Initial Contribution

libm/i387/s_remquof.S

@@ -0,0 +1,62 @@
+/*-
+ * Copyright (c) 2005 David Schultz <das@FreeBSD.ORG>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * Based on public-domain remainder routine by J.T. Conklin <jtc@NetBSD.org>.
+ */
+
+#include <machine/asm.h>
+__FBSDID("$FreeBSD: src/lib/msun/i387/s_remquof.S,v 1.1 2005/03/25 04:40:44 das Exp $"); 
+	
+ENTRY(remquof)
+	flds	8(%esp)
+	flds	4(%esp)
+1:	fprem1
+	fstsw	%ax
+	sahf
+	jp	1b
+	fstp	%st(1)
+/* Extract the three low-order bits of the quotient from C0,C3,C1. */
+	shrl	$6,%eax
+	movl	%eax,%ecx
+	andl	$0x108,%eax
+	rorl	$7,%eax
+	orl	%eax,%ecx
+	roll	$4,%eax
+	orl	%ecx,%eax
+	andl	$7,%eax
+/* Negate the quotient bits if x*y<0.  Avoid using an unpredictable branch. */
+	movl	8(%esp),%ecx
+	xorl	4(%esp),%ecx
+	sarl	$16,%ecx
+	sarl	$16,%ecx
+	xorl	%ecx,%eax
+	andl	$1,%ecx
+	addl	%ecx,%eax
+/* Store the quotient and return. */
+	movl	12(%esp),%ecx
+	movl	%eax,(%ecx)
+	ret