[PATCH, PR 54409] Remapping inlining predicates fix

[Martin Jambor]

Hi,

this patch fixes PR 54409.  The condition for dealing with offset maps
when remapping predicates which I have added recently was wrong,
fortunately a subsequent assert caught this.  We cannot shift stuff by
an offset when it is passed by value.

Conversely, the condition was unnecessarily restrictive, we can still
happily use non-aggregate and by-value conditions when offset map is
negative, that only means that by-ref stuff is not guaranteed to
survive.

Bootstrapped and tested on x86_64-linux.  OK for trunk?

Thanks,

Martin



2012-08-30  Martin Jambor  <mjam...@suse.cz>

        PR middle-end/54409
        * ipa-inline-analysis.c (remap_predicate): Fix the offset_map
        checking condition.

        * gcc/testsuite/gcc.dg/torture/pr54409.c: New test.


Index: src/gcc/ipa-inline-analysis.c
===================================================================
--- src.orig/gcc/ipa-inline-analysis.c
+++ src/gcc/ipa-inline-analysis.c
@@ -2811,8 +2811,11 @@ remap_predicate (struct inline_summary *
                 if (!operand_map
                     || (int)VEC_length (int, operand_map) <= c->operand_num
                     || VEC_index (int, operand_map, c->operand_num) == -1
-                    || (!c->agg_contents
-                        && VEC_index (int, offset_map, c->operand_num) != 0)
+                    /* TODO: For non-aggregate conditions, adding an offset is
+                       basically an arithmetic jump function processing which
+                       we should support in future.  */
+                    || ((!c->agg_contents || !c->by_ref)
+                        && VEC_index (int, offset_map, c->operand_num) > 0)
                     || (c->agg_contents && c->by_ref
                         && VEC_index (int, offset_map, c->operand_num) < 0))
                   cond_predicate = true_predicate ();
Index: src/gcc/testsuite/gcc.dg/torture/pr54409.c
===================================================================
--- /dev/null
+++ src/gcc/testsuite/gcc.dg/torture/pr54409.c
@@ -0,0 +1,28 @@
+/* { dg-do compile } */
+
+int b;
+
+struct S
+{
+  char *p;
+  struct {
+  } s;
+  int a;
+};
+
+static _Bool
+fn2 (int *p1)
+{
+  if (b)
+    {
+      struct S *c = (struct S *) &p1;
+      return c->a;
+    }
+}
+
+_Bool
+fn3 (struct S *p1)
+{
+  if (fn2 ((int *) &p1->s))
+    return 0;
+}