[backport from gcc-4.8/trunk r186321 <mikpe@it.uu.se>]

gcc/

2012-04-11  Richard Guenther  <rguenther@suse.de>

	PR middle-end/52621
	* tree-chrec.c (evolution_function_is_invariant_rec_p): Properly
	consider loop nesting.
	(evolution_function_is_univariate_p): Properly check the remainder
	for chrecs.

gcc/testsuite/

2012-04-11  Richard Guenther  <rguenther@suse.de>

	PR middle-end/52621
	* gfortran.dg/pr52621.f90: New testcase.

--- gcc-4.6.3/gcc/testsuite/gfortran.dg/pr52621.f90.~1~	1970-01-01 01:00:00.000000000 +0100
+++ gcc-4.6.3/gcc/testsuite/gfortran.dg/pr52621.f90	2012-06-10 11:53:57.000000000 +0200
@@ -0,0 +1,20 @@
+! { dg-do compile }
+! { dg-options "-O2 -fprefetch-loop-arrays" }
+
+      SUBROUTINE GHDSYM(IZ,IS,LMMAX,S,LMS,Y,L2M,DRL,NLAY2,K0,DCUT)!,
+!
+      COMPLEX Y(L2M,L2M),H(33),S(LMS)
+      COMPLEX RU,CI,CZ,K0,FF,Z,Z1,Z2,Z3,ST
+!
+      DO 140 KK=1,4
+            DO 130 L=1,L2M
+               L1=L*L-L
+               DO 120 M=1,L
+                  IPM=L1+M
+                  IMM=L1-M+2
+                  S(IPM)=S(IPM)+Z3*Y(L,M)
+                  IF (M.NE.1) S(IMM)=S(IMM)+Z3*Y(M-1,L)*CSGN
+120            CONTINUE
+130         CONTINUE
+140   CONTINUE
+      END
--- gcc-4.6.3/gcc/tree-chrec.c.~1~	2011-02-12 01:12:52.000000000 +0100
+++ gcc-4.6.3/gcc/tree-chrec.c	2012-06-10 11:53:57.000000000 +0200
@@ -1008,6 +1008,8 @@ evolution_function_is_invariant_rec_p (t
   if (TREE_CODE (chrec) == POLYNOMIAL_CHREC)
     {
       if (CHREC_VARIABLE (chrec) == (unsigned) loopnum
+	  || flow_loop_nested_p (get_loop (loopnum),
+				 get_loop (CHREC_VARIABLE (chrec)))
 	  || !evolution_function_is_invariant_rec_p (CHREC_RIGHT (chrec),
 						     loopnum)
 	  || !evolution_function_is_invariant_rec_p (CHREC_LEFT (chrec),
@@ -1111,6 +1113,8 @@ evolution_function_is_univariate_p (cons
 	  break;
 
 	default:
+	  if (tree_contains_chrecs (CHREC_LEFT (chrec), NULL))
+	    return false;
 	  break;
 	}
 
@@ -1124,6 +1128,8 @@ evolution_function_is_univariate_p (cons
 	  break;
 
 	default:
+	  if (tree_contains_chrecs (CHREC_RIGHT (chrec), NULL))
+	    return false;
 	  break;
 	}