re PR tree-optimization/82819 ([graphite] ICE in set_codegen_error, at…

re PR tree-optimization/82819 ([graphite] ICE in set_codegen_error, at graphite-isl-ast-to-gimple.c:206)

2018-01-24  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/82819
	* graphite-isl-ast-to-gimple.c (binary_op_to_tree): Avoid
	code generating pluses that are no-ops in the target precision.

	* gcc.dg/graphite/pr82819.c: New testcase.

From-SVN: r257012

gcc/ChangeLog

 2018-01-24  Richard Biener  <rguenther@suse.de>
 
+	PR tree-optimization/82819
+	* graphite-isl-ast-to-gimple.c (binary_op_to_tree): Avoid
+	code generating pluses that are no-ops in the target precision.
+
+2018-01-24  Richard Biener  <rguenther@suse.de>
+
 	PR middle-end/84000
 	* tree-cfg.c (replace_loop_annotate): Handle annot_expr_parallel_kind.
 

gcc/graphite-isl-ast-to-gimple.c

@@ -326,7 +326,8 @@ binary_op_to_tree (tree type, __isl_take isl_ast_expr *expr, ivs_params &ip)
   /* From our constraint generation we may get modulo operations that
      we cannot represent explicitely but that are no-ops for TYPE.
      Elide those.  */
-  if (expr_type == isl_ast_op_pdiv_r
+  if ((expr_type == isl_ast_op_pdiv_r
+       || expr_type == isl_ast_op_add)
       && isl_ast_expr_get_type (arg_expr) == isl_ast_expr_int
       && (wi::exact_log2 (widest_int_from_isl_expr_int (arg_expr))
 	  >= TYPE_PRECISION (type)))

gcc/testsuite/ChangeLog

+2018-01-24  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/82819
+	* gcc.dg/graphite/pr82819.c: New testcase.
+
 2018-01-23  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/83921

gcc/testsuite/gcc.dg/graphite/pr82819.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -floop-nest-optimize" } */
+
+short int *ts;
+
+void
+c2 (unsigned long long int s4, int ns)
+{
+  short int *b2 = (short int *)&ns;
+
+  while (ns != 0)
+    {
+      int xn;
+
+      for (xn = 0; xn < 3; ++xn)
+	for (*b2 = 0; *b2 < 2; ++*b2)
+	  s4 += xn;
+      if (s4 != 0)
+	b2 = ts;
+      ++ns;
+    }
+}