15144b0f96
It should become useless when gcc 3.4 will be imported, as libgcc from gcc 3.4 contains this bits for arm.
151 lines
6.3 KiB
Plaintext
151 lines
6.3 KiB
Plaintext
$NetBSD: timesoftfloat.txt,v 1.1 2000/06/06 08:15:11 bjh21 Exp $
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$FreeBSD$
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Documentation for the `timesoftfloat' Program of SoftFloat Release 2a
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John R. Hauser
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1998 December 14
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-------------------------------------------------------------------------------
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Introduction
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The `timesoftfloat' program evaluates the speed of SoftFloat's floating-
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point routines. Each routine can be evaluated for every relevant rounding
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mode, tininess mode, and/or rounding precision.
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-------------------------------------------------------------------------------
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Contents
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Introduction
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Contents
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Legal Notice
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Executing `timesoftfloat'
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Options
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-help
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-precision32, -precision64, -precision80
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-nearesteven, -tozero, -down, -up
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-tininessbefore, -tininessafter
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Function Sets
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-------------------------------------------------------------------------------
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Legal Notice
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The `timesoftfloat' program was written by John R. Hauser.
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THIS SOFTWARE IS DISTRIBUTED AS IS, FOR FREE. Although reasonable effort
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has been made to avoid it, THIS SOFTWARE MAY CONTAIN FAULTS THAT WILL AT
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TIMES RESULT IN INCORRECT BEHAVIOR. USE OF THIS SOFTWARE IS RESTRICTED TO
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PERSONS AND ORGANIZATIONS WHO CAN AND WILL TAKE FULL RESPONSIBILITY FOR ANY
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AND ALL LOSSES, COSTS, OR OTHER PROBLEMS ARISING FROM ITS USE.
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-------------------------------------------------------------------------------
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Executing `timesoftfloat'
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The `timesoftfloat' program is intended to be invoked from a command line
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interpreter as follows:
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timesoftfloat [<option>...] <function>
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Here square brackets ([]) indicate optional items, while angled brackets
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(<>) denote parameters to be filled in. The `<function>' argument is
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the name of the SoftFloat routine to evaluate, such as `float32_add' or
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`float64_to_int32'. The allowed options are detailed in the next section,
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_Options_. If `timesoftfloat' is executed without any arguments, a summary
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of usage is written. It is also possible to evaluate all machine functions
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in a single invocation as explained in the section _Function_Sets_ later in
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this document.
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Ordinarily, a function's speed will be evaulated separately for each of
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the four rounding modes, one after the other. If the rounding mode is not
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supposed to have any affect on the results of a function--for instance,
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some operations do not require rounding--only the nearest/even rounding mode
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is timed. In the same way, if a function is affected by the way in which
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underflow tininess is detected, `timesoftfloat' times the function both with
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tininess detected before rounding and after rounding. For extended double-
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precision operations affected by rounding precision control, `timesoftfloat'
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also times the function for all three rounding precision modes, one after
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the other. Evaluation of a function can be limited to a single rounding
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mode, a single tininess mode, and/or a single rounding precision with
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appropriate options (see _Options_).
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For each function and mode evaluated, `timesoftfloat' reports the speed of
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the function in kops/s, or ``thousands of operations per second''. This
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unit of measure differs from the traditional MFLOPS (``millions of floating-
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point operations per second'') only in being a factor of 1000 smaller.
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(1000 kops/s is exactly 1 MFLOPS.) Speeds are reported in thousands instead
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of millions because software floating-point often executes at less than
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1 MFLOPS.
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The speeds reported by `timesoftfloat' may be affected somewhat by other
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programs executing at the same time as `timesoftfloat'.
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Note that the remainder operations (`float32_rem', `float64_rem',
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`floatx80_rem' and `float128_rem') will be markedly slower than other
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operations, particularly for extended double precision (`floatx80') and
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quadruple precision (`float128'). This is inherent to the remainder
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function itself and is not a failing of the SoftFloat implementation.
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-------------------------------------------------------------------------------
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Options
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The `timesoftfloat' program accepts several command options. If mutually
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contradictory options are given, the last one has priority.
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- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
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-help
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The `-help' option causes a summary of program usage to be written, after
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which the program exits.
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- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
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-precision32, -precision64, -precision80
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For extended double-precision functions affected by rounding precision
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control, the `-precision32' option restricts evaluation to only the cases
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in which rounding precision is equivalent to single precision. The other
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rounding precision options are not timed. Likewise, the `-precision64'
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and `-precision80' options fix the rounding precision equivalent to double
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precision or extended double precision, respectively. These options are
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ignored for functions not affected by rounding precision control.
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- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
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-nearesteven, -tozero, -down, -up
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The `-nearesteven' option restricts evaluation to only the cases in which
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the rounding mode is nearest/even. The other rounding mode options are not
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timed. Likewise, `-tozero' forces rounding to zero; `-down' forces rounding
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down; and `-up' forces rounding up. These options are ignored for functions
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that are exact and thus do not round.
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- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
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-tininessbefore, -tininessafter
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The `-tininessbefore' option restricts evaluation to only the cases
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detecting underflow tininess before rounding. Tininess after rounding
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is not timed. Likewise, `-tininessafter' forces underflow tininess to be
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detected after rounding only. These options are ignored for functions not
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affected by the way in which underflow tininess is detected.
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- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
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-------------------------------------------------------------------------------
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Function Sets
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Just as `timesoftfloat' can test an operation for all four rounding modes in
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sequence, multiple operations can also be tested with a single invocation.
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Three sets are recognized: `-all1', `-all2', and `-all'. The set `-all1'
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comprises all one-operand functions; `-all2' is all two-operand functions;
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and `-all' is all functions. A function set can be used in place of a
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function name in the command line, as in
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timesoftfloat [<option>...] -all
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