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Subject: [Boost-commit] svn:boost r71280 - trunk/libs/math/example
From: pbristow_at_[hidden]
Date: 2011-04-15 10:00:50


Author: pbristow
Date: 2011-04-15 10:00:50 EDT (Fri, 15 Apr 2011)
New Revision: 71280
URL: http://svn.boost.org/trac/boost/changeset/71280

Log:
Added Johan Rade's fp_inspect utility program.
Added:
   trunk/libs/math/example/inspect_fp.cpp (contents, props changed)

Added: trunk/libs/math/example/inspect_fp.cpp
==============================================================================
--- (empty file)
+++ trunk/libs/math/example/inspect_fp.cpp 2011-04-15 10:00:50 EDT (Fri, 15 Apr 2011)
@@ -0,0 +1,224 @@
+// inspect.cpp
+
+// Copyright (c) 2006 Johan Rade
+
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt
+// or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+//-------------------------------------
+
+#include <cstring>
+
+#include <iomanip>
+#include <iostream>
+#include <limits>
+#include <boost/detail/endian.hpp>
+
+//------------------------------------------------------------------------------
+
+bool is_big_endian()
+{
+ float x = 1.0f;
+ unsigned char first_byte;
+ memcpy(&first_byte, &x, 1);
+ return first_byte != 0;
+}
+
+//------------------------------------------------------------------------------
+
+void print_processor();
+void print_endianness();
+template<class T> void print_table();
+template<class T> void print_row(const char* name, T val, bool ok = true);
+
+//------------------------------------------------------------------------------
+
+int main()
+{
+ std::cout << '\n';
+
+ print_processor();
+
+ print_endianness();
+
+ std::cout << "---------- float --------------------\n\n";
+ print_table<float>();
+
+ std::cout << "---------- double -------------------\n\n";
+ print_table<double>();
+
+ std::cout << "---------- long double --------------\n\n";
+ print_table<long double>();
+
+ return 0;
+}
+
+//------------------------------------------------------------------------------
+
+void print_processor()
+{
+#if defined(__i386) || defined(__i386__) || defined(_M_IX86) \
+ || defined(__amd64) || defined(__amd64__) || defined(_M_AMD64) \
+ || defined(__x86_64) || defined(__x86_64__) || defined(_M_X64)
+
+ std::cout << "Processor: x86 or x64\n\n";
+
+#elif defined(__ia64) || defined(__ia64__) || defined(_M_IA64)
+
+ std::cout << "Processor: ia64\n\n";
+
+#elif defined(__powerpc) || defined(__powerpc__) || defined(__POWERPC__) \
+ || defined(__ppc) || defined(__ppc__) || defined(__PPC__)
+
+ std::cout << "Processor: PowerPC\n\n";
+
+#elif defined(__m68k) || defined(__m68k__) \
+ || defined(__mc68000) || defined(__mc68000__) \
+
+ std::cout << "Processor: Motorola 68K\n\n";
+
+#else
+
+ std::cout << "Processor: Unknown\n\n";
+
+#endif
+}
+
+void print_endianness()
+{
+ if(is_big_endian())
+ std::cout << "This platform is big-endian.\n";
+ else
+ std::cout << "This platform is little-endian.\n";
+
+#ifdef BOOST_BIG_ENDIAN
+ std::cout << "BOOST_BIG_ENDIAN is defined.\n\n";
+#endif
+#if defined BOOST_LITTLE_ENDIAN
+ std::cout << "BOOST_LITTTLE_ENDIAN is defined.\n\n";
+#endif
+}
+
+//..............................................................................
+
+template<class T> void print_table()
+{
+ print_row("0", (T)0);
+ print_row("sn.min", std::numeric_limits<T>::denorm_min(),
+ std::numeric_limits<T>::has_denorm);
+ print_row("-sn.min", -std::numeric_limits<T>::denorm_min(),
+ std::numeric_limits<T>::has_denorm);
+ print_row("n.min/256", (std::numeric_limits<T>::min)()/256);
+ print_row("n.min/2", (std::numeric_limits<T>::min)()/2);
+ print_row("-n.min/2", -(std::numeric_limits<T>::min)()/2);
+ print_row("n.min", (std::numeric_limits<T>::min)());
+ print_row("1", (T)1);
+ print_row("3/4", (T)3/(T)4);
+ print_row("4/3", (T)4/(T)3);
+ print_row("max", (std::numeric_limits<T>::max)());
+ print_row("inf", std::numeric_limits<T>::infinity(),
+ std::numeric_limits<T>::has_infinity);
+ print_row("q.nan", std::numeric_limits<T>::quiet_NaN(),
+ std::numeric_limits<T>::has_quiet_NaN);
+ print_row("s.nan", std::numeric_limits<T>::signaling_NaN(),
+ std::numeric_limits<T>::has_signaling_NaN);
+
+ std::cout << "\n\n";
+}
+
+template<class T>
+void print_row(const char* name, T val, bool ok)
+{
+ std::cout << std::left << std::setw(10) << name << std::right;
+
+ std::cout << std::hex << std::setfill('0');
+
+ if(ok) {
+ if(is_big_endian()) {
+ for(size_t i = 0; i < sizeof(T); ++i) {
+ unsigned char c = *(reinterpret_cast<unsigned char*>(&val) + i);
+ std::cout << std::setw(2)
+ << static_cast<unsigned int>(c) << ' ';
+ }
+ }
+ else {
+ for(size_t i = sizeof(T) - 1; i < sizeof(T); --i) {
+ unsigned char c = *(reinterpret_cast<unsigned char*>(&val) + i);
+ std::cout << std::setw(2)
+ << static_cast<unsigned int>(c) << ' ';
+ }
+ }
+ }
+ else {
+ for(size_t i = 0; i < sizeof(T); ++i)
+ std::cout << "-- ";
+ }
+
+ std::cout << '\n';
+ std::cout << std::dec << std::setfill(' ');
+}
+
+/*
+
+Sample output on an AMD Quadcore running MSVC 10
+
+ Processor: x86 or x64
+
+ This platform is little-endian.
+ BOOST_LITTTLE_ENDIAN is defined.
+
+ ---------- float --------------------
+
+ 0 00 00 00 00
+ sn.min 00 00 00 01
+ -sn.min 80 00 00 01
+ n.min/256 00 00 80 00
+ n.min/2 00 40 00 00
+ -n.min/2 80 40 00 00
+ n.min 00 80 00 00
+ 1 3f 80 00 00
+ 3/4 3f 40 00 00
+ 4/3 3f aa aa ab
+ max 7f 7f ff ff
+ inf 7f 80 00 00
+ q.nan 7f c0 00 00
+ s.nan 7f c0 00 01
+
+
+ ---------- double -------------------
+
+ 0 00 00 00 00 00 00 00 00
+ sn.min 00 00 00 00 00 00 00 01
+ -sn.min 80 00 00 00 00 00 00 01
+ n.min/256 00 00 10 00 00 00 00 00
+ n.min/2 00 08 00 00 00 00 00 00
+ -n.min/2 80 08 00 00 00 00 00 00
+ n.min 00 10 00 00 00 00 00 00
+ 1 3f f0 00 00 00 00 00 00
+ 3/4 3f e8 00 00 00 00 00 00
+ 4/3 3f f5 55 55 55 55 55 55
+ max 7f ef ff ff ff ff ff ff
+ inf 7f f0 00 00 00 00 00 00
+ q.nan 7f f8 00 00 00 00 00 00
+ s.nan 7f f8 00 00 00 00 00 01
+
+
+ ---------- long double --------------
+
+ 0 00 00 00 00 00 00 00 00
+ sn.min 00 00 00 00 00 00 00 01
+ -sn.min 80 00 00 00 00 00 00 01
+ n.min/256 00 00 10 00 00 00 00 00
+ n.min/2 00 08 00 00 00 00 00 00
+ -n.min/2 80 08 00 00 00 00 00 00
+ n.min 00 10 00 00 00 00 00 00
+ 1 3f f0 00 00 00 00 00 00
+ 3/4 3f e8 00 00 00 00 00 00
+ 4/3 3f f5 55 55 55 55 55 55
+ max 7f ef ff ff ff ff ff ff
+ inf 7f f0 00 00 00 00 00 00
+ q.nan 7f f8 00 00 00 00 00 00
+ s.nan 7f f8 00 00 00 00 00 01
+
+ */
\ No newline at end of file


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