diff options
Diffstat (limited to 'gcc/tree-ssanames.c')
| -rw-r--r-- | gcc/tree-ssanames.c | 35 |
1 files changed, 34 insertions, 1 deletions
diff --git a/gcc/tree-ssanames.c b/gcc/tree-ssanames.c index b599bb5bf12..ed87f3ee7d4 100644 --- a/gcc/tree-ssanames.c +++ b/gcc/tree-ssanames.c @@ -1,5 +1,5 @@ /* Generic routines for manipulating SSA_NAME expressions - Copyright (C) 2003-2015 Free Software Foundation, Inc. + Copyright (C) 2003-2016 Free Software Foundation, Inc. This file is part of GCC. @@ -411,6 +411,39 @@ get_nonzero_bits (const_tree name) return ri->get_nonzero_bits (); } +/* Return TRUE is OP, an SSA_NAME has a range of values [0..1], false + otherwise. + + This can be because it is a boolean type, any unsigned integral + type with a single bit of precision, or has known range of [0..1] + via VRP analysis. */ + +bool +ssa_name_has_boolean_range (tree op) +{ + gcc_assert (TREE_CODE (op) == SSA_NAME); + + /* Boolean types always have a range [0..1]. */ + if (TREE_CODE (TREE_TYPE (op)) == BOOLEAN_TYPE) + return true; + + /* An integral type with a single bit of precision. */ + if (INTEGRAL_TYPE_P (TREE_TYPE (op)) + && TYPE_UNSIGNED (TREE_TYPE (op)) + && TYPE_PRECISION (TREE_TYPE (op)) == 1) + return true; + + /* An integral type with more precision, but the object + only takes on values [0..1] as determined by VRP + analysis. */ + if (INTEGRAL_TYPE_P (TREE_TYPE (op)) + && (TYPE_PRECISION (TREE_TYPE (op)) > 1) + && wi::eq_p (get_nonzero_bits (op), 1)) + return true; + + return false; +} + /* We no longer need the SSA_NAME expression VAR, release it so that it may be reused. |