Test cases from Cowlishaw, v2.57. All are pased cleanly.
diff --git a/Lib/test/decimaltestdata/ddFMA.decTest b/Lib/test/decimaltestdata/ddFMA.decTest
index 946d680..bc44b6a 100644
--- a/Lib/test/decimaltestdata/ddFMA.decTest
+++ b/Lib/test/decimaltestdata/ddFMA.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
precision: 16
maxExponent: 384
@@ -1663,6 +1663,34 @@
ddfma375088 fma 1 12345678 1E-34 -> 12345678.00000001 Inexact Rounded
ddfma375089 fma 1 12345678 1E-35 -> 12345678.00000001 Inexact Rounded
+-- desctructive subtraction (from remainder tests)
+
+-- +++ some of these will be off-by-one remainder vs remainderNear
+
+ddfma4000 fma -1234567890123454 1.000000000000001 1234567890123456 -> 0.765432109876546
+ddfma4001 fma -1234567890123443 1.00000000000001 1234567890123456 -> 0.65432109876557
+ddfma4002 fma -1234567890123332 1.0000000000001 1234567890123456 -> 0.5432109876668
+ddfma4003 fma -308641972530863 4.000000000000001 1234567890123455 -> 2.691358027469137
+ddfma4004 fma -308641972530863 4.000000000000001 1234567890123456 -> 3.691358027469137
+ddfma4005 fma -246913578024696 4.9999999999999 1234567890123456 -> 0.6913578024696
+ddfma4006 fma -246913578024691 4.99999999999999 1234567890123456 -> 3.46913578024691
+ddfma4007 fma -246913578024691 4.999999999999999 1234567890123456 -> 1.246913578024691
+ddfma4008 fma -246913578024691 5.000000000000001 1234567890123456 -> 0.753086421975309
+ddfma4009 fma -246913578024690 5.00000000000001 1234567890123456 -> 3.53086421975310
+ddfma4010 fma -246913578024686 5.0000000000001 1234567890123456 -> 1.3086421975314
+ddfma4011 fma -1234567890123455 1.000000000000001 1234567890123456 -> -0.234567890123455
+ddfma4012 fma -1234567890123444 1.00000000000001 1234567890123456 -> -0.34567890123444
+ddfma4013 fma -1234567890123333 1.0000000000001 1234567890123456 -> -0.4567890123333
+ddfma4014 fma -308641972530864 4.000000000000001 1234567890123455 -> -1.308641972530864
+ddfma4015 fma -308641972530864 4.000000000000001 1234567890123456 -> -0.308641972530864
+ddfma4016 fma -246913578024696 4.9999999999999 1234567890123456 -> 0.6913578024696
+ddfma4017 fma -246913578024692 4.99999999999999 1234567890123456 -> -1.53086421975308
+ddfma4018 fma -246913578024691 4.999999999999999 1234567890123456 -> 1.246913578024691
+ddfma4019 fma -246913578024691 5.000000000000001 1234567890123456 -> 0.753086421975309
+ddfma4020 fma -246913578024691 5.00000000000001 1234567890123456 -> -1.46913578024691
+ddfma4021 fma -246913578024686 5.0000000000001 1234567890123456 -> 1.3086421975314
+
+
-- Null tests
ddfma39990 fma 1 10 # -> NaN Invalid_operation
ddfma39991 fma 1 # 10 -> NaN Invalid_operation