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[PATCH] Fix PR82244


The following fixes a bug in VRP where on removal of asserts it ended
up propagating a constant in place of abnormal SSA uses.  That doesn't
work when the use is in an abnormal PHI thus instead replace the
assert with a copy in that case.

Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.

Richard.

2017-09-19  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/82244
	* tree-vrp.c (remove_range_assertions): Do not propagate
	a constant to abnormals but replace the assert with a copy.

	* gcc.dg/torture/pr82244.c: New testcase.

Index: gcc/tree-vrp.c
===================================================================
--- gcc/tree-vrp.c	(revision 252968)
+++ gcc/tree-vrp.c	(working copy)
@@ -7039,6 +7039,14 @@ remove_range_assertions (void)
 		  FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
 		    SET_USE (use_p, var);
 	      }
+	    /* But do not propagate constants as that is invalid.  */
+	    else if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs))
+	      {
+		gassign *ass = gimple_build_assign (lhs, var);
+		gsi_replace (&si, ass, true);
+		gsi_next (&si);
+		continue;
+	      }
 	    else
 	      replace_uses_by (lhs, var);
 
Index: gcc/testsuite/gcc.dg/torture/pr82244.c
===================================================================
--- gcc/testsuite/gcc.dg/torture/pr82244.c	(nonexistent)
+++ gcc/testsuite/gcc.dg/torture/pr82244.c	(working copy)
@@ -0,0 +1,31 @@
+/* { dg-do compile } */
+
+typedef struct a {
+  struct a *b;
+} a;
+
+extern int d(void);
+extern int g(void);
+extern int h(void);
+extern int _setjmp(void *);
+
+int c(void)
+{
+  1 ? d() : 0;
+
+  a *e;
+  while (e) {
+      e = (e == (a *) c) ? 0 : e->b;
+      while (e) {
+	  int f = 0;
+	  g();
+	  if (_setjmp(0)) {
+	      if (f & 6) {
+		  ;
+	      } else if (f & 2) {
+		  h();
+	      }
+	  }
+      }
+  }
+}


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