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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 13:14:23 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 13:14:23 +0000
commit73df946d56c74384511a194dd01dbe099584fd1a (patch)
treefd0bcea490dd81327ddfbb31e215439672c9a068 /src/math/modf_386.s
parentInitial commit. (diff)
downloadgolang-1.16-upstream.tar.xz
golang-1.16-upstream.zip
Adding upstream version 1.16.10.upstream/1.16.10upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/math/modf_386.s')
-rw-r--r--src/math/modf_386.s34
1 files changed, 34 insertions, 0 deletions
diff --git a/src/math/modf_386.s b/src/math/modf_386.s
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--- /dev/null
+++ b/src/math/modf_386.s
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+// 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