Merge from trunk (r239915 to r240230)fortran-dev

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/fortran-dev@240290 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 34 insertions, 1 deletions

diff --git a/gcc/hwint.h b/gcc/hwint.h
index 6b4d53737a2..ea87b2158b1 100644
--- a/gcc/hwint.h
+++ b/gcc/hwint.h
@@ -134,6 +134,31 @@ typedef HOST_WIDE_INT __gcc_host_wide_int__;
 #endif
 
 /* Inline functions operating on HOST_WIDE_INT.  */
+
+/* Return X with all but the lowest bit masked off.  */
+
+static inline unsigned HOST_WIDE_INT
+least_bit_hwi (unsigned HOST_WIDE_INT x)
+{
+  return (x & -x);
+}
+
+/* True if X is zero or a power of two.  */
+
+static inline bool
+pow2_or_zerop (unsigned HOST_WIDE_INT x)
+{
+  return least_bit_hwi (x) == x;
+}
+
+/* True if X is a power of two.  */
+
+static inline bool
+pow2p_hwi (unsigned HOST_WIDE_INT x)
+{
+  return x && pow2_or_zerop (x);
+}
+
 #if GCC_VERSION < 3004
 
 extern int clz_hwi (unsigned HOST_WIDE_INT x);
@@ -222,7 +247,7 @@ ceil_log2 (unsigned HOST_WIDE_INT x)
 static inline int
 exact_log2 (unsigned HOST_WIDE_INT x)
 {
-  return x == (x & -x) && x ? ctz_hwi (x) : -1;
+  return pow2p_hwi (x) ? ctz_hwi (x) : -1;
 }
 
 #endif /* GCC_VERSION >= 3004 */
@@ -238,6 +263,14 @@ extern HOST_WIDE_INT pos_mul_hwi (HOST_WIDE_INT, HOST_WIDE_INT);
 extern HOST_WIDE_INT mul_hwi (HOST_WIDE_INT, HOST_WIDE_INT);
 extern HOST_WIDE_INT least_common_multiple (HOST_WIDE_INT, HOST_WIDE_INT);
 
+/* Like ctz_hwi, except 0 when x == 0.  */
+
+static inline int
+ctz_or_zero (unsigned HOST_WIDE_INT x)
+{
+  return ffs_hwi (x) - 1;
+}
+
 /* Sign extend SRC starting from PREC.  */
 
 static inline HOST_WIDE_INT