New amd64 exp(3).

tested by steven@, ok otto@

2 files changed, 103 insertions, 2 deletions

diff --git a/lib/libm/Makefile b/lib/libm/Makefile
index fa0196ba871..cd0a0799563 100644
--- a/lib/libm/Makefile
+++ b/lib/libm/Makefile
@@ -1,5 +1,5 @@
 #  $NetBSD: Makefile,v 1.28 1995/11/20 22:06:19 jtc Exp $
-#  $OpenBSD: Makefile,v 1.38 2006/03/18 20:13:24 brad Exp $
+#  $OpenBSD: Makefile,v 1.39 2006/03/19 00:01:04 kettenis Exp $
 #
 #  @(#)Makefile 5.1beta 93/09/24 
 # 
@@ -66,7 +66,7 @@ ARCH_SRCS = e_acos.S e_asin.S e_atan2.S e_exp.S e_fmod.S e_log.S e_log10.S \
 .elif (${MACHINE_ARCH} == "amd64")
 .PATH:	${.CURDIR}/arch/amd64
 CPPFLAGS+=-I${.CURDIR}/arch/amd64
-ARCH_SRCS = e_acos.S e_asin.S e_atan2.S e_fmod.S e_log.S e_log10.S \
+ARCH_SRCS = e_acos.S e_asin.S e_atan2.S e_exp.S e_fmod.S e_log.S e_log10.S \
 	    e_remainder.S e_remainderf.S e_scalb.S e_sqrt.S e_sqrtf.S \
 	    s_atan.S s_atanf.S s_ceil.S s_ceilf.S s_copysign.S s_copysignf.S \
 	    s_cos.S s_cosf.S s_finite.S s_finitef.S s_floor.S s_floorf.S \
diff --git a/lib/libm/arch/amd64/e_exp.S b/lib/libm/arch/amd64/e_exp.S
new file mode 100644
index 00000000000..5ae6516e991
--- /dev/null
+++ b/lib/libm/arch/amd64/e_exp.S
@@ -0,0 +1,101 @@
+/*	$OpenBSD: e_exp.S,v 1.4 2006/03/19 00:01:04 kettenis Exp $	*/
+/*	$NetBSD: e_exp.S,v 1.12 2002/02/27 16:32:46 christos Exp $	*/
+
+/*
+ * Copyright (c) 1993,94 Winning Strategies, Inc.
+ * 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.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *      This product includes software developed by Winning Strategies, Inc.
+ * 4. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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.
+ */
+
+/*
+ * Written by:
+ *	J.T. Conklin (jtc@wimsey.com), Winning Strategies, Inc.
+ */
+
+#include <machine/asm.h>
+
+#include "abi.h"
+
+/* e^x = 2^(x * log2(e)) */
+ENTRY(__ieee754_exp)
+	XMM_ONE_ARG_DOUBLE_PROLOGUE
+	/*
+	 * If x is +-Inf, then the subtraction would give Inf-Inf = NaN.
+	 * Avoid this.  Also avoid it if x is NaN for convenience.
+	 */
+	movl	-4(%rsp),%eax
+	andl	$0x7fffffff,%eax
+	cmpl	$0x7ff00000,%eax
+	jae	x_Inf_or_NaN
+
+	fldl	ARG_DOUBLE_ONE
+
+	/*
+	 * Ensure that the rounding mode is to nearest (to give the smallest
+	 * possible fraction) and that the precision is as high as possible.
+	 * We may as well mask interrupts if we switch the mode.
+	 */
+	fstcw	-8(%rsp)
+	movl	-8(%rsp),%eax
+	andl	$0x0300,%eax
+	cmpl	$0x0300,%eax		/* RC == 0 && PC == 3? */
+	je	1f			/* jump if mode is good */
+	movl	$0x137f,-4(%rsp)
+	fldcw	-4(%rsp)
+1:
+	fldl2e
+	fmulp				/* x * log2(e) */
+	fst	%st(1)
+	frndint				/* int(x * log2(e)) */
+	fst	%st(2)
+	fsubrp				/* fract(x * log2(e)) */
+	f2xm1				/* 2^(fract(x * log2(e))) - 1 */ 
+	fld1
+	faddp				/* 2^(fract(x * log2(e))) */
+	fscale				/* e^x */
+	fstp	%st(1)
+	je	1f
+	fldcw	-8(%rsp)
+1:
+	XMM_DOUBLE_EPILOGUE
+	ret
+
+x_Inf_or_NaN:
+	/*
+	 * Return 0 if x is -Inf.  Otherwise just return x, although the
+	 * C version would return (x + x) (Real Indefinite) if x is a NaN.
+	 */
+	cmpl	$0xfff00000,-4(%rsp)
+	jne	x_not_minus_Inf
+	cmpl	$0,-8(%rsp)
+	jne	x_not_minus_Inf
+	xorpd	%xmm0,%xmm0
+	ret
+
+x_not_minus_Inf:
+	movsd	ARG_DOUBLE_ONE,%xmm0
+	ret