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Diffstat (limited to 'src/math/log1p_386.s')
| -rw-r--r-- | src/math/log1p_386.s | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/src/math/log1p_386.s b/src/math/log1p_386.s new file mode 100644 index 000000000..1c2d683a8 --- /dev/null +++ b/src/math/log1p_386.s @@ -0,0 +1,27 @@ +// Copyright 2010 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" + +// func Log1p(x float64) float64 +TEXT ·Log1p(SB),NOSPLIT,$0 + FMOVD $(2.928932188134524e-01), F0 + FMOVD x+0(FP), F0 // F0=x, F1=1-sqrt(2)/2 = 0.29289321881345247559915564 + FABS // F0=|x|, F1=1-sqrt(2)/2 + FUCOMPP F0, F1 // compare F0 to F1 + FSTSW AX + FLDLN2 // F0=log(2) + ANDW $0x0100, AX + JEQ use_fyl2x // jump if F0 >= F1 + FMOVD x+0(FP), F0 // F0=x, F1=log(2) + FYL2XP1 // F0=log(1+x)=log2(1+x)*log(2) + FMOVDP F0, ret+8(FP) + RET +use_fyl2x: + FLD1 // F0=1, F2=log(2) + FADDD x+0(FP), F0 // F0=1+x, F1=log(2) + FYL2X // F0=log(1+x)=log2(1+x)*log(2) + FMOVDP F0, ret+8(FP) + RET + |