| Charles L. Dorian | 04217ee | 2010-02-05 00:41:30 -0800 | [diff] [blame] | 1 | // Copyright 2010 The Go Authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style |
| 3 | // license that can be found in the LICENSE file. |
| 4 | |
| 5 | // func Modf(x float64) (int float64, frac float64) |
| 6 | TEXT ·Modf(SB),7,$0 |
| 7 | FMOVD x+0(FP), F0 // F0=x |
| 8 | FMOVD F0, F1 // F0=x, F1=x |
| 9 | FSTCW -2(SP) // save old Control Word |
| 10 | MOVW -2(SP), AX |
| 11 | ORW $0x0c00, AX // Rounding Control set to truncate |
| 12 | MOVW AX, -4(SP) // store new Control Word |
| 13 | FLDCW -4(SP) // load new Control Word |
| 14 | FRNDINT // F0=trunc(x), F1=x |
| 15 | FLDCW -2(SP) // load old Control Word |
| 16 | FSUBD F0, F1 // F0=trunc(x), F1=x-trunc(x) |
| 17 | FMOVDP F0, i+8(FP) // F0=x-trunc(x) |
| 18 | FMOVDP F0, f+16(FP) |
| 19 | RET |
