| /* roundf function. PowerPC64 version. |
| Copyright (C) 2004-2018 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 |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <sysdep.h> |
| #include <libm-alias-float.h> |
| |
| .section ".toc","aw" |
| .p2align 3 |
| .LC0: /* 2**23 */ |
| .long 0x4b000000 |
| .LC1: /* 0.5 */ |
| .long 0x3f000000 |
| |
| .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, 4) |
| CALL_MCOUNT 0 |
| lfs fp13,.LC0@toc(2) |
| fabs fp0,fp1 |
| fsubs fp12,fp13,fp13 /* generate 0.0 */ |
| fcmpu cr7,fp0,fp13 /* if (fabs(x) > TWO23) */ |
| mffs fp11 /* Save current FPU rounding mode and |
| "inexact" state. */ |
| fcmpu cr6,fp1,fp12 /* if (x > 0.0) */ |
| bnl- cr7,.L10 |
| mtfsfi 7,1 /* Set rounding mode toward 0. */ |
| lfs 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; */ |
| fabs fp1,fp1 /* if (x == 0.0) */ |
| /* x = 0.0; */ |
| mtfsf 0xff,fp11 /* Restore previous rounding mode and |
| "inexact" state. */ |
| 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; */ |
| fnabs fp1,fp1 /* if (x == 0.0) */ |
| /* x = -0.0; */ |
| .L9: |
| mtfsf 0xff,fp11 /* Restore previous rounding mode and |
| "inexact" state. */ |
| blr |
| .L10: |
| /* Ensure sNaN input is converted to qNaN. */ |
| fcmpu cr7,fp1,fp1 |
| beqlr cr7 |
| fadds fp1,fp1,fp1 |
| blr |
| END (__roundf) |
| |
| libm_alias_float (__round, round) |
| |
