Test cases from Cowlishaw, v2.57. All are pased cleanly.
diff --git a/Lib/test/decimaltestdata/dqFMA.decTest b/Lib/test/decimaltestdata/dqFMA.decTest
index 37d7749..f68fdf9 100644
--- a/Lib/test/decimaltestdata/dqFMA.decTest
+++ b/Lib/test/decimaltestdata/dqFMA.decTest
@@ -17,7 +17,7 @@
-- IBM UK, PO Box 31, Birmingham Road, Warwick CV34 5JL, UK --
-- mfc@uk.ibm.com --
------------------------------------------------------------------------
-version: 2.56
+version: 2.57
extended: 1
clamp: 1
@@ -1754,6 +1754,31 @@
dqadd375088 fma 1 12398765432112345678945678 1E-34 -> 12398765432112345678945678.00000001 Inexact Rounded
dqadd375089 fma 1 12398765432112345678945678 1E-35 -> 12398765432112345678945678.00000001 Inexact Rounded
+-- Destructive subtract (from remainder tests)
+
+-- +++ some of these will be off-by-one remainder vs remainderNear
+
+dqfma4000 fma -1234567890123456789012345678901233 1.000000000000000000000000000000001 1234567890123456789012345678901234 -> -0.234567890123456789012345678901233
+dqfma4001 fma -1234567890123456789012345678901222 1.00000000000000000000000000000001 1234567890123456789012345678901234 -> -0.34567890123456789012345678901222
+dqfma4002 fma -1234567890123456789012345678901111 1.0000000000000000000000000000001 1234567890123456789012345678901234 -> -0.4567890123456789012345678901111
+dqfma4003 fma -308641972530864197253086419725314 4.000000000000000000000000000000001 1234567890123456789012345678901255 -> -1.308641972530864197253086419725314
+dqfma4004 fma -308641972530864197253086419725308 4.000000000000000000000000000000001 1234567890123456789012345678901234 -> 1.691358027469135802746913580274692
+dqfma4005 fma -246913578024691357802469135780252 4.9999999999999999999999999999999 1234567890123456789012345678901234 -> -1.3086421975308642197530864219748
+dqfma4006 fma -246913578024691357802469135780247 4.99999999999999999999999999999999 1234567890123456789012345678901234 -> 1.46913578024691357802469135780247
+dqfma4007 fma -246913578024691357802469135780247 4.999999999999999999999999999999999 1234567890123456789012345678901234 -> -0.753086421975308642197530864219753
+dqfma4008 fma -246913578024691357802469135780247 5.000000000000000000000000000000001 1234567890123456789012345678901234 -> -1.246913578024691357802469135780247
+dqfma4009 fma -246913578024691357802469135780246 5.00000000000000000000000000000001 1234567890123456789012345678901234 -> 1.53086421975308642197530864219754
+dqfma4010 fma -246913578024691357802469135780242 5.0000000000000000000000000000001 1234567890123456789012345678901234 -> -0.6913578024691357802469135780242
+dqfma4011 fma -1234567890123456789012345678901232 1.000000000000000000000000000000001 1234567890123456789012345678901234 -> 0.765432109876543210987654321098768
+dqfma4012 fma -1234567890123456789012345678901221 1.00000000000000000000000000000001 1234567890123456789012345678901234 -> 0.65432109876543210987654321098779
+dqfma4013 fma -1234567890123456789012345678901110 1.0000000000000000000000000000001 1234567890123456789012345678901234 -> 0.5432109876543210987654321098890
+dqfma4014 fma -308641972530864197253086419725313 4.000000000000000000000000000000001 1234567890123456789012345678901255 -> 2.691358027469135802746913580274687
+dqfma4015 fma -308641972530864197253086419725308 4.000000000000000000000000000000001 1234567890123456789012345678901234 -> 1.691358027469135802746913580274692
+dqfma4016 fma -246913578024691357802469135780251 4.9999999999999999999999999999999 1234567890123456789012345678901234 -> 3.6913578024691357802469135780251
+dqfma4017 fma -246913578024691357802469135780247 4.99999999999999999999999999999999 1234567890123456789012345678901234 -> 1.46913578024691357802469135780247
+dqfma4018 fma -246913578024691357802469135780246 4.999999999999999999999999999999999 1234567890123456789012345678901234 -> 4.246913578024691357802469135780246
+dqfma4019 fma -246913578024691357802469135780241 5.0000000000000000000000000000001 1234567890123456789012345678901234 -> 4.3086421975308642197530864219759
+
-- Null tests
dqadd39990 fma 1 10 # -> NaN Invalid_operation
dqadd39991 fma 1 # 10 -> NaN Invalid_operation