------------------------------------------------------------------------
-- subtract.decTest -- decimal subtraction                            --
-- Copyright (c) IBM Corporation, 1981, 2008.  All rights reserved.   --
------------------------------------------------------------------------
-- Please see the document "General Decimal Arithmetic Testcases"     --
-- at http://www2.hursley.ibm.com/decimal for the description of      --
-- these testcases.                                                   --
--                                                                    --
-- These testcases are experimental ('beta' versions), and they       --
-- may contain errors.  They are offered on an as-is basis.  In       --
-- particular, achieving the same results as the tests here is not    --
-- a guarantee that an implementation complies with any Standard      --
-- or specification.  The tests are not exhaustive.                   --
--                                                                    --
-- Please send comments, suggestions, and corrections to the author:  --
--   Mike Cowlishaw, IBM Fellow                                       --
--   IBM UK, PO Box 31, Birmingham Road, Warwick CV34 5JL, UK         --
--   mfc@uk.ibm.com                                                   --
------------------------------------------------------------------------
version: 2.59

extended:    1
precision:   9
rounding:    half_up
maxExponent: 384
minexponent: -383

-- [first group are 'quick confidence check']
subx001 subtract  0   0  -> '0'
subx002 subtract  1   1  -> '0'
subx003 subtract  1   2  -> '-1'
subx004 subtract  2   1  -> '1'
subx005 subtract  2   2  -> '0'
subx006 subtract  3   2  -> '1'
subx007 subtract  2   3  -> '-1'

subx011 subtract -0   0  -> '-0'
subx012 subtract -1   1  -> '-2'
subx013 subtract -1   2  -> '-3'
subx014 subtract -2   1  -> '-3'
subx015 subtract -2   2  -> '-4'
subx016 subtract -3   2  -> '-5'
subx017 subtract -2   3  -> '-5'

subx021 subtract  0  -0  -> '0'
subx022 subtract  1  -1  -> '2'
subx023 subtract  1  -2  -> '3'
subx024 subtract  2  -1  -> '3'
subx025 subtract  2  -2  -> '4'
subx026 subtract  3  -2  -> '5'
subx027 subtract  2  -3  -> '5'

subx030 subtract  11  1  -> 10
subx031 subtract  10  1  ->  9
subx032 subtract  9   1  ->  8
subx033 subtract  1   1  ->  0
subx034 subtract  0   1  -> -1
subx035 subtract -1   1  -> -2
subx036 subtract -9   1  -> -10
subx037 subtract -10  1  -> -11
subx038 subtract -11  1  -> -12

subx040 subtract '5.75' '3.3'  -> '2.45'
subx041 subtract '5'    '-3'   -> '8'
subx042 subtract '-5'   '-3'   -> '-2'
subx043 subtract '-7'   '2.5'  -> '-9.5'
subx044 subtract '0.7'  '0.3'  -> '0.4'
subx045 subtract '1.3'  '0.3'  -> '1.0'
subx046 subtract '1.25' '1.25' -> '0.00'

subx050 subtract '1.23456789'    '1.00000000' -> '0.23456789'
subx051 subtract '1.23456789'    '1.00000089' -> '0.23456700'
subx052 subtract '0.5555555559'    '0.0000000001' -> '0.555555556' Inexact Rounded
subx053 subtract '0.5555555559'    '0.0000000005' -> '0.555555555' Inexact Rounded
subx054 subtract '0.4444444444'    '0.1111111111' -> '0.333333333' Inexact Rounded
subx055 subtract '1.0000000000'    '0.00000001' -> '0.999999990' Rounded
subx056 subtract '0.4444444444999'    '0' -> '0.444444444' Inexact Rounded
subx057 subtract '0.4444444445000'    '0' -> '0.444444445' Inexact Rounded

subx060 subtract '70'    '10000e+9' -> '-1.00000000E+13' Inexact Rounded
subx061 subtract '700'    '10000e+9' -> '-1.00000000E+13' Inexact Rounded
subx062 subtract '7000'    '10000e+9' -> '-9.99999999E+12' Inexact Rounded
subx063 subtract '70000'    '10000e+9' -> '-9.99999993E+12' Rounded
subx064 subtract '700000'    '10000e+9' -> '-9.99999930E+12' Rounded
  -- symmetry:
subx065 subtract '10000e+9'    '70' -> '1.00000000E+13' Inexact Rounded
subx066 subtract '10000e+9'    '700' -> '1.00000000E+13' Inexact Rounded
subx067 subtract '10000e+9'    '7000' -> '9.99999999E+12' Inexact Rounded
subx068 subtract '10000e+9'    '70000' -> '9.99999993E+12' Rounded
subx069 subtract '10000e+9'    '700000' -> '9.99999930E+12' Rounded

  -- change precision
subx080 subtract '10000e+9'    '70000' -> '9.99999993E+12' Rounded
precision: 6
subx081 subtract '10000e+9'    '70000' -> '1.00000E+13' Inexact Rounded
precision: 9

  -- some of the next group are really constructor tests
subx090 subtract '00.0'    '0.0'  -> '0.0'
subx091 subtract '00.0'    '0.00' -> '0.00'
subx092 subtract '0.00'    '00.0' -> '0.00'
subx093 subtract '00.0'    '0.00' -> '0.00'
subx094 subtract '0.00'    '00.0' -> '0.00'
subx095 subtract '3'    '.3'   -> '2.7'
subx096 subtract '3.'   '.3'   -> '2.7'
subx097 subtract '3.0'  '.3'   -> '2.7'
subx098 subtract '3.00' '.3'   -> '2.70'
subx099 subtract '3'    '3'    -> '0'
subx100 subtract '3'    '+3'   -> '0'
subx101 subtract '3'    '-3'   -> '6'
subx102 subtract '3'    '0.3'  -> '2.7'
subx103 subtract '3.'   '0.3'  -> '2.7'
subx104 subtract '3.0'  '0.3'  -> '2.7'
subx105 subtract '3.00' '0.3'  -> '2.70'
subx106 subtract '3'    '3.0'  -> '0.0'
subx107 subtract '3'    '+3.0' -> '0.0'
subx108 subtract '3'    '-3.0' -> '6.0'

-- the above all from add; massaged and extended.  Now some new ones...
-- [particularly important for comparisons]
-- NB: -xE-8 below were non-exponents pre-ANSI X3-274, and -1E-7 or 0E-7
-- with input rounding.
subx120 subtract  '10.23456784'    '10.23456789'  -> '-5E-8'
subx121 subtract  '10.23456785'    '10.23456789'  -> '-4E-8'
subx122 subtract  '10.23456786'    '10.23456789'  -> '-3E-8'
subx123 subtract  '10.23456787'    '10.23456789'  -> '-2E-8'
subx124 subtract  '10.23456788'    '10.23456789'  -> '-1E-8'
subx125 subtract  '10.23456789'    '10.23456789'  -> '0E-8'
subx126 subtract  '10.23456790'    '10.23456789'  -> '1E-8'
subx127 subtract  '10.23456791'    '10.23456789'  -> '2E-8'
subx128 subtract  '10.23456792'    '10.23456789'  -> '3E-8'
subx129 subtract  '10.23456793'    '10.23456789'  -> '4E-8'
subx130 subtract  '10.23456794'    '10.23456789'  -> '5E-8'
subx131 subtract  '10.23456781'    '10.23456786'  -> '-5E-8'
subx132 subtract  '10.23456782'    '10.23456786'  -> '-4E-8'
subx133 subtract  '10.23456783'    '10.23456786'  -> '-3E-8'
subx134 subtract  '10.23456784'    '10.23456786'  -> '-2E-8'
subx135 subtract  '10.23456785'    '10.23456786'  -> '-1E-8'
subx136 subtract  '10.23456786'    '10.23456786'  -> '0E-8'
subx137 subtract  '10.23456787'    '10.23456786'  -> '1E-8'
subx138 subtract  '10.23456788'    '10.23456786'  -> '2E-8'
subx139 subtract  '10.23456789'    '10.23456786'  -> '3E-8'
subx140 subtract  '10.23456790'    '10.23456786'  -> '4E-8'
subx141 subtract  '10.23456791'    '10.23456786'  -> '5E-8'
subx142 subtract  '1'              '0.999999999'  -> '1E-9'
subx143 subtract  '0.999999999'    '1'            -> '-1E-9'
subx144 subtract  '-10.23456780'   '-10.23456786' -> '6E-8'
subx145 subtract  '-10.23456790'   '-10.23456786' -> '-4E-8'
subx146 subtract  '-10.23456791'   '-10.23456786' -> '-5E-8'

precision: 3
subx150 subtract '12345678900000' '9999999999999'  -> 2.35E+12 Inexact Rounded
subx151 subtract '9999999999999'  '12345678900000' -> -2.35E+12 Inexact Rounded
precision: 6
subx152 subtract '12345678900000' '9999999999999'  -> 2.34568E+12 Inexact Rounded
subx153 subtract '9999999999999'  '12345678900000' -> -2.34568E+12 Inexact Rounded
precision: 9
subx154 subtract '12345678900000' '9999999999999'  -> 2.34567890E+12 Inexact Rounded
subx155 subtract '9999999999999'  '12345678900000' -> -2.34567890E+12 Inexact Rounded
precision: 12
subx156 subtract '12345678900000' '9999999999999'  -> 2.34567890000E+12 Inexact Rounded
subx157 subtract '9999999999999'  '12345678900000' -> -2.34567890000E+12 Inexact Rounded
precision: 15
subx158 subtract '12345678900000' '9999999999999'  -> 2345678900001
subx159 subtract '9999999999999'  '12345678900000' -> -2345678900001
precision: 9

-- additional scaled arithmetic tests [0.97 problem]
subx160 subtract '0'     '.1'      -> '-0.1'
subx161 subtract '00'    '.97983'  -> '-0.97983'
subx162 subtract '0'     '.9'      -> '-0.9'
subx163 subtract '0'     '0.102'   -> '-0.102'
subx164 subtract '0'     '.4'      -> '-0.4'
subx165 subtract '0'     '.307'    -> '-0.307'
subx166 subtract '0'     '.43822'  -> '-0.43822'
subx167 subtract '0'     '.911'    -> '-0.911'
subx168 subtract '.0'    '.02'     -> '-0.02'
subx169 subtract '00'    '.392'    -> '-0.392'
subx170 subtract '0'     '.26'     -> '-0.26'
subx171 subtract '0'     '0.51'    -> '-0.51'
subx172 subtract '0'     '.2234'   -> '-0.2234'
subx173 subtract '0'     '.2'      -> '-0.2'
subx174 subtract '.0'    '.0008'   -> '-0.0008'
-- 0. on left
subx180 subtract '0.0'     '-.1'      -> '0.1'
subx181 subtract '0.00'    '-.97983'  -> '0.97983'
subx182 subtract '0.0'     '-.9'      -> '0.9'
subx183 subtract '0.0'     '-0.102'   -> '0.102'
subx184 subtract '0.0'     '-.4'      -> '0.4'
subx185 subtract '0.0'     '-.307'    -> '0.307'
subx186 subtract '0.0'     '-.43822'  -> '0.43822'
subx187 subtract '0.0'     '-.911'    -> '0.911'
subx188 subtract '0.0'     '-.02'     -> '0.02'
subx189 subtract '0.00'    '-.392'    -> '0.392'
subx190 subtract '0.0'     '-.26'     -> '0.26'
subx191 subtract '0.0'     '-0.51'    -> '0.51'
subx192 subtract '0.0'     '-.2234'   -> '0.2234'
subx193 subtract '0.0'     '-.2'      -> '0.2'
subx194 subtract '0.0'     '-.0008'   -> '0.0008'
-- negatives of same
subx200 subtract '0'     '-.1'      -> '0.1'
subx201 subtract '00'    '-.97983'  -> '0.97983'
subx202 subtract '0'     '-.9'      -> '0.9'
subx203 subtract '0'     '-0.102'   -> '0.102'
subx204 subtract '0'     '-.4'      -> '0.4'
subx205 subtract '0'     '-.307'    -> '0.307'
subx206 subtract '0'     '-.43822'  -> '0.43822'
subx207 subtract '0'     '-.911'    -> '0.911'
subx208 subtract '.0'    '-.02'     -> '0.02'
subx209 subtract '00'    '-.392'    -> '0.392'
subx210 subtract '0'     '-.26'     -> '0.26'
subx211 subtract '0'     '-0.51'    -> '0.51'
subx212 subtract '0'     '-.2234'   -> '0.2234'
subx213 subtract '0'     '-.2'      -> '0.2'
subx214 subtract '.0'    '-.0008'   -> '0.0008'

-- more fixed, LHS swaps [really the same as testcases under add]
subx220 subtract '-56267E-12' 0  -> '-5.6267E-8'
subx221 subtract '-56267E-11' 0  -> '-5.6267E-7'
subx222 subtract '-56267E-10' 0  -> '-0.0000056267'
subx223 subtract '-56267E-9'  0  -> '-0.000056267'
subx224 subtract '-56267E-8'  0  -> '-0.00056267'
subx225 subtract '-56267E-7'  0  -> '-0.0056267'
subx226 subtract '-56267E-6'  0  -> '-0.056267'
subx227 subtract '-56267E-5'  0  -> '-0.56267'
subx228 subtract '-56267E-2'  0  -> '-562.67'
subx229 subtract '-56267E-1'  0  -> '-5626.7'
subx230 subtract '-56267E-0'  0  -> '-56267'
-- symmetry ...
subx240 subtract 0 '-56267E-12'  -> '5.6267E-8'
subx241 subtract 0 '-56267E-11'  -> '5.6267E-7'
subx242 subtract 0 '-56267E-10'  -> '0.0000056267'
subx243 subtract 0 '-56267E-9'   -> '0.000056267'
subx244 subtract 0 '-56267E-8'   -> '0.00056267'
subx245 subtract 0 '-56267E-7'   -> '0.0056267'
subx246 subtract 0 '-56267E-6'   -> '0.056267'
subx247 subtract 0 '-56267E-5'   -> '0.56267'
subx248 subtract 0 '-56267E-2'   -> '562.67'
subx249 subtract 0 '-56267E-1'   -> '5626.7'
subx250 subtract 0 '-56267E-0'   -> '56267'

-- now some more from the 'new' add
precision: 9
subx301 subtract '1.23456789'  '1.00000000' -> '0.23456789'
subx302 subtract '1.23456789'  '1.00000011' -> '0.23456778'

subx311 subtract '0.4444444444'  '0.5555555555' -> '-0.111111111' Inexact Rounded
subx312 subtract '0.4444444440'  '0.5555555555' -> '-0.111111112' Inexact Rounded
subx313 subtract '0.4444444444'  '0.5555555550' -> '-0.111111111' Inexact Rounded
subx314 subtract '0.44444444449'    '0' -> '0.444444444' Inexact Rounded
subx315 subtract '0.444444444499'   '0' -> '0.444444444' Inexact Rounded
subx316 subtract '0.4444444444999'  '0' -> '0.444444444' Inexact Rounded
subx317 subtract '0.4444444445000'  '0' -> '0.444444445' Inexact Rounded
subx318 subtract '0.4444444445001'  '0' -> '0.444444445' Inexact Rounded
subx319 subtract '0.444444444501'   '0' -> '0.444444445' Inexact Rounded
subx320 subtract '0.44444444451'    '0' -> '0.444444445' Inexact Rounded

-- some carrying effects
subx321 subtract '0.9998'  '0.0000' -> '0.9998'
subx322 subtract '0.9998'  '0.0001' -> '0.9997'
subx323 subtract '0.9998'  '0.0002' -> '0.9996'
subx324 subtract '0.9998'  '0.0003' -> '0.9995'
subx325 subtract '0.9998'  '-0.0000' -> '0.9998'
subx326 subtract '0.9998'  '-0.0001' -> '0.9999'
subx327 subtract '0.9998'  '-0.0002' -> '1.0000'
subx328 subtract '0.9998'  '-0.0003' -> '1.0001'

subx330 subtract '70'  '10000e+9' -> '-1.00000000E+13' Inexact Rounded
subx331 subtract '700'  '10000e+9' -> '-1.00000000E+13' Inexact Rounded
subx332 subtract '7000'  '10000e+9' -> '-9.99999999E+12' Inexact Rounded
subx333 subtract '70000'  '10000e+9' -> '-9.99999993E+12' Rounded
subx334 subtract '700000'  '10000e+9' -> '-9.99999930E+12' Rounded
subx335 subtract '7000000'  '10000e+9' -> '-9.99999300E+12' Rounded
-- symmetry:
subx340 subtract '10000e+9'  '70' -> '1.00000000E+13' Inexact Rounded
subx341 subtract '10000e+9'  '700' -> '1.00000000E+13' Inexact Rounded
subx342 subtract '10000e+9'  '7000' -> '9.99999999E+12' Inexact Rounded
subx343 subtract '10000e+9'  '70000' -> '9.99999993E+12' Rounded
subx344 subtract '10000e+9'  '700000' -> '9.99999930E+12' Rounded
subx345 subtract '10000e+9'  '7000000' -> '9.99999300E+12' Rounded

-- same, higher precision
precision: 15
subx346 subtract '10000e+9'  '7'   -> '9999999999993'
subx347 subtract '10000e+9'  '70'   -> '9999999999930'
subx348 subtract '10000e+9'  '700'   -> '9999999999300'
subx349 subtract '10000e+9'  '7000'   -> '9999999993000'
subx350 subtract '10000e+9'  '70000'   -> '9999999930000'
subx351 subtract '10000e+9'  '700000'   -> '9999999300000'
subx352 subtract '7' '10000e+9'   -> '-9999999999993'
subx353 subtract '70' '10000e+9'   -> '-9999999999930'
subx354 subtract '700' '10000e+9'   -> '-9999999999300'
subx355 subtract '7000' '10000e+9'   -> '-9999999993000'
subx356 subtract '70000' '10000e+9'   -> '-9999999930000'
subx357 subtract '700000' '10000e+9'   -> '-9999999300000'

-- zero preservation
precision: 6
subx360 subtract '10000e+9'  '70000' -> '1.00000E+13' Inexact Rounded
subx361 subtract 1 '0.0001' -> '0.9999'
subx362 subtract 1 '0.00001' -> '0.99999'
subx363 subtract 1 '0.000001' -> '0.999999'
subx364 subtract 1 '0.0000001' -> '1.00000' Inexact Rounded
subx365 subtract 1 '0.00000001' -> '1.00000' Inexact Rounded

-- some funny zeros [in case of bad signum]
subx370 subtract 1  0  -> 1
subx371 subtract 1 0.  -> 1
subx372 subtract 1  .0 -> 1.0
subx373 subtract 1 0.0 -> 1.0
subx374 subtract  0  1 -> -1
subx375 subtract 0.  1 -> -1
subx376 subtract  .0 1 -> -1.0
subx377 subtract 0.0 1 -> -1.0

precision: 9

-- leading 0 digit before round
subx910 subtract -103519362 -51897955.3 -> -51621406.7
subx911 subtract 159579.444 89827.5229 -> 69751.9211

subx920 subtract 333.123456 33.1234566 -> 299.999999 Inexact Rounded
subx921 subtract 333.123456 33.1234565 -> 300.000000 Inexact Rounded
subx922 subtract 133.123456 33.1234565 ->  99.9999995
subx923 subtract 133.123456 33.1234564 ->  99.9999996
subx924 subtract 133.123456 33.1234540 -> 100.000002 Rounded
subx925 subtract 133.123456 43.1234560 ->  90.0000000
subx926 subtract 133.123456 43.1234561 ->  89.9999999
subx927 subtract 133.123456 43.1234566 ->  89.9999994
subx928 subtract 101.123456 91.1234566 ->   9.9999994
subx929 subtract 101.123456 99.1234566 ->   1.9999994

-- more of the same; probe for cluster boundary problems
precision: 1
subx930 subtract  11 2           -> 9
precision: 2
subx932 subtract 101 2           -> 99
precision: 3
subx934 subtract 101 2.1         -> 98.9
subx935 subtract 101 92.01       ->  8.99
precision: 4
subx936 subtract 101 2.01        -> 98.99
subx937 subtract 101 92.01       ->  8.99
subx938 subtract 101 92.006      ->  8.994
precision: 5
subx939 subtract 101 2.001       -> 98.999
subx940 subtract 101 92.001      ->  8.999
subx941 subtract 101 92.0006     ->  8.9994
precision: 6
subx942 subtract 101 2.0001      -> 98.9999
subx943 subtract 101 92.0001     ->  8.9999
subx944 subtract 101 92.00006    ->  8.99994
precision: 7
subx945 subtract 101 2.00001     -> 98.99999
subx946 subtract 101 92.00001    ->  8.99999
subx947 subtract 101 92.000006   ->  8.999994
precision: 8
subx948 subtract 101 2.000001    -> 98.999999
subx949 subtract 101 92.000001   ->  8.999999
subx950 subtract 101 92.0000006  ->  8.9999994
precision: 9
subx951 subtract 101 2.0000001   -> 98.9999999
subx952 subtract 101 92.0000001  ->  8.9999999
subx953 subtract 101 92.00000006 ->  8.99999994

precision: 9

-- more LHS swaps [were fixed]
subx390 subtract '-56267E-10'   0 ->  '-0.0000056267'
subx391 subtract '-56267E-6'    0 ->  '-0.056267'
subx392 subtract '-56267E-5'    0 ->  '-0.56267'
subx393 subtract '-56267E-4'    0 ->  '-5.6267'
subx394 subtract '-56267E-3'    0 ->  '-56.267'
subx395 subtract '-56267E-2'    0 ->  '-562.67'
subx396 subtract '-56267E-1'    0 ->  '-5626.7'
subx397 subtract '-56267E-0'    0 ->  '-56267'
subx398 subtract '-5E-10'       0 ->  '-5E-10'
subx399 subtract '-5E-7'        0 ->  '-5E-7'
subx400 subtract '-5E-6'        0 ->  '-0.000005'
subx401 subtract '-5E-5'        0 ->  '-0.00005'
subx402 subtract '-5E-4'        0 ->  '-0.0005'
subx403 subtract '-5E-1'        0 ->  '-0.5'
subx404 subtract '-5E0'         0 ->  '-5'
subx405 subtract '-5E1'         0 ->  '-50'
subx406 subtract '-5E5'         0 ->  '-500000'
subx407 subtract '-5E8'         0 ->  '-500000000'
subx408 subtract '-5E9'         0 ->  '-5.00000000E+9'   Rounded
subx409 subtract '-5E10'        0 ->  '-5.00000000E+10'  Rounded
subx410 subtract '-5E11'        0 ->  '-5.00000000E+11'  Rounded
subx411 subtract '-5E100'       0 ->  '-5.00000000E+100' Rounded

-- more RHS swaps [were fixed]
subx420 subtract 0  '-56267E-10' ->  '0.0000056267'
subx421 subtract 0  '-56267E-6'  ->  '0.056267'
subx422 subtract 0  '-56267E-5'  ->  '0.56267'
subx423 subtract 0  '-56267E-4'  ->  '5.6267'
subx424 subtract 0  '-56267E-3'  ->  '56.267'
subx425 subtract 0  '-56267E-2'  ->  '562.67'
subx426 subtract 0  '-56267E-1'  ->  '5626.7'
subx427 subtract 0  '-56267E-0'  ->  '56267'
subx428 subtract 0  '-5E-10'     ->  '5E-10'
subx429 subtract 0  '-5E-7'      ->  '5E-7'
subx430 subtract 0  '-5E-6'      ->  '0.000005'
subx431 subtract 0  '-5E-5'      ->  '0.00005'
subx432 subtract 0  '-5E-4'      ->  '0.0005'
subx433 subtract 0  '-5E-1'      ->  '0.5'
subx434 subtract 0  '-5E0'       ->  '5'
subx435 subtract 0  '-5E1'       ->  '50'
subx436 subtract 0  '-5E5'       ->  '500000'
subx437 subtract 0  '-5E8'       ->  '500000000'
subx438 subtract 0  '-5E9'       ->  '5.00000000E+9'    Rounded
subx439 subtract 0  '-5E10'      ->  '5.00000000E+10'   Rounded
subx440 subtract 0  '-5E11'      ->  '5.00000000E+11'   Rounded
subx441 subtract 0  '-5E100'     ->  '5.00000000E+100'  Rounded


-- try borderline precision, with carries, etc.
precision: 15
subx461 subtract '1E+12' '1'       -> '999999999999'
subx462 subtract '1E+12' '-1.11'   -> '1000000000001.11'
subx463 subtract '1.11'  '-1E+12'  -> '1000000000001.11'
subx464 subtract '-1'    '-1E+12'  -> '999999999999'
subx465 subtract '7E+12' '1'       -> '6999999999999'
subx466 subtract '7E+12' '-1.11'   -> '7000000000001.11'
subx467 subtract '1.11'  '-7E+12'  -> '7000000000001.11'
subx468 subtract '-1'    '-7E+12'  -> '6999999999999'

--                 123456789012345       123456789012345      1 23456789012345
subx470 subtract '0.444444444444444'  '-0.555555555555563' -> '1.00000000000001' Inexact Rounded
subx471 subtract '0.444444444444444'  '-0.555555555555562' -> '1.00000000000001' Inexact Rounded
subx472 subtract '0.444444444444444'  '-0.555555555555561' -> '1.00000000000001' Inexact Rounded
subx473 subtract '0.444444444444444'  '-0.555555555555560' -> '1.00000000000000' Inexact Rounded
subx474 subtract '0.444444444444444'  '-0.555555555555559' -> '1.00000000000000' Inexact Rounded
subx475 subtract '0.444444444444444'  '-0.555555555555558' -> '1.00000000000000' Inexact Rounded
subx476 subtract '0.444444444444444'  '-0.555555555555557' -> '1.00000000000000' Inexact Rounded
subx477 subtract '0.444444444444444'  '-0.555555555555556' -> '1.00000000000000' Rounded
subx478 subtract '0.444444444444444'  '-0.555555555555555' -> '0.999999999999999'
subx479 subtract '0.444444444444444'  '-0.555555555555554' -> '0.999999999999998'
subx480 subtract '0.444444444444444'  '-0.555555555555553' -> '0.999999999999997'
subx481 subtract '0.444444444444444'  '-0.555555555555552' -> '0.999999999999996'
subx482 subtract '0.444444444444444'  '-0.555555555555551' -> '0.999999999999995'
subx483 subtract '0.444444444444444'  '-0.555555555555550' -> '0.999999999999994'

-- and some more, including residue effects and different roundings
precision: 9
rounding: half_up
subx500 subtract '123456789' 0             -> '123456789'
subx501 subtract '123456789' 0.000000001   -> '123456789' Inexact Rounded
subx502 subtract '123456789' 0.000001      -> '123456789' Inexact Rounded
subx503 subtract '123456789' 0.1           -> '123456789' Inexact Rounded
subx504 subtract '123456789' 0.4           -> '123456789' Inexact Rounded
subx505 subtract '123456789' 0.49          -> '123456789' Inexact Rounded
subx506 subtract '123456789' 0.499999      -> '123456789' Inexact Rounded
subx507 subtract '123456789' 0.499999999   -> '123456789' Inexact Rounded
subx508 subtract '123456789' 0.5           -> '123456789' Inexact Rounded
subx509 subtract '123456789' 0.500000001   -> '123456788' Inexact Rounded
subx510 subtract '123456789' 0.500001      -> '123456788' Inexact Rounded
subx511 subtract '123456789' 0.51          -> '123456788' Inexact Rounded
subx512 subtract '123456789' 0.6           -> '123456788' Inexact Rounded
subx513 subtract '123456789' 0.9           -> '123456788' Inexact Rounded
subx514 subtract '123456789' 0.99999       -> '123456788' Inexact Rounded
subx515 subtract '123456789' 0.999999999   -> '123456788' Inexact Rounded
subx516 subtract '123456789' 1             -> '123456788'
subx517 subtract '123456789' 1.000000001   -> '123456788' Inexact Rounded
subx518 subtract '123456789' 1.00001       -> '123456788' Inexact Rounded
subx519 subtract '123456789' 1.1           -> '123456788' Inexact Rounded

rounding: half_even
subx520 subtract '123456789' 0             -> '123456789'
subx521 subtract '123456789' 0.000000001   -> '123456789' Inexact Rounded
subx522 subtract '123456789' 0.000001      -> '123456789' Inexact Rounded
subx523 subtract '123456789' 0.1           -> '123456789' Inexact Rounded
subx524 subtract '123456789' 0.4           -> '123456789' Inexact Rounded
subx525 subtract '123456789' 0.49          -> '123456789' Inexact Rounded
subx526 subtract '123456789' 0.499999      -> '123456789' Inexact Rounded
subx527 subtract '123456789' 0.499999999   -> '123456789' Inexact Rounded
subx528 subtract '123456789' 0.5           -> '123456788' Inexact Rounded
subx529 subtract '123456789' 0.500000001   -> '123456788' Inexact Rounded
subx530 subtract '123456789' 0.500001      -> '123456788' Inexact Rounded
subx531 subtract '123456789' 0.51          -> '123456788' Inexact Rounded
subx532 subtract '123456789' 0.6           -> '123456788' Inexact Rounded
subx533 subtract '123456789' 0.9           -> '123456788' Inexact Rounded
subx534 subtract '123456789' 0.99999       -> '123456788' Inexact Rounded
subx535 subtract '123456789' 0.999999999   -> '123456788' Inexact Rounded
subx536 subtract '123456789' 1             -> '123456788'
subx537 subtract '123456789' 1.00000001    -> '123456788' Inexact Rounded
subx538 subtract '123456789' 1.00001       -> '123456788' Inexact Rounded
subx539 subtract '123456789' 1.1           -> '123456788' Inexact Rounded
-- critical few with even bottom digit...
subx540 subtract '123456788' 0.499999999   -> '123456788' Inexact Rounded
subx541 subtract '123456788' 0.5           -> '123456788' Inexact Rounded
subx542 subtract '123456788' 0.500000001   -> '123456787' Inexact Rounded

rounding: down
subx550 subtract '123456789' 0             -> '123456789'
subx551 subtract '123456789' 0.000000001   -> '123456788' Inexact Rounded
subx552 subtract '123456789' 0.000001      -> '123456788' Inexact Rounded
subx553 subtract '123456789' 0.1           -> '123456788' Inexact Rounded
subx554 subtract '123456789' 0.4           -> '123456788' Inexact Rounded
subx555 subtract '123456789' 0.49          -> '123456788' Inexact Rounded
subx556 subtract '123456789' 0.499999      -> '123456788' Inexact Rounded
subx557 subtract '123456789' 0.499999999   -> '123456788' Inexact Rounded
subx558 subtract '123456789' 0.5           -> '123456788' Inexact Rounded
subx559 subtract '123456789' 0.500000001   -> '123456788' Inexact Rounded
subx560 subtract '123456789' 0.500001      -> '123456788' Inexact Rounded
subx561 subtract '123456789' 0.51          -> '123456788' Inexact Rounded
subx562 subtract '123456789' 0.6           -> '123456788' Inexact Rounded
subx563 subtract '123456789' 0.9           -> '123456788' Inexact Rounded
subx564 subtract '123456789' 0.99999       -> '123456788' Inexact Rounded
subx565 subtract '123456789' 0.999999999   -> '123456788' Inexact Rounded
subx566 subtract '123456789' 1             -> '123456788'
subx567 subtract '123456789' 1.00000001    -> '123456787' Inexact Rounded
subx568 subtract '123456789' 1.00001       -> '123456787' Inexact Rounded
subx569 subtract '123456789' 1.1           -> '123456787' Inexact Rounded

-- symmetry...
rounding: half_up
subx600 subtract 0             '123456789' -> '-123456789'
subx601 subtract 0.000000001   '123456789' -> '-123456789' Inexact Rounded
subx602 subtract 0.000001      '123456789' -> '-123456789' Inexact Rounded
subx603 subtract 0.1           '123456789' -> '-123456789' Inexact Rounded
subx604 subtract 0.4           '123456789' -> '-123456789' Inexact Rounded
subx605 subtract 0.49          '123456789' -> '-123456789' Inexact Rounded
subx606 subtract 0.499999      '123456789' -> '-123456789' Inexact Rounded
subx607 subtract 0.499999999   '123456789' -> '-123456789' Inexact Rounded
subx608 subtract 0.5           '123456789' -> '-123456789' Inexact Rounded
subx609 subtract 0.500000001   '123456789' -> '-123456788' Inexact Rounded
subx610 subtract 0.500001      '123456789' -> '-123456788' Inexact Rounded
subx611 subtract 0.51          '123456789' -> '-123456788' Inexact Rounded
subx612 subtract 0.6           '123456789' -> '-123456788' Inexact Rounded
subx613 subtract 0.9           '123456789' -> '-123456788' Inexact Rounded
subx614 subtract 0.99999       '123456789' -> '-123456788' Inexact Rounded
subx615 subtract 0.999999999   '123456789' -> '-123456788' Inexact Rounded
subx616 subtract 1             '123456789' -> '-123456788'
subx617 subtract 1.000000001   '123456789' -> '-123456788' Inexact Rounded
subx618 subtract 1.00001       '123456789' -> '-123456788' Inexact Rounded
subx619 subtract 1.1           '123456789' -> '-123456788' Inexact Rounded

rounding: half_even
subx620 subtract 0             '123456789' -> '-123456789'
subx621 subtract 0.000000001   '123456789' -> '-123456789' Inexact Rounded
subx622 subtract 0.000001      '123456789' -> '-123456789' Inexact Rounded
subx623 subtract 0.1           '123456789' -> '-123456789' Inexact Rounded
subx624 subtract 0.4           '123456789' -> '-123456789' Inexact Rounded
subx625 subtract 0.49          '123456789' -> '-123456789' Inexact Rounded
subx626 subtract 0.499999      '123456789' -> '-123456789' Inexact Rounded
subx627 subtract 0.499999999   '123456789' -> '-123456789' Inexact Rounded
subx628 subtract 0.5           '123456789' -> '-123456788' Inexact Rounded
subx629 subtract 0.500000001   '123456789' -> '-123456788' Inexact Rounded
subx630 subtract 0.500001      '123456789' -> '-123456788' Inexact Rounded
subx631 subtract 0.51          '123456789' -> '-123456788' Inexact Rounded
subx632 subtract 0.6           '123456789' -> '-123456788' Inexact Rounded
subx633 subtract 0.9           '123456789' -> '-123456788' Inexact Rounded
subx634 subtract 0.99999       '123456789' -> '-123456788' Inexact Rounded
subx635 subtract 0.999999999   '123456789' -> '-123456788' Inexact Rounded
subx636 subtract 1             '123456789' -> '-123456788'
subx637 subtract 1.00000001    '123456789' -> '-123456788' Inexact Rounded
subx638 subtract 1.00001       '123456789' -> '-123456788' Inexact Rounded
subx639 subtract 1.1           '123456789' -> '-123456788' Inexact Rounded
-- critical few with even bottom digit...
subx640 subtract 0.499999999   '123456788' -> '-123456788' Inexact Rounded
subx641 subtract 0.5           '123456788' -> '-123456788' Inexact Rounded
subx642 subtract 0.500000001   '123456788' -> '-123456787' Inexact Rounded

rounding: down
subx650 subtract 0             '123456789' -> '-123456789'
subx651 subtract 0.000000001   '123456789' -> '-123456788' Inexact Rounded
subx652 subtract 0.000001      '123456789' -> '-123456788' Inexact Rounded
subx653 subtract 0.1           '123456789' -> '-123456788' Inexact Rounded
subx654 subtract 0.4           '123456789' -> '-123456788' Inexact Rounded
subx655 subtract 0.49          '123456789' -> '-123456788' Inexact Rounded
subx656 subtract 0.499999      '123456789' -> '-123456788' Inexact Rounded
subx657 subtract 0.499999999   '123456789' -> '-123456788' Inexact Rounded
subx658 subtract 0.5           '123456789' -> '-123456788' Inexact Rounded
subx659 subtract 0.500000001   '123456789' -> '-123456788' Inexact Rounded
subx660 subtract 0.500001      '123456789' -> '-123456788' Inexact Rounded
subx661 subtract 0.51          '123456789' -> '-123456788' Inexact Rounded
subx662 subtract 0.6           '123456789' -> '-123456788' Inexact Rounded
subx663 subtract 0.9           '123456789' -> '-123456788' Inexact Rounded
subx664 subtract 0.99999       '123456789' -> '-123456788' Inexact Rounded
subx665 subtract 0.999999999   '123456789' -> '-123456788' Inexact Rounded
subx666 subtract 1             '123456789' -> '-123456788'
subx667 subtract 1.00000001    '123456789' -> '-123456787' Inexact Rounded
subx668 subtract 1.00001       '123456789' -> '-123456787' Inexact Rounded
subx669 subtract 1.1           '123456789' -> '-123456787' Inexact Rounded


-- lots of leading zeros in intermediate result, and showing effects of
-- input rounding would have affected the following
precision: 9
rounding: half_up
subx670 subtract '123456789' '123456788.1' -> 0.9
subx671 subtract '123456789' '123456788.9' -> 0.1
subx672 subtract '123456789' '123456789.1' -> -0.1
subx673 subtract '123456789' '123456789.5' -> -0.5
subx674 subtract '123456789' '123456789.9' -> -0.9

rounding: half_even
subx680 subtract '123456789' '123456788.1' -> 0.9
subx681 subtract '123456789' '123456788.9' -> 0.1
subx682 subtract '123456789' '123456789.1' -> -0.1
subx683 subtract '123456789' '123456789.5' -> -0.5
subx684 subtract '123456789' '123456789.9' -> -0.9

subx685 subtract '123456788' '123456787.1' -> 0.9
subx686 subtract '123456788' '123456787.9' -> 0.1
subx687 subtract '123456788' '123456788.1' -> -0.1
subx688 subtract '123456788' '123456788.5' -> -0.5
subx689 subtract '123456788' '123456788.9' -> -0.9

rounding: down
subx690 subtract '123456789' '123456788.1' -> 0.9
subx691 subtract '123456789' '123456788.9' -> 0.1
subx692 subtract '123456789' '123456789.1' -> -0.1
subx693 subtract '123456789' '123456789.5' -> -0.5
subx694 subtract '123456789' '123456789.9' -> -0.9

-- input preparation tests
rounding: half_up
precision: 3

subx700 subtract '12345678900000'  -9999999999999 ->  '2.23E+13' Inexact Rounded
subx701 subtract  '9999999999999' -12345678900000 ->  '2.23E+13' Inexact Rounded
subx702 subtract '12E+3'  '-3456' ->  '1.55E+4' Inexact Rounded
subx703 subtract '12E+3'  '-3446' ->  '1.54E+4' Inexact Rounded
subx704 subtract '12E+3'  '-3454' ->  '1.55E+4' Inexact Rounded
subx705 subtract '12E+3'  '-3444' ->  '1.54E+4' Inexact Rounded

subx706 subtract '3456'  '-12E+3' ->  '1.55E+4' Inexact Rounded
subx707 subtract '3446'  '-12E+3' ->  '1.54E+4' Inexact Rounded
subx708 subtract '3454'  '-12E+3' ->  '1.55E+4' Inexact Rounded
subx709 subtract '3444'  '-12E+3' ->  '1.54E+4' Inexact Rounded

-- overflow and underflow tests [subnormals now possible]
maxexponent: 999999999
minexponent: -999999999
precision: 9
rounding: down
subx710 subtract 1E+999999999    -9E+999999999   -> 9.99999999E+999999999 Overflow Inexact Rounded
subx711 subtract 9E+999999999    -1E+999999999   -> 9.99999999E+999999999 Overflow Inexact Rounded
rounding: half_up
subx712 subtract 1E+999999999    -9E+999999999   -> Infinity Overflow Inexact Rounded
subx713 subtract 9E+999999999    -1E+999999999   -> Infinity Overflow Inexact Rounded
subx714 subtract -1.1E-999999999 -1E-999999999   -> -1E-1000000000 Subnormal
subx715 subtract 1E-999999999    +1.1e-999999999 -> -1E-1000000000 Subnormal
subx716 subtract -1E+999999999   +9E+999999999   -> -Infinity Overflow Inexact Rounded
subx717 subtract -9E+999999999   +1E+999999999   -> -Infinity Overflow Inexact Rounded
subx718 subtract +1.1E-999999999 +1E-999999999   -> 1E-1000000000 Subnormal
subx719 subtract -1E-999999999   -1.1e-999999999 -> 1E-1000000000 Subnormal

precision: 3
subx720 subtract 1  9.999E+999999999   -> -Infinity Inexact Overflow Rounded
subx721 subtract 1 -9.999E+999999999   ->  Infinity Inexact Overflow Rounded
subx722 subtract    9.999E+999999999 1 ->  Infinity Inexact Overflow Rounded
subx723 subtract   -9.999E+999999999 1 -> -Infinity Inexact Overflow Rounded
subx724 subtract 1  9.999E+999999999   -> -Infinity Inexact Overflow Rounded
subx725 subtract 1 -9.999E+999999999   ->  Infinity Inexact Overflow Rounded
subx726 subtract    9.999E+999999999 1 ->  Infinity Inexact Overflow Rounded
subx727 subtract   -9.999E+999999999 1 -> -Infinity Inexact Overflow Rounded

-- [more below]

-- long operand checks
maxexponent: 999
minexponent: -999
precision: 9
sub731 subtract 12345678000 0 ->  1.23456780E+10 Rounded
sub732 subtract 0 12345678000 -> -1.23456780E+10 Rounded
sub733 subtract 1234567800  0 ->  1.23456780E+9 Rounded
sub734 subtract 0 1234567800  -> -1.23456780E+9 Rounded
sub735 subtract 1234567890  0 ->  1.23456789E+9 Rounded
sub736 subtract 0 1234567890  -> -1.23456789E+9 Rounded
sub737 subtract 1234567891  0 ->  1.23456789E+9 Inexact Rounded
sub738 subtract 0 1234567891  -> -1.23456789E+9 Inexact Rounded
sub739 subtract 12345678901 0 ->  1.23456789E+10 Inexact Rounded
sub740 subtract 0 12345678901 -> -1.23456789E+10 Inexact Rounded
sub741 subtract 1234567896  0 ->  1.23456790E+9 Inexact Rounded
sub742 subtract 0 1234567896  -> -1.23456790E+9 Inexact Rounded

precision: 15
sub751 subtract 12345678000 0 ->  12345678000
sub752 subtract 0 12345678000 -> -12345678000
sub753 subtract 1234567800  0 ->  1234567800
sub754 subtract 0 1234567800  -> -1234567800
sub755 subtract 1234567890  0 ->  1234567890
sub756 subtract 0 1234567890  -> -1234567890
sub757 subtract 1234567891  0 ->  1234567891
sub758 subtract 0 1234567891  -> -1234567891
sub759 subtract 12345678901 0 ->  12345678901
sub760 subtract 0 12345678901 -> -12345678901
sub761 subtract 1234567896  0 ->  1234567896
sub762 subtract 0 1234567896  -> -1234567896

-- Specials
subx780 subtract -Inf   Inf   -> -Infinity
subx781 subtract -Inf   1000  -> -Infinity
subx782 subtract -Inf   1     -> -Infinity
subx783 subtract -Inf  -0     -> -Infinity
subx784 subtract -Inf  -1     -> -Infinity
subx785 subtract -Inf  -1000  -> -Infinity
subx787 subtract -1000  Inf   -> -Infinity
subx788 subtract -Inf   Inf   -> -Infinity
subx789 subtract -1     Inf   -> -Infinity
subx790 subtract  0     Inf   -> -Infinity
subx791 subtract  1     Inf   -> -Infinity
subx792 subtract  1000  Inf   -> -Infinity

subx800 subtract  Inf   Inf   ->  NaN  Invalid_operation
subx801 subtract  Inf   1000  ->  Infinity
subx802 subtract  Inf   1     ->  Infinity
subx803 subtract  Inf   0     ->  Infinity
subx804 subtract  Inf  -0     ->  Infinity
subx805 subtract  Inf  -1     ->  Infinity
subx806 subtract  Inf  -1000  ->  Infinity
subx807 subtract  Inf  -Inf   ->  Infinity
subx808 subtract -1000 -Inf   ->  Infinity
subx809 subtract -Inf  -Inf   ->  NaN  Invalid_operation
subx810 subtract -1    -Inf   ->  Infinity
subx811 subtract -0    -Inf   ->  Infinity
subx812 subtract  0    -Inf   ->  Infinity
subx813 subtract  1    -Inf   ->  Infinity
subx814 subtract  1000 -Inf   ->  Infinity
subx815 subtract  Inf  -Inf   ->  Infinity

subx821 subtract  NaN   Inf   ->  NaN
subx822 subtract -NaN   1000  -> -NaN
subx823 subtract  NaN   1     ->  NaN
subx824 subtract  NaN   0     ->  NaN
subx825 subtract  NaN  -0     ->  NaN
subx826 subtract  NaN  -1     ->  NaN
subx827 subtract  NaN  -1000  ->  NaN
subx828 subtract  NaN  -Inf   ->  NaN
subx829 subtract -NaN   NaN   -> -NaN
subx830 subtract -Inf   NaN   ->  NaN
subx831 subtract -1000  NaN   ->  NaN
subx832 subtract -1     NaN   ->  NaN
subx833 subtract -0     NaN   ->  NaN
subx834 subtract  0     NaN   ->  NaN
subx835 subtract  1     NaN   ->  NaN
subx836 subtract  1000 -NaN   -> -NaN
subx837 subtract  Inf   NaN   ->  NaN

subx841 subtract  sNaN  Inf   ->  NaN  Invalid_operation
subx842 subtract -sNaN  1000  -> -NaN  Invalid_operation
subx843 subtract  sNaN  1     ->  NaN  Invalid_operation
subx844 subtract  sNaN  0     ->  NaN  Invalid_operation
subx845 subtract  sNaN -0     ->  NaN  Invalid_operation
subx846 subtract  sNaN -1     ->  NaN  Invalid_operation
subx847 subtract  sNaN -1000  ->  NaN  Invalid_operation
subx848 subtract  sNaN  NaN   ->  NaN  Invalid_operation
subx849 subtract  sNaN sNaN   ->  NaN  Invalid_operation
subx850 subtract  NaN  sNaN   ->  NaN  Invalid_operation
subx851 subtract -Inf -sNaN   -> -NaN  Invalid_operation
subx852 subtract -1000 sNaN   ->  NaN  Invalid_operation
subx853 subtract -1    sNaN   ->  NaN  Invalid_operation
subx854 subtract -0    sNaN   ->  NaN  Invalid_operation
subx855 subtract  0    sNaN   ->  NaN  Invalid_operation
subx856 subtract  1    sNaN   ->  NaN  Invalid_operation
subx857 subtract  1000 sNaN   ->  NaN  Invalid_operation
subx858 subtract  Inf  sNaN   ->  NaN  Invalid_operation
subx859 subtract  NaN  sNaN   ->  NaN  Invalid_operation

-- propagating NaNs
subx861 subtract  NaN01   -Inf     ->  NaN1
subx862 subtract -NaN02   -1000    -> -NaN2
subx863 subtract  NaN03    1000    ->  NaN3
subx864 subtract  NaN04    Inf     ->  NaN4
subx865 subtract  NaN05    NaN61   ->  NaN5
subx866 subtract -Inf     -NaN71   -> -NaN71
subx867 subtract -1000     NaN81   ->  NaN81
subx868 subtract  1000     NaN91   ->  NaN91
subx869 subtract  Inf      NaN101  ->  NaN101
subx871 subtract  sNaN011  -Inf    ->  NaN11  Invalid_operation
subx872 subtract  sNaN012  -1000   ->  NaN12  Invalid_operation
subx873 subtract -sNaN013   1000   -> -NaN13  Invalid_operation
subx874 subtract  sNaN014   NaN171 ->  NaN14  Invalid_operation
subx875 subtract  sNaN015  sNaN181 ->  NaN15  Invalid_operation
subx876 subtract  NaN016   sNaN191 ->  NaN191 Invalid_operation
subx877 subtract -Inf      sNaN201 ->  NaN201 Invalid_operation
subx878 subtract -1000     sNaN211 ->  NaN211 Invalid_operation
subx879 subtract  1000    -sNaN221 -> -NaN221 Invalid_operation
subx880 subtract  Inf      sNaN231 ->  NaN231 Invalid_operation
subx881 subtract  NaN025   sNaN241 ->  NaN241 Invalid_operation

-- edge case spills
subx901 subtract  2.E-3  1.002  -> -1.000
subx902 subtract  2.0E-3  1.002  -> -1.0000
subx903 subtract  2.00E-3  1.0020  -> -1.00000
subx904 subtract  2.000E-3  1.00200  -> -1.000000
subx905 subtract  2.0000E-3  1.002000  -> -1.0000000
subx906 subtract  2.00000E-3  1.0020000  -> -1.00000000
subx907 subtract  2.000000E-3  1.00200000  -> -1.000000000
subx908 subtract  2.0000000E-3  1.002000000  -> -1.0000000000

-- subnormals and underflows
precision: 3
maxexponent: 999
minexponent: -999
subx1010 subtract  0  1.00E-999       ->  -1.00E-999
subx1011 subtract  0  0.1E-999        ->  -1E-1000   Subnormal
subx1012 subtract  0  0.10E-999       ->  -1.0E-1000 Subnormal
subx1013 subtract  0  0.100E-999      ->  -1.0E-1000 Subnormal Rounded
subx1014 subtract  0  0.01E-999       ->  -1E-1001   Subnormal
-- next is rounded to Emin
subx1015 subtract  0  0.999E-999      ->  -1.00E-999 Inexact Rounded Subnormal Underflow
subx1016 subtract  0  0.099E-999      ->  -1.0E-1000 Inexact Rounded Subnormal Underflow
subx1017 subtract  0  0.009E-999      ->  -1E-1001   Inexact Rounded Subnormal Underflow
subx1018 subtract  0  0.001E-999      ->  -0E-1001   Inexact Rounded Subnormal Underflow Clamped
subx1019 subtract  0  0.0009E-999     ->  -0E-1001   Inexact Rounded Subnormal Underflow Clamped
subx1020 subtract  0  0.0001E-999     ->  -0E-1001   Inexact Rounded Subnormal Underflow Clamped

subx1030 subtract  0 -1.00E-999       ->   1.00E-999
subx1031 subtract  0 -0.1E-999        ->   1E-1000   Subnormal
subx1032 subtract  0 -0.10E-999       ->   1.0E-1000 Subnormal
subx1033 subtract  0 -0.100E-999      ->   1.0E-1000 Subnormal Rounded
subx1034 subtract  0 -0.01E-999       ->   1E-1001   Subnormal
-- next is rounded to Emin
subx1035 subtract  0 -0.999E-999      ->   1.00E-999 Inexact Rounded Subnormal Underflow
subx1036 subtract  0 -0.099E-999      ->   1.0E-1000 Inexact Rounded Subnormal Underflow
subx1037 subtract  0 -0.009E-999      ->   1E-1001   Inexact Rounded Subnormal Underflow
subx1038 subtract  0 -0.001E-999      ->   0E-1001   Inexact Rounded Subnormal Underflow Clamped
subx1039 subtract  0 -0.0009E-999     ->   0E-1001   Inexact Rounded Subnormal Underflow Clamped
subx1040 subtract  0 -0.0001E-999     ->   0E-1001   Inexact Rounded Subnormal Underflow Clamped

-- some non-zero subnormal subtracts
-- subx1056 is a tricky case
rounding: half_up
subx1050 subtract  1.00E-999   0.1E-999  ->   9.0E-1000  Subnormal
subx1051 subtract  0.1E-999    0.1E-999  ->   0E-1000
subx1052 subtract  0.10E-999   0.1E-999  ->   0E-1001
subx1053 subtract  0.100E-999  0.1E-999  ->   0E-1001    Clamped
subx1054 subtract  0.01E-999   0.1E-999  ->   -9E-1001   Subnormal
subx1055 subtract  0.999E-999  0.1E-999  ->   9.0E-1000  Inexact Rounded Subnormal Underflow
subx1056 subtract  0.099E-999  0.1E-999  ->   -0E-1001   Inexact Rounded Subnormal Underflow Clamped
subx1057 subtract  0.009E-999  0.1E-999  ->   -9E-1001   Inexact Rounded Subnormal Underflow
subx1058 subtract  0.001E-999  0.1E-999  ->   -1.0E-1000 Inexact Rounded Subnormal Underflow
subx1059 subtract  0.0009E-999 0.1E-999  ->   -1.0E-1000 Inexact Rounded Subnormal Underflow
subx1060 subtract  0.0001E-999 0.1E-999  ->   -1.0E-1000 Inexact Rounded Subnormal Underflow


-- check for double-rounded subnormals
precision:   5
maxexponent: 79
minexponent: -79
subx1101 subtract  0 1.52444E-80 -> -1.524E-80 Inexact Rounded Subnormal Underflow
subx1102 subtract  0 1.52445E-80 -> -1.524E-80 Inexact Rounded Subnormal Underflow
subx1103 subtract  0 1.52446E-80 -> -1.524E-80 Inexact Rounded Subnormal Underflow
subx1104 subtract  1.52444E-80 0 ->  1.524E-80 Inexact Rounded Subnormal Underflow
subx1105 subtract  1.52445E-80 0 ->  1.524E-80 Inexact Rounded Subnormal Underflow
subx1106 subtract  1.52446E-80 0 ->  1.524E-80 Inexact Rounded Subnormal Underflow

subx1111 subtract  1.2345678E-80  1.2345671E-80 ->  0E-83 Inexact Rounded Subnormal Underflow Clamped
subx1112 subtract  1.2345678E-80  1.2345618E-80 ->  0E-83 Inexact Rounded Subnormal Underflow Clamped
subx1113 subtract  1.2345678E-80  1.2345178E-80 ->  0E-83 Inexact Rounded Subnormal Underflow Clamped
subx1114 subtract  1.2345678E-80  1.2341678E-80 ->  0E-83 Inexact Rounded Subnormal Underflow Clamped
subx1115 subtract  1.2345678E-80  1.2315678E-80 ->  3E-83         Rounded Subnormal
subx1116 subtract  1.2345678E-80  1.2145678E-80 ->  2.0E-82       Rounded Subnormal
subx1117 subtract  1.2345678E-80  1.1345678E-80 ->  1.00E-81      Rounded Subnormal
subx1118 subtract  1.2345678E-80  0.2345678E-80 ->  1.000E-80     Rounded Subnormal

precision:   34
rounding:    half_up
maxExponent: 6144
minExponent: -6143
-- Examples from SQL proposal (Krishna Kulkarni)
subx1125  subtract 130E-2  120E-2 -> 0.10
subx1126  subtract 130E-2  12E-1  -> 0.10
subx1127  subtract 130E-2  1E0    -> 0.30
subx1128  subtract 1E2     1E4    -> -9.9E+3

-- Null tests
subx9990 subtract 10  # -> NaN Invalid_operation
subx9991 subtract  # 10 -> NaN Invalid_operation