re PR tree-optimization/65063 (gcc.dg/vect/vect-double-reduc-6.c FAILs with -O3 ...

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 6cf817bde229907b493b46ee7244e000a72a270c..9523db0482702801f6f3360f501465b77778f8ba 100644 (file)
--- 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 0a1a328c7f0a15bf8ff2eebeb3d5c533d98605bf..5bbdfbbd9c03f1ed823790e1ce6d6ab021e93955 100644 (file)
--- 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 (file)
index 0000000..bcbdbf0
--- /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 8dac1ba5afd5520368e20596d643a716b1982a5a..03a38b4de842c74834227f566dde033f21d8ec1a 100644 (file)
--- 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;