| /* Function log vectorized with SSE4. |
| Copyright (C) 2014-2018 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_d_log_data.h" |
| |
| .text |
| ENTRY (_ZGVbN2v_log_sse4) |
| /* |
| ALGORITHM DESCRIPTION: |
| |
| log(x) = -log(Rcp) + log(Rcp*x), |
| where Rcp ~ 1/x (accuracy ~9 bits, obtained by rounding |
| HW approximation to 1+9 mantissa bits) |
| |
| Reduced argument R=Rcp*x-1 is used to approximate log(1+R) as polynomial |
| |
| log(Rcp) = exponent_Rcp*log(2) + log(mantissa_Rcp) |
| -log(mantissa_Rcp) is obtained from a lookup table, |
| accessed by a 9-bit index |
| */ |
| pushq %rbp |
| cfi_adjust_cfa_offset (8) |
| cfi_rel_offset (%rbp, 0) |
| movq %rsp, %rbp |
| cfi_def_cfa_register (%rbp) |
| andq $-64, %rsp |
| subq $320, %rsp |
| movaps %xmm0, %xmm6 |
| movq __svml_dlog_data@GOTPCREL(%rip), %r8 |
| movaps %xmm6, %xmm3 |
| movaps %xmm6, %xmm2 |
| |
| /* isolate exponent bits */ |
| movaps %xmm6, %xmm1 |
| psrlq $20, %xmm1 |
| movups _ExpMask(%r8), %xmm5 |
| |
| /* preserve mantissa, set input exponent to 2^(-10) */ |
| andps %xmm6, %xmm5 |
| orps _Two10(%r8), %xmm5 |
| |
| /* reciprocal approximation good to at least 11 bits */ |
| cvtpd2ps %xmm5, %xmm7 |
| cmpltpd _MinNorm(%r8), %xmm3 |
| cmpnlepd _MaxNorm(%r8), %xmm2 |
| movlhps %xmm7, %xmm7 |
| |
| /* combine and get argument value range mask */ |
| orps %xmm2, %xmm3 |
| rcpps %xmm7, %xmm0 |
| movmskpd %xmm3, %eax |
| movups _HalfMask(%r8), %xmm2 |
| |
| /* argument reduction started: R = Mantissa*Rcp - 1 */ |
| andps %xmm5, %xmm2 |
| cvtps2pd %xmm0, %xmm4 |
| subpd %xmm2, %xmm5 |
| |
| /* round reciprocal to nearest integer, will have 1+9 mantissa bits */ |
| roundpd $0, %xmm4, %xmm4 |
| mulpd %xmm4, %xmm2 |
| mulpd %xmm4, %xmm5 |
| subpd _One(%r8), %xmm2 |
| addpd %xmm2, %xmm5 |
| movups _Threshold(%r8), %xmm2 |
| |
| /* calculate index for table lookup */ |
| movaps %xmm4, %xmm3 |
| cmpltpd %xmm4, %xmm2 |
| pshufd $221, %xmm1, %xmm7 |
| psrlq $40, %xmm3 |
| |
| /* convert biased exponent to DP format */ |
| cvtdq2pd %xmm7, %xmm0 |
| movd %xmm3, %edx |
| movups _poly_coeff_1(%r8), %xmm4 |
| |
| /* polynomial computation */ |
| mulpd %xmm5, %xmm4 |
| andps _Bias(%r8), %xmm2 |
| orps _Bias1(%r8), %xmm2 |
| |
| /* |
| Table stores -log(0.5*mantissa) for larger mantissas, |
| adjust exponent accordingly |
| */ |
| subpd %xmm2, %xmm0 |
| addpd _poly_coeff_2(%r8), %xmm4 |
| |
| /* exponent*log(2.0) */ |
| mulpd _L2(%r8), %xmm0 |
| movaps %xmm5, %xmm2 |
| mulpd %xmm5, %xmm2 |
| movups _poly_coeff_3(%r8), %xmm7 |
| mulpd %xmm5, %xmm7 |
| mulpd %xmm2, %xmm4 |
| addpd _poly_coeff_4(%r8), %xmm7 |
| addpd %xmm4, %xmm7 |
| mulpd %xmm7, %xmm2 |
| movslq %edx, %rdx |
| pextrd $2, %xmm3, %ecx |
| |
| /* |
| reconstruction: |
| (exponent*log(2)) + (LogRcp + (R+poly)) |
| */ |
| addpd %xmm2, %xmm5 |
| movslq %ecx, %rcx |
| movsd _LogRcp_lookup(%r8,%rdx), %xmm1 |
| movhpd _LogRcp_lookup(%r8,%rcx), %xmm1 |
| addpd %xmm5, %xmm1 |
| addpd %xmm1, %xmm0 |
| testl %eax, %eax |
| 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 |
| movups %xmm6, 192(%rsp) |
| movups %xmm0, 256(%rsp) |
| je .LBL_1_2 |
| |
| xorb %cl, %cl |
| xorl %edx, %edx |
| movups %xmm8, 112(%rsp) |
| movups %xmm9, 96(%rsp) |
| movups %xmm10, 80(%rsp) |
| movups %xmm11, 64(%rsp) |
| movups %xmm12, 48(%rsp) |
| movups %xmm13, 32(%rsp) |
| movups %xmm14, 16(%rsp) |
| movups %xmm15, (%rsp) |
| movq %rsi, 136(%rsp) |
| movq %rdi, 128(%rsp) |
| movq %r12, 168(%rsp) |
| cfi_offset_rel_rsp (12, 168) |
| movb %cl, %r12b |
| movq %r13, 160(%rsp) |
| cfi_offset_rel_rsp (13, 160) |
| movl %eax, %r13d |
| movq %r14, 152(%rsp) |
| cfi_offset_rel_rsp (14, 152) |
| movl %edx, %r14d |
| movq %r15, 144(%rsp) |
| cfi_offset_rel_rsp (15, 144) |
| 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 |
| |
| movups 112(%rsp), %xmm8 |
| movups 96(%rsp), %xmm9 |
| movups 80(%rsp), %xmm10 |
| movups 64(%rsp), %xmm11 |
| movups 48(%rsp), %xmm12 |
| movups 32(%rsp), %xmm13 |
| movups 16(%rsp), %xmm14 |
| movups (%rsp), %xmm15 |
| movq 136(%rsp), %rsi |
| movq 128(%rsp), %rdi |
| movq 168(%rsp), %r12 |
| cfi_restore (%r12) |
| movq 160(%rsp), %r13 |
| cfi_restore (%r13) |
| movq 152(%rsp), %r14 |
| cfi_restore (%r14) |
| movq 144(%rsp), %r15 |
| cfi_restore (%r15) |
| movups 256(%rsp), %xmm0 |
| jmp .LBL_1_2 |
| |
| .LBL_1_10: |
| cfi_restore_state |
| movzbl %r12b, %r15d |
| shlq $4, %r15 |
| movsd 200(%rsp,%r15), %xmm0 |
| |
| call JUMPTARGET(__log_finite) |
| |
| movsd %xmm0, 264(%rsp,%r15) |
| jmp .LBL_1_8 |
| |
| .LBL_1_12: |
| movzbl %r12b, %r15d |
| shlq $4, %r15 |
| movsd 192(%rsp,%r15), %xmm0 |
| |
| call JUMPTARGET(__log_finite) |
| |
| movsd %xmm0, 256(%rsp,%r15) |
| jmp .LBL_1_7 |
| |
| END (_ZGVbN2v_log_sse4) |
