re PR tree-optimization/82449 (code-gen error in get_rename_from_scev)

2017-10-09  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/82449
	* sese.c (scev_analyzable_p): Check whether the SCEV is linear.
	* tree-chrec.h (evolution_function_is_constant_p): Adjust to
	allow constant addresses.
	* tree-chrec.c (scev_is_linear_expression): Constant evolutions
	are linear.

	* gfortran.dg/graphite/pr82449.f: New testcase.

From-SVN: r253546

gcc/ChangeLog

+2017-10-09  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/82449
+	* sese.c (scev_analyzable_p): Check whether the SCEV is linear.
+	* tree-chrec.h (evolution_function_is_constant_p): Adjust to
+	allow constant addresses.
+	* tree-chrec.c (scev_is_linear_expression): Constant evolutions
+	are linear.
+
 2017-10-09  Andreas Krebbel  <krebbel@linux.vnet.ibm.com>
 
 	* config/s390/s390-builtins.def (vec_nabs, vec_vfi): Fix builtin

gcc/sese.c

@@ -444,14 +444,13 @@ scev_analyzable_p (tree def, sese_l &region)
   loop = loop_containing_stmt (SSA_NAME_DEF_STMT (def));
   scev = scalar_evolution_in_region (region, loop, def);
 
-  return !chrec_contains_undetermined (scev)
-    && (TREE_CODE (scev) != SSA_NAME
-	|| !defined_in_sese_p (scev, region))
-    && (tree_does_not_contain_chrecs (scev)
-	|| evolution_function_is_affine_p (scev))
-    && (! loop
-	|| ! loop_in_sese_p (loop, region)
-	|| ! chrec_contains_symbols_defined_in_loop (scev, loop->num));
+  return (!chrec_contains_undetermined (scev)
+	  && (TREE_CODE (scev) != SSA_NAME
+	      || !defined_in_sese_p (scev, region))
+	  && scev_is_linear_expression (scev)
+	  && (! loop
+	      || ! loop_in_sese_p (loop, region)
+	      || ! chrec_contains_symbols_defined_in_loop (scev, loop->num)));
 }
 
 /* Returns the scalar evolution of T in REGION.  Every variable that

gcc/testsuite/ChangeLog

+2017-10-09  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/82449
+	* gfortran.dg/graphite/pr82449.f: New testcase.
+
 2017-10-09  Andreas Krebbel  <krebbel@linux.vnet.ibm.com>
 
 	PR target/82463

gcc/testsuite/gfortran.dg/graphite/pr82449.f

+! { dg-do compile }
+! { dg-options "-O2 -floop-nest-optimize" }
+
+      SUBROUTINE JDFIDX(MKL,KGSH)
+      DIMENSION MKL(6,6)
+      NKL=0
+  400 DO 40 KG = 1,KGSH
+      DO 40 LG = 1,KG
+      NKL = NKL + 1
+   40 MKL(LG,KG) = NKL
+      END

gcc/tree-chrec.c

@@ -1610,6 +1610,9 @@ operator_is_linear (tree scev)
 bool
 scev_is_linear_expression (tree scev)
 {
+  if (evolution_function_is_constant_p (scev))
+    return true;
+
   if (scev == NULL
       || !operator_is_linear (scev))
     return false;

gcc/tree-chrec.h

@@ -169,15 +169,9 @@ evolution_function_is_constant_p (const_tree chrec)
   if (chrec == NULL_TREE)
     return false;
 
-  switch (TREE_CODE (chrec))
-    {
-    case INTEGER_CST:
-    case REAL_CST:
-      return true;
-
-    default:
-      return false;
-    }
+  if (CONSTANT_CLASS_P (chrec))
+    return true;
+  return is_gimple_min_invariant (chrec);
 }
 
 /* Determine whether CHREC is an affine evolution function in LOOPNUM.  */