From 9f3ee7825b1eae00431ea6477fce8210aaced7db Mon Sep 17 00:00:00 2001
From: Stefan Liebler <stli@linux.ibm.com>
Date: Wed, 11 Dec 2019 15:09:30 +0100
Subject: [PATCH 22/28] S390: Use convert-to-fixed instruction for lround
functions.
If compiled with z196 zarch support, the convert-to-fixed instruction
is used to implement lround, lroundf, lroundl.
Otherwise the common-code implementation is used.
(cherry picked from commit 9d9f3527daf65fdca0eb46eaa324b81b8f94d88c)
---
sysdeps/s390/fpu/s_lround.c | 47 +++++++++++++++++++++++++++++++++++
sysdeps/s390/fpu/s_lroundf.c | 47 +++++++++++++++++++++++++++++++++++
sysdeps/s390/fpu/s_lroundl.c | 48 ++++++++++++++++++++++++++++++++++++
3 files changed, 142 insertions(+)
create mode 100644 sysdeps/s390/fpu/s_lround.c
create mode 100644 sysdeps/s390/fpu/s_lroundf.c
create mode 100644 sysdeps/s390/fpu/s_lroundl.c
diff --git a/sysdeps/s390/fpu/s_lround.c b/sysdeps/s390/fpu/s_lround.c
new file mode 100644
index 0000000000..9290ec32cd
--- /dev/null
+++ b/sysdeps/s390/fpu/s_lround.c
@@ -0,0 +1,47 @@
+/* lround() - 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>
+
+/* The sizeof (long int) differs between s390x (8byte) and s390 (4byte).
+ Thus we need different instructions as the target size is encoded there.
+ Note: On s390 this instruction is only used if build with -mzarch. */
+# ifdef __s390x__
+# define INSN "cgdbra"
+# else
+# define INSN "cfdbra"
+# endif
+
+long int
+__lround (double x)
+{
+ long int y;
+ /* The z196 zarch "convert to fixed" (cgdbra) instruction is rounding
+ x to the nearest integer with "ties away from 0" rounding mode
+ (M3-field: 1) where inexact exceptions are suppressed (M4-field: 4). */
+ __asm__ (INSN " %0,1,%1,4" : "=d" (y) : "f" (x) : "cc");
+ return y;
+}
+libm_alias_double (__lround, lround)
+
+#else
+# include <sysdeps/ieee754/dbl-64/s_lround.c>
+#endif
diff --git a/sysdeps/s390/fpu/s_lroundf.c b/sysdeps/s390/fpu/s_lroundf.c
new file mode 100644
index 0000000000..097b924c91
--- /dev/null
+++ b/sysdeps/s390/fpu/s_lroundf.c
@@ -0,0 +1,47 @@
+/* lroundf() - 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>
+
+/* The sizeof (long int) differs between s390x (8byte) and s390 (4byte).
+ Thus we need different instructions as the target size is encoded there.
+ Note: On s390 this instruction is only used if build with -mzarch. */
+# ifdef __s390x__
+# define INSN "cgebra"
+# else
+# define INSN "cfebra"
+# endif
+
+long int
+__lroundf (float x)
+{
+ long int y;
+ /* The z196 zarch "convert to fixed" (cgebra) instruction is rounding
+ x to the nearest integer with "ties away from 0" rounding mode
+ (M3-field: 1) where inexact exceptions are suppressed (M4-field: 4). */
+ __asm__ (INSN " %0,1,%1,4" : "=d" (y) : "f" (x) : "cc");
+ return y;
+}
+libm_alias_float (__lround, lround)
+
+#else
+# include <sysdeps/ieee754/flt-32/s_lroundf.c>
+#endif
diff --git a/sysdeps/s390/fpu/s_lroundl.c b/sysdeps/s390/fpu/s_lroundl.c
new file mode 100644
index 0000000000..0ef77dc667
--- /dev/null
+++ b/sysdeps/s390/fpu/s_lroundl.c
@@ -0,0 +1,48 @@
+/* lroundl() - 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>
+
+/* The sizeof (long int) differs between s390x (8byte) and s390 (4byte).
+ Thus we need different instructions as the target size is encoded there.
+ Note: On s390 this instruction is only used if build with -mzarch. */
+# ifdef __s390x__
+# define INSN "cgxbra"
+# else
+# define INSN "cfxbra"
+# endif
+
+long int
+__lroundl (_Float128 x)
+{
+ long int y;
+ /* The z196 zarch "convert to fixed" (cgxbra) instruction is rounding
+ x to the nearest integer with "ties away from 0" rounding mode
+ (M3-field: 1) where inexact exceptions are suppressed (M4-field: 4). */
+ __asm__ (INSN " %0,1,%1,4" : "=d" (y) : "f" (x) : "cc");
+ return y;
+}
+libm_alias_ldouble (__lround, lround)
+
+#else
+# include <sysdeps/ieee754/ldbl-128/s_lroundl.c>
+#endif
--
2.18.2