| // Copyright 2017 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| #include "textflag.h" |
| |
| // Constants |
| DATA ·log1pxlim<> + 0(SB)/4, $0xfff00000 |
| GLOBL ·log1pxlim<> + 0(SB), RODATA, $4 |
| DATA ·log1pxzero<> + 0(SB)/8, $0.0 |
| GLOBL ·log1pxzero<> + 0(SB), RODATA, $8 |
| DATA ·log1pxminf<> + 0(SB)/8, $0xfff0000000000000 |
| GLOBL ·log1pxminf<> + 0(SB), RODATA, $8 |
| DATA ·log1pxnan<> + 0(SB)/8, $0x7ff8000000000000 |
| GLOBL ·log1pxnan<> + 0(SB), RODATA, $8 |
| DATA ·log1pyout<> + 0(SB)/8, $0x40fce621e71da000 |
| GLOBL ·log1pyout<> + 0(SB), RODATA, $8 |
| DATA ·log1pxout<> + 0(SB)/8, $0x40f1000000000000 |
| GLOBL ·log1pxout<> + 0(SB), RODATA, $8 |
| DATA ·log1pxl2<> + 0(SB)/8, $0xbfda7aecbeba4e46 |
| GLOBL ·log1pxl2<> + 0(SB), RODATA, $8 |
| DATA ·log1pxl1<> + 0(SB)/8, $0x3ffacde700000000 |
| GLOBL ·log1pxl1<> + 0(SB), RODATA, $8 |
| DATA ·log1pxa<> + 0(SB)/8, $5.5 |
| GLOBL ·log1pxa<> + 0(SB), RODATA, $8 |
| DATA ·log1pxmone<> + 0(SB)/8, $-1.0 |
| GLOBL ·log1pxmone<> + 0(SB), RODATA, $8 |
| |
| // Minimax polynomial approximations |
| DATA ·log1pc8<> + 0(SB)/8, $0.212881813645679599E-07 |
| GLOBL ·log1pc8<> + 0(SB), RODATA, $8 |
| DATA ·log1pc7<> + 0(SB)/8, $-.148682720127920854E-06 |
| GLOBL ·log1pc7<> + 0(SB), RODATA, $8 |
| DATA ·log1pc6<> + 0(SB)/8, $0.938370938292558173E-06 |
| GLOBL ·log1pc6<> + 0(SB), RODATA, $8 |
| DATA ·log1pc5<> + 0(SB)/8, $-.602107458843052029E-05 |
| GLOBL ·log1pc5<> + 0(SB), RODATA, $8 |
| DATA ·log1pc4<> + 0(SB)/8, $0.397389654305194527E-04 |
| GLOBL ·log1pc4<> + 0(SB), RODATA, $8 |
| DATA ·log1pc3<> + 0(SB)/8, $-.273205381970859341E-03 |
| GLOBL ·log1pc3<> + 0(SB), RODATA, $8 |
| DATA ·log1pc2<> + 0(SB)/8, $0.200350613573012186E-02 |
| GLOBL ·log1pc2<> + 0(SB), RODATA, $8 |
| DATA ·log1pc1<> + 0(SB)/8, $-.165289256198351540E-01 |
| GLOBL ·log1pc1<> + 0(SB), RODATA, $8 |
| DATA ·log1pc0<> + 0(SB)/8, $0.181818181818181826E+00 |
| GLOBL ·log1pc0<> + 0(SB), RODATA, $8 |
| |
| |
| // Table of log10 correction terms |
| DATA ·log1ptab<> + 0(SB)/8, $0.585235384085551248E-01 |
| DATA ·log1ptab<> + 8(SB)/8, $0.412206153771168640E-01 |
| DATA ·log1ptab<> + 16(SB)/8, $0.273839003221648339E-01 |
| DATA ·log1ptab<> + 24(SB)/8, $0.166383778368856480E-01 |
| DATA ·log1ptab<> + 32(SB)/8, $0.866678223433169637E-02 |
| DATA ·log1ptab<> + 40(SB)/8, $0.319831684989627514E-02 |
| DATA ·log1ptab<> + 48(SB)/8, $-.000000000000000000E+00 |
| DATA ·log1ptab<> + 56(SB)/8, $-.113006378583725549E-02 |
| DATA ·log1ptab<> + 64(SB)/8, $-.367979419636602491E-03 |
| DATA ·log1ptab<> + 72(SB)/8, $0.213172484510484979E-02 |
| DATA ·log1ptab<> + 80(SB)/8, $0.623271047682013536E-02 |
| DATA ·log1ptab<> + 88(SB)/8, $0.118140812789696885E-01 |
| DATA ·log1ptab<> + 96(SB)/8, $0.187681358930914206E-01 |
| DATA ·log1ptab<> + 104(SB)/8, $0.269985148668178992E-01 |
| DATA ·log1ptab<> + 112(SB)/8, $0.364186619761331328E-01 |
| DATA ·log1ptab<> + 120(SB)/8, $0.469505379381388441E-01 |
| GLOBL ·log1ptab<> + 0(SB), RODATA, $128 |
| |
| // Log1p returns the natural logarithm of 1 plus its argument x. |
| // It is more accurate than Log(1 + x) when x is near zero. |
| // |
| // Special cases are: |
| // Log1p(+Inf) = +Inf |
| // Log1p(±0) = ±0 |
| // Log1p(-1) = -Inf |
| // Log1p(x < -1) = NaN |
| // Log1p(NaN) = NaN |
| // The algorithm used is minimax polynomial approximation |
| // with coefficients determined with a Remez exchange algorithm. |
| |
| TEXT ·log1pAsm(SB), NOSPLIT, $0-16 |
| FMOVD x+0(FP), F0 |
| MOVD $·log1pxmone<>+0(SB), R1 |
| MOVD ·log1pxout<>+0(SB), R2 |
| FMOVD 0(R1), F3 |
| MOVD $·log1pxa<>+0(SB), R1 |
| MOVWZ ·log1pxlim<>+0(SB), R0 |
| FMOVD 0(R1), F1 |
| MOVD $·log1pc8<>+0(SB), R1 |
| FMOVD 0(R1), F5 |
| MOVD $·log1pc7<>+0(SB), R1 |
| VLEG $0, 0(R1), V20 |
| MOVD $·log1pc6<>+0(SB), R1 |
| WFSDB V0, V3, V4 |
| VLEG $0, 0(R1), V18 |
| MOVD $·log1pc5<>+0(SB), R1 |
| VLEG $0, 0(R1), V16 |
| MOVD R2, R5 |
| LGDR F4, R3 |
| WORD $0xC0190006 //iilf %r1,425983 |
| BYTE $0x7F |
| BYTE $0xFF |
| SRAD $32, R3, R3 |
| SUBW R3, R1 |
| SRW $16, R1, R1 |
| BYTE $0x18 //lr %r4,%r1 |
| BYTE $0x41 |
| RISBGN $0, $15, $48, R4, R2 |
| RISBGN $16, $31, $32, R4, R5 |
| MOVW R0, R6 |
| MOVW R3, R7 |
| CMPBGT R6, R7, L8 |
| WFCEDBS V4, V4, V6 |
| MOVD $·log1pxzero<>+0(SB), R1 |
| FMOVD 0(R1), F2 |
| BVS LEXITTAGlog1p |
| WORD $0xB3130044 // lcdbr %f4,%f4 |
| WFCEDBS V2, V4, V6 |
| BEQ L9 |
| WFCHDBS V4, V2, V2 |
| BEQ LEXITTAGlog1p |
| MOVD $·log1pxnan<>+0(SB), R1 |
| FMOVD 0(R1), F0 |
| FMOVD F0, ret+8(FP) |
| RET |
| |
| L8: |
| LDGR R2, F2 |
| FSUB F4, F3 |
| FMADD F2, F4, F1 |
| MOVD $·log1pc4<>+0(SB), R2 |
| WORD $0xB3130041 // lcdbr %f4,%f1 |
| FMOVD 0(R2), F7 |
| FSUB F3, F0 |
| MOVD $·log1pc3<>+0(SB), R2 |
| FMOVD 0(R2), F3 |
| MOVD $·log1pc2<>+0(SB), R2 |
| WFMDB V1, V1, V6 |
| FMADD F7, F4, F3 |
| WFMSDB V0, V2, V1, V0 |
| FMOVD 0(R2), F7 |
| WFMADB V4, V5, V20, V5 |
| MOVD $·log1pc1<>+0(SB), R2 |
| FMOVD 0(R2), F2 |
| FMADD F7, F4, F2 |
| WFMADB V4, V18, V16, V4 |
| FMADD F3, F6, F2 |
| WFMADB V5, V6, V4, V5 |
| FMUL F6, F6 |
| MOVD $·log1pc0<>+0(SB), R2 |
| WFMADB V6, V5, V2, V6 |
| FMOVD 0(R2), F4 |
| WFMADB V0, V6, V4, V6 |
| RISBGZ $57, $60, $3, R1, R1 |
| MOVD $·log1ptab<>+0(SB), R2 |
| MOVD $·log1pxl1<>+0(SB), R3 |
| WORD $0x68112000 //ld %f1,0(%r1,%r2) |
| FMOVD 0(R3), F2 |
| WFMADB V0, V6, V1, V0 |
| MOVD $·log1pyout<>+0(SB), R1 |
| LDGR R5, F6 |
| FMOVD 0(R1), F4 |
| WFMSDB V2, V6, V4, V2 |
| MOVD $·log1pxl2<>+0(SB), R1 |
| FMOVD 0(R1), F4 |
| FMADD F4, F2, F0 |
| FMOVD F0, ret+8(FP) |
| RET |
| |
| L9: |
| MOVD $·log1pxminf<>+0(SB), R1 |
| FMOVD 0(R1), F0 |
| FMOVD F0, ret+8(FP) |
| RET |
| |
| |
| LEXITTAGlog1p: |
| FMOVD F0, ret+8(FP) |
| RET |
| |
