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#
# (C) 2008-2009 Advanced Micro Devices, Inc. All Rights Reserved.
#
# This file is part of libacml_mv.
#
# libacml_mv 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.
#
# libacml_mv 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 libacml_mv. If not, see
# <http://www.gnu.org/licenses/>.
#
#
#
# An implementation of the cos function.
#
# Prototype:
#
# double cos(double x);
#
# Computes cos(x).
# It will provide proper C99 return values,
# but may not raise floating point status bits properly.
# Based on the NAG C implementation.
#
#
#ifdef __ELF__
.section .note.GNU-stack,"",@progbits
#endif
.data
.align 32
.L__real_7fffffffffffffff: .quad 0x07fffffffffffffff #Sign bit zero
.quad 0 # for alignment
.L__real_3ff0000000000000: .quad 0x03ff0000000000000 # 1.0
.quad 0
.L__real_3fe0000000000000: .quad 0x03fe0000000000000 # 0.5
.quad 0
.L__real_3fc5555555555555: .quad 0x03fc5555555555555 # 0.166666666666
.quad 0
.L__real_3fe45f306dc9c883: .quad 0x03fe45f306dc9c883 # twobypi
.quad 0
.L__real_3ff921fb54400000: .quad 0x03ff921fb54400000 # piby2_1
.quad 0
.L__real_3dd0b4611a626331: .quad 0x03dd0b4611a626331 # piby2_1tail
.quad 0
.L__real_3dd0b4611a600000: .quad 0x03dd0b4611a600000 # piby2_2
.quad 0
.L__real_3ba3198a2e037073: .quad 0x03ba3198a2e037073 # piby2_2tail
.quad 0
.L__real_fffffffff8000000: .quad 0x0fffffffff8000000 # mask for stripping head and tail
.quad 0
.L__real_411E848000000000: .quad 0x415312d000000000 # 5e6 0x0411E848000000000 # 5e5
.quad 0
.L__real_bfe0000000000000: .quad 0x0bfe0000000000000 # - 0.5
.quad 0
.align 32
.Lcosarray:
.quad 0x3fa5555555555555 # 0.0416667 c1
.quad 0
.quad 0xbf56c16c16c16967 # -0.00138889 c2
.quad 0
.quad 0x3EFA01A019F4EC91 # 2.48016e-005 c3
.quad 0
.quad 0xbE927E4FA17F667B # -2.75573e-007 c4
.quad 0
.quad 0x3E21EEB690382EEC # 2.08761e-009 c5
.quad 0
.quad 0xbDA907DB47258AA7 # -1.13826e-011 c6
.quad 0
.align 32
.Lsinarray:
.quad 0xbfc5555555555555 # -0.166667 s1
.quad 0
.quad 0x3f81111111110bb3 # 0.00833333 s2
.quad 0
.quad 0xbf2a01a019e83e5c # -0.000198413 s3
.quad 0
.quad 0x3ec71de3796cde01 # 2.75573e-006 s4
.quad 0
.quad 0xbe5ae600b42fdfa7 # -2.50511e-008 s5
.quad 0
.quad 0x3de5e0b2f9a43bb8 # 1.59181e-010 s6
.quad 0
.text
.align 32
.p2align 5,,31
#include "fn_macros.h"
#define fname FN_PROTOTYPE(cos)
#define fname_special _cos_special@PLT
# define local variable storage offsets
.equ p_temp, 0x30 # temporary for get/put bits operation
.equ p_temp1, 0x40 # temporary for get/put bits operation
.equ r, 0x50 # pointer to r for amd_remainder_piby2
.equ rr, 0x60 # pointer to rr for amd_remainder_piby2
.equ region, 0x70 # pointer to region for amd_remainder_piby2
.equ stack_size, 0x98
.globl fname
.type fname,@function
fname:
sub $stack_size, %rsp
xorpd %xmm2, %xmm2 # zeroed out for later use
# GET_BITS_DP64(x, ux);
# get the input value to an integer register.
movsd %xmm0,p_temp(%rsp)
mov p_temp(%rsp), %rdx # rdx is ux
## if NaN or inf
mov $0x07ff0000000000000, %rax
mov %rax, %r10
and %rdx, %r10
cmp %rax, %r10
jz .Lcos_naninf
# ax = (ux & ~SIGNBIT_DP64);
mov $0x07fffffffffffffff, %r10
and %rdx, %r10 # r10 is ax
mov $1, %r8d # for determining region later on
## if (ax <= 0x3fe921fb54442d18) /* abs(x) <= pi/4 */
mov $0x03fe921fb54442d18, %rax
cmp %rax, %r10
jg .Lcos_reduce
## if (ax < 0x3f20000000000000) /* abs(x) < 2.0^(-13) */
mov $0x03f20000000000000, %rax
cmp %rax, %r10
jge .Lcos_small
## if (ax < 0x3e40000000000000) /* abs(x) < 2.0^(-27) */
mov $0x03e40000000000000, %rax
cmp %rax, %r10
jge .Lcos_smaller
# cos = 1.0;
movsd .L__real_3ff0000000000000(%rip), %xmm0 # return a 1
jmp .Lcos_cleanup
## else
.align 16
.Lcos_smaller:
# cos = 1.0 - x*x*0.5;
movsd %xmm0, %xmm2
mulsd %xmm2, %xmm2 # x^2
movsd .L__real_3ff0000000000000(%rip), %xmm0 # 1.0
mulsd .L__real_3fe0000000000000(%rip), %xmm2 # 0.5 * x^2
subsd %xmm2, %xmm0
jmp .Lcos_cleanup
## else
.align 16
.Lcos_small:
# cos = cos_piby4(x, 0.0);
movsd %xmm0, %xmm2
mulsd %xmm0, %xmm2 # x2
#;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
# region 0 or 2 - do a cos calculation
# zc = (c2 + x2 * (c3 + x2 * (c4 + x2 * (c5 + x2 * c6))));
movsd .Lcosarray+0x10(%rip), %xmm1 # c2
movsd %xmm2, %xmm4 # move for x4
mulsd %xmm2, %xmm4 # x4
movsd .Lcosarray+0x30(%rip), %xmm3 # c4
mulsd %xmm2, %xmm1 # c2x2
movsd .Lcosarray+0x50(%rip), %xmm5 # c6
mulsd %xmm2, %xmm3 # c4x2
movsd %xmm4, %xmm0 # move for x8
mulsd %xmm2, %xmm5 # c6x2
mulsd %xmm4, %xmm0 # x8
addsd .Lcosarray(%rip), %xmm1 # c1 + c2x2
mulsd %xmm4, %xmm1 # c1x4 + c2x6
addsd .Lcosarray+0x20(%rip), %xmm3 # c3 + c4x2
mulsd .L__real_bfe0000000000000(%rip), %xmm2 # -0.5x2, destroy xmm2
addsd .Lcosarray+0x40(%rip), %xmm5 # c5 + c6x2
mulsd %xmm0, %xmm3 # c3x8 + c4x10
mulsd %xmm0, %xmm4 # x12
mulsd %xmm5, %xmm4 # c5x12 + c6x14
movsd .L__real_3ff0000000000000(%rip), %xmm0 # 1
addsd %xmm3, %xmm1 # c1x4 + c2x6 + c3x8 + c4x10
movsd %xmm2, %xmm3 # preserve -0.5x2
addsd %xmm0, %xmm2 # t = 1 - 0.5x2
subsd %xmm2, %xmm0 # 1-t
addsd %xmm3, %xmm0 # (1-t) - r
addsd %xmm4, %xmm1 # c1x4 + c2x6 + c3x8 + c4x10 + c5x12 + c6x14
addsd %xmm1, %xmm0 # (1-t) - r + c1x4 + c2x6 + c3x8 + c4x10 + c5x12 + c6x14
addsd %xmm2, %xmm0 # 1 - 0.5x2 + above
jmp .Lcos_cleanup
#;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
.align 16
.Lcos_reduce:
# xneg = (ax != ux);
cmp %r10, %rdx
## if (xneg) x = -x;
jz .Lpositive
subsd %xmm0, %xmm2
movsd %xmm2, %xmm0
.Lpositive:
## if (x < 5.0e5)
cmp .L__real_411E848000000000(%rip), %r10
jae .Lcos_reduce_precise
# reduce the argument to be in a range from -pi/4 to +pi/4
# by subtracting multiples of pi/2
movsd %xmm0, %xmm2
movsd .L__real_3fe45f306dc9c883(%rip), %xmm3 # twobypi
movsd %xmm0, %xmm4
movsd .L__real_3fe0000000000000(%rip), %xmm5 # .5
mulsd %xmm3, %xmm2
#/* How many pi/2 is x a multiple of? */
# xexp = ax >> EXPSHIFTBITS_DP64;
mov %r10, %r9
shr $52, %r9 # >>EXPSHIFTBITS_DP64
# npi2 = (int)(x * twobypi + 0.5);
addsd %xmm5, %xmm2 # npi2
movsd .L__real_3ff921fb54400000(%rip), %xmm3 # piby2_1
cvttpd2dq %xmm2, %xmm0 # convert to integer
movsd .L__real_3dd0b4611a626331(%rip), %xmm1 # piby2_1tail
cvtdq2pd %xmm0, %xmm2 # and back to float.
# /* Subtract the multiple from x to get an extra-precision remainder */
# rhead = x - npi2 * piby2_1;
mulsd %xmm2, %xmm3
subsd %xmm3, %xmm4 # rhead
# rtail = npi2 * piby2_1tail;
mulsd %xmm2, %xmm1
movd %xmm0, %eax
# GET_BITS_DP64(rhead-rtail, uy);
movsd %xmm4, %xmm0
subsd %xmm1, %xmm0
movsd .L__real_3dd0b4611a600000(%rip), %xmm3 # piby2_2
movsd %xmm0,p_temp(%rsp)
movsd .L__real_3ba3198a2e037073(%rip), %xmm5 # piby2_2tail
mov p_temp(%rsp), %rcx # rcx is rhead-rtail
# xmm0=r, xmm4=rhead, xmm1=rtail, xmm2=npi2, xmm3=temp for calc, xmm5= temp for calc
# expdiff = xexp - ((uy & EXPBITS_DP64) >> EXPSHIFTBITS_DP64);
shl $1, %rcx # strip any sign bit
shr $53, %rcx # >> EXPSHIFTBITS_DP64 +1
sub %rcx, %r9 # expdiff
## if (expdiff > 15)
cmp $15, %r9
jle .Lexpdiffless15
# /* The remainder is pretty small compared with x, which
# implies that x is a near multiple of pi/2
# (x matches the multiple to at least 15 bits) */
# t = rhead;
movsd %xmm4, %xmm1
# rtail = npi2 * piby2_2;
mulsd %xmm2, %xmm3
# rhead = t - rtail;
mulsd %xmm2, %xmm5 # npi2 * piby2_2tail
subsd %xmm3, %xmm4 # rhead
# rtail = npi2 * piby2_2tail - ((t - rhead) - rtail);
subsd %xmm4, %xmm1 # t - rhead
subsd %xmm3, %xmm1 # -rtail
subsd %xmm1, %xmm5 # rtail
# r = rhead - rtail;
movsd %xmm4, %xmm0
#HARSHA
#xmm1=rtail
movsd %xmm5, %xmm1
subsd %xmm5, %xmm0
# xmm0=r, xmm4=rhead, xmm1=rtail
.Lexpdiffless15:
# region = npi2 & 3;
subsd %xmm0, %xmm4 # rhead-r
subsd %xmm1, %xmm4 # rr = (rhead-r) - rtail
#;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
## if the input was close to a pi/2 multiple
# The original NAG code missed this trick. If the input is very close to n*pi/2 after
# reduction,
# then the cos is ~ 1.0 , to within 53 bits, when r is < 2^-27. We already
# have x at this point, so we can skip the cos polynomials.
cmp $0x03f2, %rcx # if r small.
jge .Lcos_piby4 # use taylor series if not
cmp $0x03de, %rcx # if r really small.
jle .Lr_small # then cos(r) = 1
movsd %xmm0, %xmm2
mulsd %xmm2, %xmm2 # x^2
## if region is 1 or 3 do a sin calc.
and %eax, %r8d
jz .Lsinsmall
# region 1 or 3
# use simply polynomial
# *s = x - x*x*x*0.166666666666666666;
movsd .L__real_3fc5555555555555(%rip), %xmm3
mulsd %xmm0, %xmm3 # * x
mulsd %xmm2, %xmm3 # * x^2
subsd %xmm3, %xmm0 # xs
jmp .Ladjust_region
.align 16
.Lsinsmall:
# region 0 or 2
# cos = 1.0 - x*x*0.5;
movsd .L__real_3ff0000000000000(%rip), %xmm0 # 1.0
mulsd .L__real_3fe0000000000000(%rip), %xmm2 # 0.5 *x^2
subsd %xmm2, %xmm0
jmp .Ladjust_region
.align 16
.Lr_small:
## if region is 1 or 3 do a sin calc.
and %eax, %r8d
jnz .Ladjust_region
movsd .L__real_3ff0000000000000(%rip), %xmm0 # cos(r) is a 1
jmp .Ladjust_region
.align 32
.Lcos_reduce_precise:
# // Reduce x into range [-pi/4,pi/4]
# __amd_remainder_piby2(x, &r, &rr, &region);
lea region(%rsp), %rdx
lea rr(%rsp), %rsi
lea r(%rsp), %rdi
call __amd_remainder_piby2@PLT
mov $1, %r8d # for determining region later on
movsd r(%rsp), %xmm0 # x
movsd rr(%rsp), %xmm4 # xx
mov region(%rsp), %eax # region
# xmm0 = x, xmm4 = xx, r8d = 1, eax= region
#;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
.align 32
# perform taylor series to calc sinx, cosx
.Lcos_piby4:
# x2 = r * r;
#xmm4 = a part of rr for the sin path, xmm4 is overwritten in the cos path
#instead use xmm3 because that was freed up in the sin path, xmm3 is overwritten in sin path
movsd %xmm0, %xmm3
movsd %xmm0, %xmm2
mulsd %xmm0, %xmm2 # x2
## if region is 1 or 3 do a sin calc.
and %eax, %r8d
jz .Lcospiby4
# region 1 or 3
movsd .Lsinarray+0x50(%rip), %xmm3 # s6
mulsd %xmm2, %xmm3 # x2s6
movsd .Lsinarray+0x20(%rip), %xmm5 # s3
movsd %xmm4,p_temp(%rsp) # store xx
movsd %xmm2, %xmm1 # move for x4
mulsd %xmm2, %xmm1 # x4
movsd %xmm0,p_temp1(%rsp) # store x
mulsd %xmm2, %xmm5 # x2s3
movsd %xmm0, %xmm4 # move for x3
addsd .Lsinarray+0x40(%rip), %xmm3 # s5+x2s6
mulsd %xmm2, %xmm1 # x6
mulsd %xmm2, %xmm3 # x2(s5+x2s6)
mulsd %xmm2, %xmm4 # x3
addsd .Lsinarray+0x10(%rip), %xmm5 # s2+x2s3
mulsd %xmm2, %xmm5 # x2(s2+x2s3)
addsd .Lsinarray+0x30(%rip), %xmm3 # s4 + x2(s5+x2s6)
mulsd .L__real_3fe0000000000000(%rip), %xmm2 # 0.5 *x2
movsd p_temp(%rsp), %xmm0 # load xx
mulsd %xmm1, %xmm3 # x6(s4 + x2(s5+x2s6))
addsd .Lsinarray(%rip), %xmm5 # s1+x2(s2+x2s3)
mulsd %xmm0, %xmm2 # 0.5 * x2 *xx
addsd %xmm5, %xmm3 # zs
mulsd %xmm3, %xmm4 # *x3
subsd %xmm2, %xmm4 # x3*zs - 0.5 * x2 *xx
addsd %xmm4, %xmm0 # +xx
addsd p_temp1(%rsp), %xmm0 # +x
jmp .Ladjust_region
#;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
.align 16
.Lcospiby4:
#;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
# region 0 or 2 - do a cos calculation
# zc = (c2 + x2 * (c3 + x2 * (c4 + x2 * (c5 + x2 * c6))));
mulsd %xmm0, %xmm4 # x*xx
movsd .L__real_3fe0000000000000(%rip), %xmm5
movsd .Lcosarray+0x50(%rip), %xmm1 # c6
movsd .Lcosarray+0x20(%rip), %xmm0 # c3
mulsd %xmm2, %xmm5 # r = 0.5 *x2
movsd %xmm2, %xmm3 # copy of x2
movsd %xmm4,p_temp(%rsp) # store x*xx
mulsd %xmm2, %xmm1 # c6*x2
mulsd %xmm2, %xmm0 # c3*x2
subsd .L__real_3ff0000000000000(%rip), %xmm5 # -t=r-1.0 ;trash r
mulsd %xmm2, %xmm3 # x4
addsd .Lcosarray+0x40(%rip), %xmm1 # c5+x2c6
addsd .Lcosarray+0x10(%rip), %xmm0 # c2+x2C3
addsd .L__real_3ff0000000000000(%rip), %xmm5 # 1 + (-t) ;trash t
mulsd %xmm2, %xmm3 # x6
mulsd %xmm2, %xmm1 # x2(c5+x2c6)
mulsd %xmm2, %xmm0 # x2(c2+x2C3)
movsd %xmm2, %xmm4 # copy of x2
mulsd .L__real_3fe0000000000000(%rip), %xmm4 # r recalculate
addsd .Lcosarray+0x30(%rip), %xmm1 # c4 + x2(c5+x2c6)
addsd .Lcosarray(%rip), %xmm0 # c1+x2(c2+x2C3)
mulsd %xmm2, %xmm2 # x4 recalculate
subsd %xmm4, %xmm5 # (1 + (-t)) - r
mulsd %xmm3, %xmm1 # x6(c4 + x2(c5+x2c6))
addsd %xmm1, %xmm0 # zc
subsd .L__real_3ff0000000000000(%rip), %xmm4 # t relaculate
subsd p_temp(%rsp), %xmm5 # ((1 + (-t)) - r) - x*xx
mulsd %xmm2, %xmm0 # x4 * zc
addsd %xmm5, %xmm0 # x4 * zc + ((1 + (-t)) - r -x*xx)
subsd %xmm4, %xmm0 # result - (-t)
#;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
.align 32
.Ladjust_region: # positive or negative (0, 1, 2, 3)=>(1, 2, 3 ,4)=>(0, 2, 2,0)
# switch (region)
add $1, %eax
and $2, %eax
jz .Lcos_cleanup
## if the original region 1 or 2 then we negate the result.
movsd %xmm0, %xmm2
xorpd %xmm0, %xmm0
subsd %xmm2, %xmm0
.align 32
.Lcos_cleanup:
add $stack_size, %rsp
ret
.align 32
.Lcos_naninf:
call fname_special
add $stack_size, %rsp
ret