reorganize binary utilities

danielaparker · Dec 29, 2024 · 9a81b8e · 9a81b8e
1 parent 74f0336
commit 9a81b8e
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Showing 12 changed files with 370 additions and 378 deletions.
diff --git a/include/jsoncons/config/binary_config.hpp b/include/jsoncons/config/binary_config.hpp
diff --git a/include/jsoncons/config/compiler_support.hpp b/include/jsoncons/config/compiler_support.hpp
@@ -374,47 +374,118 @@ namespace jsoncons {
 #endif
 #endif
 
-namespace jsoncons {
+// The definitions below follow the definitions in compiler_support_p.h, https://github.com/01org/tinycbor
+// MIT license
+
+#ifdef __F16C__
+#  include <immintrin.h>
+#endif
+
+#ifndef __has_builtin
+#  define __has_builtin(x)  0
+#endif
+
+#if defined(__GNUC__)
+#if (__GNUC__ * 100 + __GNUC_MINOR__ >= 403) || (__has_builtin(__builtin_bswap64) && __has_builtin(__builtin_bswap32))
+#  define JSONCONS_BYTE_SWAP_64 __builtin_bswap64
+#  define JSONCONS_BYTE_SWAP_32 __builtin_bswap32
+#    ifdef __INTEL_COMPILER
+#      define JSONCONS_BYTE_SWAP_16 _bswap16
+#    elif (__GNUC__ * 100 + __GNUC_MINOR__ >= 608) || __has_builtin(__builtin_bswap16)
+#      define JSONCONS_BYTE_SWAP_16    __builtin_bswap16
+#  endif
+#endif
+#elif defined(__sun)
+#  include <sys/byteorder.h>
+#elif defined(_MSC_VER)
+// MSVC, which implies sizeof(long) == 4 
+#  define JSONCONS_BYTE_SWAP_64       _byteswap_uint64
+#  define JSONCONS_BYTE_SWAP_32       _byteswap_ulong
+#  define JSONCONS_BYTE_SWAP_16       _byteswap_ushort
+#endif
+
+namespace jsoncons { 
+namespace binary { 
 
-    class assertion_error : public std::runtime_error
+    static inline bool add_check_overflow(std::size_t v1, std::size_t v2, std::size_t *r)
     {
-    public:
-        assertion_error(const std::string& s) noexcept
-            : std::runtime_error(s)
+    #if ((defined(__GNUC__) && (__GNUC__ >= 5)) && !defined(__INTEL_COMPILER)) || __has_builtin(__builtin_add_overflow)
+        return __builtin_add_overflow(v1, v2, r);
+    #else
+        // unsigned additions are well-defined 
+        *r = v1 + v2;
+        return v1 > v1 + v2;
+    #endif
+    }
+
+    #if defined(__apple_build_version__) && ((__clang_major__ < 8) || ((__clang_major__ == 8) && (__clang_minor__ < 1)))
+    #define APPLE_MISSING_INTRINSICS 1
+    #endif
+
+    inline 
+    uint16_t encode_half(double val)
+    {
+    #if defined(__F16C__) && !defined(APPLE_MISSING_INTRINSICS)
+        return _cvtss_sh((float)val, 3);
+    #else
+        uint64_t v;
+        std::memcpy(&v, &val, sizeof(v));
+        int64_t sign = static_cast<int64_t>(v >> 63 << 15);
+        int64_t exp = (v >> 52) & 0x7ff;
+        int64_t mant = v << 12 >> 12 >> (53-11);    /* keep only the 11 most significant bits of the mantissa */
+        exp -= 1023;
+        if (exp == 1024) {
+            /* infinity or NaN */
+            exp = 16;
+            mant >>= 1;
+        } else if (exp >= 16) {
+            /* overflow, as largest number */
+            exp = 15;
+            mant = 1023;
+        } else if (exp >= -14) {
+            /* regular normal */
+        } else if (exp >= -24) {
+            /* subnormal */
+            mant |= 1024;
+            mant >>= -(exp + 14);
+            exp = -15;
+        } else {
+            /* underflow, make zero */
+            return 0;
+        }
+
+        /* safe cast here as bit operations above guarantee not to overflow */
+        return static_cast<uint16_t>(sign | ((exp + 15) << 10) | mant);
+    #endif
+    }
+
+    /* this function was copied & adapted from RFC 7049 Appendix D */
+    inline 
+    double decode_half(uint16_t half)
+    {
+    #if defined(__F16C__) && !defined(APPLE_MISSING_INTRINSICS)
+        return _cvtsh_ss(half);
+    #else
+        int64_t exp = (half >> 10) & 0x1f;
+        int64_t mant = half & 0x3ff;
+        double val;
+        if (exp == 0) 
         {
+            val = ldexp(static_cast<double>(mant), -24);
         }
-        const char* what() const noexcept override
+        else if (exp != 31) 
         {
-            return std::runtime_error::what();
+            val = ldexp(static_cast<double>(mant) + 1024.0, static_cast<int>(exp - 25));
+        } 
+        else
+        {
+            val = mant == 0 ? std::numeric_limits<double>::infinity() : std::nan("");
         }
-    };
+        return half & 0x8000 ? -val : val;
+    #endif
+    }
 
+} // namespace binary
 } // namespace jsoncons
 
-#define JSONCONS_STR2(x)  #x
-#define JSONCONS_STR(x)  JSONCONS_STR2(x)
-
-#ifdef _DEBUG
-#define JSONCONS_ASSERT(x) if (!(x)) { \
-    JSONCONS_THROW(jsoncons::assertion_error("assertion '" #x "' failed at " __FILE__ ":" \
-            JSONCONS_STR(__LINE__))); }
-#else
-#define JSONCONS_ASSERT(x) if (!(x)) { \
-    JSONCONS_THROW(jsoncons::assertion_error("assertion '" #x "' failed at  <> :" \
-            JSONCONS_STR( 0 ))); }
-#endif // _DEBUG
-
-#if defined(JSONCONS_HAS_2017)
-#  define JSONCONS_FALLTHROUGH [[fallthrough]]
-#elif defined(__clang__)
-#  define JSONCONS_FALLTHROUGH [[clang::fallthrough]]
-#elif defined(__GNUC__) && ((__GNUC__ >= 7))
-#  define JSONCONS_FALLTHROUGH __attribute__((fallthrough))
-#elif defined (__GNUC__)
-#  define JSONCONS_FALLTHROUGH // FALLTHRU
-#else
-#  define JSONCONS_FALLTHROUGH
-#endif
-
-
 #endif // JSONCONS_CONFIG_COMPILER_SUPPORT_HPP