[PATCH 01/17] S390: Use load-fp-integer instruction for nearbyint functions.

[Stefan Liebler <stli at linux dot ibm dot com>]

If compiled with z196 zarch support, the load-fp-integer instruction
is used to implement nearbyint, nearbyintf, nearbyintl.
Otherwise the common-code implementation is used.
---
 sysdeps/s390/fpu/s_nearbyint.c  | 38 ++++++++++++++++++++++++++++++++
 sysdeps/s390/fpu/s_nearbyintf.c | 38 ++++++++++++++++++++++++++++++++
 sysdeps/s390/fpu/s_nearbyintl.c | 39 +++++++++++++++++++++++++++++++++
 3 files changed, 115 insertions(+)
 create mode 100644 sysdeps/s390/fpu/s_nearbyint.c
 create mode 100644 sysdeps/s390/fpu/s_nearbyintf.c
 create mode 100644 sysdeps/s390/fpu/s_nearbyintl.c

diff --git a/sysdeps/s390/fpu/s_nearbyint.c b/sysdeps/s390/fpu/s_nearbyint.c
new file mode 100644
index 0000000000..7af92ace0c
--- /dev/null
+++ b/sysdeps/s390/fpu/s_nearbyint.c
@@ -0,0 +1,38 @@
+/* nearbyint() - S390 version.
+   Copyright (C) 2019 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/>.  */
+
+#ifdef HAVE_S390_MIN_Z196_ZARCH_ASM_SUPPORT
+# include <math.h>
+# include <libm-alias-double.h>
+
+double
+__nearbyint (double x)
+{
+  double y;
+  /* The z196 zarch "load fp integer" (fidbra) instruction is rounding
+     x to the nearest integer according to current rounding mode (M3-field: 0)
+     where inexact exceptions are suppressed (M4-field: 4).  */
+  __asm__ ("fidbra %0,0,%1,4" : "=f" (y) : "f" (x));
+  return y;
+}
+libm_alias_double (__nearbyint, nearbyint)
+
+#else
+# include <sysdeps/ieee754/dbl-64/s_nearbyint.c>
+#endif
diff --git a/sysdeps/s390/fpu/s_nearbyintf.c b/sysdeps/s390/fpu/s_nearbyintf.c
new file mode 100644
index 0000000000..66473e3b2e
--- /dev/null
+++ b/sysdeps/s390/fpu/s_nearbyintf.c
@@ -0,0 +1,38 @@
+/* nearbyintf() - S390 version.
+   Copyright (C) 2019 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/>.  */
+
+#ifdef HAVE_S390_MIN_Z196_ZARCH_ASM_SUPPORT
+# include <math.h>
+# include <libm-alias-float.h>
+
+float
+__nearbyintf (float x)
+{
+  float y;
+  /* The z196 zarch "load fp integer" (fiebra) instruction is rounding
+     x to the nearest integer according to current rounding mode (M3-field: 0)
+     where inexact exceptions are suppressed (M4-field: 4).  */
+  __asm__ ("fiebra %0,0,%1,4" : "=f" (y) : "f" (x));
+  return y;
+}
+libm_alias_float (__nearbyint, nearbyint)
+
+#else
+# include <sysdeps/ieee754/flt-32/s_nearbyintf.c>
+#endif
diff --git a/sysdeps/s390/fpu/s_nearbyintl.c b/sysdeps/s390/fpu/s_nearbyintl.c
new file mode 100644
index 0000000000..f154cf41c7
--- /dev/null
+++ b/sysdeps/s390/fpu/s_nearbyintl.c
@@ -0,0 +1,39 @@
+/* nearbyintl() - S390 version.
+   Copyright (C) 2019 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/>.  */
+
+#ifdef HAVE_S390_MIN_Z196_ZARCH_ASM_SUPPORT
+# include <math.h>
+# include <math_private.h>
+# include <libm-alias-ldouble.h>
+
+_Float128
+__nearbyintl (_Float128 x)
+{
+  _Float128 y;
+  /* The z196 zarch "load fp integer" (fixbra) instruction is rounding
+     x to the nearest integer according to current rounding mode (M3-field: 0)
+     where inexact exceptions are suppressed (M4-field: 4).  */
+  __asm__ ("fixbra %0,0,%1,4" : "=f" (y) : "f" (x));
+  return y;
+}
+libm_alias_ldouble (__nearbyint, nearbyint)
+
+#else
+# include <sysdeps/ieee754/ldbl-128/s_nearbyintl.c>
+#endif
-- 
2.19.1