Fix PR48805: Do not instantiate ADDR_EXPRs

With this patch we avoid instantiating ADDR_EXPR: it makes no sense
to translate &b[i] into &b[{0, +, 1}_1].

Bootstrapped and tested on amd64-linux.

2011-07-26  Sebastian Pop  <sebastian.pop@amd.com>

	PR middle-end/48805
	* tree-scalar-evolution.c (instantiate_scev_r): Return
	chrec_dont_know for ADDR_EXPR.

	* gcc.dg/graphite/id-pr48805.c: New.

From-SVN: r176801

gcc/ChangeLog

+2011-07-26  Sebastian Pop  <sebastian.pop@amd.com>
+
+	PR middle-end/48805
+	* tree-scalar-evolution.c (instantiate_scev_r): Return
+	chrec_dont_know for ADDR_EXPR.
+
 2011-07-26  Uros Bizjak  <ubizjak@gmail.com>
 	    H.J. Lu  <hongjiu.lu@intel.com>
 

gcc/testsuite/ChangeLog

+2011-07-26  Sebastian Pop  <sebastian.pop@amd.com>
+
+	PR middle-end/48805
+	* gcc.dg/graphite/id-pr48805.c: New.
+
 2011-07-26  Tobias Burnus  <burnus@net-b.de>
 
 	* gfortran.dg/coarray_lib_token_2.f90: New.
@@ -12,7 +17,7 @@
 	PR tree-opt/49671
 	* gcc.dg/tree-ssa/pr49671-1.c: New testcase.
 	* gcc.dg/tree-ssa/pr49671-2.c: New testcase.
-	
+
 2011-07-25  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
 
 	* lib/target-supports.exp (check_effective_target_mmap): New proc.

gcc/testsuite/gcc.dg/graphite/id-pr48805.c

+void *A(const void *a);
+void C(void);
+
+static void B(unsigned short a[])
+{
+  long i, j, tmp;
+
+  for(i = 0; i < 3; i++) {
+    for(j = 1; j <= 3; j++)
+      tmp -= a[i - j];
+
+    a[i] = (unsigned short)(tmp >> 1);
+  }
+}
+void C(void)
+{
+  unsigned short a[3], b[3];
+  B(b + 1);
+  A(a);
+}

gcc/tree-scalar-evolution.c

@@ -2645,6 +2645,7 @@ instantiate_scev_r (basic_block instantiate_below,
 				   TREE_OPERAND (chrec, 0),
 				   fold_conversions, cache, size_expr);
 
+    case ADDR_EXPR:
     case SCEV_NOT_KNOWN:
       return chrec_dont_know;