diff --git a/test/val/sub3.c b/test/val/sub3.c
new file mode 100644
index 000000000..2a3646f9a
--- /dev/null
+++ b/test/val/sub3.c
@@ -0,0 +1,192 @@
+/*
+  !!DESCRIPTION!! Subtraction Test
+  !!ORIGIN!!      SDCC regression tests
+  !!LICENCE!!     GPL, read COPYING.GPL
+*/
+
+#include <stdio.h>
+#include <limits.h>
+
+unsigned char failures=0;
+
+int int0 = 5;
+unsigned int int1 = 5;
+
+void pre_dec_test(void)
+{
+  if(int0 != 5)
+    failures++;
+  if(int1 != 5)
+    failures++;
+
+  --int0;
+  --int1;
+
+  if(int0 != 4)
+    failures++;
+  if(int1 != 4)
+    failures++;
+
+  --int0;
+  --int1;
+  --int0;
+  --int1;
+  --int0;
+  --int1;
+  --int0;
+  --int1;
+
+  if(int0 != 0)
+    failures++;
+  if(int1 != 0)
+    failures++;
+
+  --int0;
+  --int1;
+
+  if(int0 != -1)
+    failures++;
+  if(int1 != 65535U)
+    failures++;
+}
+
+void post_dec_test(void)
+{
+  if(int0 != 5)
+    failures++;
+  if(int1 != 5)
+    failures++;
+
+  int0--;
+  int1--;
+
+  if(int0 != 4)
+    failures++;
+  if(int1 != 4)
+    failures++;
+
+  int0--;
+  int1--;
+  int0--;
+  int1--;
+  int0--;
+  int1--;
+  int0--;
+  int1--;
+
+  if(int0 != 0)
+    failures++;
+  if(int1 != 0)
+    failures++;
+
+  int0--;
+  int1--;
+
+  if(int0 != -1)
+    failures++;
+  if(int1 != 65535U)
+    failures++;
+}
+
+void pre_dec_assign_test(void)
+{
+  int a;
+  unsigned int b;
+  if(int0 != 5)
+    failures++;
+  if(int1 != 5)
+    failures++;
+
+  a = --int0;
+  b = --int1;
+
+  if(int0 != 4 || a != int0)
+    failures++;
+  if(int1 != 4 || b != int1)
+    failures++;
+
+  a = --int0;
+  b = --int1;
+  a = --int0;
+  b = --int1;
+  a = --int0;
+  b = --int1;
+  a = --int0;
+  b = --int1;
+
+  if(int0 != 0 || a != int0)
+    failures++;
+  if(int1 != 0 || b != int1)
+    failures++;
+
+  a = --int0;
+  b = --int1;
+
+  if(int0 != -1 || a != int0)
+    failures++;
+  if(int1 != 65535U || b != int1)
+    failures++;
+}
+
+void post_dec_assign_test(void)
+{
+  int a;
+  unsigned int b;
+  if(int0 != 5)
+    failures++;
+  if(int1 != 5)
+    failures++;
+
+  a = int0--;
+  b = int1--;
+
+  if(int0 != 4 || a != 5)
+    failures++;
+  if(int1 != 4 || b != 5)
+    failures++;
+
+  a = int0--;
+  b = int1--;
+  a = int0--;
+  b = int1--;
+  a = int0--;
+  b = int1--;
+  a = int0--;
+  b = int1--;
+
+  if(int0 != 0 || a != 1)
+    failures++;
+  if(int1 != 0 || b != 1)
+    failures++;
+
+  a = int0--;
+  b = int1--;
+
+  if(int0 != -1 || a != 0)
+    failures++;
+  if(int1 != 65535U || b != 0)
+    failures++;
+}
+
+int main(void)
+{
+  int0 = 5;
+  int1 = 5;
+  pre_dec_test();
+
+  int0 = 5;
+  int1 = 5;
+  post_dec_test();
+
+  int0 = 5;
+  int1 = 5;
+  pre_dec_assign_test();
+
+  int0 = 5;
+  int1 = 5;
+  post_dec_assign_test();
+
+  printf("failures: %d\n",failures);
+
+  return failures;
+}