re PR tree-optimization/70288 (ICE with -O1 -fno-tree-dominator-opts)

2016-03-21  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/70288
	* tree-ssa-loop-ivcanon.c (tree_estimate_loop_size): Make sure
	we do not estimate unsimplified all-constant conditionals or
	switches as optimized away.

	* gcc.dg/torture/pr70288-1.c: New testcase.
	* gcc.dg/torture/pr70288-2.c: Likewise.

From-SVN: r234361

gcc/ChangeLog

+2016-03-21  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/70288
+	* tree-ssa-loop-ivcanon.c (tree_estimate_loop_size): Make sure
+	we do not estimate unsimplified all-constant conditionals or
+	switches as optimized away.
+
 2016-03-21  Andrey Belevantsev  <abel@ispras.ru>
 
 	PR rtl-optimization/69102

gcc/testsuite/ChangeLog

+2016-03-21  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/70288
+	* gcc.dg/torture/pr70288-1.c: New testcase.
+	* gcc.dg/torture/pr70288-2.c: Likewise.
+
 2016-03-21  Andrey Belevantsev  <abel@ispras.ru>
 
 	PR rtl-optimization/69307

gcc/testsuite/gcc.dg/torture/pr70288-1.c

+/* { dg-do compile } */
+/* { dg-require-effective-target int32plus } */
+
+int main()
+{
+  int var6 = -1267827473;
+  do {
+      ++var6;
+      double s1_115[4], s2_108[4];
+      int var8 = -161498264;
+      do {
+	  ++var8;
+	  int var12 = 1260960076;
+	  for (; var12 <= 1260960080; ++var12) {
+	      int var13 = 1960990937;
+	      do {
+		  ++var13;
+		  int var14 = 2128638723;
+		  for (; var14 <= 2128638728; ++var14) {
+		      int var22 = -1141190839;
+		      do {
+			  ++var22;
+			  if (s2_108 > s1_115) {
+			      int var23 = -890798748;
+			      do {
+				  ++var23;
+				  long long e_119[4];
+			      } while (var23 <= -890798746);
+			  }
+		      } while (var22 <= -1141190829);
+		  }
+	      } while (var13 <= 1960990946);
+	  }
+      } while (var8 <= -161498254);
+  } while (var6 <= -1267827462);
+}

gcc/testsuite/gcc.dg/torture/pr70288-2.c

+/* { dg-do compile } */
+/* { dg-require-effective-target int32plus } */
+
+int main()
+{
+  int var6 = -1267827473;
+  do {
+      ++var6;
+      double s1_115[4], s2_108[4];
+      int var8 = -161498264;
+      do {
+	  ++var8;
+	  int var12 = 1260960076;
+	  for (; var12 <= 1260960080; ++var12) {
+	      int var13 = 1960990937;
+	      do {
+		  ++var13;
+		  int var14 = 2128638723;
+		  for (; var14 <= 2128638728; ++var14) {
+		      int var22 = -1141190839;
+		      do {
+			  ++var22;
+			  if (s2_108 > s1_115) {
+			      int var23 = -890798748;
+			      do {
+				  long long e_119[4];
+			      } while (var23 <= -890798746);
+			  }
+		      } while (var22 <= -1141190829);
+		  }
+	      } while (var13 <= 1960990946);
+	  }
+      } while (var8 <= -161498254);
+  } while (var6 <= -1267827462);
+}

gcc/tree-ssa-loop-ivcanon.c

@@ -298,11 +298,17 @@ tree_estimate_loop_size (struct loop *loop, edge exit, edge edge_to_cancel, stru
 	  /* Conditionals.  */
 	  else if ((gimple_code (stmt) == GIMPLE_COND
 		    && constant_after_peeling (gimple_cond_lhs (stmt), stmt, loop)
-		    && constant_after_peeling (gimple_cond_rhs (stmt), stmt, loop))
+		    && constant_after_peeling (gimple_cond_rhs (stmt), stmt, loop)
+		    /* We don't simplify all constant compares so make sure
+		       they are not both constant already.  See PR70288.  */
+		    && (! is_gimple_min_invariant (gimple_cond_lhs (stmt))
+			|| ! is_gimple_min_invariant (gimple_cond_rhs (stmt))))
 		   || (gimple_code (stmt) == GIMPLE_SWITCH
 		       && constant_after_peeling (gimple_switch_index (
 						    as_a <gswitch *> (stmt)),
-						  stmt, loop)))
+						  stmt, loop)
+		       && ! is_gimple_min_invariant (gimple_switch_index (
+						       as_a <gswitch *> (stmt)))))
 	    {
 	      if (dump_file && (dump_flags & TDF_DETAILS))
 	        fprintf (dump_file, "   Constant conditional.\n");