1 /* sqrt function. PowerPC32 version.
2 Copyright (C) 2007, 2011 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
20 #include <math_ldbl_opt.h>
22 /* double [fp1] sqrt (double x [fp1])
23 Power4 (ISA V2.0) and above implement sqrt in hardware (not optional).
24 The fsqrt instruction generates the correct value for all inputs and
25 sets the appropriate floating point exceptions. Extented checking is
26 only needed to set errno (via __kernel_standard) if the input value
29 The fsqrt will set FPCC and FU (Floating Point Unordered or NaN
30 to indicated that the input value was negative or NaN. Use Move to
31 Condition Register from FPSCR to copy the FPCC field to cr1. The
32 branch on summary overflow transfers control to w_sqrt to process
33 any error conditions. Otherwise we can return the result directly.
35 This part of the function is a leaf routine, so no need to stack a
36 frame or execute prologue/epilogue code. This means it is safe to
37 transfer directly to w_sqrt as long as the input value (f1) is
38 preserved. Putting the sqrt result into f2 (double parameter 2)
39 allows passing both the input value and sqrt result into the extended
40 wrapper so there is no need to recompute.
42 This tactic avoids the overhead of stacking a frame for the normal
43 (non-error) case. Until gcc supports prologue shrink-wrapping
44 this is the best we can do. */
58 cfi_adjust_cfa_offset(16)
65 SETUP_GOT_ACCESS(r30,got_label)
66 addis r30,r30,_GLOBAL_OFFSET_TABLE_-got_label@ha
67 addi r30,r30,_GLOBAL_OFFSET_TABLE_-got_label@l
68 lwz r9,_LIB_VERSION@got(30)
71 lis r9,_LIB_VERSION@ha
72 lwz r0,_LIB_VERSION@l(r9)
74 /* if (_LIB_VERSION == _IEEE_) return z; */
77 /* if (x != x) return z; !isnan*/
81 return __kernel_standard (x, x, 26) */
95 bl __kernel_standard@plt
100 weak_alias (__sqrt, sqrt)
102 #ifdef NO_LONG_DOUBLE
103 weak_alias (__sqrt, sqrtl)
104 strong_alias (__sqrt, __sqrtl)
106 #if LONG_DOUBLE_COMPAT(libm, GLIBC_2_0)
107 compat_symbol (libm, __sqrt, sqrtl, GLIBC_2_0)