This patch provides a way to set the value/mask pair of known bits
globally, similarly to how we can use set_nonzero_bits for known 0
bits. This can then be used by CCP and IPA to set value/mask info
instead of throwing away the known 1 bits.
In further clean-ups, I will see if it makes sense to remove
set_nonzero_bits altogether, since it is subsumed by value/mask.
gcc/ChangeLog:
* tree-ssanames.cc (set_bitmask): New.
* tree-ssanames.h (set_bitmask): New.
---
gcc/tree-ssanames.cc | 15 +++++++++++++++
gcc/tree-ssanames.h | 1 +
2 files changed, 16 insertions(+)
diff --git a/gcc/tree-ssanames.cc b/gcc/tree-ssanames.cc
index 5fdb6a37e9f..f54394363a0 100644
--- a/gcc/tree-ssanames.cc
+++ b/gcc/tree-ssanames.cc
@@ -465,6 +465,21 @@ set_nonzero_bits (tree name, const wide_int &mask)
set_range_info (name, r);
}
+/* Update the known bits of NAME.
+
+ Zero bits in MASK cover constant values. Set bits in MASK cover
+ unknown values. VALUE are the known bits. */
+
+void
+set_bitmask (tree name, const wide_int &value, const wide_int &mask)
+{
+ gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name)));
+
+ int_range<2> r (TREE_TYPE (name));
+ r.update_bitmask (irange_bitmask (value, mask));
+ set_range_info (name, r);
+}
+
/* Return a widest_int with potentially non-zero bits in SSA_NAME
NAME, the constant for INTEGER_CST, or -1 if unknown. */
diff --git a/gcc/tree-ssanames.h b/gcc/tree-ssanames.h
index f3fa609208a..b5e3f228ee8 100644
--- a/gcc/tree-ssanames.h
+++ b/gcc/tree-ssanames.h
@@ -59,6 +59,7 @@ struct GTY(()) ptr_info_def
/* Sets the value range to SSA. */
extern bool set_range_info (tree, const vrange &);
extern void set_nonzero_bits (tree, const wide_int &);
+extern void set_bitmask (tree, const wide_int &value, const wide_int &mask);
extern wide_int get_nonzero_bits (const_tree);
extern bool ssa_name_has_boolean_range (tree);
extern void init_ssanames (struct function *, int);
--
2.40.1
