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Diffstat (limited to 'src/math/modf_386.s')
| -rw-r--r-- | src/math/modf_386.s | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/src/math/modf_386.s b/src/math/modf_386.s new file mode 100644 index 0000000..e916073 --- /dev/null +++ b/src/math/modf_386.s @@ -0,0 +1,34 @@ +// 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 Modf(f float64) (int float64, frac float64) +TEXT ·Modf(SB),NOSPLIT,$0 + // special case for f == -0.0 + MOVL f_hi+4(FP), DX // high word + MOVL f_lo+0(FP), AX // low word + CMPL DX, $(1<<31) // beginning of -0.0 + JNE notNegativeZero + CMPL AX, $0 // could be denormalized + JNE notNegativeZero + MOVL AX, int_lo+8(FP) + MOVL DX, int_hi+12(FP) + MOVL AX, frac_lo+16(FP) + MOVL DX, frac_hi+20(FP) + RET +notNegativeZero: + FMOVD f+0(FP), F0 // F0=f + FMOVD F0, F1 // F0=f, F1=f + FSTCW -2(SP) // save old Control Word + MOVW -2(SP), AX + ORW $0x0c00, AX // Rounding Control set to truncate + MOVW AX, -4(SP) // store new Control Word + FLDCW -4(SP) // load new Control Word + FRNDINT // F0=trunc(f), F1=f + FLDCW -2(SP) // load old Control Word + FSUBD F0, F1 // F0=trunc(f), F1=f-trunc(f) + FMOVDP F0, int+8(FP) // F0=f-trunc(f) + FMOVDP F0, frac+16(FP) + RET |