| // 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. |
| |
| // func Modf(x float64) (int float64, frac float64) |
| TEXT ·Modf(SB),7,$0 |
| FMOVD x+0(FP), F0 // F0=x |
| FMOVD F0, F1 // F0=x, F1=x |
| 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(x), F1=x |
| FLDCW -2(SP) // load old Control Word |
| FSUBD F0, F1 // F0=trunc(x), F1=x-trunc(x) |
| FMOVDP F0, i+8(FP) // F0=x-trunc(x) |
| FMOVDP F0, f+16(FP) |
| RET |
