Blame sysdeps/x86_64/fpu/multiarch/svml_s_expf4_core_sse4.S

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/* Function expf vectorized with SSE4.
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   Copyright (C) 2014-2018 Free Software Foundation, Inc.
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   This file is part of the GNU C Library.
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   The GNU C Library is free software; you can redistribute it and/or
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   modify it under the terms of the GNU Lesser General Public
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   License as published by the Free Software Foundation; either
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   version 2.1 of the License, or (at your option) any later version.
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   The GNU C Library is distributed in the hope that it will be useful,
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   but WITHOUT ANY WARRANTY; without even the implied warranty of
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   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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   Lesser General Public License for more details.
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   You should have received a copy of the GNU Lesser General Public
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   License along with the GNU C Library; if not, see
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   <http://www.gnu.org/licenses/>.  */
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#include <sysdep.h>
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#include "svml_s_expf_data.h"
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	.text
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ENTRY (_ZGVbN4v_expf_sse4)
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/*
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   ALGORITHM DESCRIPTION:
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     Argument representation:
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     M = rint(X*2^k/ln2) = 2^k*N+j
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     X = M*ln2/2^k + r = N*ln2 + ln2*(j/2^k) + r
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     then -ln2/2^(k+1) < r < ln2/2^(k+1)
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     Alternatively:
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     M = trunc(X*2^k/ln2)
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     then 0 < r < ln2/2^k
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     Result calculation:
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     exp(X) = exp(N*ln2 + ln2*(j/2^k) + r)
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     = 2^N * 2^(j/2^k) * exp(r)
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     2^N is calculated by bit manipulation
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     2^(j/2^k) is computed from table lookup
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     exp(r) is approximated by polynomial
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     The table lookup is skipped if k = 0.
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     For low accuracy approximation, exp(r) ~ 1 or 1+r.  */
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        pushq     %rbp
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        cfi_adjust_cfa_offset (8)
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        cfi_rel_offset (%rbp, 0)
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        movq      %rsp, %rbp
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        cfi_def_cfa_register (%rbp)
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        andq      $-64, %rsp
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        subq      $320, %rsp
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        movaps    %xmm0, %xmm5
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        movq      __svml_sexp_data@GOTPCREL(%rip), %rax
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        movups __sInvLn2(%rax), %xmm0
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/* m = x*2^k/ln2 + shifter */
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        mulps     %xmm5, %xmm0
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        movups __sShifter(%rax), %xmm6
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        movups __sLn2hi(%rax), %xmm4
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        addps     %xmm6, %xmm0
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/* n = m - shifter = rint(x*2^k/ln2) */
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        movaps    %xmm0, %xmm2
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/* remove sign of x by "and" operation */
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        movdqu __iAbsMask(%rax), %xmm7
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        subps     %xmm6, %xmm2
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/* r = x-n*ln2_hi/2^k */
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        mulps     %xmm2, %xmm4
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        pand      %xmm5, %xmm7
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/* compare against threshold */
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        pcmpgtd __iDomainRange(%rax), %xmm7
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        movups __sLn2lo(%rax), %xmm1
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/* set mask for overflow/underflow */
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        movmskps  %xmm7, %ecx
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        movaps    %xmm5, %xmm7
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        movups __sPC5(%rax), %xmm3
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        subps     %xmm4, %xmm7
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/* r = r-n*ln2_lo/2^k = x - n*ln2/2^k */
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        mulps     %xmm1, %xmm2
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/* compute 2^N with "shift" */
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        movdqu __iBias(%rax), %xmm6
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        subps     %xmm2, %xmm7
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/* c5*r+c4 */
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        mulps     %xmm7, %xmm3
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        paddd     %xmm6, %xmm0
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        pslld     $23, %xmm0
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        addps __sPC4(%rax), %xmm3
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/* (c5*r+c4)*r+c3 */
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        mulps     %xmm7, %xmm3
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        addps __sPC3(%rax), %xmm3
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/* ((c5*r+c4)*r+c3)*r+c2 */
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        mulps     %xmm7, %xmm3
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        addps __sPC2(%rax), %xmm3
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/* (((c5*r+c4)*r+c3)*r+c2)*r+c1 */
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        mulps     %xmm7, %xmm3
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        addps __sPC1(%rax), %xmm3
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/* exp(r) = ((((c5*r+c4)*r+c3)*r+c2)*r+c1)*r+c0 */
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        mulps     %xmm3, %xmm7
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        addps __sPC0(%rax), %xmm7
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/* 2^N*exp(r) */
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        mulps     %xmm7, %xmm0
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        testl     %ecx, %ecx
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        jne       .LBL_1_3
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.LBL_1_2:
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        cfi_remember_state
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        movq      %rbp, %rsp
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        cfi_def_cfa_register (%rsp)
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        popq      %rbp
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        cfi_adjust_cfa_offset (-8)
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        cfi_restore (%rbp)
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        ret
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.LBL_1_3:
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        cfi_restore_state
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        movups    %xmm5, 192(%rsp)
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        movups    %xmm0, 256(%rsp)
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        je        .LBL_1_2
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        xorb      %dl, %dl
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        xorl      %eax, %eax
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        movups    %xmm8, 112(%rsp)
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        movups    %xmm9, 96(%rsp)
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        movups    %xmm10, 80(%rsp)
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        movups    %xmm11, 64(%rsp)
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        movups    %xmm12, 48(%rsp)
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        movups    %xmm13, 32(%rsp)
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        movups    %xmm14, 16(%rsp)
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        movups    %xmm15, (%rsp)
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        movq      %rsi, 136(%rsp)
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        movq      %rdi, 128(%rsp)
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        movq      %r12, 168(%rsp)
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        cfi_offset_rel_rsp (12, 168)
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        movb      %dl, %r12b
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        movq      %r13, 160(%rsp)
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        cfi_offset_rel_rsp (13, 160)
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        movl      %ecx, %r13d
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        movq      %r14, 152(%rsp)
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        cfi_offset_rel_rsp (14, 152)
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        movl      %eax, %r14d
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        movq      %r15, 144(%rsp)
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        cfi_offset_rel_rsp (15, 144)
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        cfi_remember_state
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.LBL_1_6:
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        btl       %r14d, %r13d
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        jc        .LBL_1_12
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.LBL_1_7:
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        lea       1(%r14), %esi
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        btl       %esi, %r13d
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        jc        .LBL_1_10
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.LBL_1_8:
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        incb      %r12b
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        addl      $2, %r14d
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        cmpb      $16, %r12b
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        jb        .LBL_1_6
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        movups    112(%rsp), %xmm8
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        movups    96(%rsp), %xmm9
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        movups    80(%rsp), %xmm10
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        movups    64(%rsp), %xmm11
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        movups    48(%rsp), %xmm12
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        movups    32(%rsp), %xmm13
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        movups    16(%rsp), %xmm14
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        movups    (%rsp), %xmm15
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        movq      136(%rsp), %rsi
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        movq      128(%rsp), %rdi
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        movq      168(%rsp), %r12
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        cfi_restore (%r12)
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        movq      160(%rsp), %r13
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        cfi_restore (%r13)
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        movq      152(%rsp), %r14
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        cfi_restore (%r14)
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        movq      144(%rsp), %r15
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        cfi_restore (%r15)
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        movups    256(%rsp), %xmm0
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        jmp       .LBL_1_2
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.LBL_1_10:
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        cfi_restore_state
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        movzbl    %r12b, %r15d
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        movss     196(%rsp,%r15,8), %xmm0
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        call      JUMPTARGET(__expf_finite)
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        movss     %xmm0, 260(%rsp,%r15,8)
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        jmp       .LBL_1_8
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.LBL_1_12:
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        movzbl    %r12b, %r15d
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        movss     192(%rsp,%r15,8), %xmm0
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        call      JUMPTARGET(__expf_finite)
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        movss     %xmm0, 256(%rsp,%r15,8)
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        jmp       .LBL_1_7
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END (_ZGVbN4v_expf_sse4)