/* roundf function. PowerPC32 version. Copyright (C) 2004, 2006 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., 1 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA. */ #include .section .rodata.cst8,"aM",@progbits,8 .align 2 .LC0: /* 2**23 */ .long 0x4b000000 .LC1: /* 0.5 */ .long 0x3f000000 /* 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. */ .section ".text" ENTRY (__roundf ) mffs fp11 /* Save current FPU rounding mode. */ #ifdef SHARED mflr r11 cfi_register(lr,r11) # ifdef HAVE_ASM_PPC_REL16 bcl 20,31,1f 1: mflr r9 addis r9,r9,.LC0-1b@ha addi r9,r9,.LC0-1b@l # else bl _GLOBAL_OFFSET_TABLE_@local-4 mflr r10 lwz r9,.LC0@got(10) # endif mtlr r11 cfi_same_value (lr) lfs fp13,0(r9) #else lis r9,.LC0@ha lfs fp13,.LC0@l(r9) #endif 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. */ #ifdef SHARED lfs fp10,.LC1-.LC0(r9) #else lis r9,.LC1@ha lfs fp10,.LC1@l(r9) #endif 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 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; */ fnabs fp1,fp1 /* if (x == 0.0) */ /* x = -0.0; */ .L9: mtfsf 0x01,fp11 /* restore previous rounding mode. */ blr END (__roundf) weak_alias (__roundf, roundf)