On Tue, Nov 8, 2022 at 12:07 PM Jakub Jelinek <ja...@redhat.com> wrote:
>
> On Mon, Nov 07, 2022 at 04:38:29PM +0100, Aldy Hernandez wrote:
> > From d214bcdff2cb90ad1eb808d29bda6fb98d510b4c Mon Sep 17 00:00:00 2001
> > From: Aldy Hernandez <al...@redhat.com>
> > Date: Mon, 7 Nov 2022 14:18:57 +0100
> > Subject: [PATCH] Provide normalized and denormal format version of
> > real_isdenormal.
> >
> > Implement real_isdenormal_target() to be used within real.cc where the
> > argument is known to be in denormal format. Rewrite real_isdenormal()
> > for use outside of real.cc where the argument is known to be
> > normalized.
> >
> > gcc/ChangeLog:
> >
> > * real.cc (real_isdenormal_target): New.
> > (encode_ieee_single): Use real_isdenormal_target.
> > (encode_ieee_double): Same.
> > (encode_ieee_extended): Same.
> > (encode_ieee_quad): Same.
> > (encode_ieee_half): Same.
> > (encode_arm_bfloat_half): Same.
> > * value-range.cc (frange::flush_denormals_to_zero): Same.
> > * real.h (real_isdenormal): Rewrite to look at mode.
>
> I'd make real_isdenormal_target static inline bool
> rather than inline bool, it is only defined in real.cc, so there is
> no point exporting it.
Huh. I thought inline alone would inhibit the exporting. Thanks.
> Though, as you've added the mode argument, the real.cc inline
> could very well also be called real_isdenormal too, it wouldn't be
> a redeclaration or ODR violation.
Great, even better.
OK pending tests?
Aldy
From c3ca1d606bfb22bf4f8bc7ac0ce561bd6afc3368 Mon Sep 17 00:00:00 2001
From: Aldy Hernandez <al...@redhat.com>
Date: Mon, 7 Nov 2022 14:18:57 +0100
Subject: [PATCH] Provide normalized and denormal format version of
real_isdenormal.
Implement a variant of real_isdenormal() to be used within real.cc
where the argument is known to be in denormal format. Rewrite
real_isdenormal() for use outside of real.cc where the argument is
known to be normalized.
gcc/ChangeLog:
* real.cc (real_isdenormal): New.
* real.h (real_isdenormal): Add mode argument. Rewrite for
normalized values.
* value-range.cc (frange::flush_denormals_to_zero): Pass mode to
real_isdenormal.
---
gcc/real.cc | 10 ++++++++++
gcc/real.h | 7 ++++---
gcc/value-range.cc | 5 +++--
3 files changed, 17 insertions(+), 5 deletions(-)
diff --git a/gcc/real.cc b/gcc/real.cc
index aae7c335d59..028aad95ec4 100644
--- a/gcc/real.cc
+++ b/gcc/real.cc
@@ -111,6 +111,16 @@ static const REAL_VALUE_TYPE * real_digit (int);
static void times_pten (REAL_VALUE_TYPE *, int);
static void round_for_format (const struct real_format *, REAL_VALUE_TYPE *);
+
+/* Determine whether a floating-point value X is a denormal. R is
+ expected to be in denormal form, so this function is only
+ meaningful after a call to round_for_format. */
+
+static inline bool
+real_isdenormal (const REAL_VALUE_TYPE *r)
+{
+ return (r->sig[SIGSZ-1] & SIG_MSB) == 0;
+}
/* Initialize R with a positive zero. */
diff --git a/gcc/real.h b/gcc/real.h
index 306e9593866..b14bcdd3fde 100644
--- a/gcc/real.h
+++ b/gcc/real.h
@@ -286,11 +286,12 @@ 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. */
+/* Determine whether floating-point value R is a denormal. This
+ function is only valid for normalized values. */
inline bool
-real_isdenormal (const REAL_VALUE_TYPE *r)
+real_isdenormal (const REAL_VALUE_TYPE *r, machine_mode mode)
{
- return r->cl == rvc_normal && (r->sig[SIGSZ-1] & SIG_MSB) == 0;
+ return r->cl == rvc_normal && REAL_EXP (r) < REAL_MODE_FORMAT (mode)->emin;
}
/* Determine whether a floating-point value X is finite. */
diff --git a/gcc/value-range.cc b/gcc/value-range.cc
index a855aaf626c..859c7fb4af9 100644
--- a/gcc/value-range.cc
+++ b/gcc/value-range.cc
@@ -266,15 +266,16 @@ frange::flush_denormals_to_zero ()
if (undefined_p () || known_isnan ())
return;
+ machine_mode mode = TYPE_MODE (type ());
// Flush [x, -DENORMAL] to [x, -0.0].
- if (real_isdenormal (&m_max) && real_isneg (&m_max))
+ if (real_isdenormal (&m_max, mode) && real_isneg (&m_max))
{
m_max = dconst0;
if (HONOR_SIGNED_ZEROS (m_type))
m_max.sign = 1;
}
// Flush [+DENORMAL, x] to [+0.0, x].
- if (real_isdenormal (&m_min) && !real_isneg (&m_min))
+ if (real_isdenormal (&m_min, mode) && !real_isneg (&m_min))
m_min = dconst0;
}
--
2.38.1
