[RFC][IPA-VRP] ADDR_EXPR and nonnull

[kugan]

Hi,

While computing jump function value range for pointer, I am wondering if 
we can assume that any tree with ADDR_EXPR will be nonnull.

That is, in cases like:

int arr[10];
foo (&arr[1]);

OR

struct st
{
  int a;
  int b;
};
struct st s2;
foo (&s2.a);

Attached patch tries to do this. I am not sure if this can be wrong. Any 
thoughts?

Attached patch bootstraps and regression testing didn't introduce any 
new regressions.

Thanks,
Kugan


gcc/ChangeLog:

2016-10-19  Kugan Vivekanandarajah  <kug...@linaro.org>

        * ipa-prop.c (ipa_compute_jump_functions_for_edge): Set
        value range to nonull for ADDR_EXPR.

gcc/testsuite/ChangeLog:

2016-10-19  Kugan Vivekanandarajah  <kug...@linaro.org>

        * gcc.dg/ipa/vrp5.c: New test.
        * gcc.dg/ipa/vrp6.c: New test.
diff --git a/gcc/ipa-prop.c b/gcc/ipa-prop.c
index 353b638..b795d30 100644
--- a/gcc/ipa-prop.c
+++ b/gcc/ipa-prop.c
@@ -1670,9 +1670,10 @@ ipa_compute_jump_functions_for_edge (struct 
ipa_func_body_info *fbi,
 
       if (POINTER_TYPE_P (TREE_TYPE (arg)))
        {
-         if (TREE_CODE (arg) == SSA_NAME
-             && param_type
-             && get_ptr_nonnull (arg))
+         if ((TREE_CODE (arg) == SSA_NAME
+              && param_type
+              && get_ptr_nonnull (arg))
+             || (TREE_CODE (arg) == ADDR_EXPR))
            {
              jfunc->vr_known = true;
              jfunc->m_vr.type = VR_ANTI_RANGE;
diff --git a/gcc/testsuite/gcc.dg/ipa/vrp5.c b/gcc/testsuite/gcc.dg/ipa/vrp5.c
index e69de29..8e43a65 100644
--- a/gcc/testsuite/gcc.dg/ipa/vrp5.c
+++ b/gcc/testsuite/gcc.dg/ipa/vrp5.c
@@ -0,0 +1,28 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-ipa-cp-details -fdump-tree-vrp1" } */
+
+static __attribute__((noinline, noclone))
+int foo (int *p)
+{
+  if (!p)
+    return 0;
+  *p = 1;
+}
+
+struct st
+{
+  int a;
+  int b;
+};
+
+int bar (struct st *s)
+{
+int arr[10];
+  if (!s)
+    return 0;
+  foo (&s->a);
+  foo (&arr[1]);
+}
+
+/* { dg-final { scan-ipa-dump "Setting nonnull for 0" "cp" } } */
+/* { dg-final { scan-tree-dump-times "if" 1 "vrp1" } } */
diff --git a/gcc/testsuite/gcc.dg/ipa/vrp6.c b/gcc/testsuite/gcc.dg/ipa/vrp6.c
index e69de29..f837758 100644
--- a/gcc/testsuite/gcc.dg/ipa/vrp6.c
+++ b/gcc/testsuite/gcc.dg/ipa/vrp6.c
@@ -0,0 +1,28 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-ipa-cp-details -fdump-tree-vrp1" } */
+
+static __attribute__((noinline, noclone))
+int foo (int *p)
+{
+  if (!p)
+    return 0;
+  *p = 1;
+}
+
+struct st
+{
+  int a;
+  int b;
+};
+
+int bar (struct st *s)
+{
+struct st s2;
+  if (!s)
+    return 0;
+  foo (&s->a);
+  foo (&s2.a);
+}
+
+/* { dg-final { scan-ipa-dump "Setting nonnull for 0" "cp" } } */
+/* { dg-final { scan-tree-dump-times "if" 1 "vrp1" } } */