[src/trunk]: src/lib/libc/quad Add IEEE 754 versions of __float{, }disf which ...

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

details:   https://anonhg.NetBSD.org/src/rev/cd07d5932e8a
branches:  trunk
changeset: 789589:cd07d5932e8a
user:      matt <matt%NetBSD.org@localhost>
date:      Fri Aug 23 17:41:03 2013 +0000

description:
Add IEEE 754 versions of __float{,}disf which use no floating point.

diffstat:

 lib/libc/quad/floatdisf_ieee754.c   |  89 +++++++++++++++++++++++++++++++++++++
 lib/libc/quad/floatundisf_ieee754.c |  82 ++++++++++++++++++++++++++++++++++
 2 files changed, 171 insertions(+), 0 deletions(-)

diffs (179 lines):

diff -r d17baa699c89 -r cd07d5932e8a lib/libc/quad/floatdisf_ieee754.c
--- /dev/null   Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/libc/quad/floatdisf_ieee754.c Fri Aug 23 17:41:03 2013 +0000
@@ -0,0 +1,89 @@
+/*     $NetBSD: floatdisf_ieee754.c,v 1.1 2013/08/23 17:41:03 matt Exp $       */
+
+/*-
+ * Copyright (c) 2013 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 <sys/cdefs.h>
+#if defined(LIBC_SCCS) && !defined(lint)
+__RCSID("$NetBSD: floatdisf_ieee754.c,v 1.1 2013/08/23 17:41:03 matt Exp $");
+#endif /* LIBC_SCCS and not lint */
+
+#if defined(SOFTFLOAT) || defined(__ARM_EABI__)
+#include "softfloat/softfloat-for-gcc.h"
+#endif
+
+#include <limits.h>
+#include <machine/ieee.h>
+#include "quad.h"
+
+float __floatdisf(quad_t);
+
+/*
+ * Convert signed quad to float.
+ */
+float
+__floatdisf(quad_t x)
+{
+       union ieee_single_u ux = { .sngu_f = 0.0 };
+
+       if (x == 0)
+               return 0.0;
+       if (x == 1)
+               return 1.0;
+
+       if (x < 0) {
+               if (x == QUAD_MIN)
+                       return -0x1.0p63;
+               ux.sngu_sign = 1;
+               x = -x;
+       }
+#if defined(_LP64) || defined(__mips_n32)
+       u_int l = __builtin_clzll(x);
+       x <<= (l + 1);  /* clear implicit bit */
+
+       ux.sngu_frac = (u_quad_t)x >> (64 - SNG_FRACBITS);
+#else
+       union uu u = { .q = x };
+       uint32_t frac;
+       if (u.ul[H] == 0) {
+               u_int l = __builtin_clz(u.ul[L]);
+               frac = u.ul[L] << (l + 1);      /* clear implicit bit */
+               l += 32;
+       } else {
+               u_int l = __builtin_clz(u.ul[H]);
+               frac = u.ul[H] << (l + 1);      /* clear implicit bit */
+               frac |= u.ul[L] >> (32 - (l + 1));
+       }
+
+       ux.sngu_frac = frac >> (32 - SNG_FRACBITS);
+#endif
+       ux.sngu_exp = SNG_EXP_BIAS + 63 - l;
+
+       return ux.sngu_f;
+}
diff -r d17baa699c89 -r cd07d5932e8a lib/libc/quad/floatundisf_ieee754.c
--- /dev/null   Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/libc/quad/floatundisf_ieee754.c       Fri Aug 23 17:41:03 2013 +0000
@@ -0,0 +1,82 @@
+/*     $NetBSD: floatundisf_ieee754.c,v 1.1 2013/08/23 17:41:03 matt Exp $     */
+
+/*-
+ * Copyright (c) 2013 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 <sys/cdefs.h>
+#if defined(LIBC_SCCS) && !defined(lint)
+__RCSID("$NetBSD: floatundisf_ieee754.c,v 1.1 2013/08/23 17:41:03 matt Exp $");
+#endif /* LIBC_SCCS and not lint */
+
+#if defined(SOFTFLOAT) || defined(__ARM_EABI__)
+#include "softfloat/softfloat-for-gcc.h"
+#endif
+
+#include <machine/ieee.h>
+#include "quad.h"
+
+float __floatundisf(u_quad_t);
+
+/*
+ * Convert unsigned quad to float.
+ */
+float
+__floatundisf(u_quad_t x)
+{
+       union ieee_single_u ux = { .sngu_f = 0.0 };
+
+       if (x == 0)
+               return 0.0;
+       if (x == 1)
+               return 1.0;
+
+#if defined(_LP64) || defined(__mips_n32)
+       u_int l = __builtin_clzll(x);
+       x <<= (l + 1);  /* clear implicit bit */
+
+       ux.sngu_frac = x >> (64 - SNG_FRACBITS);
+#else
+       union uu u = { .uq = x };
+       uint32_t frac;
+       if (u.ul[H] == 0) {
+               u_int l = __builtin_clz(u.ul[L]);
+               frac = u.ul[L] << (l + 1);      /* clear implicit bit */
+               l += 32;
+       } else {
+               u_int l = __builtin_clz(u.ul[H]);
+               frac = u.ul[H] << (l + 1);      /* clear implicit bit */
+               frac |= u.ul[L] >> (32 - (l + 1));
+       }
+
+       ux.sngu_frac = frac >> (32 - SNG_FRACBITS);
+#endif
+       ux.sngu_exp = SNG_EXP_BIAS + 63 - l;
+
+       return ux.sngu_f;
+}