doc/timesoftfloat.html - berkeley-testfloat-3 - Git at Google


 <HTML>

 <HEAD>
 <TITLE>timesoftfloat</TITLE>
 </HEAD>

 <BODY>

 <H1>Berkeley TestFloat Release 3: <CODE>timesoftfloat</CODE></H1>

 <P>
 John R. Hauser<BR>
 2014 ______<BR>
 </P>

 <P>
 *** CONTENT DONE.
 </P>

 <P>
 *** REPLACE QUOTATION MARKS.
 <BR>
 *** REPLACE APOSTROPHES.
 <BR>
 *** REPLACE EM DASH.
 </P>


 <H2>Overview</H2>

 <P>
 The <CODE>timesoftfloat</CODE> program provides a simple way to evaluate the
 speed of the floating-point operations of the Berkeley SoftFloat library.
 Program <CODE>timesoftfloat</CODE> is included with the Berkeley TestFloat
 package, a small collection of programs for testing that an implementation of
 floating-point conforms to the IEEE Standard for Binary Floating-Point
 Arithmetic.
 Although <CODE>timesoftfloat</CODE> does not test floating-point correctness
 like other TestFloat programs, nevertheless <CODE>timesoftfloat</CODE> is a
 partner to TestFloat's <CODE>testsoftfloat</CODE> program.
 For more about TestFloat generally and <CODE>testsoftfloat</CODE> specifically,
 see file
 <A HREF="TestFloat-general.html"><NOBR><CODE>TestFloat-general.html</CODE></NOBR></A>.
 </P>

 <P>
 Ordinarily, <CODE>timesoftfloat</CODE> will measure a function's speed
 separately for each rounding mode defined by the IEEE Floating-Point Standard,
 one after the other.
 If an operation is not supposed to require rounding, it will by default be
 timed only with the rounding mode set to <CODE>near_even</CODE> (nearest/even).
 In the same way, if an operation is affected by the way in which underflow
 tininess is detected, <CODE>timesoftfloat</CODE> times the function with
 tininess detected both before rounding and after rounding.
 For <NOBR>80-bit</NOBR> double-extended-precision operations affected by
 rounding precision control, <CODE>timesoftfloat</CODE> also times the function
 for each of the three rounding precision modes, one after the other.
 Evaluation of a function can be limited to a single rounding mode, a single
 tininess mode, and/or a single rounding precision with appropriate command-line
 options.
 </P>

 <P>
 For each function and mode evaluated, <CODE>timesoftfloat</CODE> reports the
 measured speed of the function in Mops/s, or ``millions of operations per
 second''.
 The speeds reported by <CODE>timesoftfloat</CODE> may be affected somewhat by
 other software executing at the same time as <CODE>timesoftfloat</CODE>.
 Be aware also that the exact execution time of any SoftFloat function depends
 partly on the values of arguments and the state of the processor's caches at
 the time the function is called.
 Your actual experience with SoftFloat may differ from the speeds reported by
 <CODE>timesoftfloat</CODE> for all these reasons.
 </P>

 <P>
 Note that the remainder operations (<CODE>f32_rem</CODE>, <CODE>f64_rem</CODE>,
 <CODE>extF80_rem</CODE>, and <CODE>f128_rem</CODE>) will be markedly slower
 than other operations, particularly for double-extended-precision
 (<CODE>extF80_rem</CODE>) and quadruple precision (<CODE>f128_rem</CODE>).
 This is inherent to the remainder operation itself and is not a failing of the
 SoftFloat implementation.
 </P>


 <H2>Command Syntax</H2>

 <P>
 The <CODE>timesoftfloat</CODE> program is executed as a command with this
 syntax:
 <PRE>
      timesoftfloat [&lt;option&gt;...] &lt;function&gt;
 </PRE>
 Square brackets (<CODE>[ ]</CODE>) denote optional arguments,
 <CODE>&lt;option&gt;</CODE> is a supported option, and
 <CODE>&lt;function&gt;</CODE> is the name of either a testable function or a
 function set.
 The available options and function sets are documented below.
 If <CODE>timesoftfloat</CODE> is executed without any arguments, a summary of
 usage is written.
 </P>


 <H2>Options</H2>

 <P>
 The <CODE>timesoftfloat</CODE> program accepts several command options.
 If mutually contradictory options are given, the last one has priority.
 </P>

 <H3><CODE>-help</CODE></H3>

 <P>
 The <CODE>-help</CODE> option causes a summary of program usage to be written,
 after which the program exits.
 </P>

 <H3><CODE>-precision32, -precision64, -precision80</CODE></H3>

 <P>
 For <NOBR>80-bit</NOBR> double-extended-precision funcions affected by
 rounding precision control, the <CODE>-precision32</CODE> option restricts
 timing of an operation to only the cases in which the rounding precision is
 <NOBR>32 bits</NOBR>, equivalent to <NOBR>32-bit</NOBR> single-precision.
 Other rounding precision choices are not timed.
 Likewise, <CODE>-precision64</CODE> fixes the rounding precision to
 <NOBR>64 bits</NOBR>, equivalent to <NOBR>64-bit</NOBR> double-precision;
 and <CODE>-precision80</CODE> fixes the rounding precision to the full
 <NOBR>80 bits</NOBR> of the double-extended-precision format.
 All these options are ignored for operations not affected by rounding precision
 control.
 </P>

 <H3><CODE>-rnear_even, -rnear_maxMag, -rminMag, -rmin, -rmax</CODE></H3>

 <P>
 The <CODE>-rnear_even</CODE> option restricts timing of an operation to only
 the cases in which the rounding mode is nearest/even.
 Other rounding mode choices are not timed.
 Likewise, <CODE>-rnear_maxMag</CODE> forces rounding to nearest/maximum
 magnitude (nearest-away), <CODE>-rminMag</CODE> forces rounding to minimum
 magnitude (toward zero), <CODE>-rmin</CODE> forces rounding to minimum (down,
 toward negative infinity), and <CODE>-rmax</CODE> forces rounding to maximum
 (up, toward positive infinity).
 These options are ignored for operations that are exact and thus do not round.
 </P>

 <H3><CODE>-tininessbefore, -tininessafter</CODE></H3>

 <P>
 The <CODE>-tininessbefore</CODE> option restricts timing of an operation to
 only the cases in which tininess on underflow is detected before rounding.
 Likewise, <CODE>-tininessafter</CODE> restricts measurement to only the cases
 in which tininess on underflow is detected after rounding.
 </P>

 <H3><CODE>-notexact, -exact</CODE></H3>

 <P>
 For functions that round to an integer (conversions to integer types and the
 <CODE>roundToInt</CODE> functions), the <CODE>-notexact</CODE> option restricts
 timing of an operation to only the cases for which the
 <CODE><I>exact</I></CODE> operand (specifying whether the <I>inexact</I>
 exception flag may be raised) is <CODE>false</CODE>.
 Likewise, the <CODE>-exact</CODE> option restricts measurement to only the
 cases for which the <CODE><I>exact</I></CODE> operand is <CODE>true</CODE>.
 </P>


 <H2>Function Sets</H2>

 <P>
 Just as <CODE>timesoftfloat</CODE> can time a function for all five rounding
 modes in sequence, multiple functions can be timed with a single execution of
 <CODE>timesoftfloat</CODE>.
 Three sets are recognized:
 <CODE>-all1</CODE>, <CODE>-all2</CODE>, and <CODE>-all</CODE>.
 The set <CODE>-all1</CODE> comprises all one-operand operations,
 <CODE>-all2</CODE> is all two-operand operations, and <CODE>-all</CODE> is
 obviously all operations.
 A function set is used in place of a function name in the
 <CODE>timesoftfloat</CODE> command line, such as
 <PRE>
      timesoftfloat [&lt;option&gt;...] -all1
 </PRE>
 </P>

 <P>
 For the purpose of deciding the number of operands of an operation, any
 <CODE><I>roundingMode</I></CODE> and <CODE><I>exact</I></CODE> arguments are
 ignored.
 (Such arguments specify the rounding mode and whether the <I>inexact</I>
 exception flag may be raised, respectively.)
 Thus, functions that convert to integer type and the <CODE>roundToInt</CODE>
 functions are included in the set of one-operand operations timed by
 <CODE>-all1</CODE>.
 </P>


 </BODY>

	<HTML>

	<HEAD>
	<TITLE>timesoftfloat</TITLE>
	</HEAD>

	<BODY>

	<H1>Berkeley TestFloat Release 3: <CODE>timesoftfloat</CODE></H1>

	<P>
	John R. Hauser<BR>
	2014 ______<BR>
	</P>

	<P>
	*** CONTENT DONE.
	</P>

	<P>
	*** REPLACE QUOTATION MARKS.
	<BR>
	*** REPLACE APOSTROPHES.
	<BR>
	*** REPLACE EM DASH.
	</P>


	<H2>Overview</H2>

	<P>
	The <CODE>timesoftfloat</CODE> program provides a simple way to evaluate the
	speed of the floating-point operations of the Berkeley SoftFloat library.
	Program <CODE>timesoftfloat</CODE> is included with the Berkeley TestFloat
	package, a small collection of programs for testing that an implementation of
	floating-point conforms to the IEEE Standard for Binary Floating-Point
	Arithmetic.
	Although <CODE>timesoftfloat</CODE> does not test floating-point correctness
	like other TestFloat programs, nevertheless <CODE>timesoftfloat</CODE> is a
	partner to TestFloat's <CODE>testsoftfloat</CODE> program.
	For more about TestFloat generally and <CODE>testsoftfloat</CODE> specifically,
	see file
	<A HREF="TestFloat-general.html"><NOBR><CODE>TestFloat-general.html</CODE></NOBR></A>.
	</P>

	<P>
	Ordinarily, <CODE>timesoftfloat</CODE> will measure a function's speed
	separately for each rounding mode defined by the IEEE Floating-Point Standard,
	one after the other.
	If an operation is not supposed to require rounding, it will by default be
	timed only with the rounding mode set to <CODE>near_even</CODE> (nearest/even).
	In the same way, if an operation is affected by the way in which underflow
	tininess is detected, <CODE>timesoftfloat</CODE> times the function with
	tininess detected both before rounding and after rounding.
	For <NOBR>80-bit</NOBR> double-extended-precision operations affected by
	rounding precision control, <CODE>timesoftfloat</CODE> also times the function
	for each of the three rounding precision modes, one after the other.
	Evaluation of a function can be limited to a single rounding mode, a single
	tininess mode, and/or a single rounding precision with appropriate command-line
	options.
	</P>

	<P>
	For each function and mode evaluated, <CODE>timesoftfloat</CODE> reports the
	measured speed of the function in Mops/s, or ``millions of operations per
	second''.
	The speeds reported by <CODE>timesoftfloat</CODE> may be affected somewhat by
	other software executing at the same time as <CODE>timesoftfloat</CODE>.
	Be aware also that the exact execution time of any SoftFloat function depends
	partly on the values of arguments and the state of the processor's caches at
	the time the function is called.
	Your actual experience with SoftFloat may differ from the speeds reported by
	<CODE>timesoftfloat</CODE> for all these reasons.
	</P>

	<P>
	Note that the remainder operations (<CODE>f32_rem</CODE>, <CODE>f64_rem</CODE>,
	<CODE>extF80_rem</CODE>, and <CODE>f128_rem</CODE>) will be markedly slower
	than other operations, particularly for double-extended-precision
	(<CODE>extF80_rem</CODE>) and quadruple precision (<CODE>f128_rem</CODE>).
	This is inherent to the remainder operation itself and is not a failing of the
	SoftFloat implementation.
	</P>


	<H2>Command Syntax</H2>

	<P>
	The <CODE>timesoftfloat</CODE> program is executed as a command with this
	syntax:
	<PRE>
	timesoftfloat [<option>...] <function>
	</PRE>
	Square brackets (<CODE>[ ]</CODE>) denote optional arguments,
	<CODE><option></CODE> is a supported option, and
	<CODE><function></CODE> is the name of either a testable function or a
	function set.
	The available options and function sets are documented below.
	If <CODE>timesoftfloat</CODE> is executed without any arguments, a summary of
	usage is written.
	</P>


	<H2>Options</H2>

	<P>
	The <CODE>timesoftfloat</CODE> program accepts several command options.
	If mutually contradictory options are given, the last one has priority.
	</P>

	<H3><CODE>-help</CODE></H3>

	<P>
	The <CODE>-help</CODE> option causes a summary of program usage to be written,
	after which the program exits.
	</P>

	<H3><CODE>-precision32, -precision64, -precision80</CODE></H3>

	<P>
	For <NOBR>80-bit</NOBR> double-extended-precision funcions affected by
	rounding precision control, the <CODE>-precision32</CODE> option restricts
	timing of an operation to only the cases in which the rounding precision is
	<NOBR>32 bits</NOBR>, equivalent to <NOBR>32-bit</NOBR> single-precision.
	Other rounding precision choices are not timed.
	Likewise, <CODE>-precision64</CODE> fixes the rounding precision to
	<NOBR>64 bits</NOBR>, equivalent to <NOBR>64-bit</NOBR> double-precision;
	and <CODE>-precision80</CODE> fixes the rounding precision to the full
	<NOBR>80 bits</NOBR> of the double-extended-precision format.
	All these options are ignored for operations not affected by rounding precision
	control.
	</P>

	<H3><CODE>-rnear_even, -rnear_maxMag, -rminMag, -rmin, -rmax</CODE></H3>

	<P>
	The <CODE>-rnear_even</CODE> option restricts timing of an operation to only
	the cases in which the rounding mode is nearest/even.
	Other rounding mode choices are not timed.
	Likewise, <CODE>-rnear_maxMag</CODE> forces rounding to nearest/maximum
	magnitude (nearest-away), <CODE>-rminMag</CODE> forces rounding to minimum
	magnitude (toward zero), <CODE>-rmin</CODE> forces rounding to minimum (down,
	toward negative infinity), and <CODE>-rmax</CODE> forces rounding to maximum
	(up, toward positive infinity).
	These options are ignored for operations that are exact and thus do not round.
	</P>

	<H3><CODE>-tininessbefore, -tininessafter</CODE></H3>

	<P>
	The <CODE>-tininessbefore</CODE> option restricts timing of an operation to
	only the cases in which tininess on underflow is detected before rounding.
	Likewise, <CODE>-tininessafter</CODE> restricts measurement to only the cases
	in which tininess on underflow is detected after rounding.
	</P>

	<H3><CODE>-notexact, -exact</CODE></H3>

	<P>
	For functions that round to an integer (conversions to integer types and the
	<CODE>roundToInt</CODE> functions), the <CODE>-notexact</CODE> option restricts
	timing of an operation to only the cases for which the
	<CODE><I>exact</I></CODE> operand (specifying whether the <I>inexact</I>
	exception flag may be raised) is <CODE>false</CODE>.
	Likewise, the <CODE>-exact</CODE> option restricts measurement to only the
	cases for which the <CODE><I>exact</I></CODE> operand is <CODE>true</CODE>.
	</P>


	<H2>Function Sets</H2>

	<P>
	Just as <CODE>timesoftfloat</CODE> can time a function for all five rounding
	modes in sequence, multiple functions can be timed with a single execution of
	<CODE>timesoftfloat</CODE>.
	Three sets are recognized:
	<CODE>-all1</CODE>, <CODE>-all2</CODE>, and <CODE>-all</CODE>.
	The set <CODE>-all1</CODE> comprises all one-operand operations,
	<CODE>-all2</CODE> is all two-operand operations, and <CODE>-all</CODE> is
	obviously all operations.
	A function set is used in place of a function name in the
	<CODE>timesoftfloat</CODE> command line, such as
	<PRE>
	timesoftfloat [<option>...] -all1
	</PRE>
	</P>

	<P>
	For the purpose of deciding the number of operands of an operation, any
	<CODE><I>roundingMode</I></CODE> and <CODE><I>exact</I></CODE> arguments are
	ignored.
	(Such arguments specify the rounding mode and whether the <I>inexact</I>
	exception flag may be raised, respectively.)
	Thus, functions that convert to integer type and the <CODE>roundToInt</CODE>
	functions are included in the set of one-operand operations timed by
	<CODE>-all1</CODE>.
	</P>


	</BODY>