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 <HTML>

 <HEAD>
 <TITLE>Berkeley SoftFloat History</TITLE>
 </HEAD>

 <BODY>

 <H1>History of Berkeley SoftFloat, to Release 3e</H1>

 <P>
 John R. Hauser<BR>
 2018 January 20<BR>
 </P>


 <H3>Release 3e (2018 January)</H3>

 <UL>

 <LI>
 Changed the default numeric code for optional rounding mode <CODE>odd</CODE>
 (round to odd, also known as <EM>jamming</EM>) from 5 to 6.

 <LI>
 Modified the behavior of rounding mode <CODE>odd</CODE> when rounding to an
 integer value (either conversion to an integer format or a
 &lsquo;<CODE>roundToInt</CODE>&rsquo; function).
 Previously, for those cases only, rounding mode <CODE>odd</CODE> acted the same
 as rounding to minimum magnitude.
 Now all operations are rounded consistently.

 <LI>
 Fixed some errors in the specialization code modeling Intel x86 floating-point,
 specifically the integers returned on invalid operations and the propagation of
 NaN payloads in a few rare cases.

 <LI>
 Added specialization code modeling ARM floating-point, conforming to VFPv2 or
 later.

 <LI>
 Added an example target for ARM processors.

 <LI>
 Fixed a minor bug whereby function <CODE>f16_to_ui64</CODE> might return a
 different integer than expected in the case that the floating-point operand is
 negative.

 <LI>
 Added example target-specific optimization for GCC, employing GCC instrinsics
 and support for <NOBR>128-bit</NOBR> integer arithmetic.

 <LI>
 Made other minor improvements.

 </UL>


 <H3>Release 3d (2017 August)</H3>

 <UL>

 <LI>
 Fixed bugs in the square root functions for <NOBR>64-bit</NOBR>
 double-precision, <NOBR>80-bit</NOBR> double-extended-precision, and
 <NOBR>128-bit</NOBR> quadruple-precision.
 For <NOBR>64-bit</NOBR> double-precision (<CODE>f64_sqrt</CODE>), the result
 could sometimes be off by <NOBR>1 unit</NOBR> in the last place
 (<NOBR>1 ulp</NOBR>) from what it should be.
 For the larger formats, the square root could be wrong in a large portion of
 the less-significant bits.
 (A bug in <CODE>f128_sqrt</CODE> was first reported by Alexei Sibidanov.)

 </UL>


 <H3>Release 3c (2017 February)</H3>

 <UL>

 <LI>
 Added optional rounding mode <CODE>odd</CODE> (round to odd, also known as
 <EM>jamming</EM>).

 <LI>
 Corrected the documentation concerning non-canonical representations in
 <NOBR>80-bit</NOBR> double-extended-precision.

 </UL>


 <H3>Release 3b (2016 July)</H3>

 <UL>

 <LI>
 Implemented the common <NOBR>16-bit</NOBR> &ldquo;half-precision&rdquo;
 floating-point format (<CODE>float16_t</CODE>).

 <LI>
 Made the integer values returned on invalid conversions to integer formats
 be determined by the port-specific specialization instead of being the same for
 all ports.

 <LI>
 Added preprocessor macro <CODE>THREAD_LOCAL</CODE> to allow the floating-point
 state (modes and exception flags) to be made per-thread.

 <LI>
 Modified the provided Makefiles to allow some options to be overridden from the
 <CODE>make</CODE> command.

 <LI>
 Made other minor improvements.

 </UL>


 <H3>Release 3a (2015 October)</H3>

 <UL>

 <LI>
 Replaced the license text supplied by the University of California, Berkeley.

 </UL>


 <H3>Release 3 (2015 February)</H3>

 <UL>

 <LI>
 Complete rewrite, funded by the University of California, Berkeley, and
 consequently having a different use license than earlier releases.
 Major changes included renaming most types and functions, upgrading some
 algorithms, restructuring the source files, and making SoftFloat into a true
 library.

 <LI>
 Added functions to convert between floating-point and unsigned integers, both
 <NOBR>32-bit</NOBR> and <NOBR>64-bit</NOBR> (<CODE>uint32_t</CODE> and
 <CODE>uint64_t</CODE>).

 <LI>
 Added functions for fused multiply-add, for all supported floating-point
 formats except <NOBR>80-bit</NOBR> double-extended-precision.

 <LI>
 Added support for a fifth rounding mode, <CODE>near_maxMag</CODE> (round to
 nearest, with ties to maximum magnitude, away from zero).

 <LI>
 Dropped the <CODE>timesoftfloat</CODE> program (now part of the Berkeley
 TestFloat package).

 </UL>


 <H3>Release 2c (2015 January)</H3>

 <UL>

 <LI>
 Fixed mistakes affecting some <NOBR>64-bit</NOBR> processors.

 <LI>
 Further improved the documentation and the wording for the legal restrictions
 on using SoftFloat releases <NOBR>through 2c</NOBR> (not applicable to
 <NOBR>Release 3</NOBR> or later).

 </UL>


 <H3>Release 2b (2002 May)</H3>

 <UL>

 <LI>
 Made minor updates to the documentation, including improved wording for the
 legal restrictions on using SoftFloat.

 </UL>


 <H3>Release 2a (1998 December)</H3>

 <UL>

 <LI>
 Added functions to convert between <NOBR>64-bit</NOBR> integers
 (<CODE>int64</CODE>) and all supported floating-point formats.

 <LI>
 Fixed a bug in all <NOBR>64-bit</NOBR>-version square root functions except
 <CODE>float32_sqrt</CODE> that caused the result sometimes to be off by
 <NOBR>1 unit</NOBR> in the last place (<NOBR>1 ulp</NOBR>) from what it should
 be.
 (Bug discovered by Paul Donahue.)

 <LI>
 Improved the Makefiles.
 </UL>


 <H3>Release 2 (1997 June)</H3>

 <UL>

 <LI>
 Created the <NOBR>64-bit</NOBR> (<CODE>bits64</CODE>) version, adding the
 <CODE>floatx80</CODE> and <CODE>float128</CODE> formats.

 <LI>
 Changed the source directory structure, splitting the sources into a
 <CODE>bits32</CODE> and a <CODE>bits64</CODE> version.
 Renamed <CODE>environment.h</CODE> to <CODE>milieu.h</CODE> to avoid confusion
 with environment variables.

 <LI>
 Fixed a small error that caused <CODE>float64_round_to_int</CODE> often to
 round the wrong way in nearest/even mode when the operand was between
 2<SUP>20</SUP> and 2<SUP>21</SUP> and halfway between two integers.

 </UL>


 <H3>Release 1a (1996 July)</H3>

 <UL>

 <LI>
 Corrected a mistake that caused borderline underflow cases not to raise the
 underflow flag when they should have.
 (Problem reported by Doug Priest.)

 <LI>
 Added the <CODE>float_detect_tininess</CODE> variable to control whether
 tininess is detected before or after rounding.

 </UL>


 <H3>Release 1 (1996 July)</H3>

 <UL>

 <LI>
 Original release, based on work done for the International Computer Science
 Institute (ICSI) in Berkeley, California.

 </UL>


 </BODY>

	<HTML>

	<HEAD>
	<TITLE>Berkeley SoftFloat History</TITLE>
	</HEAD>

	<BODY>

	<H1>History of Berkeley SoftFloat, to Release 3e</H1>

	<P>
	John R. Hauser<BR>
	2018 January 20<BR>
	</P>


	<H3>Release 3e (2018 January)</H3>

	<UL>

	<LI>
	Changed the default numeric code for optional rounding mode <CODE>odd</CODE>
	(round to odd, also known as <EM>jamming</EM>) from 5 to 6.

	<LI>
	Modified the behavior of rounding mode <CODE>odd</CODE> when rounding to an
	integer value (either conversion to an integer format or a
	‘<CODE>roundToInt</CODE>’ function).
	Previously, for those cases only, rounding mode <CODE>odd</CODE> acted the same
	as rounding to minimum magnitude.
	Now all operations are rounded consistently.

	<LI>
	Fixed some errors in the specialization code modeling Intel x86 floating-point,
	specifically the integers returned on invalid operations and the propagation of
	NaN payloads in a few rare cases.

	<LI>
	Added specialization code modeling ARM floating-point, conforming to VFPv2 or
	later.

	<LI>
	Added an example target for ARM processors.

	<LI>
	Fixed a minor bug whereby function <CODE>f16_to_ui64</CODE> might return a
	different integer than expected in the case that the floating-point operand is
	negative.

	<LI>
	Added example target-specific optimization for GCC, employing GCC instrinsics
	and support for <NOBR>128-bit</NOBR> integer arithmetic.

	<LI>
	Made other minor improvements.

	</UL>


	<H3>Release 3d (2017 August)</H3>

	<UL>

	<LI>
	Fixed bugs in the square root functions for <NOBR>64-bit</NOBR>
	double-precision, <NOBR>80-bit</NOBR> double-extended-precision, and
	<NOBR>128-bit</NOBR> quadruple-precision.
	For <NOBR>64-bit</NOBR> double-precision (<CODE>f64_sqrt</CODE>), the result
	could sometimes be off by <NOBR>1 unit</NOBR> in the last place
	(<NOBR>1 ulp</NOBR>) from what it should be.
	For the larger formats, the square root could be wrong in a large portion of
	the less-significant bits.
	(A bug in <CODE>f128_sqrt</CODE> was first reported by Alexei Sibidanov.)

	</UL>


	<H3>Release 3c (2017 February)</H3>

	<UL>

	<LI>
	Added optional rounding mode <CODE>odd</CODE> (round to odd, also known as
	<EM>jamming</EM>).

	<LI>
	Corrected the documentation concerning non-canonical representations in
	<NOBR>80-bit</NOBR> double-extended-precision.

	</UL>


	<H3>Release 3b (2016 July)</H3>

	<UL>

	<LI>
	Implemented the common <NOBR>16-bit</NOBR> “half-precision”
	floating-point format (<CODE>float16_t</CODE>).

	<LI>
	Made the integer values returned on invalid conversions to integer formats
	be determined by the port-specific specialization instead of being the same for
	all ports.

	<LI>
	Added preprocessor macro <CODE>THREAD_LOCAL</CODE> to allow the floating-point
	state (modes and exception flags) to be made per-thread.

	<LI>
	Modified the provided Makefiles to allow some options to be overridden from the
	<CODE>make</CODE> command.

	<LI>
	Made other minor improvements.

	</UL>


	<H3>Release 3a (2015 October)</H3>

	<UL>

	<LI>
	Replaced the license text supplied by the University of California, Berkeley.

	</UL>


	<H3>Release 3 (2015 February)</H3>

	<UL>

	<LI>
	Complete rewrite, funded by the University of California, Berkeley, and
	consequently having a different use license than earlier releases.
	Major changes included renaming most types and functions, upgrading some
	algorithms, restructuring the source files, and making SoftFloat into a true
	library.

	<LI>
	Added functions to convert between floating-point and unsigned integers, both
	<NOBR>32-bit</NOBR> and <NOBR>64-bit</NOBR> (<CODE>uint32_t</CODE> and
	<CODE>uint64_t</CODE>).

	<LI>
	Added functions for fused multiply-add, for all supported floating-point
	formats except <NOBR>80-bit</NOBR> double-extended-precision.

	<LI>
	Added support for a fifth rounding mode, <CODE>near_maxMag</CODE> (round to
	nearest, with ties to maximum magnitude, away from zero).

	<LI>
	Dropped the <CODE>timesoftfloat</CODE> program (now part of the Berkeley
	TestFloat package).

	</UL>


	<H3>Release 2c (2015 January)</H3>

	<UL>

	<LI>
	Fixed mistakes affecting some <NOBR>64-bit</NOBR> processors.

	<LI>
	Further improved the documentation and the wording for the legal restrictions
	on using SoftFloat releases <NOBR>through 2c</NOBR> (not applicable to
	<NOBR>Release 3</NOBR> or later).

	</UL>


	<H3>Release 2b (2002 May)</H3>

	<UL>

	<LI>
	Made minor updates to the documentation, including improved wording for the
	legal restrictions on using SoftFloat.

	</UL>


	<H3>Release 2a (1998 December)</H3>

	<UL>

	<LI>
	Added functions to convert between <NOBR>64-bit</NOBR> integers
	(<CODE>int64</CODE>) and all supported floating-point formats.

	<LI>
	Fixed a bug in all <NOBR>64-bit</NOBR>-version square root functions except
	<CODE>float32_sqrt</CODE> that caused the result sometimes to be off by
	<NOBR>1 unit</NOBR> in the last place (<NOBR>1 ulp</NOBR>) from what it should
	be.
	(Bug discovered by Paul Donahue.)

	<LI>
	Improved the Makefiles.
	</UL>


	<H3>Release 2 (1997 June)</H3>

	<UL>

	<LI>
	Created the <NOBR>64-bit</NOBR> (<CODE>bits64</CODE>) version, adding the
	<CODE>floatx80</CODE> and <CODE>float128</CODE> formats.

	<LI>
	Changed the source directory structure, splitting the sources into a
	<CODE>bits32</CODE> and a <CODE>bits64</CODE> version.
	Renamed <CODE>environment.h</CODE> to <CODE>milieu.h</CODE> to avoid confusion
	with environment variables.

	<LI>
	Fixed a small error that caused <CODE>float64_round_to_int</CODE> often to
	round the wrong way in nearest/even mode when the operand was between
	2<SUP>20</SUP> and 2<SUP>21</SUP> and halfway between two integers.

	</UL>


	<H3>Release 1a (1996 July)</H3>

	<UL>

	<LI>
	Corrected a mistake that caused borderline underflow cases not to raise the
	underflow flag when they should have.
	(Problem reported by Doug Priest.)

	<LI>
	Added the <CODE>float_detect_tininess</CODE> variable to control whether
	tininess is detected before or after rounding.

	</UL>


	<H3>Release 1 (1996 July)</H3>

	<UL>

	<LI>
	Original release, based on work done for the International Computer Science
	Institute (ICSI) in Berkeley, California.

	</UL>


	</BODY>