[Boost-commit] svn:boost r71280 - trunk/libs/math/example

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 
+  
+  */
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