1 files changed, 58 insertions, 0 deletions
diff --git a/test/TestSignAlgorithm.pas b/test/TestSignAlgorithm.pas
new file mode 100644
index 00000000..915e5681
--- /dev/null
+++ b/test/TestSignAlgorithm.pas
@@ -0,0 +1,58 @@
+program TestSignAlgorithm;
+
+uses
+  sysutils;
+
+const
+  a1 = 2;
+  a2 = 1;
+  a3 = 0;
+  a4 = -1;
+  a5 = -2;
+
+var
+  index, number: longint;
+
+begin
+  writeln;
+  writeln ('This tests the arithmetic procedure used in libavutil and libavcodec.');
+  writeln ('positive numbers should give 1, negative numbers -1.');
+  writeln ('-17: ', not((-17 shr 30) and $00000002) + 2);
+  writeln ('-16: ', not((-16 shr 30) and $00000002) + 2);
+  writeln ('-15: ', not((-15 shr 30) and $00000002) + 2);
+  writeln (' -3: ', not(( -3 shr 30) and $00000002) + 2);
+  writeln (' -2: ', not(( -2 shr 30) and $00000002) + 2);
+  writeln (' -1: ', not(( -1 shr 30) and $00000002) + 2);
+  writeln ('  0: ', not((  0 shr 30) and $00000002) + 2);
+  writeln ('  1: ', not((  1 shr 30) and $00000002) + 2);
+  writeln ('  2: ', not((  2 shr 30) and $00000002) + 2);
+  writeln ('  3: ', not((  3 shr 30) and $00000002) + 2);
+  writeln ('  8: ', not((  8 shr 30) and $00000002) + 2);
+  writeln ('MaxInt:     ', MaxInt:12, ' ', IntToHex(MaxInt,8), ' ', not((MaxInt shr 30) and $00000002) + 2);
+  writeln ('MaxLongint: ', MaxLongint:12, ' ', IntToHex(MaxLongint,8), ' ', not((MaxLongint shr 30) and $00000002) + 2);
+  writeln ('MinInt:     ', -MaxInt - 1:12, ' ', IntToHex(-MaxInt - 1,8), ' ', not(((-MaxInt - 1) shr 30) and $00000002) + 2);
+  writeln ('MinLongInt: ', -MaxLongint - 1:12, ' ', IntToHex(-MaxLongint - 1,8), ' ', not(((-MaxLongint - 1) shr 30) and $00000002) + 2);
+  writeln (a1, ' ', IntToHex(a1,8) , ' ', not((a1 shr 30) and $00000002) + 2);
+  writeln (a2, ' ', IntToHex(a2,8) , ' ', not((a2 shr 30) and $00000002) + 2);
+  writeln (a3, ' ', IntToHex(a3,8) , ' ', not((a3 shr 30) and $00000002) + 2);
+  writeln (a4, ' ', IntToHex(a4,8) , ' ', not((a4 shr 30) and $00000002) + 2);
+  writeln (a5, ' ', IntToHex(a5,8) , ' ', not((a5 shr 30) and $00000002) + 2);
+  writeln;
+  writeln ('Hit RETURN for more positive numbers. The last one overflows and becomes negative.');
+  readln;
+  number := 1;
+  for index := 1 to 32 do
+  begin
+    writeln (index:2, ': ', number:11, ' ', IntToHex(number shr 30 ,8):10, ' ', not((number shr 30) and $00000002) + 2);
+    number := number * 2;
+  end;
+  writeln;
+  writeln ('Hit RETURN for more positive numbers.');
+  readln;
+  number := -1;
+  for index := 1 to 32 do
+  begin
+    writeln (index:2, ': ', number:11, ' ', IntToHex(number shr 30 ,8):10, ' ', not((number shr 30) and $00000002) + 2);
+    number := number * 2;
+  end;
+end.
+\ No newline at end of file