From: Richard Biener <rguenther@suse.de>
Date: Wed, 18 Feb 2015 13:08:58 +0000 (+0000)
Subject: re PR tree-optimization/65063 (gcc.dg/vect/vect-double-reduc-6.c FAILs with -O3 ... 
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=8039a35df1ddf6a7ff4a77396f283547c145aa84;p=gcc.git

re PR tree-optimization/65063 (gcc.dg/vect/vect-double-reduc-6.c FAILs with -O3 -fno-tree-loop-ivcanon -fno-tree-vectorize)

2015-02-18  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/65063
	* tree-predcom.c (determine_unroll_factor): Return 1 if we
	have replaced looparound PHIs.

	* gcc.dg/pr65063.c: New testcase.

From-SVN: r220788
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 6cf817bde22..9523db04827 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2015-02-18  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/65063
+	* tree-predcom.c (determine_unroll_factor): Return 1 if we
+	have replaced looparound PHIs.
+
 2015-02-18  Martin Liska  <mliska@suse.cz>
 
 	* lto-streamer.c (lto_streamer_init): Encapsulate
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 0a1a328c7f0..5bbdfbbd9c0 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2015-02-18  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/65063
+	* gcc.dg/pr65063.c: New testcase.
+
 2015-02-18  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/62217
diff --git a/gcc/testsuite/gcc.dg/pr65063.c b/gcc/testsuite/gcc.dg/pr65063.c
new file mode 100644
index 00000000000..bcbdbf098d8
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr65063.c
@@ -0,0 +1,33 @@
+/* { dg-do run } */
+/* { dg-options "-O3 -fno-tree-loop-ivcanon -fno-tree-vectorize" } */
+
+static int in[8][4];
+static int out[4];
+static const int check_result[] = {0, 16, 256, 4096};
+
+static inline void foo ()
+{
+  int sum;
+  int i, j, k;
+  for (k = 0; k < 4; k++)
+    {
+      sum = 1;
+      for (j = 0; j < 4; j++)
+	for (i = 0; i < 4; i++)
+	  sum *= in[i + k][j];
+      out[k] = sum;
+    }
+}
+
+int main ()
+{
+  int i, j, k;
+  for (i = 0; i < 8; i++)
+    for (j = 0; j < 4; j++)
+      in[i][j] = (i + 2) / 3;
+  foo ();
+  for (k = 0; k < 4; k++)
+    if (out[k] != check_result[k])
+      __builtin_abort ();
+  return 0;
+}
diff --git a/gcc/tree-predcom.c b/gcc/tree-predcom.c
index 8dac1ba5afd..03a38b4de84 100644
--- a/gcc/tree-predcom.c
+++ b/gcc/tree-predcom.c
@@ -1775,9 +1775,21 @@ determine_unroll_factor (vec<chain_p> chains)
 
   FOR_EACH_VEC_ELT (chains, i, chain)
     {
-      if (chain->type == CT_INVARIANT || chain->combined)
+      if (chain->type == CT_INVARIANT)
 	continue;
 
+      if (chain->combined)
+	{
+	  /* For combined chains, we can't handle unrolling if we replace
+	     looparound PHIs.  */
+	  dref a;
+	  unsigned j;
+	  for (j = 1; chain->refs.iterate (j, &a); j++)
+	    if (gimple_code (a->stmt) == GIMPLE_PHI)
+	      return 1;
+	  continue;
+	}
+
       /* The best unroll factor for this chain is equal to the number of
 	 temporary variables that we create for it.  */
       af = chain->length;