[src/trunk]: src/lib/libm Add scalbn{,f,l} for VAX.

[matt <matt%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/a5630aa19e85
branches:  trunk
changeset: 767744:a5630aa19e85
user:      matt <matt%NetBSD.org@localhost>
date:      Thu Jul 28 20:53:20 2011 +0000

description:
Add scalbn{,f,l} for VAX.

diffstat:

 lib/libm/Makefile            |   5 +-
 lib/libm/arch/vax/n_scalbn.S |  77 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 80 insertions(+), 2 deletions(-)

diffs (105 lines):

diff -r b0d951a0e797 -r a5630aa19e85 lib/libm/Makefile
--- a/lib/libm/Makefile Thu Jul 28 20:50:55 2011 +0000
+++ b/lib/libm/Makefile Thu Jul 28 20:53:20 2011 +0000
@@ -1,4 +1,4 @@
-#  $NetBSD: Makefile,v 1.112 2011/07/26 16:10:16 joerg Exp $
+#  $NetBSD: Makefile,v 1.113 2011/07/28 20:53:20 matt Exp $
 #
 #  @(#)Makefile 5.1beta 93/09/24
 #
@@ -100,12 +100,13 @@
 .endif
 # end of m68k
 .elif (${MACHINE_ARCH} == "vax")
-#.PATH:        ${.CURDIR}/arch/vax
+.PATH: ${.CURDIR}/arch/vax
 
 #NOIEEE_ARCH= n_infnan.S n_argred.S n_sqrt.S
 #ARCH_SRCS = n_atan2.S n_cabs.S n_cbrt.S n_support.S n_sincos.S n_tan.S
 # XXX - ripped out due to lack of the insn polyd in the Mariah chip,
 # and emulation code isn't written yet.
+ARCHS_SRCS = n_scalbn.S
 WARNS?=4
 .endif
 
diff -r b0d951a0e797 -r a5630aa19e85 lib/libm/arch/vax/n_scalbn.S
--- /dev/null   Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/libm/arch/vax/n_scalbn.S      Thu Jul 28 20:53:20 2011 +0000
@@ -0,0 +1,77 @@
+/*-
+ * Copyright (c) 2011 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Matt Thomas of 3am Software Foundry.
+ *
+ * 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
+ */
+
+#include <machine/asm.h>
+#include <sys/errno.h>
+
+RCSID("$NetBSD: n_scalbn.S,v 1.1 2011/07/28 20:53:20 matt Exp $")
+
+ENTRY(scalbnf, 0)
+       cvtfd   4(%ap), %r0
+       movl    8(%ap), %r2
+       jr      1f
+
+ALTENTRY(scalbnl)
+ENTRY(scalbn, 0)
+       movd    4(%ap), %r0
+       movl    12(%ap), %r2
+
+       /*
+        * First see if the result will be within bounds
+        */
+1:     cmpl    %r2,$(256+55)
+       jgeq    overflow
+       cmpl    %r2,$-(256+55)
+       jleq    underflow
+
+       extzv   $7, $9, %r0, %r3        /* extract exponent */
+       jneq    5f                      /* 0 * N is still 0 */
+       cmpw    %r3, $-256              /* is this a NAN? */
+       jgtr    2f                      /*    nope */
+       ret
+
+2:     movzbl  %r3, %r3                /* clear sign bit */
+       addl2   %r2, %r3                /* add to exponent */
+       jleq    underflow               /*   <= 0? */
+
+3:     jbs     $8, %r3, overflow       /* did exponent overflow? */
+       insv    $7, $8, %r3, %r0        /* replace exponent */
+       ret
+
+underflow:
+       clrq    %r0                     /* return 0.0 */
+       jr      copysign                /* or mabye -0.0 */
+overflow:
+       pushl   $ERANGE                 /* overflow */
+       calls   $1, _C_LABEL(infnan)    /* possibly signal */
+copysign:
+       jbc     $15, 4(%ap), 5f         /* if clear, don't set sign-bit */
+       bisw2   $0x8000, %r0            /* preserve sign-bit */
+5:
+       ret