From 16f504a9dca3fe3b70568f67b7d41241ae485288 Mon Sep 17 00:00:00 2001
From: Daniel Baumann
+John R. Hauser
+The
+The
+The default build of
+The
+For more about the operation of
+The Berkeley TestFloat Release 3e:
+
+testfloat
+2018 January 20
+Overview
+
+testfloat
program tests an implementation of floating-point
+arithmetic for conformity to the IEEE Standard for Binary Floating-Point
+Arithmetic.
+testfloat
is part of the Berkeley TestFloat package, a small
+collection of programs for performing such tests.
+For general information about TestFloat, see file
+TestFloat-general.html
testfloat
program is an all-in-one tool for testing
+floating-point arithmetic.
+It generates test operand values, invokes a floating-point operation with the
+generated operands, and examines the corresponding computed results, reporting
+unexpected results as likely errors.
+While the processes of generating inputs and examining results are generic, a
+particular build of testfloat
is limited to testing only the one
+implementation of floating-point it has been compiled to invoke.
+For example, while one instance of testfloat
might be compiled to
+execute a computer’s hardware instruction for floating-point addition, a
+different version might be compiled to call a subroutine called
+myAddFloat
that is linked into the testfloat
program.
+To test a new implementation of floating-point (a new set of machine
+instructions or a new set of subroutines), a new testfloat
must be
+compiled containing the code needed to invoke the new floating-point.
+testfloat
assumes that C types
+float
and double
are +
, -
,
+*
, /
, type conversions, etc.
+This tests the floating-point arithmetic seen by C programs.
+Depending on the compiler and the options selected during compilation, this may
+or may not be the same as the computer’s floating-point hardware, if any.
+testfloat
program will ordinarily test an operation for all
+five rounding modes defined by the IEEE Floating-Point Standard, one after the
+other, plus possibly a sixth mode, round to odd (depending on the
+options selected when testfloat
was compiled).
+If the rounding mode is not supposed to have any affect on the
+results—for instance, some operations do not require rounding—only
+the nearest/even rounding mode is checked.
+For double-extended-precision operations affected by rounding precision
+control, testfloat
also tests all three rounding precision modes,
+one after the other.
+Testing can be limited to a single rounding mode and/or rounding precision with
+appropriate command-line options.
+testfloat
and how to interpret its
+output, refer to
+TestFloat-general.html
Command Syntax
+
+testfloat
program is executed as a command with this syntax:
+
+
+Square brackets (
+testfloat [<option>...] <function>
+
+[ ]
) denote optional arguments,
+<option>
is a supported option, and
+<function>
is the name of either a testable operation
+or a function set.
+The available options and function sets are documented below.
+The -list
option can be used to obtain a list of all testable
+operations for a given build of testfloat
.
+If testfloat
is executed without any arguments, a summary of usage
+is written.
+
+The testfloat
program accepts several command options.
+If mutually contradictory options are given, the last one has priority.
+
-help
+The -help
option causes a summary of program usage to be written,
+after which the program exits.
+
-list
+The -list
option causes a list of testable operations to be
+written, after which the program exits.
+An operation is testable by testfloat
if the program knows some
+way to invoke the operation.
+
-seed <num>
+The -seed
option sets the seed for the pseudo-random number
+generator used for generating test cases.
+The argument to -seed
is a nonnegative integer.
+Executing the same compiled testfloat
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
-level <num>
+The -level
option sets the level of testing.
+The argument to -level
can be either 1
-errors <num>
+The -errors
option instructs testfloat
to report no
+more than the specified number of errors for any combination of operation,
+rounding mode, etc.
+The argument to -errors
must be a nonnegative decimal integer.
+Once the specified number of error reports has been generated,
+testfloat
ends the current test and begins the next one, if any.
+The default is -errors
20
+Against intuition, -errors
0
testfloat
to report every error it finds.
+
-errorstop
+The -errorstop
option causes the program to exit after the first
+operation for which any errors are reported.
+
-forever
+The -forever
option causes a single operation 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
-checkNaNs
+The -checkNaNs
option causes testfloat
to verify the
+bitwise correctness of NaN results.
+In order for this option to be sensible, testfloat
must have been
+compiled so that its internal reference implementation of floating-point
+(Berkeley SoftFloat) generates the proper NaN results for the system being
+tested.
+
-checkInvInts
+The -checkInvInts
option causes testfloat
to verify
+the bitwise correctness of integer results of invalid operations.
+In order for this option to be sensible, testfloat
must have been
+compiled so that its internal reference implementation of floating-point
+(Berkeley SoftFloat) generates the proper integer results for the system being
+tested.
+
-checkAll
+Enables both -checkNaNs
and -checkInvInts
.
+
-precision32, -precision64, -precision80
+For -precision32
option restricts
+testing to only the cases in which the rounding precision is
+-precision64
fixes the rounding precision to
+-precision80
fixes the rounding precision to the full
+
+The precision-control options may not be supported at all if no +double-extended-precision operations are testable. +
+ +-rnear_even, -rnear_maxMag, -rminMag, -rmin, -rmax, -rodd
+The -rnear_even
option restricts testing to only the cases in
+which the rounding mode is nearest/even.
+The other rounding mode choices are not tested.
+Likewise, -rnear_maxMag
forces rounding to nearest/maximum
+magnitude (nearest-away), -rminMag
forces rounding to minimum
+magnitude (toward zero), -rmin
forces rounding to minimum (down,
+toward negative infinity), -rmax
forces rounding to maximum (up,
+toward positive infinity), and -rodd
, if supported, forces
+rounding to odd.
+These options are ignored for operations that are exact and thus do not round,
+or that have the rounding mode included in the function name (such as
+f32_to_i32_r_near_maxMag
).
+
-tininessbefore, -tininessafter
+The -tininessbefore
option indicates that the floating-point
+implementation being tested detects tininess on underflow before rounding.
+The -tininessafter
option indicates that tininess is detected
+after rounding.
+The testfloat
program alters its expectations accordingly.
+These options override the default selected when testfloat
was
+compiled.
+Choosing the wrong one of these two options should cause error reports for some
+(but not all) operations.
+
+Just as testfloat
can test an operation for all five or six
+rounding modes in sequence, multiple operations can be tested with a single
+execution of testfloat
.
+Two sets are recognized: -all1
and -all2
.
+The set -all1
is all one-operand operations, while
+-all2
is all two-operand operations.
+A function set is used in place of an operation name in the
+testfloat
command line, such as
+
++ + + + + -- cgit v1.2.3+testfloat [<option>...] -all1 ++