[committed] PR82289: Computing peeling costs for irrelevant drs

[Richard Sandiford]

This PR shows that we weren't filtering out irrelevant stmts in
vect_get_peeling_costs_all_drs (unlike related loops in which
we iterate over all datarefs).

Tested on aarch64-linux-gnu, x86_64-linux-gnu and powerpc64le-linux-gnu.
Installed as obvious.

Richard


2017-09-22  Richard Sandiford  <richard.sandif...@linaro.org>

gcc/
        PR tree-optimization/82289
        * tree-vect-data-refs.c (vect_get_peeling_costs_all_drs): Check
        STMT_VINFO_RELEVANT_P.

gcc/testsuite/
        PR tree-optimization/82289
        * gcc.dg/vect/pr82289.c: New test.

Index: gcc/tree-vect-data-refs.c
===================================================================
--- gcc/tree-vect-data-refs.c   2017-09-22 17:44:23.043135080 +0100
+++ gcc/tree-vect-data-refs.c   2017-09-22 17:50:04.801574308 +0100
@@ -1326,6 +1326,9 @@ vect_get_peeling_costs_all_drs (vec<data
     {
       gimple *stmt = DR_STMT (dr);
       stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
+      if (!STMT_VINFO_RELEVANT_P (stmt_info))
+       continue;
+
       /* For interleaving, only the alignment of the first access
          matters.  */
       if (STMT_VINFO_GROUPED_ACCESS (stmt_info)
Index: gcc/testsuite/gcc.dg/vect/pr82289.c
===================================================================
--- /dev/null   2017-09-22 10:29:41.244937880 +0100
+++ gcc/testsuite/gcc.dg/vect/pr82289.c 2017-09-22 17:50:04.800626671 +0100
@@ -0,0 +1,28 @@
+/* { dg-do compile } */
+
+int a, b, c, *d, *f[1];
+
+void fn1 (int *j)
+{
+  int e, g, h = 1;
+  for (; e; e++)
+    {
+      if (g > 0)
+        {
+          d = j;
+          return;
+        }
+      if (!h)
+        while (g)
+          ;
+      while (h < 1)
+        if (a)
+          {
+            fn1 (&h);
+            h = 0;
+          }
+      f[e] = &c;
+    }
+  while (1)
+    ;
+}