[08/17] S390: Use convert-to-fixed instruction for lrint functions.
Commit Message
If compiled with z196 zarch support, the convert-to-fixed instruction
is used to implement lrint, lrintf, lrintl.
Otherwise the common-code implementation is used.
---
sysdeps/s390/fpu/s_lrint.c | 55 ++++++++++++++++++++++++++++++++++++
sysdeps/s390/fpu/s_lrintf.c | 55 ++++++++++++++++++++++++++++++++++++
sysdeps/s390/fpu/s_lrintl.c | 56 +++++++++++++++++++++++++++++++++++++
3 files changed, 166 insertions(+)
create mode 100644 sysdeps/s390/fpu/s_lrint.c
create mode 100644 sysdeps/s390/fpu/s_lrintf.c
create mode 100644 sysdeps/s390/fpu/s_lrintl.c
Comments
PING.
This patch is still needed. If there are no further comments, I'll
commit this s390-only patch in a few days.
Bye,
Stefan
new file mode 100644
@@ -0,0 +1,55 @@
+/* lrint() - 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
+__lrint (double x)
+{
+ long int y;
+ /* The z196 zarch "convert to fixed" (cgdbra) instruction is rounding
+ according to current rounding mode (M3-field: 0).
+ First convert x with suppressed inexact exception and check if the
+ resulting value is beyond the target limits (indicated by cc=3;
+ Note: a nan is also indicated by cc=3).
+ If the resulting value is within the target limits, redo
+ without suppressing the inexact exception. */
+ __asm__ (INSN " %0,0,%1,4 \n\t"
+ "jo 1f \n\t"
+ INSN " %0,0,%1,0 \n\t"
+ "1:"
+ : "=&d" (y) : "f" (x) : "cc");
+ return y;
+}
+libm_alias_double (__lrint, lrint)
+
+#else
+# include <sysdeps/ieee754/dbl-64/s_lrint.c>
+#endif
new file mode 100644
@@ -0,0 +1,55 @@
+/* lrintf() - 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
+__lrintf (float x)
+{
+ long int y;
+ /* The z196 zarch "convert to fixed" (cgebra) instruction is rounding
+ according to current rounding mode (M3-field: 0).
+ First convert x with suppressed inexact exception and check if the
+ resulting value is beyond the target limits (indicated by cc=3;
+ Note: a nan is also indicated by cc=3).
+ If the resulting value is within the target limits, redo
+ without suppressing the inexact exception. */
+ __asm__ (INSN " %0,0,%1,4 \n\t"
+ "jo 1f \n\t"
+ INSN " %0,0,%1,0 \n\t"
+ "1:"
+ : "=&d" (y) : "f" (x) : "cc");
+ return y;
+}
+libm_alias_float (__lrint, lrint)
+
+#else
+# include <sysdeps/ieee754/flt-32/s_lrintf.c>
+#endif
new file mode 100644
@@ -0,0 +1,56 @@
+/* lrintl() - 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
+__lrintl (_Float128 x)
+{
+ long int y;
+ /* The z196 zarch "convert to fixed" (cgxbra) instruction is rounding
+ according to current rounding mode (M3-field: 0).
+ First convert x with suppressed inexact exception and check if the
+ resulting value is beyond the target limits (indicated by cc=3;
+ Note: a nan is also indicated by cc=3).
+ If the resulting value is within the target limits, redo
+ without suppressing the inexact exception. */
+ __asm__ (INSN " %0,0,%1,4 \n\t"
+ "jo 1f \n\t"
+ INSN " %0,0,%1,0 \n\t"
+ "1:"
+ : "=&d" (y) : "f" (x) : "cc");
+ return y;
+}
+libm_alias_ldouble (__lrint, lrint)
+
+#else
+# include <sysdeps/ieee754/ldbl-128/s_lrintl.c>
+#endif