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| // 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"
|
| // Minimax polynomial approximations
| DATA ·logrodataL21<> + 0(SB)/8, $-.499999999999999778E+00
| DATA ·logrodataL21<> + 8(SB)/8, $0.333333333333343751E+00
| DATA ·logrodataL21<> + 16(SB)/8, $-.250000000001606881E+00
| DATA ·logrodataL21<> + 24(SB)/8, $0.199999999971603032E+00
| DATA ·logrodataL21<> + 32(SB)/8, $-.166666663114122038E+00
| DATA ·logrodataL21<> + 40(SB)/8, $-.125002923782692399E+00
| DATA ·logrodataL21<> + 48(SB)/8, $0.111142014580396256E+00
| DATA ·logrodataL21<> + 56(SB)/8, $0.759438932618934220E-01
| DATA ·logrodataL21<> + 64(SB)/8, $0.142857144267212549E+00
| DATA ·logrodataL21<> + 72(SB)/8, $-.993038938793590759E-01
| DATA ·logrodataL21<> + 80(SB)/8, $-1.0
| GLOBL ·logrodataL21<> + 0(SB), RODATA, $88
|
| // Constants
| DATA ·logxminf<> + 0(SB)/8, $0xfff0000000000000
| GLOBL ·logxminf<> + 0(SB), RODATA, $8
| DATA ·logxnan<> + 0(SB)/8, $0x7ff8000000000000
| GLOBL ·logxnan<> + 0(SB), RODATA, $8
| DATA ·logx43f<> + 0(SB)/8, $0x43f0000000000000
| GLOBL ·logx43f<> + 0(SB), RODATA, $8
| DATA ·logxl2<> + 0(SB)/8, $0x3fda7aecbeba4e46
| GLOBL ·logxl2<> + 0(SB), RODATA, $8
| DATA ·logxl1<> + 0(SB)/8, $0x3ffacde700000000
| GLOBL ·logxl1<> + 0(SB), RODATA, $8
|
| /* Input transform scale and add constants */
| DATA ·logxm<> + 0(SB)/8, $0x3fc77604e63c84b1
| DATA ·logxm<> + 8(SB)/8, $0x40fb39456ab53250
| DATA ·logxm<> + 16(SB)/8, $0x3fc9ee358b945f3f
| DATA ·logxm<> + 24(SB)/8, $0x40fb39418bf3b137
| DATA ·logxm<> + 32(SB)/8, $0x3fccfb2e1304f4b6
| DATA ·logxm<> + 40(SB)/8, $0x40fb393d3eda3022
| DATA ·logxm<> + 48(SB)/8, $0x3fd0000000000000
| DATA ·logxm<> + 56(SB)/8, $0x40fb393969e70000
| DATA ·logxm<> + 64(SB)/8, $0x3fd11117aafbfe04
| DATA ·logxm<> + 72(SB)/8, $0x40fb3936eaefafcf
| DATA ·logxm<> + 80(SB)/8, $0x3fd2492af5e658b2
| DATA ·logxm<> + 88(SB)/8, $0x40fb39343ff01715
| DATA ·logxm<> + 96(SB)/8, $0x3fd3b50c622a43dd
| DATA ·logxm<> + 104(SB)/8, $0x40fb39315adae2f3
| DATA ·logxm<> + 112(SB)/8, $0x3fd56bbeea918777
| DATA ·logxm<> + 120(SB)/8, $0x40fb392e21698552
| GLOBL ·logxm<> + 0(SB), RODATA, $128
|
| // Log returns the natural logarithm of the argument.
| //
| // Special cases are:
| // Log(+Inf) = +Inf
| // Log(0) = -Inf
| // Log(x < 0) = NaN
| // Log(NaN) = NaN
| // The algorithm used is minimax polynomial approximation using a table of
| // polynomial coefficients determined with a Remez exchange algorithm.
|
| TEXT ·logAsm(SB), NOSPLIT, $0-16
| FMOVD x+0(FP), F0
| MOVD $·logrodataL21<>+0(SB), R9
| MOVH $0x8006, R4
| LGDR F0, R1
| MOVD $0x3FF0000000000000, R6
| SRAD $48, R1, R1
| MOVD $0x40F03E8000000000, R8
| SUBW R1, R4
| WORD $0xEC2420BB //risbg %r2,%r4,32,128+59,0
| BYTE $0x00
| BYTE $0x55
| WORD $0xEC62000F //risbgn %r6,%r2,64-64+0,64-64+0+16-1,64-0-16
| BYTE $0x30
| BYTE $0x59
| WORD $0xEC82101F //risbgn %r8,%r2,64-64+16,64-64+16+16-1,64-16-16
| BYTE $0x20
| BYTE $0x59
| MOVW R1, R7
| CMPBGT R7, $22, L17
| LTDBR F0, F0
| MOVD $·logx43f<>+0(SB), R1
| FMOVD 0(R1), F2
| BLEU L3
| MOVH $0x8005, R12
| MOVH $0x8405, R0
| BR L15
| L7:
| LTDBR F0, F0
| BLEU L3
| L15:
| FMUL F2, F0
| LGDR F0, R1
| SRAD $48, R1, R1
| SUBW R1, R0, R2
| SUBW R1, R12, R3
| BYTE $0x18 //lr %r4,%r2
| BYTE $0x42
| ANDW $0xFFFFFFF0, R3
| ANDW $0xFFFFFFF0, R2
| BYTE $0x18 //lr %r5,%r1
| BYTE $0x51
| MOVW R1, R7
| CMPBLE R7, $22, L7
| WORD $0xEC63000F //risbgn %r6,%r3,64-64+0,64-64+0+16-1,64-0-16
| BYTE $0x30
| BYTE $0x59
| WORD $0xEC82101F //risbgn %r8,%r2,64-64+16,64-64+16+16-1,64-16-16
| BYTE $0x20
| BYTE $0x59
| L2:
| MOVH R5, R5
| MOVH $0x7FEF, R1
| CMPW R5, R1
| BGT L1
| LDGR R6, F2
| FMUL F2, F0
| WORD $0xEC4439BB //risbg %r4,%r4,57,128+59,3
| BYTE $0x03
| BYTE $0x55
| FMOVD 80(R9), F2
| MOVD $·logxm<>+0(SB), R7
| ADD R7, R4
| FMOVD 72(R9), F4
| WORD $0xED004000 //madb %f2,%f0,0(%r4)
| BYTE $0x20
| BYTE $0x1E
| FMOVD 64(R9), F1
| FMOVD F2, F0
| FMOVD 56(R9), F2
| WFMADB V0, V2, V4, V2
| WFMDB V0, V0, V6
| FMOVD 48(R9), F4
| WFMADB V0, V2, V4, V2
| FMOVD 40(R9), F4
| WFMADB V2, V6, V1, V2
| FMOVD 32(R9), F1
| WFMADB V6, V4, V1, V4
| FMOVD 24(R9), F1
| WFMADB V6, V2, V1, V2
| FMOVD 16(R9), F1
| WFMADB V6, V4, V1, V4
| MOVD $·logxl1<>+0(SB), R1
| FMOVD 8(R9), F1
| WFMADB V6, V2, V1, V2
| FMOVD 0(R9), F1
| WFMADB V6, V4, V1, V4
| FMOVD 8(R4), F1
| WFMADB V0, V2, V4, V2
| LDGR R8, F4
| WFMADB V6, V2, V0, V2
| WORD $0xED401000 //msdb %f1,%f4,0(%r1)
| BYTE $0x10
| BYTE $0x1F
| MOVD ·logxl2<>+0(SB), R1
| WORD $0xB3130001 //lcdbr %f0,%f1
| LDGR R1, F4
| WFMADB V0, V4, V2, V0
| L1:
| FMOVD F0, ret+8(FP)
| RET
| L3:
| LTDBR F0, F0
| BEQ L20
| BGE L1
| BVS L1
|
| MOVD $·logxnan<>+0(SB), R1
| FMOVD 0(R1), F0
| BR L1
| L20:
| MOVD $·logxminf<>+0(SB), R1
| FMOVD 0(R1), F0
| FMOVD F0, ret+8(FP)
| RET
| L17:
| BYTE $0x18 //lr %r5,%r1
| BYTE $0x51
| BR L2
|
|
