[PATCH 0/9] LoongArch: Use builtins with GCC >= 13

[PATCH 0/9] LoongArch: Use builtins with GCC >= 13

[Xiaolin Tang]

Patch 0001-0007:
GCC 13, LoongArch support builtins for {,l,ll}rint, logb,
use these built-ins instead of generic function implementation.

Patch 0008:
GCC 13, LoongArch support ___builtin_scalbn{,f} with -fno-math-errno,
but only "libm" can use -fno-math-errno in GLIBC, and scalbn is in libc
instead of libm because __printf_fp calls it. So inline assembler of
the scalbn functions is a better choice for LoongArch.

Patch 0009: Add LoongArch support for scalb[f].

Discuss with Xi Ruoyao<xry111@xry111.site>
Link:
https://sourceware.org/pipermail/libc-alpha/2022-November/143425.html

Xi Ruoyao (1):
  LoongArch: Use __builtin_rint{,f} with GCC >= 13

Xiaolin Tang (8):
  Use GCC builtins for lrint functions if desired.
  LoongArch: Use __builtin_lrint{,f} with GCC >= 13
  Use GCC builtins for llrint functions if desired.
  LoongArch: Use __builtin_llrint{,f} with GCC >= 13
  Use GCC builtins for logb functions if desired.
  LoongArch: Use __builtin_logb{,f} with GCC >= 13
  LoongArch: Add support for scalbn[f]
  LoongArch: Add support for scalb[f]

 sysdeps/generic/math-use-builtins-llrint.h    |  4 ++
 sysdeps/generic/math-use-builtins-logb.h      |  4 ++
 sysdeps/generic/math-use-builtins-lrint.h     |  4 ++
 sysdeps/generic/math-use-builtins.h           |  3 +
 sysdeps/ieee754/dbl-64/s_llrint.c             | 18 ++++--
 sysdeps/ieee754/dbl-64/s_logb.c               |  5 ++
 sysdeps/ieee754/dbl-64/s_lrint.c              | 18 ++++--
 sysdeps/ieee754/float128/float128_private.h   |  6 ++
 sysdeps/ieee754/flt-32/s_llrintf.c            | 18 ++++--
 sysdeps/ieee754/flt-32/s_logbf.c              |  5 ++
 sysdeps/ieee754/flt-32/s_lrintf.c             | 18 ++++--
 sysdeps/ieee754/ldbl-128/s_llrintl.c          | 17 ++++--
 sysdeps/ieee754/ldbl-128/s_logbl.c            |  6 ++
 sysdeps/ieee754/ldbl-128/s_lrintl.c           | 17 ++++--
 sysdeps/loongarch/fpu/e_scalb.c               | 60 +++++++++++++++++++
 sysdeps/loongarch/fpu/e_scalbf.c              | 60 +++++++++++++++++++
 .../loongarch/fpu/math-use-builtins-llrint.h  | 10 ++++
 .../loongarch/fpu/math-use-builtins-logb.h    | 10 ++++
 .../loongarch/fpu/math-use-builtins-lrint.h   | 10 ++++
 .../loongarch/fpu/math-use-builtins-rint.h    |  9 +++
 sysdeps/loongarch/fpu/s_scalbn.c              | 29 +++++++++
 sysdeps/loongarch/fpu/s_scalbnf.c             | 29 +++++++++
 22 files changed, 326 insertions(+), 34 deletions(-)
 create mode 100644 sysdeps/generic/math-use-builtins-llrint.h
 create mode 100644 sysdeps/generic/math-use-builtins-logb.h
 create mode 100644 sysdeps/generic/math-use-builtins-lrint.h
 create mode 100644 sysdeps/loongarch/fpu/e_scalb.c
 create mode 100644 sysdeps/loongarch/fpu/e_scalbf.c
 create mode 100644 sysdeps/loongarch/fpu/math-use-builtins-llrint.h
 create mode 100644 sysdeps/loongarch/fpu/math-use-builtins-logb.h
 create mode 100644 sysdeps/loongarch/fpu/math-use-builtins-lrint.h
 create mode 100644 sysdeps/loongarch/fpu/math-use-builtins-rint.h
 create mode 100644 sysdeps/loongarch/fpu/s_scalbn.c
 create mode 100644 sysdeps/loongarch/fpu/s_scalbnf.c

-- 
2.20.1

[PATCH 1/9] LoongArch: Use __builtin_rint{,f} with GCC >= 13

[Xiaolin Tang]

From: Xi Ruoyao <xry111@xry111.site>

GCC 13 compiles these built-ins to frint.{d,s} instruction.

Link: https://gcc.gnu.org/r13-3919
---
 sysdeps/loongarch/fpu/math-use-builtins-rint.h | 9 +++++++++
 1 file changed, 9 insertions(+)
 create mode 100644 sysdeps/loongarch/fpu/math-use-builtins-rint.h

diff --git a/sysdeps/loongarch/fpu/math-use-builtins-rint.h b/sysdeps/loongarch/fpu/math-use-builtins-rint.h
new file mode 100644
index 0000000000..cd91482f5f
--- /dev/null
+++ b/sysdeps/loongarch/fpu/math-use-builtins-rint.h
@@ -0,0 +1,9 @@
+#if __GNUC_PREREQ (13, 0)
+#  define USE_RINT_BUILTIN 1
+#  define USE_RINTF_BUILTIN 1
+#else
+#  define USE_RINT_BUILTIN 0
+#  define USE_RINTF_BUILTIN 0
+#endif
+#define USE_RINTL_BUILTIN 0
+#define USE_RINTF128_BUILTIN 0
-- 
2.20.1

[PATCH 8/9] LoongArch: Add support for scalbn[f]

[Xiaolin Tang]

Add inline assembler for the scalbn functions. Passes GLIBC regression.

GCC 13, LoongArch support ___builtin_scalbn{,f} with -fno-math-errno,
but only "libm" can use -fno-math-errno in GLIBC, and scalbn is in libc
instead of libm because __printf_fp calls it.
---
 sysdeps/loongarch/fpu/s_scalbn.c  | 29 +++++++++++++++++++++++++++++
 sysdeps/loongarch/fpu/s_scalbnf.c | 29 +++++++++++++++++++++++++++++
 2 files changed, 58 insertions(+)
 create mode 100644 sysdeps/loongarch/fpu/s_scalbn.c
 create mode 100644 sysdeps/loongarch/fpu/s_scalbnf.c

diff --git a/sysdeps/loongarch/fpu/s_scalbn.c b/sysdeps/loongarch/fpu/s_scalbn.c
new file mode 100644
index 0000000000..c03e81a31e
--- /dev/null
+++ b/sysdeps/loongarch/fpu/s_scalbn.c
@@ -0,0 +1,29 @@
+/* scalbn().  LoongArch version.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#define NO_MATH_REDIRECT
+#include <math.h>
+
+double
+__scalbn (double x, int fn)
+{
+  double tmp;
+  asm volatile ("movgr2fr.d \t%0, %1" : "=f" (tmp) : "r" (fn));
+  asm volatile ("fscaleb.d \t%0, %1, %2" : "=f" (x) : "f" (x), "f" (tmp));
+  return x;
+}
diff --git a/sysdeps/loongarch/fpu/s_scalbnf.c b/sysdeps/loongarch/fpu/s_scalbnf.c
new file mode 100644
index 0000000000..15e6428044
--- /dev/null
+++ b/sysdeps/loongarch/fpu/s_scalbnf.c
@@ -0,0 +1,29 @@
+/* scalbnf().  LoongArch version.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#define NO_MATH_REDIRECT
+#include <math.h>
+
+float
+__scalbnf (float x, int fn)
+{
+  float tmp;
+  asm volatile ("movgr2fr.w \t%0, %1" : "=f" (tmp) : "r" (fn));
+  asm volatile ("fscaleb.s \t%0, %1, %2" : "=f" (x) : "f" (x), "f" (tmp));
+  return x;
+}
-- 
2.20.1

[PATCH 9/9] LoongArch: Add support for scalb[f]

[Xiaolin Tang]

Add inline assembler for the scalb functions. Passes GLIBC regression.
---
 sysdeps/loongarch/fpu/e_scalb.c  | 60 ++++++++++++++++++++++++++++++++
 sysdeps/loongarch/fpu/e_scalbf.c | 60 ++++++++++++++++++++++++++++++++
 2 files changed, 120 insertions(+)
 create mode 100644 sysdeps/loongarch/fpu/e_scalb.c
 create mode 100644 sysdeps/loongarch/fpu/e_scalbf.c

diff --git a/sysdeps/loongarch/fpu/e_scalb.c b/sysdeps/loongarch/fpu/e_scalb.c
new file mode 100644
index 0000000000..9fdf21fa3a
--- /dev/null
+++ b/sysdeps/loongarch/fpu/e_scalb.c
@@ -0,0 +1,60 @@
+/* scalb().  LoongArch version.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#define NO_MATH_REDIRECT
+#include <math.h>
+#include <libm-alias-finite.h>
+#include <fpu_control.h>
+#include <float.h>
+
+double
+__ieee754_scalb (double x, double fn)
+{
+  int x_cond;
+  int fn_cond;
+  asm volatile ("fclass.d \t%0, %1" : "=f" (x_cond) : "f" (x));
+  asm volatile ("fclass.d \t%0, %1" : "=f" (fn_cond) : "f" (fn));
+
+  if (__glibc_unlikely(( x_cond | fn_cond) & _FCLASS_NAN))
+      return x * fn;
+  else if (__glibc_unlikely(fn_cond & _FCLASS_INF))
+    {
+      if (!(fn_cond & _FCLASS_MINF))
+	  return x * fn;
+      else
+	  return x / -fn;
+    }
+  else if (__glibc_likely(-DBL_MAX < fn && fn < DBL_MAX))
+    {
+      double rint_fn, tmp;
+
+      /* rint_fn = rint(fn) */
+      asm volatile ("frint.d \t%0, %1" : "=f" (rint_fn) : "f" (fn));
+
+      if (rint_fn != fn )
+	  return (x - x) / (x - x);
+
+      asm volatile ("ftintrz.l.d \t%0, %1" : "=f" (tmp) : "f" (rint_fn));
+      asm volatile ("fscaleb.d \t%0, %1, %2" : "=f" (x) : "f" (x), "f" (tmp));
+    }
+  else
+    asm volatile ("fscaleb.d \t%0, %1, %2" : "=f" (x) : "f" (x), "f" (fn));
+
+  return x;
+}
+libm_alias_finite (__ieee754_scalb, __scalb)
diff --git a/sysdeps/loongarch/fpu/e_scalbf.c b/sysdeps/loongarch/fpu/e_scalbf.c
new file mode 100644
index 0000000000..fae2e92e20
--- /dev/null
+++ b/sysdeps/loongarch/fpu/e_scalbf.c
@@ -0,0 +1,60 @@
+/* scalbf().  LoongArch version.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#define NO_MATH_REDIRECT
+#include <math.h>
+#include <libm-alias-finite.h>
+#include <fpu_control.h>
+#include <float.h>
+
+float
+__ieee754_scalbf (float x, float fn)
+{
+  int x_cond;
+  int fn_cond;
+  asm volatile ("fclass.s \t%0, %1" : "=f" (x_cond) : "f" (x));
+  asm volatile ("fclass.s \t%0, %1" : "=f" (fn_cond) : "f" (fn));
+
+  if (__glibc_unlikely(( x_cond | fn_cond) & _FCLASS_NAN))
+      return x * fn;
+  else if (__glibc_unlikely(fn_cond & _FCLASS_INF))
+    {
+      if (!(fn_cond & _FCLASS_MINF))
+	  return x * fn;
+      else
+	  return x / -fn;
+    }
+  else if (__glibc_likely(-FLT_MAX < fn && fn < FLT_MAX))
+    {
+      float rintf_fn, tmp;
+
+      /* rintf_fn = rintf(fn) */
+      asm volatile ("frint.s \t%0, %1" : "=f" (rintf_fn) : "f" (fn));
+
+      if (rintf_fn != fn )
+	  return (x - x) / (x - x);
+
+      asm volatile ("ftintrz.w.s \t%0, %1" : "=f" (tmp) : "f" (rintf_fn));
+      asm volatile ("fscaleb.s \t%0, %1, %2" : "=f" (x) : "f" (x), "f" (tmp));
+    }
+  else
+    asm volatile ("fscaleb.s \t%0, %1, %2" : "=f" (x) : "f" (x), "f" (fn));
+
+  return x;
+}
+libm_alias_finite (__ieee754_scalb, __scalb)
-- 
2.20.1

[PATCH 8/9] LoongArch: Add support for scalbn[f]

[Xiaolin Tang]

Add inline assembler for the scalbn functions. Passes GLIBC regression.

GCC 13, LoongArch support ___builtin_scalbn{,f} with -fno-math-errno,
but only "libm" can use -fno-math-errno in GLIBC, and scalbn is in libc
instead of libm because __printf_fp calls it.
---
 sysdeps/loongarch/fpu/s_scalbn.c  | 29 +++++++++++++++++++++++++++++
 sysdeps/loongarch/fpu/s_scalbnf.c | 29 +++++++++++++++++++++++++++++
 2 files changed, 58 insertions(+)
 create mode 100644 sysdeps/loongarch/fpu/s_scalbn.c
 create mode 100644 sysdeps/loongarch/fpu/s_scalbnf.c

diff --git a/sysdeps/loongarch/fpu/s_scalbn.c b/sysdeps/loongarch/fpu/s_scalbn.c
new file mode 100644
index 0000000000..c03e81a31e
--- /dev/null
+++ b/sysdeps/loongarch/fpu/s_scalbn.c
@@ -0,0 +1,29 @@
+/* scalbn().  LoongArch version.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#define NO_MATH_REDIRECT
+#include <math.h>
+
+double
+__scalbn (double x, int fn)
+{
+  double tmp;
+  asm volatile ("movgr2fr.d \t%0, %1" : "=f" (tmp) : "r" (fn));
+  asm volatile ("fscaleb.d \t%0, %1, %2" : "=f" (x) : "f" (x), "f" (tmp));
+  return x;
+}
diff --git a/sysdeps/loongarch/fpu/s_scalbnf.c b/sysdeps/loongarch/fpu/s_scalbnf.c
new file mode 100644
index 0000000000..15e6428044
--- /dev/null
+++ b/sysdeps/loongarch/fpu/s_scalbnf.c
@@ -0,0 +1,29 @@
+/* scalbnf().  LoongArch version.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#define NO_MATH_REDIRECT
+#include <math.h>
+
+float
+__scalbnf (float x, int fn)
+{
+  float tmp;
+  asm volatile ("movgr2fr.w \t%0, %1" : "=f" (tmp) : "r" (fn));
+  asm volatile ("fscaleb.s \t%0, %1, %2" : "=f" (x) : "f" (x), "f" (tmp));
+  return x;
+}
-- 
2.20.1