re PR c/84873 (ICE: verify_ssa failed (error: definition in block 3 does not…

re PR c/84873 (ICE: verify_ssa failed (error: definition in block 3 does not dominate use in block 4))

2018-03-15  Richard Biener  <rguenther@suse.de>

	PR c/84873
	* c-gimplify.c (c_gimplify_expr): Do not fold expressions.

	* c-c++-common/pr84873.c: New testcase.

From-SVN: r258556

gcc/c-family/ChangeLog

+2018-03-15  Richard Biener  <rguenther@suse.de>
+
+	PR c/84873
+	* c-gimplify.c (c_gimplify_expr): Do not fold expressions.
+
 2018-03-13  Martin Sebor  <msebor@redhat.com>
 
 	PR tree-optimization/84725

gcc/c-family/c-gimplify.c

@@ -245,7 +245,15 @@ c_gimplify_expr (tree *expr_p, gimple_seq *pre_p ATTRIBUTE_UNUSED,
 				    unsigned_type_node)
 	    && !types_compatible_p (TYPE_MAIN_VARIANT (TREE_TYPE (*op1_p)),
 				    integer_type_node))
-	  *op1_p = convert (unsigned_type_node, *op1_p);
+	  {
+	    /* ???  Do not use convert () here or fold arbitrary trees
+	       since folding can introduce tree sharing which is not
+	       allowed during gimplification.  */
+	    if (TREE_CODE (*op1_p) == INTEGER_CST)
+	      *op1_p = fold_convert (unsigned_type_node, *op1_p);
+	    else
+	      *op1_p = build1 (NOP_EXPR, unsigned_type_node, *op1_p);
+	  }
 	break;
       }
 

gcc/testsuite/ChangeLog

+2018-03-15  Richard Biener  <rguenther@suse.de>
+
+	PR c/84873
+	* c-c++-common/pr84873.c: New testcase.
+
 2018-03-15  Tamar Christina  <tamar.christina@arm.com>
 
 	PR target/84711

gcc/testsuite/c-c++-common/pr84873.c

+/* { dg-do compile } */
+/* { dg-additional-options "-frounding-math" } */
+
+int
+i1 (int w3, int n9)
+{
+  return w3 >> ((long int)(1 + 0.1) + -!n9);
+}