From: "Alex Bennée" <alex.bennee@linaro.org>
To: richard.henderson@linaro.org, peter.maydell@linaro.org,
laurent@vivier.eu, bharata@linux.vnet.ibm.com,
andrew@andrewdutcher.com
Cc: qemu-devel@nongnu.org, "Alex Bennée" <alex.bennee@linaro.org>,
"Aurelien Jarno" <aurelien@aurel32.net>
Subject: [Qemu-devel] [PATCH v4 20/22] fpu/softfloat: re-factor minmax
Date: Tue, 6 Feb 2018 16:48:13 +0000 [thread overview]
Message-ID: <20180206164815.10084-21-alex.bennee@linaro.org> (raw)
In-Reply-To: <20180206164815.10084-1-alex.bennee@linaro.org>
Let's do the same re-factor treatment for minmax functions. I still
use the MACRO trick to expand but now all the checking code is common.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
v2
- minor indentation fix
v3
- fix merge conflicts from dropping MINMAX patch
- fix naming of structs
v4
- use is_nan/is_snan
- pick_nan_parts->pick_nan
- minmax_decomposed->minmax_floats
---
fpu/softfloat.c | 227 +++++++++++++++++++++++++-----------------------
include/fpu/softfloat.h | 6 ++
2 files changed, 126 insertions(+), 107 deletions(-)
diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 558d37ecf9..cb889a7a84 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -1664,6 +1664,126 @@ float64 uint16_to_float64(uint16_t a, float_status *status)
return uint64_to_float64(a, status);
}
+/* Float Min/Max */
+/* min() and max() functions. These can't be implemented as
+ * 'compare and pick one input' because that would mishandle
+ * NaNs and +0 vs -0.
+ *
+ * minnum() and maxnum() functions. These are similar to the min()
+ * and max() functions but if one of the arguments is a QNaN and
+ * the other is numerical then the numerical argument is returned.
+ * SNaNs will get quietened before being returned.
+ * minnum() and maxnum correspond to the IEEE 754-2008 minNum()
+ * and maxNum() operations. min() and max() are the typical min/max
+ * semantics provided by many CPUs which predate that specification.
+ *
+ * minnummag() and maxnummag() functions correspond to minNumMag()
+ * and minNumMag() from the IEEE-754 2008.
+ */
+static FloatParts minmax_floats(FloatParts a, FloatParts b, bool ismin,
+ bool ieee, bool ismag, float_status *s)
+{
+ if (unlikely(is_nan(a.cls) || is_nan(b.cls))) {
+ if (ieee) {
+ /* Takes two floating-point values `a' and `b', one of
+ * which is a NaN, and returns the appropriate NaN
+ * result. If either `a' or `b' is a signaling NaN,
+ * the invalid exception is raised.
+ */
+ if (is_snan(a.cls) || is_snan(b.cls)) {
+ return pick_nan(a, b, s);
+ } else if (is_nan(a.cls) && !is_nan(b.cls)) {
+ return b;
+ } else if (is_nan(b.cls) && !is_nan(a.cls)) {
+ return a;
+ }
+ }
+ return pick_nan(a, b, s);
+ } else {
+ int a_exp, b_exp;
+ bool a_sign, b_sign;
+
+ switch (a.cls) {
+ case float_class_normal:
+ a_exp = a.exp;
+ break;
+ case float_class_inf:
+ a_exp = INT_MAX;
+ break;
+ case float_class_zero:
+ a_exp = INT_MIN;
+ break;
+ default:
+ g_assert_not_reached();
+ break;
+ }
+ switch (b.cls) {
+ case float_class_normal:
+ b_exp = b.exp;
+ break;
+ case float_class_inf:
+ b_exp = INT_MAX;
+ break;
+ case float_class_zero:
+ b_exp = INT_MIN;
+ break;
+ default:
+ g_assert_not_reached();
+ break;
+ }
+
+ a_sign = a.sign;
+ b_sign = b.sign;
+ if (ismag) {
+ a_sign = b_sign = 0;
+ }
+
+ if (a_sign == b_sign) {
+ bool a_less = a_exp < b_exp;
+ if (a_exp == b_exp) {
+ a_less = a.frac < b.frac;
+ }
+ return a_sign ^ a_less ^ ismin ? b : a;
+ } else {
+ return a_sign ^ ismin ? b : a;
+ }
+ }
+}
+
+#define MINMAX(sz, name, ismin, isiee, ismag) \
+float ## sz float ## sz ## _ ## name(float ## sz a, float ## sz b, \
+ float_status *s) \
+{ \
+ FloatParts pa = float ## sz ## _unpack_canonical(a, s); \
+ FloatParts pb = float ## sz ## _unpack_canonical(b, s); \
+ FloatParts pr = minmax_floats(pa, pb, ismin, isiee, ismag, s); \
+ \
+ return float ## sz ## _round_pack_canonical(pr, s); \
+}
+
+MINMAX(16, min, true, false, false)
+MINMAX(16, minnum, true, true, false)
+MINMAX(16, minnummag, true, true, true)
+MINMAX(16, max, false, false, false)
+MINMAX(16, maxnum, false, true, false)
+MINMAX(16, maxnummag, false, true, true)
+
+MINMAX(32, min, true, false, false)
+MINMAX(32, minnum, true, true, false)
+MINMAX(32, minnummag, true, true, true)
+MINMAX(32, max, false, false, false)
+MINMAX(32, maxnum, false, true, false)
+MINMAX(32, maxnummag, false, true, true)
+
+MINMAX(64, min, true, false, false)
+MINMAX(64, minnum, true, true, false)
+MINMAX(64, minnummag, true, true, true)
+MINMAX(64, max, false, false, false)
+MINMAX(64, maxnum, false, true, false)
+MINMAX(64, maxnummag, false, true, true)
+
+#undef MINMAX
+
/* Multiply A by 2 raised to the power N. */
static FloatParts scalbn_decomposed(FloatParts a, int n, float_status *s)
{
@@ -6913,113 +7033,6 @@ int float128_compare_quiet(float128 a, float128 b, float_status *status)
return float128_compare_internal(a, b, 1, status);
}
-/* min() and max() functions. These can't be implemented as
- * 'compare and pick one input' because that would mishandle
- * NaNs and +0 vs -0.
- *
- * minnum() and maxnum() functions. These are similar to the min()
- * and max() functions but if one of the arguments is a QNaN and
- * the other is numerical then the numerical argument is returned.
- * minnum() and maxnum correspond to the IEEE 754-2008 minNum()
- * and maxNum() operations. min() and max() are the typical min/max
- * semantics provided by many CPUs which predate that specification.
- *
- * minnummag() and maxnummag() functions correspond to minNumMag()
- * and minNumMag() from the IEEE-754 2008.
- */
-#define MINMAX(s) \
-static inline float ## s float ## s ## _minmax(float ## s a, float ## s b, \
- int ismin, int isieee, \
- int ismag, \
- float_status *status) \
-{ \
- flag aSign, bSign; \
- uint ## s ## _t av, bv, aav, abv; \
- a = float ## s ## _squash_input_denormal(a, status); \
- b = float ## s ## _squash_input_denormal(b, status); \
- if (float ## s ## _is_any_nan(a) || \
- float ## s ## _is_any_nan(b)) { \
- if (isieee) { \
- if (float ## s ## _is_quiet_nan(a, status) && \
- !float ## s ##_is_any_nan(b)) { \
- return b; \
- } else if (float ## s ## _is_quiet_nan(b, status) && \
- !float ## s ## _is_any_nan(a)) { \
- return a; \
- } \
- } \
- return propagateFloat ## s ## NaN(a, b, status); \
- } \
- aSign = extractFloat ## s ## Sign(a); \
- bSign = extractFloat ## s ## Sign(b); \
- av = float ## s ## _val(a); \
- bv = float ## s ## _val(b); \
- if (ismag) { \
- aav = float ## s ## _abs(av); \
- abv = float ## s ## _abs(bv); \
- if (aav != abv) { \
- if (ismin) { \
- return (aav < abv) ? a : b; \
- } else { \
- return (aav < abv) ? b : a; \
- } \
- } \
- } \
- if (aSign != bSign) { \
- if (ismin) { \
- return aSign ? a : b; \
- } else { \
- return aSign ? b : a; \
- } \
- } else { \
- if (ismin) { \
- return (aSign ^ (av < bv)) ? a : b; \
- } else { \
- return (aSign ^ (av < bv)) ? b : a; \
- } \
- } \
-} \
- \
-float ## s float ## s ## _min(float ## s a, float ## s b, \
- float_status *status) \
-{ \
- return float ## s ## _minmax(a, b, 1, 0, 0, status); \
-} \
- \
-float ## s float ## s ## _max(float ## s a, float ## s b, \
- float_status *status) \
-{ \
- return float ## s ## _minmax(a, b, 0, 0, 0, status); \
-} \
- \
-float ## s float ## s ## _minnum(float ## s a, float ## s b, \
- float_status *status) \
-{ \
- return float ## s ## _minmax(a, b, 1, 1, 0, status); \
-} \
- \
-float ## s float ## s ## _maxnum(float ## s a, float ## s b, \
- float_status *status) \
-{ \
- return float ## s ## _minmax(a, b, 0, 1, 0, status); \
-} \
- \
-float ## s float ## s ## _minnummag(float ## s a, float ## s b, \
- float_status *status) \
-{ \
- return float ## s ## _minmax(a, b, 1, 1, 1, status); \
-} \
- \
-float ## s float ## s ## _maxnummag(float ## s a, float ## s b, \
- float_status *status) \
-{ \
- return float ## s ## _minmax(a, b, 0, 1, 1, status); \
-}
-
-MINMAX(32)
-MINMAX(64)
-
-
floatx80 floatx80_scalbn(floatx80 a, int n, float_status *status)
{
flag aSign;
diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h
index 52621e0b79..35df225a55 100644
--- a/include/fpu/softfloat.h
+++ b/include/fpu/softfloat.h
@@ -245,6 +245,12 @@ float16 float16_mul(float16, float16, float_status *status);
float16 float16_muladd(float16, float16, float16, int, float_status *status);
float16 float16_div(float16, float16, float_status *status);
float16 float16_scalbn(float16, int, float_status *status);
+float16 float16_min(float16, float16, float_status *status);
+float16 float16_max(float16, float16, float_status *status);
+float16 float16_minnum(float16, float16, float_status *status);
+float16 float16_maxnum(float16, float16, float_status *status);
+float16 float16_minnummag(float16, float16, float_status *status);
+float16 float16_maxnummag(float16, float16, float_status *status);
int float16_is_quiet_nan(float16, float_status *status);
int float16_is_signaling_nan(float16, float_status *status);
--
2.15.1
next prev parent reply other threads:[~2018-02-06 16:48 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-06 16:47 [Qemu-devel] [PATCH v4 00/22] re-factor softfloat and add fp16 functions Alex Bennée
2018-02-06 16:47 ` [Qemu-devel] [PATCH v4 01/22] fpu/softfloat: implement float16_squash_input_denormal Alex Bennée
2018-02-06 16:47 ` [Qemu-devel] [PATCH v4 02/22] include/fpu/softfloat: remove USE_SOFTFLOAT_STRUCT_TYPES Alex Bennée
2018-02-06 16:47 ` [Qemu-devel] [PATCH v4 03/22] fpu/softfloat-types: new header to prevent excessive re-builds Alex Bennée
2018-02-06 16:47 ` [Qemu-devel] [PATCH v4 04/22] target/*/cpu.h: remove softfloat.h Alex Bennée
2018-02-06 16:47 ` [Qemu-devel] [PATCH v4 05/22] include/fpu/softfloat: implement float16_abs helper Alex Bennée
2018-02-06 16:47 ` [Qemu-devel] [PATCH v4 06/22] include/fpu/softfloat: implement float16_chs helper Alex Bennée
2018-02-06 16:48 ` [Qemu-devel] [PATCH v4 07/22] include/fpu/softfloat: implement float16_set_sign helper Alex Bennée
2018-02-06 16:48 ` [Qemu-devel] [PATCH v4 08/22] include/fpu/softfloat: add some float16 constants Alex Bennée
2018-02-06 16:48 ` [Qemu-devel] [PATCH v4 09/22] fpu/softfloat: improve comments on ARM NaN propagation Alex Bennée
2018-02-06 16:48 ` [Qemu-devel] [PATCH v4 10/22] fpu/softfloat: move the extract functions to the top of the file Alex Bennée
2018-02-06 16:48 ` [Qemu-devel] [PATCH v4 11/22] fpu/softfloat: define decompose structures Alex Bennée
2018-02-06 16:48 ` [Qemu-devel] [PATCH v4 12/22] fpu/softfloat: re-factor add/sub Alex Bennée
2018-02-06 16:48 ` [Qemu-devel] [PATCH v4 13/22] fpu/softfloat: re-factor mul Alex Bennée
2018-02-13 15:20 ` Peter Maydell
2018-02-13 15:39 ` Richard Henderson
2018-02-19 16:04 ` Alex Bennée
2018-02-06 16:48 ` [Qemu-devel] [PATCH v4 14/22] fpu/softfloat: re-factor div Alex Bennée
2018-02-13 15:22 ` Peter Maydell
2018-02-06 16:48 ` [Qemu-devel] [PATCH v4 15/22] fpu/softfloat: re-factor muladd Alex Bennée
2018-02-06 16:48 ` [Qemu-devel] [PATCH v4 16/22] fpu/softfloat: re-factor round_to_int Alex Bennée
2018-02-13 15:14 ` Peter Maydell
2018-02-06 16:48 ` [Qemu-devel] [PATCH v4 17/22] fpu/softfloat: re-factor float to int/uint Alex Bennée
2018-02-06 16:48 ` [Qemu-devel] [PATCH v4 18/22] fpu/softfloat: re-factor int/uint to float Alex Bennée
2018-02-06 16:48 ` [Qemu-devel] [PATCH v4 19/22] fpu/softfloat: re-factor scalbn Alex Bennée
2018-02-06 16:48 ` Alex Bennée [this message]
2018-02-06 16:48 ` [Qemu-devel] [PATCH v4 21/22] fpu/softfloat: re-factor compare Alex Bennée
2018-02-06 16:48 ` [Qemu-devel] [PATCH v4 22/22] fpu/softfloat: re-factor sqrt Alex Bennée
2018-02-13 15:50 ` Peter Maydell
2018-02-13 16:23 ` Richard Henderson
2018-02-13 16:34 ` Peter Maydell
2018-02-20 21:01 ` [Qemu-devel] [PATCH] fpu/softfloat: use hardware sqrt if we can (EXPERIMENT!) Alex Bennée
2018-02-21 20:44 ` Alex Bennée
2018-03-21 20:16 ` Emilio G. Cota
2018-02-13 17:50 ` [Qemu-devel] [PATCH v4 22/22] fpu/softfloat: re-factor sqrt Richard Henderson
2018-02-06 17:42 ` [Qemu-devel] [PATCH v4 00/22] re-factor softfloat and add fp16 functions no-reply
2018-02-13 14:52 ` Peter Maydell
2018-02-17 13:23 ` Alex Bennée
2018-02-19 13:56 ` Peter Maydell
2018-02-22 1:23 ` Fam Zheng
2018-02-13 15:51 ` Peter Maydell
2018-02-13 17:31 ` Laurent Vivier
2018-02-20 12:43 ` Alex Bennée
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180206164815.10084-21-alex.bennee@linaro.org \
--to=alex.bennee@linaro.org \
--cc=andrew@andrewdutcher.com \
--cc=aurelien@aurel32.net \
--cc=bharata@linux.vnet.ibm.com \
--cc=laurent@vivier.eu \
--cc=peter.maydell@linaro.org \
--cc=qemu-devel@nongnu.org \
--cc=richard.henderson@linaro.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).