The Embedded Artistry gdtoa library includes modernized test cases based on the test applications originally used with the archive. The original tests and test data is kept as a reference within this repository.
Please note that this repository is archived.
This directory contains source for several test programs:
dt is for conversion to/from double; it permits input of pairs of 32-bit hex integers as #hhhhhhhh hhhhhhhh (i.e., the initial '#' indicates hex input). No initial # ==> decimal input. After the input number is an optional : mode ndigits (colon, and decimal integers for parameters "mode" and "ndigits" to gdtoa).
Qtest, ddtest, dtest, ftest, xLtest and xtest are for conversion to/from
f IEEE single precision
d IEEE double precision
xL IEEE extended precision, as on Motorola 680x0 chips
x IEEE extended precision, as on Intel 80x87 chips or
software emulation of Motorola 680x0 chips
Q quad precision, as on Sun Sparc chips
dd double double, pairs of IEEE double numbers
whose sum is the desired value
They're all similar, except for the precision. They test both directed roundings and interval input (the strtoI* routines). Lines that begin with "r" specify or interrogate the desired rounding direction:
0 = toward 0
1 = nearest (default)
2 = toward +Infinity
3 = toward -Infinity
These are the FPI_Round_* values in gdota.h. The "r" value is sticky: it stays in effect til changed. To change the value, give a line that starts with r followed by 0, 1, 2, or 3. To check the value, give "r" by itself.
Lines that begin with n followed by a number specify the ndig argument for subsequent calls to the relevant g_*fmt routine.
Lines that start with # followed by the appropriate number of hexadecimal strings (see the comments) give the big-endian internal representation of the desired number.
When routines Qtest, xLtest, and xtest are used on machines whose long double is of type "quad" (for Qtest) or "extended" (for x*test), they try to print with %Lg as another way to show binary values.
Program ddtest also accepts (white-space separated) pairs of decimal input numbers; it converts both with strtod and feeds the result to g_ddfmt.
Program dItest exercises strtodI and strtoId.
Programs dItestsi and ddtestsi are for testing the sudden-underflow logic (on double and double-double conversions).
Program strtodt tests strtod on some hard cases (in file testnos3) posted by Fred Tydeman to comp.arch.arithmetic on 26 Feb. 1996. To get correct results on Intel (x86) systems, the rounding precision must be set to 53 bits. This can be done, e.g., by invoking fpinit_ASL(), whose source appears in http://www.netlib.org/ampl/solvers/fpinit.c .
These are simple test programs, not meant for exhaustive testing, but for manually testing "interesting" cases. Paxson's testbase is good for more exhaustive testing, in part with random inputs. See ftp://ftp.ee.lbl.gov/testbase-report.ps.Z .