Add real_isdenormal.

There are 6 idioms of the same check and I'd like to add more.

It seems there are macros as well as functions for things like
REAL_VALUE_ISINF and REAL_VALUE_NEGATIVE.  I don't know if there was
historical need for this duplicity, but I think it's cleaner if we
start gravitating towards inline functions only.

gcc/ChangeLog:

	* real.cc (encode_ieee_single): Use real_isdenormal.
	(encode_ieee_double): Same.
	(encode_ieee_extended): Same.
	(encode_ieee_quad): Same.
	(encode_ieee_half): Same.
	(encode_arm_bfloat_half): Same.
	* real.h (real_isdenormal): New.

1 files changed, 7 insertions, 0 deletions

diff --git a/gcc/real.h b/gcc/real.h
index 2f490ef..f9528d7 100644
--- a/gcc/real.h
+++ b/gcc/real.h
@@ -286,6 +286,13 @@ extern bool real_isnan (const REAL_VALUE_TYPE *);
 /* Determine whether a floating-point value X is a signaling NaN.  */
 extern bool real_issignaling_nan (const REAL_VALUE_TYPE *);
 
+/* Determine whether a floating-point value X is a denormal.  */
+inline bool
+real_isdenormal (const REAL_VALUE_TYPE *r)
+{
+  return (r->sig[SIGSZ-1] & SIG_MSB) == 0;
+}
+
 /* Determine whether a floating-point value X is finite.  */
 extern bool real_isfinite (const REAL_VALUE_TYPE *);