] = hiMant >> 8;
+ bytes[5] = hiMant;
+ bytes[6] = loMant >> 24;
+ bytes[7] = loMant >> 16;
+ bytes[8] = loMant >> 8;
+ bytes[9] = loMant;
+}
+
+/*
+ * C O N V E R T F R O M I E E E E X T E N D E D
+ */
+
+/*
+ * Copyright (C) 1988-1991 Apple Computer, Inc.
+ * All rights reserved.
+ *
+ * Machine-independent I/O routines for IEEE floating-point numbers.
+ *
+ * NaN's and infinities are converted to HUGE_VAL or HUGE, which
+ * happens to be infinity on IEEE machines. Unfortunately, it is
+ * impossible to preserve NaN's in a machine-independent way.
+ * Infinities are, however, preserved on IEEE machines.
+ *
+ * These routines have been tested on the following machines:
+ * Apple Macintosh, MPW 3.1 C compiler
+ * Apple Macintosh, THINK C compiler
+ * Silicon Graphics IRIS, MIPS compiler
+ * Cray X/MP and Y/MP
+ * Digital Equipment VAX
+ *
+ *
+ * Implemented by Malcolm Slaney and Ken Turkowski.
+ *
+ * Malcolm Slaney contributions during 1988-1990 include big- and little-
+ * endian file I/O, conversion to and from Motorola's extended 80-bit
+ * floating-point format, and conversions to and from IEEE single-
+ * precision floating-point format.
+ *
+ * In 1991, Ken Turkowski implemented the conversions to and from
+ * IEEE double-precision format, added more precision to the extended
+ * conversions, and accommodated conversions involving +/- infinity,
+ * NaN's, and denormalized numbers.
+ */
+
+#ifndef HUGE_VAL
+# define HUGE_VAL HUGE
+#endif /*HUGE_VAL*/
+
+# define UnsignedToFloat(u) (((double) ((long) (u - 2147483647L - 1))) + 2147483648.0)
+
+/****************************************************************
+ * Extended precision IEEE floating-point conversion routine.
+ ****************************************************************/
+
+double ConvertFromIeeeExtended(const unsigned char *bytes)
+{
+ double f;
+ int expon;
+ unsigned long hiMant, loMant;
+
+ expon = ((bytes[0] & 0x7F) << 8) | (bytes[1] & 0xFF);
+ hiMant = ((unsigned long)(bytes[2] & 0xFF) << 24)
+ | ((unsigned long) (bytes[3] & 0xFF) << 16)
+ | ((unsigned long) (bytes[4] & 0xFF) << 8)
+ | ((unsigned long) (bytes[5] & 0xFF));
+ loMant = ((unsigned long) (bytes[6] & 0xFF) << 24)
+ | ((unsigned long) (bytes[7] & 0xFF) << 16)
+ | ((unsigned long) (bytes[8] & 0xFF) << 8)
+ | ((unsigned long) (bytes[9] & 0xFF));
+
+ if (expon == 0 && hiMant == 0 && loMant == 0) {
+ f = 0;
+ }
+ else {
+ if (expon == 0x7FFF) { /* Infinity or NaN */
+ f = HUGE_VAL;
+ }
+ else {
+ expon -= 16383;
+ f = ldexp(UnsignedToFloat(hiMant), expon-=31);
+ f += ldexp(UnsignedToFloat(loMant), expon-=32);
+ }
+ }
+
+ if (bytes[0] & 0x80)
+ return -f;
+ else
+ return f;
+}
+
+#endif USE_APPLE_IEEE
projects / wxWidgets.git / commitdiff
