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 #include "textflag.h" 6 7 // func Modf(f float64) (int float64, frac float64) 8 TEXT Modf(SB),NOSPLIT,$0 9 FMOVD f+0(FP), F0 // F0=f 10 FMOVD F0, F1 // F0=f, F1=f 11 FSTCW -2(SP) // save old Control Word 12 MOVW -2(SP), AX 13 ORW $0x0c00, AX // Rounding Control set to truncate 14 MOVW AX, -4(SP) // store new Control Word 15 FLDCW -4(SP) // load new Control Word 16 FRNDINT // F0=trunc(f), F1=f 17 FLDCW -2(SP) // load old Control Word 18 FSUBD F0, F1 // F0=trunc(f), F1=f-trunc(f) 19 FMOVDP F0, int+8(FP) // F0=f-trunc(f) 20 FMOVDP F0, frac+16(FP) 21 RET 22