[gcc r13-2393] Add real_isdenormal.

[Aldy Hernandez <aldyh@gcc.gnu.org>]

https://gcc.gnu.org/g:6832dd39d7b5ede0122a27633ef1859ce3d893a6

commit r13-2393-g6832dd39d7b5ede0122a27633ef1859ce3d893a6
Author: Aldy Hernandez <aldyh@redhat.com>
Date:   Sat Sep 3 10:40:10 2022 +0200

    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.

Diff:
---
 gcc/real.cc | 12 ++++++------
 gcc/real.h  |  7 +++++++
 2 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/gcc/real.cc b/gcc/real.cc
index 96f05ec68ca..73bbac645d9 100644
--- a/gcc/real.cc
+++ b/gcc/real.cc
@@ -2954,7 +2954,7 @@ encode_ieee_single (const struct real_format *fmt, long *buf,
 {
   unsigned long image, sig, exp;
   unsigned long sign = r->sign;
-  bool denormal = (r->sig[SIGSZ-1] & SIG_MSB) == 0;
+  bool denormal = real_isdenormal (r);
 
   image = sign << 31;
   sig = (r->sig[SIGSZ-1] >> (HOST_BITS_PER_LONG - 24)) & 0x7fffff;
@@ -3175,7 +3175,7 @@ encode_ieee_double (const struct real_format *fmt, long *buf,
 {
   unsigned long image_lo, image_hi, sig_lo, sig_hi, exp;
   unsigned long sign = r->sign;
-  bool denormal = (r->sig[SIGSZ-1] & SIG_MSB) == 0;
+  bool denormal = real_isdenormal (r);
 
   image_hi = sign << 31;
   image_lo = 0;
@@ -3433,7 +3433,7 @@ encode_ieee_extended (const struct real_format *fmt, long *buf,
 		      const REAL_VALUE_TYPE *r)
 {
   unsigned long image_hi, sig_hi, sig_lo;
-  bool denormal = (r->sig[SIGSZ-1] & SIG_MSB) == 0;
+  bool denormal = real_isdenormal (r);
 
   image_hi = r->sign << 15;
   sig_hi = sig_lo = 0;
@@ -3964,7 +3964,7 @@ encode_ieee_quad (const struct real_format *fmt, long *buf,
 {
   unsigned long image3, image2, image1, image0, exp;
   unsigned long sign = r->sign;
-  bool denormal = (r->sig[SIGSZ-1] & SIG_MSB) == 0;
+  bool denormal = real_isdenormal (r);
   REAL_VALUE_TYPE u;
 
   image3 = sign << 31;
@@ -4721,7 +4721,7 @@ encode_ieee_half (const struct real_format *fmt, long *buf,
 {
   unsigned long image, sig, exp;
   unsigned long sign = r->sign;
-  bool denormal = (r->sig[SIGSZ-1] & SIG_MSB) == 0;
+  bool denormal = real_isdenormal (r);
 
   image = sign << 15;
   sig = (r->sig[SIGSZ-1] >> (HOST_BITS_PER_LONG - 11)) & 0x3ff;
@@ -4835,7 +4835,7 @@ encode_arm_bfloat_half (const struct real_format *fmt, long *buf,
 {
   unsigned long image, sig, exp;
   unsigned long sign = r->sign;
-  bool denormal = (r->sig[SIGSZ-1] & SIG_MSB) == 0;
+  bool denormal = real_isdenormal (r);
 
   image = sign << 15;
   sig = (r->sig[SIGSZ-1] >> (HOST_BITS_PER_LONG - 8)) & 0x7f;
diff --git a/gcc/real.h b/gcc/real.h
index 2f490ef9b72..f9528d765ec 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 *);