// 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 WORD $0xB3120000 //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 WORD $0xEC4239BC //risbg %r4,%r2,57,128+60,3 BYTE $0x03 BYTE $0x55 WORD $0xED105058 //cdb %f1,.L19-.L18(%r5) BYTE $0x00 BYTE $0x19 WORD $0xEC12000F //risbgn %r1,%r2,64-64+0,64-64+0+16-1,64-0-16 BYTE $0x30 BYTE $0x59 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