dnl PSPP - a program for statistical analysis.
dnl Copyright (C) 2017 Free Software Foundation, Inc.
dnl
dnl This program is free software: you can redistribute it and/or modify
dnl it under the terms of the GNU General Public License as published by
dnl the Free Software Foundation, either version 3 of the License, or
dnl (at your option) any later version.
dnl
dnl This program is distributed in the hope that it will be useful,
dnl but WITHOUT ANY WARRANTY; without even the implied warranty of
dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
dnl GNU General Public License for more details.
dnl
dnl You should have received a copy of the GNU General Public License
dnl along with this program.  If not, see <http://www.gnu.org/licenses/>.
dnl
AT_BANNER([floating point formats])

AT_SETUP([floating point format conversions])
AT_DATA([float-format.txt], [dnl
# Each of the tests below checks that conversion between
# floating-point formats works correctly.  Comparisons that use ==
# require that conversion from any format on the line to any other
# format on the line work losslessly.  Comparisons that use => only
# check that conversions work losslessly in the given direction.

# Key to format names:
# isl: IEEE single-precision, little endian
# isb: IEEE single-precision, big endian
# idl: IEEE double-precision, little endian
# idb: IEEE double-precision, big endian
# vf: VAX F
# vd: VAX D
# vg: VAX G
# zs: Z architecture short
# zl: Z architecture long
# x: hexadecimal digits

# IEEE special values.
 0 == isb('00000000')
x('Infinity') == isb('7f800000')
x('-Infinity') == isb('ff800000')
x('NaN:') => isb('7f800001')		# NaN requires nonzero fraction.
x('NaN:e000000000000000') == isb('7ff00000') == idb('7ffe000000000000')
x('NaN:5a5a5e0000000000') == isb('7fad2d2f') == idb('7ff5a5a5e0000000')
x('NaN:975612abcdef4000') == idb('7ff975612abcdef4')
x('-NaN:e000000000000000') == isb('fff00000') == idb('fffe000000000000')
x('-NaN:5a5a5e0000000000') == isb('ffad2d2f') == idb('fff5a5a5e0000000')
x('-NaN:975612abcdef4000') == idb('fff975612abcdef4')

# PSPP special values.
x('Missing') == isb('ff7fffff') == idb('ffefffffffffffff') == isl('ffff7fff') == idl('ffffffffffffefff') == vf('ffffffff') == vd('ffffffffffffffff') == vg('ffffffffffffffff') == zs('ffffffff') == zl('ffffffffffffffff')
x('Lowest') == isb('ff7ffffe') == idb('ffeffffffffffffe') == isl('feff7fff') == idl('feffffffffffefff') == vf('fffffeff') == vd('fffffeffffffffff') == vg('fffffeffffffffff') == zs('fffffffe') == zl('fffffffffffffffe')
x('Highest') == isb('7f7fffff') == idb('7fefffffffffffff') == isl('ffff7f7f') == idl('ffffffffffffef7f') == vf('ff7fffff') == vd('ffffffffff7fffff') == vg('ffffffffff7fffff') == zs('7fffffff') == zl('7fffffffffffffff')

# From Wikipedia.
0.15625 == isb('3e200000')
-118.625 == isb('c2ed4000')

# http://www.psc.edu/general/software/packages/ieee/ieee.html
x('NaN:0400000000000000') == isb('7f820000')
x('-NaN:2225540000000000') == isb('ff9112aa')
2 == isb('40000000')
6.5 == isb('40d00000')
-6.5 == isb('c0d00000')
x('.4p-124') == isb('00800000')
x('.2p-124') == isb('00400000')

# Using converter at http://babbage.cs.qc.edu/IEEE-754/Decimal.html
# plus Emacs 'calc' to convert decimal to hexadecimal
x('.7b74bc6a7ef9db23p8') => isb('42f6e979')		# 123.456
x('.7b74bc6a7ef9db23p8') => idb('405edd2f1a9fbe77')
x('.817427d2d4642004p-12') => isb('39017428')		# .0001234567
x('.817427d2d4642004p-12') => idb('3f202e84fa5a8c84')
x('.446c3b15f9926688p168') => isb('7f800000')		# 1e50; overflow
x('.446c3b15f9926688p168') => idb('4a511b0ec57e649a')

# From multiple editions of the z/Architecture Principles of Operation
# manual.
	      1.0 == zs('41100000') == isb('3f800000')
	      0.5 == zs('40800000') == isb('3f000000')
       x('.4p-4') == zs('3f400000') == isb('3c800000')
		0 == zs('00000000') == isb('00000000')
	             zs('80000000') == isb('80000000')
	      -15 == zs('c1f00000') == isb('c1700000')
# x('.ffffffp252') == zs('7fffffff')
      x('.3b4p8') == zs('423b4000')
     x('.1p-256') == zs('00100000')
     x('.4p-124') == zs('21400000') == isb('00800000')
     x('.8p-148') == zs('1b800000') == isb('00000001')
# x('.ffffffp128') == zs('60ffffff') == isb('7f7fffff')
     x('.1p-256') == zs('00100000')
     x('.1p-256') => isb('00000000')              # Underflow to zero.
 x('.ffffffp248') == zs('7effffff')
 x('.ffffffp248') => isb('7f800000')              # Overflow to +Infinity.

            x('.4p-1020') => zl('0000000000000000')     # Underflow to zero.
            x('.4p-1020') == idb('0010000000000000')
            x('.4p-1072') => zl('0000000000000000')     # Underflow to zero.
            x('.4p-1072') => idb('0000000000000001')
x('.fffffffffffff8p1024') => zl('7fffffffffffffff')     # Overflow to maxval.
x('.fffffffffffff8p1024') => idb('7fefffffffffffff')
            x('.1p-256') == zl('0010000000000000') == idb('2fb0000000000000')
 x('.ffffffffffffffp248') == zl('7effffffffffffff')
 x('.ffffffffffffffp248') => idb('4f70000000000000')	# Loses precision.
])
AT_CHECK(
  [sed 's/#.*//
s/^[ 	]*//
s/[ 	]*$//
/^$/d
s/^\(..*\)$/DEBUG FLOAT FORMAT \1./' < float-format.txt > float-format.sps])
AT_CHECK([pspp --testing-mode -O format=csv float-format.sps])
AT_CLEANUP