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Diffstat (limited to 'sysdeps/powerpc/powerpc32/power4/fpu/w_sqrtf.S')
| -rw-r--r-- | sysdeps/powerpc/powerpc32/power4/fpu/w_sqrtf.S | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/sysdeps/powerpc/powerpc32/power4/fpu/w_sqrtf.S b/sysdeps/powerpc/powerpc32/power4/fpu/w_sqrtf.S new file mode 100644 index 0000000000..e5b8b9d565 --- /dev/null +++ b/sysdeps/powerpc/powerpc32/power4/fpu/w_sqrtf.S @@ -0,0 +1,111 @@ +/* sqrtf function. PowerPC32 version. + Copyright (C) 2007 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 <sysdep.h> +#include <math_ldbl_opt.h> + +/* float [fp1] sqrts (float x [fp1]) + Power4 (ISA V2.0) and above implement sqrt in hardware (not optional). + The fsqrts instruction generates the correct value for all inputs and + sets the appropriate floating point exceptions. Extented checking is + only needed to set errno (via __kernel_standard) if the input value + is negative. + + The fsqrts will set FPCC and FU (Floating Point Unordered or NaN + to indicated that the input value was negative or NaN. Use Move to + Condition Register from FPSCR to copy the FPCC field to cr1. The + branch on summary overflow transfers control to w_sqrt to process + any error conditions. Otherwise we can return the result directly. + + This part of the function is a leaf routine, so no need to stack a + frame or execute prologue/epilogue code. This means it is safe to + transfer directly to w_sqrt as long as the input value (f1) is + preserved. Putting the the sqrt result into f2 (float parameter 2) + allows passing both the input value and sqrt result into the extended + wrapper so there is no need to recompute. + + This tactic avoids the overhead of stacking a frame for the normal + (non-error) case. Until gcc supports prologue shrink-wrapping + this is the best we can do. */ + + .section ".text" + .machine power4 +EALIGN (__sqrtf, 5, 0) + fsqrts fp2,fp1 + mcrfs cr1,4 + bso- cr1,.Lw_sqrtf + fmr fp1,fp2 + blr + .align 4 +.Lw_sqrtf: + mflr r0 + stwu r1,-16(r1) + cfi_adjust_cfa_offset(16) + fmr fp12,fp2 + stw r0,20(r1) + stw r30,8(r1) + cfi_offset(lr,20) + cfi_offset(r30,8) +#ifdef SHARED +# ifdef HAVE_ASM_PPC_REL16 + bcl 20,31,.LCF1 +.LCF1: + mflr r30 + addis r30,r30,_GLOBAL_OFFSET_TABLE_-.LCF1@ha + addi r30,r30,_GLOBAL_OFFSET_TABLE_-.LCF1@l + lwz r9,_LIB_VERSION@got(30) + lwz r0,0(r9) +# else + bl _GLOBAL_OFFSET_TABLE_@local-4 + mflr r30 + lwz r9,_LIB_VERSION@got(30) + lwz r0,0(r9) +# endif +#else + lis r9,_LIB_VERSION@ha + lwz r0,_LIB_VERSION@l(r9) +#endif +/* if (_LIB_VERSION == _IEEE_) return z; */ + cmpwi cr7,r0,-1 + beq- cr7,.L4 +/* if (x != x, 0) return z; !isnan */ + fcmpu cr7,fp1,fp1 + bne- cr7,.L4 +/* if (x < 0.0) + return __kernel_standard (x, x, 126) */ + fmr fp2,fp1 + fabs fp0,fp1 + li r3,126 + fcmpu cr7,1,0 + bne- cr7,.L11 +.L4: + lwz r0,20(r1) + fmr fp1,fp12 + lwz r30,8(r1) + addi r1,r1,16 + mtlr r0 + blr +.L11: + bl __kernel_standard@plt + fmr fp12,fp1 + b .L4 + END (__sqrtf) + +weak_alias (__sqrtf, sqrtf) + |