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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
RISBGZ $32, $59, $0, R4, R2
RISBGN $0, $15, $48, R2, R6
RISBGN $16, $31, $32, R2, R8
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
RISBGN $0, $15, $48, R3, R6
RISBGN $16, $31, $32, R2, R8
L2:
MOVH R5, R5
MOVH $0x7FEF, R1
CMPW R5, R1
BGT L1
LDGR R6, F2
FMUL F2, F0
RISBGZ $57, $59, $3, R4, R4
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
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