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diff src/build-msvctools/math/ilogbf.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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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/build-msvctools/math/ilogbf.S	Mon Jun 17 22:43:11 2013 -0400
@@ -0,0 +1,35 @@
+/*
+ * Written by J.T. Conklin <jtc@netbsd.org>.
+ * Public domain.
+ */
+
+	.file	"ilogbf.S"
+	.text
+	.align 4
+.globl _ilogbf
+	.def	_ilogbf;	.scl	2;	.type	32;	.endef
+_ilogbf:
+	flds	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