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+// Copyright 2016 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 tanhrodataL18<>+0(SB)/8, $-1.0
+DATA tanhrodataL18<>+8(SB)/8, $-2.0
+DATA tanhrodataL18<>+16(SB)/8, $1.0
+DATA tanhrodataL18<>+24(SB)/8, $2.0
+DATA tanhrodataL18<>+32(SB)/8, $0.20000000000000011868E+01
+DATA tanhrodataL18<>+40(SB)/8, $0.13333333333333341256E+01
+DATA tanhrodataL18<>+48(SB)/8, $0.26666666663549111502E+00
+DATA tanhrodataL18<>+56(SB)/8, $0.66666666658721844678E+00
+DATA tanhrodataL18<>+64(SB)/8, $0.88890217768964374821E-01
+DATA tanhrodataL18<>+72(SB)/8, $0.25397199429103821138E-01
+DATA tanhrodataL18<>+80(SB)/8, $-.346573590279972643E+00
+DATA tanhrodataL18<>+88(SB)/8, $20.E0
+GLOBL tanhrodataL18<>+0(SB), RODATA, $96
+
+// Constants
+DATA tanhrlog2<>+0(SB)/8, $0x4007154760000000
+GLOBL tanhrlog2<>+0(SB), RODATA, $8
+DATA tanhxadd<>+0(SB)/8, $0xc2f0000100003ff0
+GLOBL tanhxadd<>+0(SB), RODATA, $8
+DATA tanhxmone<>+0(SB)/8, $-1.0
+GLOBL tanhxmone<>+0(SB), RODATA, $8
+DATA tanhxzero<>+0(SB)/8, $0
+GLOBL tanhxzero<>+0(SB), RODATA, $8
+
+// Polynomial coefficients
+DATA tanhtab<>+0(SB)/8, $0.000000000000000000E+00
+DATA tanhtab<>+8(SB)/8, $-.171540871271399150E-01
+DATA tanhtab<>+16(SB)/8, $-.306597931864376363E-01
+DATA tanhtab<>+24(SB)/8, $-.410200970469965021E-01
+DATA tanhtab<>+32(SB)/8, $-.486343079978231466E-01
+DATA tanhtab<>+40(SB)/8, $-.538226193725835820E-01
+DATA tanhtab<>+48(SB)/8, $-.568439602538111520E-01
+DATA tanhtab<>+56(SB)/8, $-.579091847395528847E-01
+DATA tanhtab<>+64(SB)/8, $-.571909584179366341E-01
+DATA tanhtab<>+72(SB)/8, $-.548312665987204407E-01
+DATA tanhtab<>+80(SB)/8, $-.509471843643441085E-01
+DATA tanhtab<>+88(SB)/8, $-.456353588448863359E-01
+DATA tanhtab<>+96(SB)/8, $-.389755254243262365E-01
+DATA tanhtab<>+104(SB)/8, $-.310332908285244231E-01
+DATA tanhtab<>+112(SB)/8, $-.218623539150173528E-01
+DATA tanhtab<>+120(SB)/8, $-.115062908917949451E-01
+GLOBL tanhtab<>+0(SB), RODATA, $128
+
+// Tanh returns the hyperbolic tangent of the argument.
+//
+// Special cases are:
+// Tanh(±0) = ±0
+// Tanh(±Inf) = ±1
+// Tanh(NaN) = NaN
+// The algorithm used is minimax polynomial approximation using a table of
+// polynomial coefficients determined with a Remez exchange algorithm.
+
+TEXT ·tanhAsm(SB),NOSPLIT,$0-16
+ FMOVD x+0(FP), F0
+ // special case Tanh(±0) = ±0
+ FMOVD $(0.0), F1
+ FCMPU F0, F1
+ BEQ tanhIsZero
+ MOVD $tanhrodataL18<>+0(SB), R5
+ LTDBR F0, F0
+ MOVD $0x4034000000000000, R1
+ BLTU L15
+ FMOVD F0, F1
+L2:
+ MOVD $tanhxadd<>+0(SB), R2
+ FMOVD 0(R2), F2
+ MOVD tanhrlog2<>+0(SB), R2
+ LDGR R2, F4
+ WFMSDB V0, V4, V2, V4
+ MOVD $tanhtab<>+0(SB), R3
+ LGDR F4, R2
+ RISBGZ $57, $60, $3, R2, R4
+ WORD $0xED105058 //cdb %f1,.L19-.L18(%r5)
+ BYTE $0x00
+ BYTE $0x19
+ RISBGN $0, $15, $48, R2, R1
+ WORD $0x68543000 //ld %f5,0(%r4,%r3)
+ LDGR R1, F6
+ BLT L3
+ MOVD $tanhxzero<>+0(SB), R1
+ FMOVD 0(R1), F2
+ WFCHDBS V0, V2, V4
+ BEQ L9
+ WFCHDBS V2, V0, V2
+ BNE L1
+ MOVD $tanhxmone<>+0(SB), R1
+ FMOVD 0(R1), F0
+ FMOVD F0, ret+8(FP)
+ RET
+
+L3:
+ FADD F4, F2
+ FMOVD tanhrodataL18<>+80(SB), F4
+ FMADD F4, F2, F0
+ FMOVD tanhrodataL18<>+72(SB), F1
+ WFMDB V0, V0, V3
+ FMOVD tanhrodataL18<>+64(SB), F2
+ WFMADB V0, V1, V2, V1
+ FMOVD tanhrodataL18<>+56(SB), F4
+ FMOVD tanhrodataL18<>+48(SB), F2
+ WFMADB V1, V3, V4, V1
+ FMOVD tanhrodataL18<>+40(SB), F4
+ WFMADB V3, V2, V4, V2
+ FMOVD tanhrodataL18<>+32(SB), F4
+ WORD $0xB9270022 //lhr %r2,%r2
+ WFMADB V3, V1, V4, V1
+ FMOVD tanhrodataL18<>+24(SB), F4
+ WFMADB V3, V2, V4, V3
+ WFMADB V0, V5, V0, V2
+ WFMADB V0, V1, V3, V0
+ WORD $0xA7183ECF //lhi %r1,16079
+ WFMADB V0, V2, V5, V2
+ FMUL F6, F2
+ MOVW R2, R10
+ MOVW R1, R11
+ CMPBLE R10, R11, L16
+ FMOVD F6, F0
+ WORD $0xED005010 //adb %f0,.L28-.L18(%r5)
+ BYTE $0x00
+ BYTE $0x1A
+ WORD $0xA7184330 //lhi %r1,17200
+ FADD F2, F0
+ MOVW R2, R10
+ MOVW R1, R11
+ CMPBGT R10, R11, L17
+ WORD $0xED605010 //sdb %f6,.L28-.L18(%r5)
+ BYTE $0x00
+ BYTE $0x1B
+ FADD F6, F2
+ WFDDB V0, V2, V0
+ FMOVD F0, ret+8(FP)
+ RET
+
+L9:
+ FMOVD tanhrodataL18<>+16(SB), F0
+L1:
+ FMOVD F0, ret+8(FP)
+ RET
+
+L15:
+ FNEG F0, F1
+ BR L2
+L16:
+ FADD F6, F2
+ FMOVD tanhrodataL18<>+8(SB), F0
+ FMADD F4, F2, F0
+ FMOVD tanhrodataL18<>+0(SB), F4
+ FNEG F0, F0
+ WFMADB V0, V2, V4, V0
+ FMOVD F0, ret+8(FP)
+ RET
+
+L17:
+ WFDDB V0, V4, V0
+ FMOVD tanhrodataL18<>+16(SB), F2
+ WFSDB V0, V2, V0
+ FMOVD F0, ret+8(FP)
+ RET
+
+tanhIsZero: //return ±0
+ FMOVD F0, ret+8(FP)
+ RET