From: rguenth <rguenth@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Mon, 21 Mar 2016 09:11:37 +0000 (+0000)
Subject: 2016-03-21  Richard Biener  <rguenther@suse.de>
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=93505d2263b79f3e5967ae1fec082cf0843e610a;p=thirdparty%2Fgcc.git

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.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@234361 138bc75d-0d04-0410-961f-82ee72b054a4
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index f4431a02bdb8..2efe7ea31fa7 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+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
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index d022eb12fa99..f7ca6848fd04 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+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
diff --git a/gcc/testsuite/gcc.dg/torture/pr70288-1.c b/gcc/testsuite/gcc.dg/torture/pr70288-1.c
new file mode 100644
index 000000000000..1fb049548faa
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr70288-1.c
@@ -0,0 +1,36 @@
+/* { 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);
+}
diff --git a/gcc/testsuite/gcc.dg/torture/pr70288-2.c b/gcc/testsuite/gcc.dg/torture/pr70288-2.c
new file mode 100644
index 000000000000..ad90fd45887f
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr70288-2.c
@@ -0,0 +1,35 @@
+/* { 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);
+}
diff --git a/gcc/tree-ssa-loop-ivcanon.c b/gcc/tree-ssa-loop-ivcanon.c
index 1a4d6df7062b..72f91b273421 100644
--- a/gcc/tree-ssa-loop-ivcanon.c
+++ b/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");