diff options
Diffstat (limited to 'sysdeps/powerpc/powerpc64/fpu/s_roundf.S')
| -rw-r--r-- | sysdeps/powerpc/powerpc64/fpu/s_roundf.S | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/sysdeps/powerpc/powerpc64/fpu/s_roundf.S b/sysdeps/powerpc/powerpc64/fpu/s_roundf.S new file mode 100644 index 0000000000..fd8eb0aea3 --- /dev/null +++ b/sysdeps/powerpc/powerpc64/fpu/s_roundf.S @@ -0,0 +1,71 @@ +/* roundf function. PowerPC64 version. + Copyright (C) 2004 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <sysdep.h> + + .section ".toc","aw" +.LC0: /* 2**23 */ + .tc FD_41600000_0[TC],0x4160000000000000 +.LC1: /* 0.5 */ + .tc FD_3fe00000_0[TC],0x3fe0000000000000 +.LC2: /* -0.0 */ + .tc FD_80000000_0[TC],0x8000000000000000 + .section ".text" + +/* float [fp1] roundf (float x [fp1]) + IEEE 1003.1 round function. IEEE specifies "round to the nearest + integer value, rounding halfway cases away from zero, regardless of + the current rounding mode." However PowerPC Architecture defines + "Round to Nearest" as "Choose the best approximation. In case of a + tie, choose the one that is even (least significant bit o).". + So we can't use the PowerPC "Round to Nearest" mode. Instead we set + "Round toward Zero" mode and round by adding +-0.5 before rounding + to the integer value. */ + +ENTRY (__roundf ) + mffs fp11 /* Save current FPU rounding mode. */ + lfd fp13,.LC0@toc(2) + fabs fp0,fp1 + fsubs fp12,fp13,fp13 /* generate 0.0 */ + fcmpu cr7,fp0,fp13 /* if (fabs(x) > TWO23) */ + fcmpu cr6,fp1,fp12 /* if (x > 0.0) */ + bnllr- cr7 + mtfsfi 7,1 /* Set rounding mode toward 0. */ + lfd fp10,.LC1@toc(2) + ble- cr6,.L4 + fadds fp1,fp1,fp10 /* x+= 0.5; */ + fadds fp1,fp1,fp13 /* x+= TWO23; */ + fsubs fp1,fp1,fp13 /* x-= TWO23; */ +.L9: + mtfsf 0x01,fp11 /* restore previous rounding mode. */ + blr +.L4: + fsubs fp9,fp1,fp10 /* x+= 0.5; */ + bge- cr6,.L9 /* if (x < 0.0) */ + fsubs fp1,fp9,fp13 /* x-= TWO23; */ + fadds fp1,fp1,fp13 /* x+= TWO23; */ + fcmpu cr5,fp1,fp12 /* if (x > 0.0) */ + mtfsf 0x01,fp11 /* restore previous rounding mode. */ + bnelr+ cr5 + lfd fp1,.LC2@toc(2) /* x must be -0.0 for the 0.0 case. */ + blr + END (__roundf) + +weak_alias (__roundf, roundf) + |