1 files changed, 64 insertions, 0 deletions
diff --git a/gcc/testsuite/gcc.dg/tree-ssa-chrec/ssa-chrec-43.c b/gcc/testsuite/gcc.dg/tree-ssa-chrec/ssa-chrec-43.c
new file mode 100644
index 00000000000..16ea96731b2
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa-chrec/ssa-chrec-43.c
@@ -0,0 +1,64 @@
+/* { dg-do compile } */ 
+/* { dg-options "-O1 -fscalar-evolutions -fdump-tree-scev-details" } */
+
+
+int main ()
+{
+  int a = 1;
+  int b = 2;
+  int c = 0;
+  int d = 5;
+  int e;
+  
+  while (a) 
+    {
+      /* The following statement produces the evolution function:
+	 (add_to_evolution 
+	   loop_num = 1
+	   chrec_before = 1
+	   to_add = {{2, +, 0}_1, +, 10}_1
+	   res = {{{1, +, 2}_1, +, 0}_1, +, 10}_1
+	 )
+	 Note that the evolution of B in the inner loop_2 is not
+	 relevant to the evolution of A in the loop_1.  */
+      a += b; 
+      
+      /* And finally the following statement produces the expected scev:
+	 (add_to_evolution 
+	   loop_num = 1
+	   chrec_before = {{{1, +, 2}_1, +, 0}_1, +, 10}_1
+	   to_add = {5, +, 9}_1
+	   res = {{{1, +, 7}_1, +, 9}_1, +, 10}_1
+	 )
+	 That ends this not so formal proof ("CQFD" in french ;-).  */
+      a += d;
+      
+      for (e = 0; e < 10; e++)
+	b += c;
+      /* After having analyzed this loop, the overall effect is added to the evolution of b.  
+	 This corresponds to the following operation:
+	 (add_to_evolution 
+	   loop_num = 1
+	   chrec_before = {2, +, {0, +, 1}_1}_2
+	   to_add = {0, +, 10}_1
+	   res = {{{2, +, 0}_1, +, 10}_1, +, {0, +, 1}_1}_2
+	 ).
+	 Note that the variable c has not yet been updated in the loop, and thus its value 
+	 at this version is "{0, +, 1}_1".  Since the loop_2 runs exactly 10 times, the overall
+	 effect of the loop is "10 * {0, +, 1}_1": that is the TO_ADD argument.  
+      */
+      
+      c += 1;
+      d += 9;
+    }
+}
+
+/* 
+   c  ->  {0, +, 1}_1
+   e  ->  {0, +, 1}_2
+   b  ->  {{2, +, 0, +, 10}_1, +, {0, +, 1}_1}_2
+   d  ->  {5, +, 9}_1
+   a  ->  {1, +, 7, +, 9, +, 10}_1
+*/
+
+/* FIXME. */