From: Alan Hayward <alan.hayward@arm.com>
Date: Mon, 1 Aug 2016 14:33:23 +0000 (+0000)
Subject: re PR tree-optimization/71818 (ICE in as_a, at is-a.h:192 w/ -O2 -ftree-vectorize)
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=2a93954eab0822f95212374d7677b85b659ae4a1;p=gcc.git

re PR tree-optimization/71818 (ICE in as_a, at is-a.h:192 w/ -O2 -ftree-vectorize)

2016-08-01  Alan Hayward  <alan.hayward@arm.com>

gcc/
	PR tree-optimization/71818
	* tree-vect-loop-manip.c (vect_can_advance_ivs_p): Don't advance IVs
	with non invariant evolutions

testsuite/
	PR tree-optimization/71818
	* gcc.dg/vect/pr71818.c: New

From-SVN: r238955
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index d5643ceaae3..e97f2ccc630 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2015-08-01  Alan Hayward <alan.hayward@arm.com>
+
+	PR tree-optimization/71818
+	* tree-vect-loop-manip.c (vect_can_advance_ivs_p): Don't advance IVs
+	with non invariant evolutions
+
 2016-08-01  Georg-Johann Lay  <avr@gjlay.de>
 
 	PR target/72767
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 2e015d927da..8b65b3ee01f 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2015-08-01  Alan Hayward <alan.hayward@arm.com>
+
+	PR tree-optimization/71818
+	* gcc.dg/vect/pr71818.c: New
+
 2016-08-01  Martin Liska  <mliska@suse.cz>
 
 	PR tree-optimization/71857
diff --git a/gcc/testsuite/gcc.dg/vect/pr71818.c b/gcc/testsuite/gcc.dg/vect/pr71818.c
new file mode 100644
index 00000000000..2946551f8bb
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/pr71818.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+
+char a;
+short b;
+int c, d;
+void fn1() {
+  char e = 75, g;
+  unsigned char *f = &e;
+  a = 21;
+  for (; a <= 48; a++) {
+    for (; e <= 6;)
+      ;
+    g -= e -= b || g <= c;
+  }
+  d = *f;
+}
diff --git a/gcc/tree-vect-loop-manip.c b/gcc/tree-vect-loop-manip.c
index c1381b366cf..ec863b4af1f 100644
--- a/gcc/tree-vect-loop-manip.c
+++ b/gcc/tree-vect-loop-manip.c
@@ -40,6 +40,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "cfgloop.h"
 #include "tree-scalar-evolution.h"
 #include "tree-vectorizer.h"
+#include "tree-ssa-loop-ivopts.h"
 
 /*************************************************************************
   Simple Loop Peeling Utilities
@@ -1591,11 +1592,27 @@ vect_can_advance_ivs_p (loop_vec_info loop_vinfo)
 	  return false;
         }
 
+      /* FORNOW: We do not transform initial conditions of IVs
+	 which evolution functions are not invariants in the loop.  */
+
+      if (!expr_invariant_in_loop_p (loop, evolution_part))
+	{
+	  if (dump_enabled_p ())
+	    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
+			     "evolution not invariant in loop.\n");
+	  return false;
+	}
+
       /* FORNOW: We do not transform initial conditions of IVs
 	 which evolution functions are a polynomial of degree >= 2.  */
 
       if (tree_is_chrec (evolution_part))
-	return false;
+	{
+	  if (dump_enabled_p ())
+	    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
+			     "evolution is chrec.\n");
+	  return false;
+	}
     }
 
   return true;