/* 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 .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)