diff options
Diffstat (limited to 'sysdeps/s390/fpu/s_lrint.c')
-rw-r--r-- | sysdeps/s390/fpu/s_lrint.c | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/sysdeps/s390/fpu/s_lrint.c b/sysdeps/s390/fpu/s_lrint.c new file mode 100644 index 0000000000..7be60665b5 --- /dev/null +++ b/sysdeps/s390/fpu/s_lrint.c @@ -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 |