diff --git a/CHANGELOG.md b/CHANGELOG.md
index d1e43d21..e2badf05 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -23,6 +23,7 @@ The espeak-ng project is a fork of the espeak project.
    Use cmn-latn-pinyin for interpreting latin characters as pinyin
 *  Update list of voice varants for Android application
 *  Add Chromium extension (guest271314)
+*  Replace `ieee80.c` by a free software implementation (Ulrich Müller)
 
 bug fixes:
 *  Fix reading malformed SSML (Christopher Brannon)
diff --git a/COPYING.IEEE b/COPYING.IEEE
deleted file mode 100644
index 37700179..00000000
--- a/COPYING.IEEE
+++ /dev/null
@@ -1,17 +0,0 @@
-Source: http://www.realitypixels.com/turk/opensource/
-
-Open Source Repository
-
-courtesy of
-Ken Turkowski
-
-The source code available from this page may be freely downloaded and used in
-any applications for any purpose, as long as the code is used in its entirety
-and the copyright notice and warranty information is retained.
-
-If you make any improvements to this software, you should provide me with said
-improvements.
-
-If any of this code is incorporated into a commercial product, you should
-notify me of this by email, and provide me with a complimentary copy of said
-product. :-)
diff --git a/Makefile.am b/Makefile.am
index d4ffac01..de35cb02 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -15,11 +15,9 @@ SHARED_VERSION=2:51:1 # = *.so.1.1.51
 
 MKDIR=mkdir -p
 
-# -Wno-endif-labels : Needed to prevent warnings in ieee80.c.
 AM_CFLAGS = \
 	-Isrc/include -Isrc/include/compat -I$(srcdir)/src/speechPlayer/include -I$(srcdir)/src/ucd-tools/src/include \
-	-D_BSD_SOURCE -D_DEFAULT_SOURCE -D_POSIX_C_SOURCE=200112L \
-	-Wno-endif-labels
+	-D_BSD_SOURCE -D_DEFAULT_SOURCE -D_POSIX_C_SOURCE=200112L
 
 EXTRA_DIST=
 CLEANFILES = dictsource/ru_listx dictsource/cmn_listx dictsource/yue_listx
diff --git a/README.md b/README.md
index a574b7b0..db39e8eb 100644
--- a/README.md
+++ b/README.md
@@ -130,13 +130,6 @@ the 1.24.02 source commit.
 eSpeak NG Text-to-Speech is released under the [GPL version 3](COPYING) or
 later license.
 
-The `ieee80.c` implementation is taken directly from
-[ToFromIEEE.c.txt](http://www.realitypixels.com/turk/opensource/ToFromIEEE.c.txt)
-which has been made available for use in Open Source applications per the
-[license statement](COPYING.IEEE) on http://www.realitypixels.com/turk/opensource/.
-The only modifications made to the code is to comment out the `TEST_FP` define
-to make it useable in the eSpeak NG library, and to fix compiler warnings.
-
 The `getopt.c` compatibility implementation for getopt support on Windows is
 taken from the NetBSD `getopt_long` implementation, which is licensed under a
 [2-clause BSD](COPYING.BSD2) license.
diff --git a/src/libespeak-ng/ieee80.c b/src/libespeak-ng/ieee80.c
index 43c10191..a57ef83d 100644
--- a/src/libespeak-ng/ieee80.c
+++ b/src/libespeak-ng/ieee80.c
@@ -1,976 +1,74 @@
-
-//#define TEST_FP
-
-/* Copyright (C) 1989-1991 Apple Computer, Inc.
+/*
+ * Copyright (C) 2022 Ulrich Müller <ulm@gentoo.org>
  *
- * All rights reserved.
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
  *
- * Warranty Information
- *  Even though Apple has reviewed this software, Apple makes no warranty
- *  or representation, either express or implied, with respect to this
- *  software, its quality, accuracy, merchantability, or fitness for a
- *  particular purpose.  As a result, this software is provided "as is,"
- *  and you, its user, are assuming the entire risk as to its quality
- *  and accuracy.
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
  *
- * This code may be used and freely distributed as long as it includes
- * this copyright notice and the above warranty information.
- *
- * 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
- *	Sequent Balance (Multiprocesor 386)
- *	NeXT
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see: <http://www.gnu.org/licenses/>.
  *
  *
- * 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.
+ * Alternatively, at your option, you can distribute this file under
+ * the terms of the 2-clause BSD license.
  */
 
+#include <math.h>
+#include <stdint.h>
+#include "ieee80.h"
 
-#include	<stdio.h>
-#include	<math.h>
-#include	"ieee80.h"
+#ifndef INFINITY
+# define INFINITY 0.
+#endif
 
-typedef float Single;
+#ifndef NAN
+# define NAN 0.
+#endif
 
-#ifndef THINK_C
- typedef double Double;
-#else THINK_C
- typedef short double Double;
-#endif THINK_C
-
-#ifndef HUGE_VAL
-# define HUGE_VAL HUGE
-#endif HUGE_VAL
-
-
-/****************************************************************
- * The following two routines make up for deficiencies in many
- * compilers to convert properly between unsigned integers and
- * floating-point.  Some compilers which have this bug are the
- * THINK_C compiler for the Macintosh and the C compiler for the
- * Silicon Graphics MIPS-based Iris.
- ****************************************************************/
-
-#ifdef applec	/* The Apple C compiler works */
-# define FloatToUnsigned(f)	((unsigned long)(f))
-# define UnsignedToFloat(u)	((defdouble)(u))
-#else applec
-# define FloatToUnsigned(f)	((unsigned long)(((long)((f) - 2147483648.0)) + 2147483647L + 1))
-# define UnsignedToFloat(u)	(((defdouble)((long)((u) - 2147483647L - 1))) + 2147483648.0)
-#endif applec
-
-
-/****************************************************************
- * Single precision IEEE floating-point conversion routines
- ****************************************************************/
-
-#define SEXP_MAX		255
-#define SEXP_OFFSET		127
-#define SEXP_SIZE		8
-#define SEXP_POSITION	(32-SEXP_SIZE-1)
-
-
-defdouble
-ConvertFromIeeeSingle(bytes)
-char* bytes;
+/*
+ * Convert an IEEE 754 80-bit extended precision floating-point number
+ * to a double. Input is expected as 10 bytes in big-endian order.
+ *
+ * Implemented according to the format described in:
+ * https://en.wikipedia.org/wiki/Extended_precision
+ * https://en.wikipedia.org/wiki/IEEE_754
+ */
+double
+ieee_extended_to_double(const unsigned char *bytes)
 {
-	defdouble	f;
-	long	mantissa, expon;
-	long	bits;
+	int sign, exp, i;
+	uint64_t mant;
+	double ret;
 
-	bits =	((unsigned long)(bytes[0] & 0xFF) << 24)
-		|	((unsigned long)(bytes[1] & 0xFF) << 16)
-		|	((unsigned long)(bytes[2] & 0xFF) << 8)
-		|	 (unsigned long)(bytes[3] & 0xFF);		/* Assemble bytes into a long */
+	sign = (bytes[0] & 0x80) != 0;
+	exp = (bytes[0] & 0x7f) << 8 | bytes[1];
 
-	if ((bits & 0x7FFFFFFF) == 0) {
-		f = 0;
+	/* Unfortunately, there is no 64-bit variant of ntohl(), and we
+	   cannot use be64toh() either, because it is nonstandard */
+	mant = 0;
+	for (i = 2; i < 10; i++)
+		mant = (mant << 8) | bytes[i];
+
+	switch (exp) {
+	case 0:			/* zero or denormalized number */
+		ret = (mant == 0) ? 0. : ldexp(mant, - (16382 + 63));
+		break;
+	case 0x7fff:		/* infinity or not a number */
+		/* Convert infinity to INFINITY, and anything else
+		   (signalling NaN, quiet NaN, indefinite) to NAN */
+		ret = ((mant & 0x7fffffffffffffff) == 0) ? INFINITY : NAN;
+		break;
+	default:
+		ret = ldexp(mant, exp - (16383 + 63));
 	}
 
-	else {
-		expon = (bits & 0x7F800000) >> SEXP_POSITION;
-		if (expon == SEXP_MAX) {		/* Infinity or NaN */
-			f = HUGE_VAL;		/* Map NaN's to infinity */
-		}
-		else {
-			if (expon == 0) {	/* Denormalized number */
-				mantissa = (bits & 0x7fffff);
-				f = ldexp((defdouble)mantissa, expon - SEXP_OFFSET - SEXP_POSITION + 1);
-			}
-			else {				/* Normalized number */
-				mantissa = (bits & 0x7fffff) + 0x800000;	/* Insert hidden bit */
-				f = ldexp((defdouble)mantissa, expon - SEXP_OFFSET - SEXP_POSITION);
-			}
-		}
-	}
+	if (sign) ret = -ret;
 
-	if (bits & 0x80000000)
-		return -f;
-	else
-		return f;
+	return ret;
 }
-
-
-/****************************************************************/
-
-
-void
-ConvertToIeeeSingle(num, bytes)
-defdouble num;
-char* bytes;
-{
-	long	sign;
-	register long bits;
-
-	if (num < 0) {	/* Can't distinguish a negative zero */
-		sign = 0x80000000;
-		num *= -1;
-	} else {
-		sign = 0;
-	}
-
-	if (num == 0) {
-		bits = 0;
-	}
-
-	else {
-		defdouble fMant;
-		int expon;
-
-		fMant = frexp(num, &expon);
-
-		if ((expon > (SEXP_MAX-SEXP_OFFSET+1)) || !(fMant < 1)) {
-			/* NaN's and infinities fail second test */
-			bits = sign | 0x7F800000;		/* +/- infinity */
-		}
-
-		else {
-			long mantissa;
-
-			if (expon < -(SEXP_OFFSET-2)) {	/* Smaller than normalized */
-				int shift = (SEXP_POSITION+1) + (SEXP_OFFSET-2) + expon;
-				if (shift < 0) {	/* Way too small: flush to zero */
-					bits = sign;
-				}
-				else {			/* Nonzero denormalized number */
-					mantissa = (long)(fMant * (1L << shift));
-					bits = sign | mantissa;
-				}
-			}
-
-			else {				/* Normalized number */
-				mantissa = (long)floor(fMant * (1L << (SEXP_POSITION+1)));
-				mantissa -= (1L << SEXP_POSITION);			/* Hide MSB */
-				bits = sign | ((long)((expon + SEXP_OFFSET - 1)) << SEXP_POSITION) | mantissa;
-			}
-		}
-	}
-
-	bytes[0] = bits >> 24;	/* Copy to byte string */
-	bytes[1] = bits >> 16;
-	bytes[2] = bits >> 8;
-	bytes[3] = bits;
-}
-
-
-/****************************************************************
- * Double precision IEEE floating-point conversion routines
- ****************************************************************/
-
-#define DEXP_MAX		2047
-#define DEXP_OFFSET		1023
-#define DEXP_SIZE		11
-#define DEXP_POSITION	(32-DEXP_SIZE-1)
-
-
-defdouble
-ConvertFromIeeeDouble(bytes)
-char* bytes;
-{
-	defdouble	f;
-	long	mantissa, expon;
-	unsigned long first, second;
-
-	first = ((unsigned long)(bytes[0] & 0xFF) << 24)
-		|	((unsigned long)(bytes[1] & 0xFF) << 16)
-		|	((unsigned long)(bytes[2] & 0xFF) << 8)
-		|	 (unsigned long)(bytes[3] & 0xFF);
-	second= ((unsigned long)(bytes[4] & 0xFF) << 24)
-		|	((unsigned long)(bytes[5] & 0xFF) << 16)
-		|	((unsigned long)(bytes[6] & 0xFF) << 8)
-		|	 (unsigned long)(bytes[7] & 0xFF);
-	
-	if (first == 0 && second == 0) {
-		f = 0;
-	}
-
-	else {
-		expon = (first & 0x7FF00000) >> DEXP_POSITION;
-		if (expon == DEXP_MAX) {		/* Infinity or NaN */
-			f = HUGE_VAL;		/* Map NaN's to infinity */
-		}
-		else {
-			if (expon == 0) {	/* Denormalized number */
-				mantissa = (first & 0x000FFFFF);
-				f = ldexp((defdouble)mantissa, expon - DEXP_OFFSET - DEXP_POSITION + 1);
-				f += ldexp(UnsignedToFloat(second), expon - DEXP_OFFSET - DEXP_POSITION + 1 - 32);
-			}
-			else {				/* Normalized number */
-				mantissa = (first & 0x000FFFFF) + 0x00100000;	/* Insert hidden bit */
-				f = ldexp((defdouble)mantissa, expon - DEXP_OFFSET - DEXP_POSITION);
-				f += ldexp(UnsignedToFloat(second), expon - DEXP_OFFSET - DEXP_POSITION - 32);
-			}
-		}
-	}
-
-	if (first & 0x80000000)
-		return -f;
-	else
-		return f;
-}
-
-
-/****************************************************************/
-
-
-void
-ConvertToIeeeDouble(num, bytes)
-defdouble num;
-char *bytes;
-{
-	long	sign;
-	long	first, second;
-
-	if (num < 0) {	/* Can't distinguish a negative zero */
-		sign = 0x80000000;
-		num *= -1;
-	} else {
-		sign = 0;
-	}
-
-	if (num == 0) {
-		first = 0;
-		second = 0;
-	}
-
-	else {
-		defdouble fMant, fsMant;
-		int expon;
-
-		fMant = frexp(num, &expon);
-
-		if ((expon > (DEXP_MAX-DEXP_OFFSET+1)) || !(fMant < 1)) {
-			/* NaN's and infinities fail second test */
-			first = sign | 0x7FF00000;		/* +/- infinity */
-			second = 0;
-		}
-
-		else {
-			long mantissa;
-
-			if (expon < -(DEXP_OFFSET-2)) {	/* Smaller than normalized */
-				int shift = (DEXP_POSITION+1) + (DEXP_OFFSET-2) + expon;
-				if (shift < 0) {	/* Too small for something in the MS word */
-					first = sign;
-					shift += 32;
-					if (shift < 0) {	/* Way too small: flush to zero */
-						second = 0;
-					}
-					else {			/* Pretty small demorn */
-						second = FloatToUnsigned(floor(ldexp(fMant, shift)));
-					}
-				}
-				else {			/* Nonzero denormalized number */
-					fsMant = ldexp(fMant, shift);
-					mantissa = (long)floor(fsMant);
-					first = sign | mantissa;
-					second = FloatToUnsigned(floor(ldexp(fsMant - mantissa, 32)));
-				}
-			}
-
-			else {				/* Normalized number */
-				fsMant = ldexp(fMant, DEXP_POSITION+1);
-				mantissa = (long)floor(fsMant);
-				mantissa -= (1L << DEXP_POSITION);			/* Hide MSB */
-				fsMant -= (1L << DEXP_POSITION);
-				first = sign | ((long)((expon + DEXP_OFFSET - 1)) << DEXP_POSITION) | mantissa;
-				second = FloatToUnsigned(floor(ldexp(fsMant - mantissa, 32)));
-			}
-		}
-	}
-	
-	bytes[0] = first >> 24;
-	bytes[1] = first >> 16;
-	bytes[2] = first >> 8;
-	bytes[3] = first;
-	bytes[4] = second >> 24;
-	bytes[5] = second >> 16;
-	bytes[6] = second >> 8;
-	bytes[7] = second;
-}
-
-
-/****************************************************************
- * Extended precision IEEE floating-point conversion routines.
- * Extended is an 80-bit number as defined by Motorola,
- * with a sign bit, 15 bits of exponent (offset 16383?),
- * and a 64-bit mantissa, with no hidden bit.
- ****************************************************************/
-
-defdouble
-ConvertFromIeeeExtended(bytes)
-char* bytes;
-{
-	defdouble	f;
-	long	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;
-}
-
-
-/****************************************************************/
-
-
-void
-ConvertToIeeeExtended(num, bytes)
-defdouble num;
-char *bytes;
-{
-	int	sign;
-	int expon;
-	defdouble 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;
-}
-
-/****************************************************************
- * Testing routines for the floating-point conversions.
- ****************************************************************/
-
-
-#ifdef applec
-# define IEEE
-#endif applec
-#ifdef THINK_C
-# define IEEE
-#endif THINK_C
-#ifdef sgi
-# define IEEE
-#endif sgi
-#ifdef sequent
-# define IEEE
-# define LITTLE_ENDIAN
-#endif sequent
-#ifdef sun
-# define IEEE
-#endif sun
-#ifdef NeXT
-# define IEEE
-#endif NeXT
-
-#ifdef TEST_FP
-
-union SParts {
-	Single s;
-	long i;
-};
-union DParts {
-	Double d;
-	long i[2];
-};
-union EParts {
-	defdouble e;
-	short i[6];
-};
-
-
-int
-GetHexValue(x)
-register int x;
-{
-	x &= 0x7F;
-	
-	if ('0' <= x && x <= '9')
-		x -= '0';
-	else if ('a' <= x && x <= 'f')
-		x = x - 'a' + 0xA;
-	else if ('A' <= x && x <= 'F')
-		x = x - 'A' + 0xA;
-	else
-		x = 0;
-	
-	return(x);
-}
-
-
-void
-Hex2Bytes(hex, bytes)
-register char *hex, *bytes;
-{
-	for ( ; *hex; hex += 2) {
-		*bytes++ = (GetHexValue(hex[0]) << 4) | GetHexValue(hex[1]);
-		if (hex[1] == 0)
-			break;	/* Guard against odd bytes */
-	}
-}
-
-
-int
-GetHexSymbol(x)
-register int x;
-{
-	x &= 0xF;
-	if (x <= 9)
-		x += '0';
-	else
-		x += 'A' - 0xA;
-	return(x);
-}
-
-
-void
-Bytes2Hex(bytes, hex, nBytes)
-register char *bytes, *hex;
-register int nBytes;
-{
-	for ( ; nBytes--; bytes++) {
-		*hex++ = GetHexSymbol(*bytes >> 4);
-		*hex++ = GetHexSymbol(*bytes);
-	}
-	*hex = 0;
-}
-
-
-void
-MaybeSwapBytes(bytes, nBytes)
-char* bytes;
-int nBytes;
-{
-#ifdef LITTLE_ENDIAN
-	register char *p, *q, t;
-	for (p = bytes, q = bytes+nBytes-1; p < q; p++, q--) {
-		t = *p;
-		*p = *q;
-		*q = t;
-	}
-#else
-	if (bytes, nBytes);		/* Just so it's used, to avoid warnings */
-#endif LITTLE_ENDIAN
-	
-}
-
-
-float
-MachineIEEESingle(bytes)
-char* bytes;
-{
-	float t;
-	MaybeSwapBytes(bytes, 4);
-	t = *((float*)(bytes));
-	MaybeSwapBytes(bytes, 4);
-	return (t);
-}
-
-
-Double
-MachineIEEEDouble(bytes)
-char* bytes;
-{
-	Double t;
-	MaybeSwapBytes(bytes, 8);
-	t = *((Double*)(bytes));
-	MaybeSwapBytes(bytes, 8);
-	return (t);
-}
-
-
-void
-TestFromIeeeSingle(hex)
-char *hex;
-{
-	defdouble f;
-	union SParts p;
-	char bytes[4];
-
-	Hex2Bytes(hex, bytes);
-	f = ConvertFromIeeeSingle(bytes);
-	p.s = f;
-
-#ifdef IEEE
-	printf("IEEE(%g) [%s] --> float(%g) [%08lX]\n",
-	MachineIEEESingle(bytes),
-	hex, f, p.i);
-#else IEEE
-	printf("IEEE[%s] --> float(%g) [%08lX]\n", hex, f, p.i);
-#endif IEEE
-}
-
-
-void
-TestToIeeeSingle(f)
-defdouble f;
-{
-	union SParts p;
-	char bytes[4];
-	char hex[8+1];
-
-	p.s = f;
-
-	ConvertToIeeeSingle(f, bytes);
-	Bytes2Hex(bytes, hex, 4);
-#ifdef IEEE
-	printf("float(%g) [%08lX] --> IEEE(%g) [%s]\n",
-		f, p.i,
-		MachineIEEESingle(bytes),
-		hex
-	);
-#else IEEE
-	printf("float(%g) [%08lX] --> IEEE[%s]\n", f, p.i, hex);
-#endif IEEE
-}
-
-
-void
-TestFromIeeeDouble(hex)
-char *hex;
-{
-	defdouble f;
-	union DParts p;
-	char bytes[8];
-	
-	Hex2Bytes(hex, bytes);
-	f = ConvertFromIeeeDouble(bytes);
-	p.d = f;
-
-#ifdef IEEE
-	printf("IEEE(%g) [%.8s %.8s] --> double(%g) [%08lX %08lX]\n",
-	MachineIEEEDouble(bytes),
-	hex, hex+8, f, p.i[0], p.i[1]);
-#else IEEE
-	printf("IEEE[%.8s %.8s] --> double(%g) [%08lX %08lX]\n",
-		hex, hex+8, f, p.i[0], p.i[1]);
-#endif IEEE
-
-}
-
-void
-TestToIeeeDouble(f)
-defdouble f;
-{
-	union DParts p;
-	char bytes[8];
-	char hex[16+1];
-
-	p.d = f;
-
-	ConvertToIeeeDouble(f, bytes);
-	Bytes2Hex(bytes, hex, 8);
-#ifdef IEEE
-	printf("double(%g) [%08lX %08lX] --> IEEE(%g) [%.8s %.8s]\n",
-		f, p.i[0], p.i[1],
-		MachineIEEEDouble(bytes),
-		hex, hex+8
-	);
-#else IEEE
-	printf("double(%g) [%08lX %08lX] --> IEEE[%.8s %.8s]\n",
-		f, p.i[0], p.i[1], hex, hex+8
-	);
-#endif IEEE
-
-}
-
-
-void
-TestFromIeeeExtended(hex)
-char *hex;
-{
-	defdouble f;
-	union EParts p;
-	char bytes[12];
-
-	Hex2Bytes(hex, bytes);
-	f = ConvertFromIeeeExtended(bytes);
-	p.e = f;
-
-	bytes[11] = bytes[9];
-	bytes[10] = bytes[8];
-	bytes[9] = bytes[7];
-	bytes[8] = bytes[6];
-	bytes[7] = bytes[5];
-	bytes[6] = bytes[4];
-	bytes[5] = bytes[3];
-	bytes[4] = bytes[2];
-	bytes[3] = 0;
-	bytes[2] = 0;
-
-#if defined(applec) || defined(THINK_C)
-	printf("IEEE(%g) [%.4s %.8s %.8s] --> extended(%g) [%04X %04X%04X %04X%04X]\n",
-		*((defdouble*)(bytes)),
-		hex, hex+4, hex+12, f,
-		p.i[0]&0xFFFF, p.i[2]&0xFFFF, p.i[3]&0xFFFF, p.i[4]&0xFFFF, p.i[5]&0xFFFF
-	);
-#else /* !Macintosh */
-	printf("IEEE[%.4s %.8s %.8s] --> extended(%g) [%04X %04X%04X %04X%04X]\n",
-		hex, hex+4, hex+12, f,
-		p.i[0]&0xFFFF, p.i[2]&0xFFFF, p.i[3]&0xFFFF, p.i[4]&0xFFFF, p.i[5]&0xFFFF
-	);
-#endif /* Macintosh */
-}
-
-
-void
-TestToIeeeExtended(f)
-defdouble f;
-{
-	char bytes[12];
-	char hex[24+1];
-
-	ConvertToIeeeExtended(f, bytes);
-	Bytes2Hex(bytes, hex, 10);
-
-	bytes[11] = bytes[9];
-	bytes[10] = bytes[8];
-	bytes[9] = bytes[7];
-	bytes[8] = bytes[6];
-	bytes[7] = bytes[5];
-	bytes[6] = bytes[4];
-	bytes[5] = bytes[3];
-	bytes[4] = bytes[2];
-	bytes[3] = 0;
-	bytes[2] = 0;
-
-#if defined(applec) || defined(THINK_C)
-	printf("extended(%g) --> IEEE(%g) [%.4s %.8s %.8s]\n",
-		f, *((defdouble*)(bytes)),
-		hex, hex+4, hex+12
-	);
-#else /* !Macintosh */
-	printf("extended(%g) --> IEEE[%.4s %.8s %.8s]\n",
-		f,
-		hex, hex+4, hex+12
-	);
-#endif /* Macintosh */
-}
-
-#include	<signal.h>
-
-void SignalFPE(i, j)
-int	i;
-void (*j)();
-{
-	printf("[Floating Point Interrupt Caught.]\n", i, j);
-	signal(SIGFPE, SignalFPE);
-}
-	
-void
-main()
-{
-	long d[3];
-	char bytes[12];
-
-	signal(SIGFPE, SignalFPE);
-
-	TestFromIeeeSingle("00000000");
-	TestFromIeeeSingle("80000000");
-	TestFromIeeeSingle("3F800000");
-	TestFromIeeeSingle("BF800000");
-	TestFromIeeeSingle("40000000");
-	TestFromIeeeSingle("C0000000");
-	TestFromIeeeSingle("7F800000");
-	TestFromIeeeSingle("FF800000");
-	TestFromIeeeSingle("00800000");
-	TestFromIeeeSingle("00400000");
-	TestFromIeeeSingle("00000001");
-	TestFromIeeeSingle("80000001");
-	TestFromIeeeSingle("3F8FEDCB");
-	TestFromIeeeSingle("7FC00100");	/* Quiet NaN(1) */
-	TestFromIeeeSingle("7F800100");	/* Signalling NaN(1) */
-
-	TestToIeeeSingle(0.0);
-	TestToIeeeSingle(-0.0);
-	TestToIeeeSingle(1.0);
-	TestToIeeeSingle(-1.0);
-	TestToIeeeSingle(2.0);
-	TestToIeeeSingle(-2.0);
-	TestToIeeeSingle(3.0);
-	TestToIeeeSingle(-3.0);
-#if !(defined(sgi) || defined(NeXT))
-	TestToIeeeSingle(HUGE_VAL);
-	TestToIeeeSingle(-HUGE_VAL);
-#endif /* !sgi, !NeXT */
-
-#ifdef IEEE
-	/* These only work on big-endian IEEE machines */
-	d[0] = 0x00800000L; MaybeSwapBytes((char*)d,4); TestToIeeeSingle(*((float*)(&d[0])));		/* Smallest normalized */
-	d[0] = 0x00400000L; MaybeSwapBytes((char*)d,4); TestToIeeeSingle(*((float*)(&d[0])));		/* Almost largest denormalized */
-	d[0] = 0x00000001L; MaybeSwapBytes((char*)d,4); TestToIeeeSingle(*((float*)(&d[0])));		/* Smallest denormalized */
-	d[0] = 0x00000001L; MaybeSwapBytes((char*)d,4); TestToIeeeSingle(*((float*)(&d[0])) * 0.5);	/* Smaller than smallest denorm */
-	d[0] = 0x3F8FEDCBL; MaybeSwapBytes((char*)d,4); TestToIeeeSingle(*((float*)(&d[0])));
-#if !(defined(sgi) || defined(NeXT))
-	d[0] = 0x7FC00100L; MaybeSwapBytes((char*)d,4); TestToIeeeSingle(*((float*)(&d[0])));		/* Quiet NaN(1) */
-	d[0] = 0x7F800100L; MaybeSwapBytes((char*)d,4); TestToIeeeSingle(*((float*)(&d[0])));		/* Signalling NaN(1) */
-#endif /* !sgi, !NeXT */
-#endif IEEE
-
-
-
-	TestFromIeeeDouble("0000000000000000");
-	TestFromIeeeDouble("8000000000000000");
-	TestFromIeeeDouble("3FF0000000000000");
-	TestFromIeeeDouble("BFF0000000000000");
-	TestFromIeeeDouble("4000000000000000");
-	TestFromIeeeDouble("C000000000000000");
-	TestFromIeeeDouble("7FF0000000000000");
-	TestFromIeeeDouble("FFF0000000000000");
-	TestFromIeeeDouble("0010000000000000");
-	TestFromIeeeDouble("0008000000000000");
-	TestFromIeeeDouble("0000000000000001");
-	TestFromIeeeDouble("8000000000000001");
-	TestFromIeeeDouble("3FFFEDCBA9876543");
-	TestFromIeeeDouble("7FF8002000000000");	/* Quiet NaN(1) */
-	TestFromIeeeDouble("7FF0002000000000");	/* Signalling NaN(1) */
-
-	TestToIeeeDouble(0.0);
-	TestToIeeeDouble(-0.0);
-	TestToIeeeDouble(1.0);
-	TestToIeeeDouble(-1.0);
-	TestToIeeeDouble(2.0);
-	TestToIeeeDouble(-2.0);
-	TestToIeeeDouble(3.0);
-	TestToIeeeDouble(-3.0);
-#if !(defined(sgi) || defined(NeXT))
-	TestToIeeeDouble(HUGE_VAL);
-	TestToIeeeDouble(-HUGE_VAL);
-#endif /* !sgi, !NeXT */
-
-#ifdef IEEE
-	/* These only work on IEEE machines */
-	Hex2Bytes("0010000000000000", bytes); MaybeSwapBytes(bytes,8); TestToIeeeDouble(*((Double*)(bytes)));	/* Smallest normalized */
-	Hex2Bytes("0010000080000000", bytes); MaybeSwapBytes(bytes,8); TestToIeeeDouble(*((Double*)(bytes)));	/* Normalized, problem with unsigned */
-	Hex2Bytes("0008000000000000", bytes); MaybeSwapBytes(bytes,8); TestToIeeeDouble(*((Double*)(bytes)));	/* Almost largest denormalized */
-	Hex2Bytes("0000000080000000", bytes); MaybeSwapBytes(bytes,8); TestToIeeeDouble(*((Double*)(bytes)));	/* Denorm problem with unsigned */
-	Hex2Bytes("0000000000000001", bytes); MaybeSwapBytes(bytes,8); TestToIeeeDouble(*((Double*)(bytes)));	/* Smallest denormalized */
-	Hex2Bytes("0000000000000001", bytes); MaybeSwapBytes(bytes,8); TestToIeeeDouble(*((Double*)(bytes)) * 0.5);	/* Smaller than smallest denorm */
-	Hex2Bytes("3FFFEDCBA9876543", bytes); MaybeSwapBytes(bytes,8); TestToIeeeDouble(*((Double*)(bytes)));	/* accuracy test */
-#if !(defined(sgi) || defined(NeXT))
-	Hex2Bytes("7FF8002000000000", bytes); MaybeSwapBytes(bytes,8); TestToIeeeDouble(*((Double*)(bytes)));	/* Quiet NaN(1) */
-	Hex2Bytes("7FF0002000000000", bytes); MaybeSwapBytes(bytes,8); TestToIeeeDouble(*((Double*)(bytes)));	/* Signalling NaN(1) */
-#endif /* !sgi, !NeXT */
-#endif IEEE
-
-	TestFromIeeeExtended("00000000000000000000");	/* +0 */
-	TestFromIeeeExtended("80000000000000000000");	/* -0 */
-	TestFromIeeeExtended("3FFF8000000000000000");	/* +1 */
-	TestFromIeeeExtended("BFFF8000000000000000");	/* -1 */
-	TestFromIeeeExtended("40008000000000000000");	/* +2 */
-	TestFromIeeeExtended("C0008000000000000000");	/* -2 */
-	TestFromIeeeExtended("7FFF0000000000000000");	/* +infinity */
-	TestFromIeeeExtended("FFFF0000000000000000");	/* -infinity */
-	TestFromIeeeExtended("7FFF8001000000000000");	/* Quiet NaN(1) */
-	TestFromIeeeExtended("7FFF0001000000000000");	/* Signalling NaN(1) */
-	TestFromIeeeExtended("3FFFFEDCBA9876543210");	/* accuracy test */
-
-	TestToIeeeExtended(0.0);
-	TestToIeeeExtended(-0.0);
-	TestToIeeeExtended(1.0);
-	TestToIeeeExtended(-1.0);
-	TestToIeeeExtended(2.0);
-	TestToIeeeExtended(-2.0);
-#if !(defined(sgi) || defined(NeXT))
-	TestToIeeeExtended(HUGE_VAL);
-	TestToIeeeExtended(-HUGE_VAL);
-#endif /* !sgi, !NeXT */
-
-#if defined(applec) || defined(THINK_C)
-	Hex2Bytes("7FFF00008001000000000000", bytes); TestToIeeeExtended(*((long double*)(bytes)));	/* Quiet NaN(1) */
-	Hex2Bytes("7FFF00000001000000000000", bytes); TestToIeeeExtended(*((long double*)(bytes)));	/* Signalling NaN(1) */
-	Hex2Bytes("7FFE00008000000000000000", bytes); TestToIeeeExtended(*((long double*)(bytes)));
-	Hex2Bytes("000000008000000000000000", bytes); TestToIeeeExtended(*((long double*)(bytes)));
-	Hex2Bytes("000000000000000000000001", bytes); TestToIeeeExtended(*((long double*)(bytes)));
-	Hex2Bytes("3FFF0000FEDCBA9876543210", bytes); TestToIeeeExtended(*((long double*)(bytes)));
-#endif /* applec, THINK_C */
-}
-
-
-/* This is the output of the test program on a big-endian IEEE machine:
-IEEE(0) [00000000] --> float(0) [00000000]
-IEEE(-0) [80000000] --> float(-0) [80000000]
-IEEE(1) [3F800000] --> float(1) [3F800000]
-IEEE(-1) [BF800000] --> float(-1) [BF800000]
-IEEE(2) [40000000] --> float(2) [40000000]
-IEEE(-2) [C0000000] --> float(-2) [C0000000]
-IEEE(INF) [7F800000] --> float(INF) [7F800000]
-IEEE(-INF) [FF800000] --> float(-INF) [FF800000]
-IEEE(1.17549e-38) [00800000] --> float(1.17549e-38) [00800000]
-IEEE(5.87747e-39) [00400000] --> float(5.87747e-39) [00400000]
-IEEE(1.4013e-45) [00000001] --> float(1.4013e-45) [00000001]
-IEEE(-1.4013e-45) [80000001] --> float(-1.4013e-45) [80000001]
-IEEE(1.12444) [3F8FEDCB] --> float(1.12444) [3F8FEDCB]
-IEEE(NAN(001)) [7FC00100] --> float(INF) [7F800000]
-IEEE(NAN(001)) [7F800100] --> float(INF) [7F800000]
-float(0) [00000000] --> IEEE(0) [00000000]
-float(-0) [80000000] --> IEEE(0) [00000000]
-float(1) [3F800000] --> IEEE(1) [3F800000]
-float(-1) [BF800000] --> IEEE(-1) [BF800000]
-float(2) [40000000] --> IEEE(2) [40000000]
-float(-2) [C0000000] --> IEEE(-2) [C0000000]
-float(3) [40400000] --> IEEE(3) [40400000]
-float(-3) [C0400000] --> IEEE(-3) [C0400000]
-float(INF) [7F800000] --> IEEE(INF) [7F800000]
-float(-INF) [FF800000] --> IEEE(-INF) [FF800000]
-float(1.17549e-38) [00800000] --> IEEE(1.17549e-38) [00800000]
-float(5.87747e-39) [00400000] --> IEEE(5.87747e-39) [00400000]
-float(1.4013e-45) [00000001] --> IEEE(1.4013e-45) [00000001]
-float(7.00649e-46) [00000000] --> IEEE(0) [00000000]
-float(1.12444) [3F8FEDCB] --> IEEE(1.12444) [3F8FEDCB]
-float(NAN(001)) [7FC00100] --> IEEE(INF) [7F800000]
-float(NAN(001)) [7FC00100] --> IEEE(INF) [7F800000]
-IEEE(0) [00000000 00000000] --> double(0) [00000000 00000000]
-IEEE(-0) [80000000 00000000] --> double(-0) [80000000 00000000]
-IEEE(1) [3FF00000 00000000] --> double(1) [3FF00000 00000000]
-IEEE(-1) [BFF00000 00000000] --> double(-1) [BFF00000 00000000]
-IEEE(2) [40000000 00000000] --> double(2) [40000000 00000000]
-IEEE(-2) [C0000000 00000000] --> double(-2) [C0000000 00000000]
-IEEE(INF) [7FF00000 00000000] --> double(INF) [7FF00000 00000000]
-IEEE(-INF) [FFF00000 00000000] --> double(-INF) [FFF00000 00000000]
-IEEE(2.22507e-308) [00100000 00000000] --> double(2.22507e-308) [00100000 00000000]
-IEEE(1.11254e-308) [00080000 00000000] --> double(1.11254e-308) [00080000 00000000]
-IEEE(4.94066e-324) [00000000 00000001] --> double(4.94066e-324) [00000000 00000001]
-IEEE(-4.94066e-324) [80000000 00000001] --> double(-4.94066e-324) [80000000 00000001]
-IEEE(1.99556) [3FFFEDCB A9876543] --> double(1.99556) [3FFFEDCB A9876543]
-IEEE(NAN(001)) [7FF80020 00000000] --> double(INF) [7FF00000 00000000]
-IEEE(NAN(001)) [7FF00020 00000000] --> double(INF) [7FF00000 00000000]
-double(0) [00000000 00000000] --> IEEE(0) [00000000 00000000]
-double(-0) [80000000 00000000] --> IEEE(0) [00000000 00000000]
-double(1) [3FF00000 00000000] --> IEEE(1) [3FF00000 00000000]
-double(-1) [BFF00000 00000000] --> IEEE(-1) [BFF00000 00000000]
-double(2) [40000000 00000000] --> IEEE(2) [40000000 00000000]
-double(-2) [C0000000 00000000] --> IEEE(-2) [C0000000 00000000]
-double(3) [40080000 00000000] --> IEEE(3) [40080000 00000000]
-double(-3) [C0080000 00000000] --> IEEE(-3) [C0080000 00000000]
-double(INF) [7FF00000 00000000] --> IEEE(INF) [7FF00000 00000000]
-double(-INF) [FFF00000 00000000] --> IEEE(-INF) [FFF00000 00000000]
-double(2.22507e-308) [00100000 00000000] --> IEEE(2.22507e-308) [00100000 00000000]
-double(2.22507e-308) [00100000 80000000] --> IEEE(2.22507e-308) [00100000 80000000]
-double(1.11254e-308) [00080000 00000000] --> IEEE(1.11254e-308) [00080000 00000000]
-double(1.061e-314) [00000000 80000000] --> IEEE(1.061e-314) [00000000 80000000]
-double(4.94066e-324) [00000000 00000001] --> IEEE(4.94066e-324) [00000000 00000001]
-double(2.47033e-324) [00000000 00000000] --> IEEE(0) [00000000 00000000]
-double(1.99556) [3FFFEDCB A9876543] --> IEEE(1.99556) [3FFFEDCB A9876543]
-double(NAN(001)) [7FF80020 00000000] --> IEEE(INF) [7FF00000 00000000]
-double(NAN(001)) [7FF80020 00000000] --> IEEE(INF) [7FF00000 00000000]
-IEEE(0) [0000 00000000 00000000] --> extended(0) [0000 00000000 00000000]
-IEEE(-0) [8000 00000000 00000000] --> extended(-0) [8000 00000000 00000000]
-IEEE(1) [3FFF 80000000 00000000] --> extended(1) [3FFF 80000000 00000000]
-IEEE(-1) [BFFF 80000000 00000000] --> extended(-1) [BFFF 80000000 00000000]
-IEEE(2) [4000 80000000 00000000] --> extended(2) [4000 80000000 00000000]
-IEEE(-2) [C000 80000000 00000000] --> extended(-2) [C000 80000000 00000000]
-IEEE(INF) [7FFF 00000000 00000000] --> extended(INF) [7FFF 00000000 00000000]
-IEEE(-INF) [FFFF 00000000 00000000] --> extended(-INF) [FFFF 00000000 00000000]
-IEEE(NAN(001)) [7FFF 80010000 00000000] --> extended(INF) [7FFF 00000000 00000000]
-IEEE(NAN(001)) [7FFF 00010000 00000000] --> extended(INF) [7FFF 00000000 00000000]
-IEEE(1.99111) [3FFF FEDCBA98 76543210] --> extended(1.99111) [3FFF FEDCBA98 76543210]
-extended(0) --> IEEE(0) [0000 00000000 00000000]
-extended(-0) --> IEEE(0) [0000 00000000 00000000]
-extended(1) --> IEEE(1) [3FFF 80000000 00000000]
-extended(-1) --> IEEE(-1) [BFFF 80000000 00000000]
-extended(2) --> IEEE(2) [4000 80000000 00000000]
-extended(-2) --> IEEE(-2) [C000 80000000 00000000]
-extended(INF) --> IEEE(INF) [7FFF 00000000 00000000]
-extended(-INF) --> IEEE(-INF) [FFFF 00000000 00000000]
-extended(NAN(001)) --> IEEE(INF) [7FFF 00000000 00000000]
-extended(NAN(001)) --> IEEE(INF) [7FFF 00000000 00000000]
-extended(5.94866e+4931) --> IEEE(5.94866e+4931) [7FFE 80000000 00000000]
-extended(1e-4927) --> IEEE(1e-4927) [0000 80000000 00000000]
-extended(1e-4927) --> IEEE(1e-4927) [0000 00000000 00000001]
-extended(1.99111) --> IEEE(1.99111) [3FFF FEDCBA98 76543210]
-*/
-
-#endif TEST_FP
-
diff --git a/src/libespeak-ng/ieee80.h b/src/libespeak-ng/ieee80.h
index df4da90f..7f922b92 100644
--- a/src/libespeak-ng/ieee80.h
+++ b/src/libespeak-ng/ieee80.h
@@ -1,63 +1 @@
-/* Copyright (C) 1989-1991 Apple Computer, Inc.
- *
- * All rights reserved.
- *
- * Warranty Information
- *  Even though Apple has reviewed this software, Apple makes no warranty
- *  or representation, either express or implied, with respect to this
- *  software, its quality, accuracy, merchantability, or fitness for a
- *  particular purpose.  As a result, this software is provided "as is,"
- *  and you, its user, are assuming the entire risk as to its quality
- *  and accuracy.
- *
- * This code may be used and freely distributed as long as it includes
- * this copyright notice and the above warranty information.
- *
- * 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
- *	Sequent Balance (Multiprocesor 386)
- *	NeXT
- *
- *
- * 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 IEEE_H
-#define IEEE_H
-
-#ifndef applec
- typedef double defdouble;
-#else applec
- typedef long double defdouble;
-#endif applec
-
-defdouble ConvertFromIeeeSingle(  char *bytes);
-defdouble ConvertFromIeeeDouble(  char *bytes);
-defdouble ConvertFromIeeeExtended(char *bytes);
-
-void ConvertToIeeeSingle(  defdouble num, char *bytes);
-void ConvertToIeeeDouble(  defdouble num, char *bytes);
-void ConvertToIeeeExtended(defdouble num, char *bytes);
-
-#endif
+double ieee_extended_to_double(const unsigned char *);
diff --git a/src/libespeak-ng/spect.c b/src/libespeak-ng/spect.c
index 4b89c7ef..817837a0 100644
--- a/src/libespeak-ng/spect.c
+++ b/src/libespeak-ng/spect.c
@@ -49,7 +49,7 @@ static double read_double(FILE *stream)
 {
 	unsigned char bytes[10];
 	fread(bytes, sizeof(char), 10, stream);
-	return ConvertFromIeeeExtended((char *)bytes);
+	return ieee_extended_to_double(bytes);
 }
 
 float polint(float xa[], float ya[], int n, float x)