re PR tree-optimization/90021 (ICE in index_in_loop_nest, at tree-data-ref.h:587 since r270203)

	PR tree-optimization/92001
	* tree-chrec.c (evolution_function_is_univariate_p): New parameter
	and check univariate against it.
	* tree-chrec.h (evolution_function_is_univariate_p): New parameter.
	* tree-data-ref.c (add_other_self_distances): Pass new argument.

	gcc/testsuite
	* gcc/testsuite/gfortran.dg/pr90021.f90: New test.

From-SVN: r270499

gcc/ChangeLog

+2019-04-23  Bin Cheng  <bin.cheng@linux.alibaba.com>
+
+	PR tree-optimization/92001
+	* tree-chrec.c (evolution_function_is_univariate_p): New parameter
+	and check univariate against it.
+	* tree-chrec.h (evolution_function_is_univariate_p): New parameter.
+	* tree-data-ref.c (add_other_self_distances): Pass new argument.
+
 2019-04-21  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR target/90178

gcc/testsuite/ChangeLog

+2018-04-23  Bin Cheng  <bin.cheng@linux.alibaba.com>
+
+	PR tree-optimization/92001
+	* gcc/testsuite/gfortran.dg/pr90021.f90: New test.
+
 2019-04-22  Steven G. Kargl  <kargl@gcc.gnu.org>
 
 	PR fortran/90166

gcc/testsuite/gfortran.dg/pr90021.f90

+! { dg-do compile }
+! { dg-options "-fno-tree-loop-ivcanon -O1 -floop-interchange -fno-tree-ccp -fno-tree-ch -fipa-pta" }
+! PR tree-optimization/90021
+
+MODULE a
+  INTEGER b
+CONTAINS
+  SUBROUTINE bar(c)
+    REAL c(1)
+    INTEGER g, d, e, f 
+    DO g = 1,3
+      DO f = 1,1
+        DO e = 1,3
+          DO d = 1,1
+            c(f-1+d) = c(f-1+d)*b
+          END DO
+        END DO
+      END DO
+    END DO
+  END
+  END

gcc/tree-chrec.c

@@ -1142,23 +1142,30 @@ evolution_function_is_affine_multivariate_p (const_tree chrec, int loopnum)
 }
 
 /* Determine whether the given tree is a function in zero or one
-   variables.  */
+   variables with respect to loop specified by LOOPNUM.  Note only positive
+   LOOPNUM stands for a real loop.  */
 
 bool
-evolution_function_is_univariate_p (const_tree chrec)
+evolution_function_is_univariate_p (const_tree chrec, int loopnum)
 {
   if (chrec == NULL_TREE)
     return true;
 
+  tree sub_chrec;
   switch (TREE_CODE (chrec))
     {
     case POLYNOMIAL_CHREC:
       switch (TREE_CODE (CHREC_LEFT (chrec)))
 	{
 	case POLYNOMIAL_CHREC:
-	  if (CHREC_VARIABLE (chrec) != CHREC_VARIABLE (CHREC_LEFT (chrec)))
+	  sub_chrec = CHREC_LEFT (chrec);
+	  if (CHREC_VARIABLE (chrec) != CHREC_VARIABLE (sub_chrec)
+	      && (loopnum <= 0
+		  || CHREC_VARIABLE (sub_chrec) == (unsigned) loopnum
+		  || flow_loop_nested_p (get_loop (cfun, loopnum),
+					 get_chrec_loop (sub_chrec))))
 	    return false;
-	  if (!evolution_function_is_univariate_p (CHREC_LEFT (chrec)))
+	  if (!evolution_function_is_univariate_p (sub_chrec, loopnum))
 	    return false;
 	  break;
 
@@ -1171,9 +1178,14 @@ evolution_function_is_univariate_p (const_tree chrec)
       switch (TREE_CODE (CHREC_RIGHT (chrec)))
 	{
 	case POLYNOMIAL_CHREC:
-	  if (CHREC_VARIABLE (chrec) != CHREC_VARIABLE (CHREC_RIGHT (chrec)))
+	  sub_chrec = CHREC_RIGHT (chrec);
+	  if (CHREC_VARIABLE (chrec) != CHREC_VARIABLE (sub_chrec)
+	      && (loopnum <= 0
+		  || CHREC_VARIABLE (sub_chrec) == (unsigned) loopnum
+		  || flow_loop_nested_p (get_loop (cfun, loopnum),
+					 get_chrec_loop (sub_chrec))))
 	    return false;
-	  if (!evolution_function_is_univariate_p (CHREC_RIGHT (chrec)))
+	  if (!evolution_function_is_univariate_p (sub_chrec, loopnum))
 	    return false;
 	  break;
 

gcc/tree-chrec.h

@@ -85,7 +85,7 @@ extern bool chrec_contains_symbols_defined_in_loop (const_tree, unsigned);
 extern bool chrec_contains_undetermined (const_tree);
 extern bool tree_contains_chrecs (const_tree, int *);
 extern bool evolution_function_is_affine_multivariate_p (const_tree, int);
-extern bool evolution_function_is_univariate_p (const_tree);
+extern bool evolution_function_is_univariate_p (const_tree, int = 0);
 extern unsigned nb_vars_in_chrec (tree);
 extern bool evolution_function_is_invariant_p (tree, int);
 extern bool scev_is_linear_expression (tree);

gcc/tree-data-ref.c

@@ -4431,7 +4431,7 @@ add_other_self_distances (struct data_dependence_relation *ddr)
 
       if (TREE_CODE (access_fun) == POLYNOMIAL_CHREC)
 	{
-	  if (!evolution_function_is_univariate_p (access_fun))
+	  if (!evolution_function_is_univariate_p (access_fun, loop->num))
 	    {
 	      if (DDR_NUM_SUBSCRIPTS (ddr) != 1)
 		{