test for bug #1720

tests/webtbs/tw1720.pp

@@ -0,0 +1,27 @@
+{ Source provided for Free Pascal Bug Report 1720 }
+{ Submitted by "Jesse Towner" on  2001-12-09 }
+{ e-mail: jesse@gdnmail.net }
+var a, b, c : single;
+begin
+    (* ... other floating point code goes here *)
+
+    a := 5.6;
+    b := 3.4;
+    b:= b + sqrt(b)- ln(a);
+
+    c := a - (b-(b-1));
+
+    if abs(c-(a-1))>0.01 then
+      begin
+        Writeln('Error in floating point code');
+        halt(1);
+      end;
+    (* sometimes, depending on the previous code,
+       the code generator will chose to swap the
+       operands. however, it just calls the
+       reverse version of the instruction without
+       swapping the operands. this results in
+       giving a value of (b-a) or -2.2 for c. the
+       same goes for floating point division. *)
+end.
+