glibc/sysdeps/powerpc/powerpc32/fpu/s_trunc.S

91 lines
2.6 KiB
ArmAsm

/* trunc function. PowerPC32 version.
Copyright (C) 2004-2017 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>
.section .rodata.cst4,"aM",@progbits,4
.align 2
.LC0: /* 2**52 */
.long 0x59800000
/* double [fp1] trunc (double x [fp1])
IEEE 1003.1 trunc function. IEEE specifies "trunc to the integer
value, in floating format, nearest to but no larger in magnitude
then the argument."
We set "round toward Zero" mode and trunc by adding +-2**52 then
subtracting +-2**52. */
.section ".text"
ENTRY (__trunc)
#ifdef SHARED
mflr r11
cfi_register(lr,r11)
SETUP_GOT_ACCESS(r9,got_label)
addis r9,r9,.LC0-got_label@ha
lfs fp13,.LC0-got_label@l(r9)
mtlr r11
cfi_same_value (lr)
#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 toward 0 mode. */
ble- cr6,.L4
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:
bge- cr6,.L9 /* if (x < 0.0) */
fsub fp1,fp1,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 (__trunc)
weak_alias (__trunc, trunc)
#ifdef NO_LONG_DOUBLE
weak_alias (__trunc, truncl)
strong_alias (__trunc, __truncl)
#endif
#if LONG_DOUBLE_COMPAT(libm, GLIBC_2_1)
compat_symbol (libm, __trunc, truncl, GLIBC_2_1)
#endif