[PATCH] Fix ICE in VN

[Richard Biener]

The following fixes an ICE privately reported to me by Jeff.

Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.

Richard.

2019-09-24  Richard Biener  <rguent...@suse.de>

        * tree-ssa-sccvn.c (vn_reference_lookup_3): Valueize MEM_REF
        base.

        * gcc.dg/torture/20190924-1.c: New testcase.

Index: gcc/tree-ssa-sccvn.c
===================================================================
--- gcc/tree-ssa-sccvn.c        (revision 276054)
+++ gcc/tree-ssa-sccvn.c        (working copy)
@@ -2935,8 +2935,9 @@ vn_reference_lookup_3 (ao_ref *ref, tree
          else
            return (void *)-1;
        }
-      if (TREE_CODE (rhs) != SSA_NAME
-         && TREE_CODE (rhs) != ADDR_EXPR)
+      if (TREE_CODE (rhs) == SSA_NAME)
+       rhs = SSA_VAL (rhs);
+      else if (TREE_CODE (rhs) != ADDR_EXPR)
        return (void *)-1;
 
       /* The bases of the destination and the references have to agree.  */
Index: gcc/testsuite/gcc.dg/torture/20190924-1.c
===================================================================
--- gcc/testsuite/gcc.dg/torture/20190924-1.c   (nonexistent)
+++ gcc/testsuite/gcc.dg/torture/20190924-1.c   (working copy)
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+
+struct acct_gather_energy {
+   int base_consumed_energy;
+   int consumed_energy;
+   int previous_consumed_energy;
+};
+static struct acct_gather_energy xcc_energy;
+struct acct_gather_energy *new;
+int _get_joules_task(int first)
+{
+  if (!first && new->previous_consumed_energy)
+    first = 1;
+  new->base_consumed_energy = new->consumed_energy;
+  __builtin_memcpy(&xcc_energy, new, sizeof(struct acct_gather_energy));
+  return xcc_energy.base_consumed_energy;
+}