[PATCH] Read global value/mask in IPA.

[Aldy Hernandez via Gcc-patches]

Instead of reading the known zero bits in IPA, read the value/mask
pair which is available.

There is a slight change of behavior here.  I have removed the check
for SSA_NAME, as the ranger can calculate the range and value/mask for
INTEGER_CST.  This simplifies the code a bit, since there's no special
casing when setting the jfunc bits.  The default range for VR is
undefined, so I think it's safe just to check for undefined_p().

OK?

gcc/ChangeLog:

        * ipa-prop.cc (ipa_compute_jump_functions_for_edge): Read global
        value/mask.
---
 gcc/ipa-prop.cc | 18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/gcc/ipa-prop.cc b/gcc/ipa-prop.cc
index 5d790ff1265..4f6ed7b89bd 100644
--- a/gcc/ipa-prop.cc
+++ b/gcc/ipa-prop.cc
@@ -2402,8 +2402,7 @@ ipa_compute_jump_functions_for_edge (struct 
ipa_func_body_info *fbi,
        }
       else
        {
-         if (TREE_CODE (arg) == SSA_NAME
-             && param_type
+         if (param_type
              && Value_Range::supports_type_p (TREE_TYPE (arg))
              && Value_Range::supports_type_p (param_type)
              && irange::supports_p (TREE_TYPE (arg))
@@ -2422,15 +2421,14 @@ ipa_compute_jump_functions_for_edge (struct 
ipa_func_body_info *fbi,
            gcc_assert (!jfunc->m_vr);
        }
 
-      if (INTEGRAL_TYPE_P (TREE_TYPE (arg))
-         && (TREE_CODE (arg) == SSA_NAME || TREE_CODE (arg) == INTEGER_CST))
+      if (INTEGRAL_TYPE_P (TREE_TYPE (arg)) && !vr.undefined_p ())
        {
-         if (TREE_CODE (arg) == SSA_NAME)
-           ipa_set_jfunc_bits (jfunc, 0,
-                               widest_int::from (get_nonzero_bits (arg),
-                                                 TYPE_SIGN (TREE_TYPE (arg))));
-         else
-           ipa_set_jfunc_bits (jfunc, wi::to_widest (arg), 0);
+         irange &r = as_a <irange> (vr);
+         irange_bitmask bm = r.get_bitmask ();
+         signop sign = TYPE_SIGN (TREE_TYPE (arg));
+         ipa_set_jfunc_bits (jfunc,
+                             widest_int::from (bm.value (), sign),
+                             widest_int::from (bm.mask (), sign));
        }
       else if (POINTER_TYPE_P (TREE_TYPE (arg)))
        {
-- 
2.40.1