<HTML> <HEAD> <TITLE>testsoftfloat</TITLE> </HEAD> <BODY> <H1>Berkeley TestFloat Release 3e: <CODE>testsoftfloat</CODE></H1> <P> John R. Hauser<BR> 2018 January 20<BR> </P> <H2>Overview</H2> <P> The <CODE>testsoftfloat</CODE> program tests that a build of the Berkeley SoftFloat library conforms to the IEEE Standard for Binary Floating-Point Arithmetic as expected. Program <CODE>testsoftfloat</CODE> is part of the Berkeley TestFloat package, a small collection of programs for performing such tests. For general information about TestFloat, as well as for basics about the operation of <CODE>testsoftfloat</CODE> and how to interpret its output, see file <A HREF="TestFloat-general.html"><NOBR><CODE>TestFloat-general.html</CODE></NOBR></A>. </P> <P> Note that, even if there are no bugs in the source code for SoftFloat (not guaranteed), a build of SoftFloat might still fail due to an issue with the build process, such as an incompatible compiler option or a compiler bug. </P> <P> The <CODE>testsoftfloat</CODE> program will ordinarily test a function for all five rounding modes defined by the IEEE Floating-Point Standard, one after the other, plus possibly a sixth mode, <I>round to odd</I> (depending on the options selected when <CODE>testsoftfloat</CODE> was compiled). If an operation is not supposed to require rounding, it will by default be tested 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>testsoftfloat</CODE> tests 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>testsoftfloat</CODE> also tests the function for all three rounding precision modes, one after the other. Testing can be limited to a single rounding mode, a single tininess mode, and/or a single rounding precision with appropriate command-line options. </P> <H2>Command Syntax</H2> <P> The <CODE>testsoftfloat</CODE> program is executed as a command with this syntax: <BLOCKQUOTE> <PRE> testsoftfloat [<<I>option</I>>...] <<I>function</I>> </PRE> </BLOCKQUOTE> Square brackets (<CODE>[ ]</CODE>) denote optional arguments, <CODE><<I>option</I>></CODE> is a supported option, and <CODE><<I>function</I>></CODE> is the name of either a testable function or a function set. The available options and function sets are documented below. If <CODE>testsoftfloat</CODE> is executed without any arguments, a summary of usage is written. </P> <H2>Options</H2> <P> The <CODE>testsoftfloat</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>-seed <<I>num</I>></CODE></H3> <P> The <CODE>-seed</CODE> option sets the seed for the pseudo-random number generator used for generating test cases. The argument to <CODE>-seed</CODE> is a nonnegative integer. Executing the same <CODE>testsoftfloat</CODE> program with the same arguments (including the same pseudo-random number seed) should always perform the same sequence of tests, whereas changing the pseudo-random number seed should result in a different sequence of tests. The default seed number <NOBR>is 1</NOBR>. </P> <H3><CODE>-level <<I>num</I>></CODE></H3> <P> The <CODE>-level</CODE> option sets the level of testing. The argument to <CODE>-level</CODE> can be either 1 <NOBR>or 2</NOBR>. The default is <NOBR>level 1</NOBR>. Level 2 performs many more tests than <NOBR>level 1</NOBR> and thus can reveal bugs not found by <NOBR>level 1</NOBR>. </P> <H3><CODE>-errors <<I>num</I>></CODE></H3> <P> The <CODE>-errors</CODE> option instructs <CODE>testsoftfloat</CODE> to report no more than the specified number of errors for any combination of function, rounding mode, etc. The argument to <CODE>-errors</CODE> must be a nonnegative decimal integer. Once the specified number of error reports has been generated, <CODE>testsoftfloat</CODE> ends the current test and begins the next one, if any. The default is <NOBR><CODE>-errors</CODE> <CODE>20</CODE></NOBR>. </P> <P> Against intuition, <NOBR><CODE>-errors</CODE> <CODE>0</CODE></NOBR> causes <CODE>testsoftfloat</CODE> to report every error it finds. </P> <H3><CODE>-errorstop</CODE></H3> <P> The <CODE>-errorstop</CODE> option causes the program to exit after the first function for which any errors are reported. </P> <H3><CODE>-forever</CODE></H3> <P> The <CODE>-forever</CODE> option causes a single function to be repeatedly tested. Only one rounding mode and/or rounding precision can be tested in a single execution. If not specified, the rounding mode defaults to nearest/even. For <NOBR>80-bit</NOBR> double-extended-precision functions, the rounding precision defaults to full double-extended precision. The testing level is set to 2 by this option. </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 testing to only the cases in which the rounding precision is <NOBR>32 bits</NOBR>, equivalent to <NOBR>32-bit</NOBR> single-precision. The other rounding precision choices are not tested. 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, -rodd</CODE></H3> <P> The <CODE>-rnear_even</CODE> option restricts testing to only the cases in which the rounding mode is nearest/even. The other rounding mode choices are not tested. 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), <CODE>-rmax</CODE> forces rounding to maximum (up, toward positive infinity), and <CODE>-rodd</CODE>, if supported, forces rounding to odd. 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 testing to only the cases in which tininess on underflow is detected before rounding. Likewise, <CODE>-tininessafter</CODE> restricts testing 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 testing 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 testing 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>testsoftfloat</CODE> can test a function for all five or six rounding modes in sequence, multiple functions can be tested with a single execution of <CODE>testsoftfloat</CODE>. Two sets are recognized: <CODE>-all1</CODE> and <CODE>-all2</CODE>. The set <CODE>-all1</CODE> is all one-operand operations, while <CODE>-all2</CODE> is all two-operand operations. A function set is used in place of a function name in the <CODE>testsoftfloat</CODE> command line, such as <BLOCKQUOTE> <PRE> testsoftfloat [<<I>option</I>>...] -all1 </PRE> </BLOCKQUOTE> </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 tested by <CODE>-all1</CODE>. </P> </BODY>