diff options
Diffstat (limited to 'sysdeps/x86_64/fpu/multiarch/svml_s_powf4_core_sse4.S')
-rw-r--r-- | sysdeps/x86_64/fpu/multiarch/svml_s_powf4_core_sse4.S | 374 |
1 files changed, 374 insertions, 0 deletions
diff --git a/sysdeps/x86_64/fpu/multiarch/svml_s_powf4_core_sse4.S b/sysdeps/x86_64/fpu/multiarch/svml_s_powf4_core_sse4.S new file mode 100644 index 0000000000..6068f51c46 --- /dev/null +++ b/sysdeps/x86_64/fpu/multiarch/svml_s_powf4_core_sse4.S @@ -0,0 +1,374 @@ +/* Function powf vectorized with SSE4. + Copyright (C) 2014-2015 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_powf_data.h" + + .text +ENTRY (_ZGVbN4vv_powf_sse4) +/* + ALGORITHM DESCRIPTION: + + We are using the next identity: pow(x,y) = 2^(y * log2(x)). + + 1) log2(x) calculation + Here we use the following formula. + Let |x|=2^k1*X1, where k1 is integer, 1<=X1<2. + Let C ~= 1/ln(2), + Rcp1 ~= 1/X1, X2=Rcp1*X1, + Rcp2 ~= 1/X2, X3=Rcp2*X2, + Rcp3 ~= 1/X3, Rcp3C ~= C/X3. + Then + log2|x| = k1 + log2(1/Rcp1) + log2(1/Rcp2) + log2(C/Rcp3C) + + log2(X1*Rcp1*Rcp2*Rcp3C/C), + where X1*Rcp1*Rcp2*Rcp3C = C*(1+q), q is very small. + + The values of Rcp1, log2(1/Rcp1), Rcp2, log2(1/Rcp2), + Rcp3C, log2(C/Rcp3C) are taken from tables. + Values of Rcp1, Rcp2, Rcp3C are such that RcpC=Rcp1*Rcp2*Rcp3C + is exactly represented in target precision. + + log2(X1*Rcp1*Rcp2*Rcp3C/C) = log2(1+q) = ln(1+q)/ln2 = + = 1/(ln2)*q - 1/(2ln2)*q^2 + 1/(3ln2)*q^3 - ... = + = 1/(C*ln2)*cq - 1/(2*C^2*ln2)*cq^2 + 1/(3*C^3*ln2)*cq^3 - ... = + = (1 + a1)*cq + a2*cq^2 + a3*cq^3 + ..., + where + cq=X1*Rcp1*Rcp2*Rcp3C-C, + a1=1/(C*ln(2))-1 is small, + a2=1/(2*C^2*ln2), + a3=1/(3*C^3*ln2), + ... + Log2 result is split by three parts: HH+HL+HLL + + 2) Calculation of y*log2(x) + Split y into YHi+YLo. + Get high PH and medium PL parts of y*log2|x|. + Get low PLL part of y*log2|x|. + Now we have PH+PL+PLL ~= y*log2|x|. + + 3) Calculation of 2^(y*log2(x)) + Let's represent PH+PL+PLL in the form N + j/2^expK + Z, + where expK=7 in this implementation, N and j are integers, + 0<=j<=2^expK-1, |Z|<2^(-expK-1). Hence + 2^(PH+PL+PLL) ~= 2^N * 2^(j/2^expK) * 2^Z, + where 2^(j/2^expK) is stored in a table, and + 2^Z ~= 1 + B1*Z + B2*Z^2 ... + B5*Z^5. + We compute 2^(PH+PL+PLL) as follows: + Break PH into PHH + PHL, where PHH = N + j/2^expK. + Z = PHL + PL + PLL + Exp2Poly = B1*Z + B2*Z^2 ... + B5*Z^5 + Get 2^(j/2^expK) from table in the form THI+TLO. + Now we have 2^(PH+PL+PLL) ~= 2^N * (THI + TLO) * (1 + Exp2Poly). + Get significand of 2^(PH+PL+PLL) in the form ResHi+ResLo: + ResHi := THI + ResLo := THI * Exp2Poly + TLO + Get exponent ERes of the result: + Res := ResHi + ResLo: + Result := ex(Res) + N. */ + + pushq %rbp + cfi_adjust_cfa_offset (8) + cfi_rel_offset (%rbp, 0) + movq %rsp, %rbp + cfi_def_cfa_register (%rbp) + andq $-64, %rsp + subq $256, %rsp + movaps %xmm0, %xmm3 + movhlps %xmm0, %xmm3 + movaps %xmm1, %xmm5 + movups %xmm8, 112(%rsp) + movaps %xmm5, %xmm2 + cvtps2pd %xmm3, %xmm8 + cvtps2pd %xmm5, %xmm7 + movups %xmm9, 96(%rsp) + movaps %xmm0, %xmm4 + cvtps2pd %xmm0, %xmm9 + movq __svml_spow_data@GOTPCREL(%rip), %rdx + movups %xmm10, 176(%rsp) + movups %xmm13, 48(%rsp) + movups _ExpMask(%rdx), %xmm6 + +/* preserve mantissa, set input exponent to 2^(-10) */ + movaps %xmm6, %xmm10 + andps %xmm8, %xmm6 + andps %xmm9, %xmm10 + +/* exponent bits selection */ + psrlq $20, %xmm9 + orps _Two10(%rdx), %xmm6 + psrlq $20, %xmm8 + orps _Two10(%rdx), %xmm10 + +/* reciprocal approximation good to at least 11 bits */ + cvtpd2ps %xmm6, %xmm13 + cvtpd2ps %xmm10, %xmm1 + movlhps %xmm13, %xmm13 + movhlps %xmm5, %xmm2 + movlhps %xmm1, %xmm1 + movups %xmm12, 208(%rsp) + rcpps %xmm13, %xmm12 + movups %xmm11, 80(%rsp) + cvtps2pd %xmm2, %xmm11 + rcpps %xmm1, %xmm2 + movups %xmm14, 144(%rsp) + cvtps2pd %xmm12, %xmm14 + movups %xmm15, 160(%rsp) + cvtps2pd %xmm2, %xmm15 + shufps $221, %xmm8, %xmm9 + +/* round reciprocal to nearest integer, will have 1+9 mantissa bits */ + roundpd $0, %xmm14, %xmm14 + +/* biased exponent in DP format */ + pshufd $238, %xmm9, %xmm8 + roundpd $0, %xmm15, %xmm15 + cvtdq2pd %xmm8, %xmm1 + mulpd %xmm15, %xmm10 + mulpd %xmm14, %xmm6 + cvtdq2pd %xmm9, %xmm2 + subpd _One(%rdx), %xmm10 + subpd _One(%rdx), %xmm6 + +/* table lookup */ + movaps %xmm14, %xmm8 + movaps %xmm15, %xmm9 + psrlq $40, %xmm8 + psrlq $40, %xmm9 + movd %xmm8, %r8d + movd %xmm9, %eax + psubd _NMINNORM(%rdx), %xmm4 + movdqu _ABSMASK(%rdx), %xmm3 + pextrd $2, %xmm8, %r9d + pand %xmm5, %xmm3 + movups _Threshold(%rdx), %xmm8 + pextrd $2, %xmm9, %ecx + movaps %xmm8, %xmm9 + cmpltpd %xmm15, %xmm9 + cmpltpd %xmm14, %xmm8 + andps _Bias(%rdx), %xmm9 + movaps %xmm10, %xmm14 + andps _Bias(%rdx), %xmm8 + movaps %xmm6, %xmm15 + orps _Bias1(%rdx), %xmm9 + orps _Bias1(%rdx), %xmm8 + subpd %xmm9, %xmm2 + subpd %xmm8, %xmm1 + mulpd %xmm10, %xmm14 + mulpd %xmm6, %xmm15 + mulpd _L2(%rdx), %xmm2 + mulpd _L2(%rdx), %xmm1 + movups _poly_coeff_3(%rdx), %xmm9 + movaps %xmm9, %xmm8 + mulpd %xmm10, %xmm8 + mulpd %xmm6, %xmm9 + addpd _poly_coeff_4(%rdx), %xmm8 + addpd _poly_coeff_4(%rdx), %xmm9 + mulpd %xmm14, %xmm8 + mulpd %xmm15, %xmm9 + +/* reconstruction */ + addpd %xmm8, %xmm10 + addpd %xmm9, %xmm6 + movslq %eax, %rax + movslq %r8d, %r8 + movslq %ecx, %rcx + movslq %r9d, %r9 + movsd _Log2Rcp_lookup(%rdx,%rax), %xmm13 + movsd _Log2Rcp_lookup(%rdx,%r8), %xmm12 + movhpd _Log2Rcp_lookup(%rdx,%rcx), %xmm13 + movhpd _Log2Rcp_lookup(%rdx,%r9), %xmm12 + addpd %xmm10, %xmm13 + addpd %xmm6, %xmm12 + addpd %xmm13, %xmm2 + addpd %xmm12, %xmm1 + mulpd %xmm7, %xmm2 + mulpd %xmm11, %xmm1 + movups __dbInvLn2(%rdx), %xmm11 + movdqa %xmm4, %xmm12 + movaps %xmm11, %xmm10 + mulpd %xmm2, %xmm10 + mulpd %xmm1, %xmm11 + +/* to round down; if dR is an integer we will get R = 1, which is ok */ + movaps %xmm10, %xmm8 + movaps %xmm11, %xmm9 + subpd __dbHALF(%rdx), %xmm8 + subpd __dbHALF(%rdx), %xmm9 + addpd __dbShifter(%rdx), %xmm8 + addpd __dbShifter(%rdx), %xmm9 + movaps %xmm8, %xmm6 + movaps %xmm9, %xmm7 + subpd __dbShifter(%rdx), %xmm6 + subpd __dbShifter(%rdx), %xmm7 + +/* [0..1) */ + subpd %xmm6, %xmm10 + subpd %xmm7, %xmm11 + mulpd __dbC1(%rdx), %xmm10 + mulpd __dbC1(%rdx), %xmm11 + +/* hi bits */ + shufps $221, %xmm1, %xmm2 + movdqu _NMAXVAL(%rdx), %xmm1 + pcmpgtd %xmm1, %xmm12 + pcmpeqd %xmm1, %xmm4 + por %xmm4, %xmm12 + movdqa %xmm3, %xmm1 + movdqu _INF(%rdx), %xmm4 + pcmpgtd %xmm4, %xmm1 + pcmpeqd %xmm4, %xmm3 + +/* iAbsX = iAbsX&iAbsMask */ + pand __iAbsMask(%rdx), %xmm2 + por %xmm3, %xmm1 + +/* iRangeMask = (iAbsX>iDomainRange) */ + pcmpgtd __iDomainRange(%rdx), %xmm2 + por %xmm1, %xmm12 + movups __lbLOWKBITS(%rdx), %xmm3 + por %xmm2, %xmm12 + +/* low K bits */ + movaps %xmm3, %xmm2 + andps %xmm9, %xmm3 + andps %xmm8, %xmm2 + psrlq $11, %xmm8 + +/* dpP= _dbT+lJ*T_ITEM_GRAN */ + movd %xmm2, %r10d + psrlq $11, %xmm9 + movd %xmm3, %ecx + +/* NB : including +/- sign for the exponent!! */ + psllq $52, %xmm8 + psllq $52, %xmm9 + pextrw $4, %xmm2, %r11d + pextrw $4, %xmm3, %r8d + movmskps %xmm12, %eax + shll $3, %r10d + shll $3, %ecx + shll $3, %r11d + shll $3, %r8d + movq 13952(%rdx,%r10), %xmm6 + movq 13952(%rdx,%rcx), %xmm7 + movhpd 13952(%rdx,%r11), %xmm6 + movhpd 13952(%rdx,%r8), %xmm7 + mulpd %xmm6, %xmm10 + mulpd %xmm7, %xmm11 + addpd %xmm10, %xmm6 + addpd %xmm11, %xmm7 + paddq %xmm8, %xmm6 + paddq %xmm9, %xmm7 + cvtpd2ps %xmm6, %xmm1 + cvtpd2ps %xmm7, %xmm4 + movlhps %xmm4, %xmm1 + testl %eax, %eax + jne .LBL_1_3 + +.LBL_1_2: + cfi_remember_state + movups 112(%rsp), %xmm8 + movaps %xmm1, %xmm0 + movups 96(%rsp), %xmm9 + movups 176(%rsp), %xmm10 + movups 80(%rsp), %xmm11 + movups 208(%rsp), %xmm12 + movups 48(%rsp), %xmm13 + movups 144(%rsp), %xmm14 + movups 160(%rsp), %xmm15 + 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 %xmm0, 64(%rsp) + movups %xmm5, 128(%rsp) + movups %xmm1, 192(%rsp) + je .LBL_1_2 + + xorb %cl, %cl + xorl %edx, %edx + movq %rsi, 8(%rsp) + movq %rdi, (%rsp) + movq %r12, 40(%rsp) + cfi_offset_rel_rsp (12, 40) + movb %cl, %r12b + movq %r13, 32(%rsp) + cfi_offset_rel_rsp (13, 32) + movl %eax, %r13d + movq %r14, 24(%rsp) + cfi_offset_rel_rsp (14, 24) + movl %edx, %r14d + movq %r15, 16(%rsp) + cfi_offset_rel_rsp (15, 16) + 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 + + movq 8(%rsp), %rsi + movq (%rsp), %rdi + movq 40(%rsp), %r12 + cfi_restore (%r12) + movq 32(%rsp), %r13 + cfi_restore (%r13) + movq 24(%rsp), %r14 + cfi_restore (%r14) + movq 16(%rsp), %r15 + cfi_restore (%r15) + movups 192(%rsp), %xmm1 + jmp .LBL_1_2 + +.LBL_1_10: + cfi_restore_state + movzbl %r12b, %r15d + movss 68(%rsp,%r15,8), %xmm0 + movss 132(%rsp,%r15,8), %xmm1 + + call powf@PLT + + movss %xmm0, 196(%rsp,%r15,8) + jmp .LBL_1_8 + +.LBL_1_12: + movzbl %r12b, %r15d + movss 64(%rsp,%r15,8), %xmm0 + movss 128(%rsp,%r15,8), %xmm1 + + call powf@PLT + + movss %xmm0, 192(%rsp,%r15,8) + jmp .LBL_1_7 + +END (_ZGVbN4vv_powf_sse4) |