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view src/build-msvctools/math/ilogb.S @ 3061:f8299bb6c872

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Initial support for native MSVC compilation. * add MSVC support files: compiler wrappers and support libraries * adapt libiconv to work with MSVC * adapt gettext to work with MSVC
author Michael Goffioul <michael.goffioul@gmail.com>
date Mon, 17 Jun 2013 22:43:11 -0400
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/*
 * Written by J.T. Conklin <jtc@netbsd.org>.
 * Public domain.
 */


	.file	"ilogb.S"
	.text
	.align 4
.globl _ilogb
	.def	_ilogb;	.scl	2;	.type	32;	.endef
_ilogb:

	fldl	4(%esp)
/* I added the following ugly construct because ilogb(+-Inf) is
   required to return INT_MAX in ISO C99.
   -- jakub@redhat.com.  */
	fxam			/* Is NaN or +-Inf?  */
	fstsw   %ax
	movb    $0x45, %dh
	andb    %ah, %dh
	cmpb    $0x05, %dh
	je      1f		/* Is +-Inf, jump.  */

	fxtract
	pushl	%eax
	fstp	%st

	fistpl	(%esp)
	fwait
	popl	%eax

	ret

1:	fstp	%st
	movl	$0x7fffffff, %eax
	ret