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Diffstat (limited to 'sysdeps/alpha/fpu/e_sqrt.c')
| -rw-r--r-- | sysdeps/alpha/fpu/e_sqrt.c | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/sysdeps/alpha/fpu/e_sqrt.c b/sysdeps/alpha/fpu/e_sqrt.c new file mode 100644 index 0000000000..958c699f54 --- /dev/null +++ b/sysdeps/alpha/fpu/e_sqrt.c @@ -0,0 +1,187 @@ +/* Copyright (C) 1996-2014 Free Software Foundation, Inc. + Contributed by David Mosberger (davidm@cs.arizona.edu). + 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 <math.h> +#include <math_private.h> +#include <shlib-compat.h> + +#if !defined(_IEEE_FP_INEXACT) + +/* + * This version is much faster than generic sqrt implementation, but + * it doesn't handle the inexact flag. It doesn't handle exceptional + * values either, but will defer to the full ieee754_sqrt routine which + * can. + */ + +/* Careful with rearranging this without consulting the assembly below. */ +const static struct sqrt_data_struct { + unsigned long dn, up, half, almost_three_half; + unsigned long one_and_a_half, two_to_minus_30, one, nan; + const int T2[64]; +} sqrt_data __attribute__((used)) = { + 0x3fefffffffffffff, /* __dn = nextafter(1,-Inf) */ + 0x3ff0000000000001, /* __up = nextafter(1,+Inf) */ + 0x3fe0000000000000, /* half */ + 0x3ff7ffffffc00000, /* almost_three_half = 1.5-2^-30 */ + 0x3ff8000000000000, /* one_and_a_half */ + 0x3e10000000000000, /* two_to_minus_30 */ + 0x3ff0000000000000, /* one */ + 0xffffffffffffffff, /* nan */ + + { 0x1500, 0x2ef8, 0x4d67, 0x6b02, 0x87be, 0xa395, 0xbe7a, 0xd866, + 0xf14a, 0x1091b,0x11fcd,0x13552,0x14999,0x15c98,0x16e34,0x17e5f, + 0x18d03,0x19a01,0x1a545,0x1ae8a,0x1b5c4,0x1bb01,0x1bfde,0x1c28d, + 0x1c2de,0x1c0db,0x1ba73,0x1b11c,0x1a4b5,0x1953d,0x18266,0x16be0, + 0x1683e,0x179d8,0x18a4d,0x19992,0x1a789,0x1b445,0x1bf61,0x1c989, + 0x1d16d,0x1d77b,0x1dddf,0x1e2ad,0x1e5bf,0x1e6e8,0x1e654,0x1e3cd, + 0x1df2a,0x1d635,0x1cb16,0x1be2c,0x1ae4e,0x19bde,0x1868e,0x16e2e, + 0x1527f,0x1334a,0x11051,0xe951, 0xbe01, 0x8e0d, 0x5924, 0x1edd } +}; + +asm ("\ + /* Define offsets into the structure defined in C above. */ \n\ + $DN = 0*8 \n\ + $UP = 1*8 \n\ + $HALF = 2*8 \n\ + $ALMOST_THREE_HALF = 3*8 \n\ + $NAN = 7*8 \n\ + $T2 = 8*8 \n\ + \n\ + /* Stack variables. */ \n\ + $K = 0 \n\ + $Y = 8 \n\ + \n\ + .text \n\ + .align 5 \n\ + .globl __ieee754_sqrt \n\ + .ent __ieee754_sqrt \n\ +__ieee754_sqrt: \n\ + ldgp $29, 0($27) \n\ + subq $sp, 16, $sp \n\ + .frame $sp, 16, $26, 0\n" +#ifdef PROF +" lda $28, _mcount \n\ + jsr $28, ($28), _mcount\n" +#endif +" .prologue 1 \n\ + \n\ + .align 4 \n\ + stt $f16, $K($sp) # e0 : \n\ + mult $f31, $f31, $f31 # .. fm : \n\ + lda $4, sqrt_data # e0 : \n\ + fblt $f16, $fixup # .. fa : \n\ + \n\ + ldah $2, 0x5fe8 # e0 : \n\ + ldq $3, $K($sp) # .. e1 : \n\ + ldt $f12, $HALF($4) # e0 : \n\ + ldt $f18, $ALMOST_THREE_HALF($4) # .. e1 : \n\ + \n\ + sll $3, 52, $5 # e0 : \n\ + lda $6, 0x7fd # .. e1 : \n\ + fnop # .. fa : \n\ + fnop # .. fm : \n\ + \n\ + subq $5, 1, $5 # e1 : \n\ + srl $3, 33, $1 # .. e0 : \n\ + cmpule $5, $6, $5 # e0 : \n\ + beq $5, $fixup # .. e1 : \n\ + \n\ + mult $f16, $f12, $f11 # fm : $f11 = x * 0.5 \n\ + subl $2, $1, $2 # .. e0 : \n\ + addt $f12, $f12, $f17 # .. fa : $f17 = 1.0 \n\ + srl $2, 12, $1 # e0 : \n\ + \n\ + and $1, 0xfc, $1 # e0 : \n\ + addq $1, $4, $1 # e1 : \n\ + ldl $1, $T2($1) # e0 : \n\ + addt $f12, $f17, $f15 # .. fa : $f15 = 1.5 \n\ + \n\ + subl $2, $1, $2 # e0 : \n\ + ldt $f14, $DN($4) # .. e1 : \n\ + sll $2, 32, $2 # e0 : \n\ + stq $2, $Y($sp) # e0 : \n\ + \n\ + ldt $f13, $Y($sp) # e0 : \n\ + mult/su $f11, $f13, $f10 # fm 2: $f10 = (x * 0.5) * y \n\ + mult $f10, $f13, $f10 # fm 4: $f10 = ((x*0.5)*y)*y \n\ + subt $f15, $f10, $f1 # fa 4: $f1 = (1.5-0.5*x*y*y) \n\ + \n\ + mult $f13, $f1, $f13 # fm 4: yp = y*(1.5-0.5*x*y^2)\n\ + mult/su $f11, $f13, $f1 # fm 4: $f11 = x * 0.5 * yp \n\ + mult $f1, $f13, $f11 # fm 4: $f11 = (x*0.5*yp)*yp \n\ + subt $f18, $f11, $f1 # fa 4: $f1=(1.5-2^-30)-x/2*yp^2\n\ + \n\ + mult $f13, $f1, $f13 # fm 4: ypp = $f13 = yp*$f1 \n\ + subt $f15, $f12, $f1 # .. fa : $f1 = (1.5 - 0.5) \n\ + ldt $f15, $UP($4) # .. e0 : \n\ + mult/su $f16, $f13, $f10 # fm 4: z = $f10 = x * ypp \n\ + \n\ + mult $f10, $f13, $f11 # fm 4: $f11 = z*ypp \n\ + mult $f10, $f12, $f12 # fm : $f12 = z*0.5 \n\ + subt $f1, $f11, $f1 # fa 4: $f1 = 1 - z*ypp \n\ + mult $f12, $f1, $f12 # fm 4: $f12 = z/2*(1 - z*ypp)\n\ + \n\ + addt $f10, $f12, $f0 # fa 4: zp=res= z+z/2*(1-z*ypp)\n\ + mult/c $f0, $f14, $f12 # fm 4: zmi = zp * DN \n\ + mult/c $f0, $f15, $f11 # fm : zpl = zp * UP \n\ + mult/c $f0, $f12, $f1 # fm : $f1 = zp * zmi \n\ + \n\ + mult/c $f0, $f11, $f15 # fm : $f15 = zp * zpl \n\ + subt/su $f1, $f16, $f13 # .. fa : y1 = zp*zmi - x \n\ + subt/su $f15, $f16, $f14 # fa 4: y2 = zp*zpl - x \n\ + fcmovge $f13, $f12, $f0 # fa 3: res = (y1>=0)?zmi:res \n\ + \n\ + fcmovlt $f14, $f11, $f0 # fa 4: res = (y2<0)?zpl:res \n\ + addq $sp, 16, $sp # .. e0 : \n\ + ret # .. e1 : \n\ + \n\ + .align 4 \n\ +$fixup: \n\ + addq $sp, 16, $sp \n\ + br __full_ieee754_sqrt !samegp \n\ + \n\ + .end __ieee754_sqrt"); + +/* Avoid the __sqrt_finite alias that dbl-64/e_sqrt.c would give... */ +#undef strong_alias +#define strong_alias(a,b) + +/* ... defining our own. */ +#if SHLIB_COMPAT (libm, GLIBC_2_15, GLIBC_2_18) +asm (".global __sqrt_finite1; __sqrt_finite1 = __ieee754_sqrt"); +#else +asm (".global __sqrt_finite; __sqrt_finite = __ieee754_sqrt"); +#endif + +static double __full_ieee754_sqrt(double) __attribute_used__; +#define __ieee754_sqrt __full_ieee754_sqrt + +#elif SHLIB_COMPAT (libm, GLIBC_2_15, GLIBC_2_18) +# define __sqrt_finite __sqrt_finite1 +#endif /* _IEEE_FP_INEXACT */ + +#include <sysdeps/ieee754/dbl-64/e_sqrt.c> + +/* Work around forgotten symbol in alphaev6 build. */ +#if SHLIB_COMPAT (libm, GLIBC_2_15, GLIBC_2_18) +# undef __sqrt_finite +# undef __ieee754_sqrt +compat_symbol (libm, __sqrt_finite1, __sqrt_finite, GLIBC_2_15); +versioned_symbol (libm, __ieee754_sqrt, __sqrt_finite, GLIBC_2_18); +#endif |