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| <H1>Berkeley TestFloat Release 3: <CODE>testfloat_ver</CODE></H1> |
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| <P> |
| John R. Hauser<BR> |
| 2015 February 16<BR> |
| </P> |
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| <H2>Overview</H2> |
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| <P> |
| The <CODE>testfloat_ver</CODE> program takes test-case results obtained from |
| exercising an implementation of floating-point arithmetic and verifies that |
| those results conform to the IEEE Standard for Binary Floating-Point |
| Arithmetic. |
| <CODE>testfloat_ver</CODE> is part of the Berkeley TestFloat package, a small |
| collection of programs for performing such tests. |
| For general information about TestFloat, see file |
| <A HREF="TestFloat-general.html"><NOBR><CODE>TestFloat-general.html</CODE></NOBR></A>. |
| </P> |
| |
| <P> |
| A single execution of <CODE>testfloat_ver</CODE> verifies results for only a |
| single floating-point operation and associated options. |
| The <CODE>testfloat_ver</CODE> program must be repeatedly executed to verify |
| results for each operation to be tested. |
| </P> |
| |
| <P> |
| The test cases to be verified are read by <CODE>testfloat_ver</CODE> from |
| standard input. |
| This input will typically be piped from another program that, for each test |
| case, invokes the floating-point operation and writes out the results. |
| The format of <CODE>testfloat_ver</CODE>’s input is raw hexadecimal text, |
| described in the section below titled <I>Input Format</I>. |
| </P> |
| |
| <P> |
| For each test case given to it, <CODE>testfloat_ver</CODE> examines the |
| computed results and reports any unexpected results as likely errors. |
| |
| For more about the operation of <CODE>testfloat_ver</CODE> and how to interpret |
| its output, refer to |
| <A HREF="TestFloat-general.html"><NOBR><CODE>TestFloat-general.html</CODE></NOBR></A>. |
| </P> |
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| |
| <H2>Command Syntax</H2> |
| |
| <P> |
| The <CODE>testfloat_ver</CODE> program is executed as a command with this |
| syntax: |
| <BLOCKQUOTE> |
| <PRE> |
| testfloat_ver [<option>...] <function> |
| </PRE> |
| </BLOCKQUOTE> |
| Square brackets (<CODE>[ ]</CODE>) denote optional arguments, |
| <CODE><option></CODE> is a supported option, and |
| <CODE><function></CODE> is the name of a testable operation. |
| The available options are documented below. |
| The testable operation names are listed in |
| <A HREF="TestFloat-general.html"><NOBR><CODE>TestFloat-general.html</CODE></NOBR></A>. |
| If <CODE>testfloat_ver</CODE> is executed without any arguments, a summary of |
| usage is written. |
| </P> |
| |
| |
| <H2>Options</H2> |
| |
| <P> |
| The <CODE>testfloat_ver</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>-errors <num></CODE></H3> |
| |
| <P> |
| The <CODE>-errors</CODE> option instructs <CODE>testfloat_ver</CODE> to report |
| no more than the specified number of errors. |
| The argument to <CODE>-errors</CODE> must be a nonnegative decimal integer. |
| Once the specified number of error reports has been generated, the program |
| exits. |
| 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>testfloat_ver</CODE> to continue for any number of errors. |
| </P> |
| |
| <H3><CODE>-checkNaNs</CODE></H3> |
| |
| <P> |
| The <CODE>-checkNaNs</CODE> option causes <CODE>testfloat_ver</CODE> to verify |
| the bitwise correctness of NaN results. |
| In order for this option to be sensible, <CODE>testfloat_ver</CODE> must have |
| been compiled so that its internal reference implementation of floating-point |
| (SoftFloat) generates the proper NaN results for the system being tested. |
| </P> |
| |
| <H3><CODE>-precision32, -precision64, -precision80</CODE></H3> |
| |
| <P> |
| When <CODE><function></CODE> is an <NOBR>80-bit</NOBR> |
| double-extended-precision operation affected by rounding precision control, the |
| <CODE>-precision32</CODE> option indicates that the rounding precision should |
| be <NOBR>32 bits</NOBR>, equivalent to <NOBR>32-bit</NOBR> single-precision. |
| Likewise, <CODE>-precision64</CODE> indicates that the rounding precision |
| should be <NOBR>64 bits</NOBR>, equivalent to <NOBR>64-bit</NOBR> |
| double-precision, and <CODE>-precision80</CODE> indicates that the rounding |
| precision should be 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. |
| When rounding precision is applicable but not specified, the default assumption |
| is the full <NOBR>80 bits</NOBR>, same as <CODE>-precision80</CODE>. |
| </P> |
| |
| <H3><CODE>-rnear_even, -rnear_maxMag, -rminMag, -rmin, -rmax</CODE></H3> |
| |
| <P> |
| When <CODE><function></CODE> is an operation that requires rounding, the |
| <CODE>-rnear_even</CODE> option indicates that rounding should be to |
| nearest/even, <CODE>-rnear_maxMag</CODE> indicates rounding to nearest/maximum |
| magnitude (nearest-away), <CODE>-rminMag</CODE> indicates rounding to minimum |
| magnitude (toward zero), <CODE>-rmin</CODE> indicates rounding to minimum |
| (down, toward negative infinity), and <CODE>-rmax</CODE> indicates rounding to |
| maximum (up, toward positive infinity). |
| These options are ignored for operations that are exact and thus do not round. |
| When rounding mode is relevant but not specified, the default assumption is |
| rounding to nearest/even, same as <CODE>-rnear_even</CODE>. |
| </P> |
| |
| <H3><CODE>-tininessbefore, -tininessafter</CODE></H3> |
| |
| <P> |
| When <CODE><function></CODE> is an operation that requires rounding, the |
| <CODE>-tininessbefore</CODE> option indicates that tininess on underflow should |
| be detected before rounding, while <CODE>-tininessafter</CODE> indicates that |
| tininess on underflow should be detected after rounding. |
| These options are ignored for operations that are exact and thus do not round. |
| When the method of tininess detection matters but is not specified, the default |
| assumption is that tininess should be detected before rounding, same as |
| <CODE>-tininessbefore</CODE>. |
| </P> |
| |
| <H3><CODE>-notexact, -exact</CODE></H3> |
| |
| <P> |
| When <CODE><function></CODE> is an operation that rounds to an integer |
| (either conversion to an integer type or a <CODE>roundToInt</CODE> operation), |
| the <CODE>-notexact</CODE> option indicates that the <I>inexact</I> exception |
| flag should never be raised, while <CODE>-exact</CODE> indicates that the |
| <I>inexact</I> exception flag should be raised when the result is inexact. |
| For other operations, these options are ignored. |
| If neither option is specified, the default assumption is that the |
| <I>inexact</I> exception flag should not be raised when rounding to an integer, |
| same as <CODE>-notexact</CODE>. |
| </P> |
| |
| |
| <H2>Input Format</H2> |
| |
| <P> |
| For a given <CODE><function></CODE> argument, the input format expected |
| by <CODE>testfloat_ver</CODE> is the same as the output generated by program |
| <A HREF="testfloat_gen.html"><NOBR><CODE>testfloat_gen</CODE></NOBR></A> for |
| the same argument. |
| </P> |
| |
| <P> |
| Input to <CODE>testfloat_ver</CODE> is expected to be text, with each line |
| containing the data for one test case. |
| The number of input lines thus equals the number of test cases. |
| A single test case is organized as follows: first are the operands for the |
| operation, next is the result value obtained, and last is a number indicating |
| the exception flags that were raised. |
| These values are all expected to be provided as raw hexadecimal numbers |
| separated on the line by spaces. |
| For example, for the command |
| <BLOCKQUOTE> |
| <PRE> |
| testfloat_ver f64_add |
| </PRE> |
| </BLOCKQUOTE> |
| valid input could include these lines: |
| <BLOCKQUOTE> |
| <PRE> |
| 3F90EB5825D6851E C3E0080080000000 C3E0080080000000 01 |
| 41E3C00000000000 C182024F8AE474A8 41E377F6C1D46E2D 01 |
| 7FD80FFFFFFFFFFF 7FEFFFFFFFFFFF80 7FF0000000000000 05 |
| 3FFFED6A25C534BE 3CA1000000020000 3FFFED6A25C534BF 01 |
| ... |
| </PRE> |
| </BLOCKQUOTE> |
| On each line above, the first two hexadecimal numbers represent the |
| <NOBR>64-bit</NOBR> floating-point operands, the third hexadecimal number is |
| the <NOBR>64-bit</NOBR> floating-point result of the operation (the sum), and |
| the last hexadecimal number gives the exception flags that were raised by the |
| operation. |
| </P> |
| |
| <P> |
| Note that, for floating-point values, the sign and exponent are at the |
| most-significant end of the number. |
| Thus, for the first number on the first line above, the leading hexadecimal |
| digits <CODE>3F9</CODE> are the sign and encoded exponent of the |
| <NOBR>64-bit</NOBR> floating-point value, and the remaining digits are the |
| encoded significand. |
| </P> |
| |
| <P> |
| Exception flags are encoded with one bit per flag as follows: |
| <BLOCKQUOTE> |
| <TABLE CELLSPACING=0 CELLPADDING=0> |
| <TR> |
| <TD>bit 0<CODE> </CODE></TD> |
| <TD><I>inexact</I> exception</TD> |
| </TR> |
| <TR><TD>bit 1</TD><TD><I>underflow</I> exception</TD></TR> |
| <TR><TD>bit 2</TD><TD><I>overflow</I> exception</TD></TR> |
| <TR> |
| <TD>bit 3</TD> |
| <TD><I>infinite</I> exception (“divide by zero”)</TD> |
| </TR> |
| <TR><TD>bit 4</TD><TD><I>invalid</I> exception</TD></TR> |
| </TABLE> |
| </BLOCKQUOTE> |
| </P> |
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