Merge branch 'master' into gfortran-testdevel/gfortran-test

1 files changed, 36 insertions, 0 deletions

diff --git a/gcc/rtl-ssa/accesses.h b/gcc/rtl-ssa/accesses.h
index 98403f7..b3a31fb 100644
--- a/gcc/rtl-ssa/accesses.h
+++ b/gcc/rtl-ssa/accesses.h
@@ -1044,6 +1044,42 @@ public:
   int comparison;
 };
 
+// This class represents the result of looking for a use of a particular
+// definition at a particular point, here referred to as point P.
+// There are four states:
+//
+// - USE is null if the definition has no uses.
+//
+// - Otherwise, COMPARISON is 0 if we found a definition at P.  USE then
+//   contains this use.
+//
+// - Otherwise, COMPARISON is greater than 0 if we found a use that precedes P.
+//   USE then contains this use.
+//
+// - Otherwise, COMPARISON is less than zero and we found a use that follows P.
+//   USE then contains this use.
+class use_lookup
+{
+public:
+  // If we found a use at P, return that use, otherwise return null.
+  use_info *matching_use () const;
+
+  // If we found a use at P, return that use, otherwise return prev_use ().
+  use_info *matching_or_prev_use () const;
+
+  // If we found a use at P, return that use, otherwise return next_use ().
+  use_info *matching_or_next_use () const;
+
+  // Return the last use that occurs before P, or null if none.
+  use_info *prev_use () const;
+
+  // Return the first use that occurs after P, or null if none.
+  use_info *next_use () const;
+
+  use_info *use;
+  int comparison;
+};
+
 void pp_resource (pretty_printer *, resource_info);
 void pp_access (pretty_printer *, const access_info *,
 		unsigned int flags = PP_ACCESS_DEFAULT);