[05/17] S390: Use load-fp-integer instruction for trunc functions.

Message ID 1572881244-6781-5-git-send-email-stli@linux.ibm.com
State Superseded
Headers

Commit Message

Stefan Liebler Nov. 4, 2019, 3:27 p.m. UTC
  If compiled with z196 zarch support, the load-fp-integer instruction
is used to implement trunc, truncf, truncl.
Otherwise the common-code implementation is used.
---
 sysdeps/s390/fpu/s_trunc.c  | 39 ++++++++++++++++++++++++++++++++++++
 sysdeps/s390/fpu/s_truncf.c | 39 ++++++++++++++++++++++++++++++++++++
 sysdeps/s390/fpu/s_truncl.c | 40 +++++++++++++++++++++++++++++++++++++
 3 files changed, 118 insertions(+)
 create mode 100644 sysdeps/s390/fpu/s_trunc.c
 create mode 100644 sysdeps/s390/fpu/s_truncf.c
 create mode 100644 sysdeps/s390/fpu/s_truncl.c
  

Comments

Stefan Liebler Dec. 2, 2019, 2:57 p.m. UTC | #1
This patch is superseded by the patch-series which is always using 
wordsize-64 version and allows to use the GCC builtins in common-code 
implementation:
"[PATCH 00/13] Use GCC builtins for some math functions if desired."
https://www.sourceware.org/ml/libc-alpha/2019-12/msg00029.html

Bye,
Stefan
  

Patch

diff --git a/sysdeps/s390/fpu/s_trunc.c b/sysdeps/s390/fpu/s_trunc.c
new file mode 100644
index 0000000000..7744843a91
--- /dev/null
+++ b/sysdeps/s390/fpu/s_trunc.c
@@ -0,0 +1,39 @@ 
+/* trunc() - 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
+# define NO_MATH_REDIRECT
+# include <math.h>
+# include <libm-alias-double.h>
+
+double
+__trunc (double x)
+{
+  double y;
+  /* The z196 zarch "load fp integer" (fidbra) instruction is rounding
+     x to the nearest integer with "round towards zero" rounding mode
+     (M3-field: 5) where inexact exceptions are suppressed (M4-field: 4).  */
+  __asm__ ("fidbra %0,5,%1,4" : "=f" (y) : "f" (x));
+  return y;
+}
+libm_alias_double (__trunc, trunc)
+
+#else
+# include <sysdeps/ieee754/dbl-64/s_trunc.c>
+#endif
diff --git a/sysdeps/s390/fpu/s_truncf.c b/sysdeps/s390/fpu/s_truncf.c
new file mode 100644
index 0000000000..40c126eef2
--- /dev/null
+++ b/sysdeps/s390/fpu/s_truncf.c
@@ -0,0 +1,39 @@ 
+/* truncf() - 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
+# define NO_MATH_REDIRECT
+# include <math.h>
+# include <libm-alias-float.h>
+
+float
+__truncf (float x)
+{
+  float y;
+  /* The z196 zarch "load fp integer" (fiebra) instruction is rounding
+     x to the nearest integer with "round towards zero" rounding mode
+     (M3-field: 5) where inexact exceptions are suppressed (M4-field: 4).  */
+  __asm__ ("fiebra %0,5,%1,4" : "=f" (y) : "f" (x));
+  return y;
+}
+libm_alias_float (__trunc, trunc)
+
+#else
+# include <sysdeps/ieee754/flt-32/s_truncf.c>
+#endif
diff --git a/sysdeps/s390/fpu/s_truncl.c b/sysdeps/s390/fpu/s_truncl.c
new file mode 100644
index 0000000000..68de3ea6bc
--- /dev/null
+++ b/sysdeps/s390/fpu/s_truncl.c
@@ -0,0 +1,40 @@ 
+/* truncl() - 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
+# define NO_MATH_REDIRECT
+# include <math.h>
+# include <math_private.h>
+# include <libm-alias-ldouble.h>
+
+_Float128
+__truncl (_Float128 x)
+{
+  _Float128 y;
+  /* The z196 zarch "load fp integer" (fixbra) instruction is rounding
+     x to the nearest integer with "round towards zero" rounding mode
+     (M3-field: 5) where inexact exceptions are suppressed (M4-field: 4).  */
+  __asm__ ("fixbra %0,5,%1,4" : "=f" (y) : "f" (x));
+  return y;
+}
+libm_alias_ldouble (__trunc, trunc)
+
+#else
+# include <sysdeps/ieee754/ldbl-128/s_truncl.c>
+#endif