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/* Function expf vectorized with AVX2.
Copyright (C) 2014-2016 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 "svml_s_expf_data.h"
.text
ENTRY(_ZGVdN8v_expf_avx2)
/*
ALGORITHM DESCRIPTION:
Argument representation:
M = rint(X*2^k/ln2) = 2^k*N+j
X = M*ln2/2^k + r = N*ln2 + ln2*(j/2^k) + r
then -ln2/2^(k+1) < r < ln2/2^(k+1)
Alternatively:
M = trunc(X*2^k/ln2)
then 0 < r < ln2/2^k
Result calculation:
exp(X) = exp(N*ln2 + ln2*(j/2^k) + r)
= 2^N * 2^(j/2^k) * exp(r)
2^N is calculated by bit manipulation
2^(j/2^k) is computed from table lookup
exp(r) is approximated by polynomial
The table lookup is skipped if k = 0.
For low accuracy approximation, exp(r) ~ 1 or 1+r. */
pushq %rbp
cfi_adjust_cfa_offset (8)
cfi_rel_offset (%rbp, 0)
movq %rsp, %rbp
cfi_def_cfa_register (%rbp)
andq $-64, %rsp
subq $448, %rsp
movq __svml_sexp_data@GOTPCREL(%rip), %rax
vmovaps %ymm0, %ymm2
vmovups __sInvLn2(%rax), %ymm7
vmovups __sShifter(%rax), %ymm4
vmovups __sLn2hi(%rax), %ymm3
vmovups __sPC5(%rax), %ymm1
/* m = x*2^k/ln2 + shifter */
vfmadd213ps %ymm4, %ymm2, %ymm7
/* n = m - shifter = rint(x*2^k/ln2) */
vsubps %ymm4, %ymm7, %ymm0
vpaddd __iBias(%rax), %ymm7, %ymm4
/* remove sign of x by "and" operation */
vandps __iAbsMask(%rax), %ymm2, %ymm5
/* compare against threshold */
vpcmpgtd __iDomainRange(%rax), %ymm5, %ymm6
/* r = x-n*ln2_hi/2^k */
vmovaps %ymm2, %ymm5
vfnmadd231ps %ymm0, %ymm3, %ymm5
/* r = r-n*ln2_lo/2^k = x - n*ln2/2^k */
vfnmadd132ps __sLn2lo(%rax), %ymm5, %ymm0
/* c5*r+c4 */
vfmadd213ps __sPC4(%rax), %ymm0, %ymm1
/* (c5*r+c4)*r+c3 */
vfmadd213ps __sPC3(%rax), %ymm0, %ymm1
/* ((c5*r+c4)*r+c3)*r+c2 */
vfmadd213ps __sPC2(%rax), %ymm0, %ymm1
/* (((c5*r+c4)*r+c3)*r+c2)*r+c1 */
vfmadd213ps __sPC1(%rax), %ymm0, %ymm1
/* exp(r) = ((((c5*r+c4)*r+c3)*r+c2)*r+c1)*r+c0 */
vfmadd213ps __sPC0(%rax), %ymm0, %ymm1
/* set mask for overflow/underflow */
vmovmskps %ymm6, %ecx
/* compute 2^N with "shift" */
vpslld $23, %ymm4, %ymm6
/* 2^N*exp(r) */
vmulps %ymm1, %ymm6, %ymm0
testl %ecx, %ecx
jne .LBL_1_3
.LBL_1_2:
cfi_remember_state
movq %rbp, %rsp
cfi_def_cfa_register (%rsp)
popq %rbp
cfi_adjust_cfa_offset (-8)
cfi_restore (%rbp)
ret
.LBL_1_3:
cfi_restore_state
vmovups %ymm2, 320(%rsp)
vmovups %ymm0, 384(%rsp)
je .LBL_1_2
xorb %dl, %dl
xorl %eax, %eax
vmovups %ymm8, 224(%rsp)
vmovups %ymm9, 192(%rsp)
vmovups %ymm10, 160(%rsp)
vmovups %ymm11, 128(%rsp)
vmovups %ymm12, 96(%rsp)
vmovups %ymm13, 64(%rsp)
vmovups %ymm14, 32(%rsp)
vmovups %ymm15, (%rsp)
movq %rsi, 264(%rsp)
movq %rdi, 256(%rsp)
movq %r12, 296(%rsp)
cfi_offset_rel_rsp (12, 296)
movb %dl, %r12b
movq %r13, 288(%rsp)
cfi_offset_rel_rsp (13, 288)
movl %ecx, %r13d
movq %r14, 280(%rsp)
cfi_offset_rel_rsp (14, 280)
movl %eax, %r14d
movq %r15, 272(%rsp)
cfi_offset_rel_rsp (15, 272)
cfi_remember_state
.LBL_1_6:
btl %r14d, %r13d
jc .LBL_1_12
.LBL_1_7:
lea 1(%r14), %esi
btl %esi, %r13d
jc .LBL_1_10
.LBL_1_8:
incb %r12b
addl $2, %r14d
cmpb $16, %r12b
jb .LBL_1_6
vmovups 224(%rsp), %ymm8
vmovups 192(%rsp), %ymm9
vmovups 160(%rsp), %ymm10
vmovups 128(%rsp), %ymm11
vmovups 96(%rsp), %ymm12
vmovups 64(%rsp), %ymm13
vmovups 32(%rsp), %ymm14
vmovups (%rsp), %ymm15
vmovups 384(%rsp), %ymm0
movq 264(%rsp), %rsi
movq 256(%rsp), %rdi
movq 296(%rsp), %r12
cfi_restore (%r12)
movq 288(%rsp), %r13
cfi_restore (%r13)
movq 280(%rsp), %r14
cfi_restore (%r14)
movq 272(%rsp), %r15
cfi_restore (%r15)
jmp .LBL_1_2
.LBL_1_10:
cfi_restore_state
movzbl %r12b, %r15d
vmovss 324(%rsp,%r15,8), %xmm0
vzeroupper
call expf@PLT
vmovss %xmm0, 388(%rsp,%r15,8)
jmp .LBL_1_8
.LBL_1_12:
movzbl %r12b, %r15d
vmovss 320(%rsp,%r15,8), %xmm0
vzeroupper
call expf@PLT
vmovss %xmm0, 384(%rsp,%r15,8)
jmp .LBL_1_7
END(_ZGVdN8v_expf_avx2)
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