| /* round function. PowerPC32 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 <math_ldbl_opt.h> |
| #include <libm-alias-double.h> |
| |
| .section .rodata.cst8,"aM",@progbits,8 |
| .align 2 |
| .LC0: /* 2**52 */ |
| .long 0x59800000 |
| .LC1: /* 0.5 */ |
| .long 0x3f000000 |
| |
| /* double [fp1] round (double 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. */ |
| |
| .section ".text" |
| ENTRY (__round) |
| #ifdef SHARED |
| mflr r11 |
| cfi_register(lr,r11) |
| SETUP_GOT_ACCESS(r9,got_label) |
| addis r9,r9,.LC0-got_label@ha |
| addi r9,r9,.LC0-got_label@l |
| mtlr r11 |
| cfi_same_value (lr) |
| lfs fp13,0(r9) |
| #else |
| lis r9,.LC0@ha |
| lfs fp13,.LC0@l(r9) |
| #endif |
| fabs fp0,fp1 |
| fsub fp12,fp13,fp13 /* generate 0.0 */ |
| fcmpu cr7,fp0,fp13 /* if (fabs(x) > TWO52) */ |
| 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. */ |
| #ifdef SHARED |
| lfs fp10,.LC1-.LC0(r9) |
| #else |
| lis r9,.LC1@ha |
| lfs fp10,.LC1@l(r9) |
| #endif |
| ble- cr6,.L4 |
| fadd fp1,fp1,fp10 /* x+= 0.5; */ |
| fadd fp1,fp1,fp13 /* x+= TWO52; */ |
| fsub fp1,fp1,fp13 /* x-= TWO52; */ |
| fabs fp1,fp1 /* if (x == 0.0) */ |
| /* x = 0.0; */ |
| mtfsf 0xff,fp11 /* Restore previous rounding mode and |
| "inexact" state. */ |
| blr |
| .L4: |
| fsub fp9,fp1,fp10 /* x+= 0.5; */ |
| bge- cr6,.L9 /* if (x < 0.0) */ |
| fsub fp1,fp9,fp13 /* x-= TWO52; */ |
| fadd fp1,fp1,fp13 /* x+= TWO52; */ |
| 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 |
| fadd fp1,fp1,fp1 |
| blr |
| END (__round) |
| |
| libm_alias_double (__round, round) |