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-rw-r--r--sysdeps/i386/fpu/s_frexp.S82
1 files changed, 82 insertions, 0 deletions
diff --git a/sysdeps/i386/fpu/s_frexp.S b/sysdeps/i386/fpu/s_frexp.S
new file mode 100644
index 0000000000..6a05f26720
--- /dev/null
+++ b/sysdeps/i386/fpu/s_frexp.S
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+/* ix87 specific frexp implementation for double.
+   Copyright (C) 1997 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include <machine/asm.h>
+
+#ifdef __ELF__
+	.section .rodata
+#else
+	.text
+#endif
+
+	.align ALIGNARG(4)
+	ASM_TYPE_DIRECTIVE(two54,@object)
+two54:	.byte 0, 0, 0, 0, 0, 0, 0x50, 0x43
+	ASM_SIZE_DIRECTIVE(two54)
+
+#ifdef PIC
+#define MO(op) op##@GOTOFF(%edx)
+#else
+#define MO(op) op
+#endif
+
+	.text
+ENTRY(__frexp)
+	movl	4(%esp), %ecx
+	movl	8(%esp), %eax
+	movl	%eax, %edx
+	andl	$0x7fffffff, %eax
+	orl	%eax, %ecx
+	jz	1f
+	xorl	%ecx, %ecx
+	cmpl	$0x7ff00000, %eax
+	jae	1f
+
+	cmpl	$0x00100000, %eax
+	jae	2f
+
+	fldl	4(%esp)
+#ifdef	PIC
+	call	3f
+3:	popl	%edx
+	addl	$_GLOBAL_OFFSET_TABLE_+[.-3b], %edx
+#endif
+	fmull	MO(two54)
+	movl	$-54, %ecx
+	fstpl	4(%esp)
+	movl	8(%esp), %eax
+	movl	%eax, %edx
+	andl	$0x7fffffff, %eax
+
+2:	shrl	$20, %eax
+	andl	$0x800fffff, %edx
+	subl	$1022, %eax
+	orl	$0x3fe00000, %edx
+	addl	%eax, %ecx
+	movl	%edx, 8(%esp)
+
+	/* Store %ecx in the variable pointed to by the second argument,
+	   get the factor from the stack and return.  */
+1:	movl	12(%esp), %eax
+	fldl	4(%esp)
+	movl	%ecx, (%eax)
+	ret
+END(__frexp)
+weak_alias (__frexp, frexp)