Reorganized polyfills

src/ArduinoJson/Numbers/FloatTraits.hpp

@@ -0,0 +1,150 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2018
+// MIT License
+
+#pragma once
+
+#include <stdint.h>
+#include <stdlib.h>  // for size_t
+#include "../Configuration.hpp"
+#include "../Polyfills/math.hpp"
+
+namespace ArduinoJson {
+namespace Internals {
+
+template <typename T, size_t = sizeof(T)>
+struct FloatTraits {};
+
+template <typename T>
+struct FloatTraits<T, 8 /*64bits*/> {
+  typedef int64_t mantissa_type;
+  static const short mantissa_bits = 52;
+  static const mantissa_type mantissa_max =
+      (static_cast<mantissa_type>(1) << mantissa_bits) - 1;
+
+  typedef int16_t exponent_type;
+  static const exponent_type exponent_max = 308;
+
+  template <typename TExponent>
+  static T make_float(T m, TExponent e) {
+    if (e > 0) {
+      for (uint8_t index = 0; e != 0; index++) {
+        if (e & 1) m *= positiveBinaryPowerOfTen(index);
+        e >>= 1;
+      }
+    } else {
+      e = TExponent(-e);
+      for (uint8_t index = 0; e != 0; index++) {
+        if (e & 1) m *= negativeBinaryPowerOfTen(index);
+        e >>= 1;
+      }
+    }
+    return m;
+  }
+
+  static T positiveBinaryPowerOfTen(int index) {
+    static T factors[] = {
+        1e1, 1e2, 1e4, 1e8, 1e16, 1e32,
+        // workaround to support platforms with single precision literals
+        forge(0x4D384F03, 0xE93FF9F5), forge(0x5A827748, 0xF9301D32),
+        forge(0x75154FDD, 0x7F73BF3C)};
+    return factors[index];
+  }
+
+  static T negativeBinaryPowerOfTen(int index) {
+    static T factors[] = {
+        1e-1, 1e-2, 1e-4, 1e-8, 1e-16, 1e-32,
+        // workaround to support platforms with single precision literals
+        forge(0x32A50FFD, 0x44F4A73D), forge(0x255BBA08, 0xCF8C979D),
+        forge(0x0AC80628, 0x64AC6F43)};
+    return factors[index];
+  }
+
+  static T negativeBinaryPowerOfTenPlusOne(int index) {
+    static T factors[] = {
+        1e0, 1e-1, 1e-3, 1e-7, 1e-15, 1e-31,
+        // workaround to support platforms with single precision literals
+        forge(0x32DA53FC, 0x9631D10D), forge(0x25915445, 0x81B7DEC2),
+        forge(0x0AFE07B2, 0x7DD78B14)};
+    return factors[index];
+  }
+
+  static T nan() {
+    return forge(0x7ff80000, 0x00000000);
+  }
+
+  static T inf() {
+    return forge(0x7ff00000, 0x00000000);
+  }
+
+  static T forge(uint32_t msb, uint32_t lsb) {
+    union {
+      uint64_t integerBits;
+      T floatBits;
+    };
+    integerBits = (uint64_t(msb) << 32) | lsb;
+    return floatBits;
+  }
+};
+
+template <typename T>
+struct FloatTraits<T, 4 /*32bits*/> {
+  typedef int32_t mantissa_type;
+  static const short mantissa_bits = 23;
+  static const mantissa_type mantissa_max =
+      (static_cast<mantissa_type>(1) << mantissa_bits) - 1;
+
+  typedef int8_t exponent_type;
+  static const exponent_type exponent_max = 38;
+
+  template <typename TExponent>
+  static T make_float(T m, TExponent e) {
+    if (e > 0) {
+      for (uint8_t index = 0; e != 0; index++) {
+        if (e & 1) m *= positiveBinaryPowerOfTen(index);
+        e >>= 1;
+      }
+    } else {
+      e = -e;
+      for (uint8_t index = 0; e != 0; index++) {
+        if (e & 1) m *= negativeBinaryPowerOfTen(index);
+        e >>= 1;
+      }
+    }
+    return m;
+  }
+
+  static T positiveBinaryPowerOfTen(int index) {
+    static T factors[] = {1e1f, 1e2f, 1e4f, 1e8f, 1e16f, 1e32f};
+    return factors[index];
+  }
+
+  static T negativeBinaryPowerOfTen(int index) {
+    static T factors[] = {1e-1f, 1e-2f, 1e-4f, 1e-8f, 1e-16f, 1e-32f};
+    return factors[index];
+  }
+
+  static T negativeBinaryPowerOfTenPlusOne(int index) {
+    static T factors[] = {1e0f, 1e-1f, 1e-3f, 1e-7f, 1e-15f, 1e-31f};
+    return factors[index];
+  }
+
+  static T forge(uint32_t bits) {
+    union {
+      uint32_t integerBits;
+      T floatBits;
+    };
+    integerBits = bits;
+    return floatBits;
+  }
+
+  static T nan() {
+    return forge(0x7fc00000);
+  }
+
+  static T inf() {
+    return forge(0x7f800000);
+  }
+};
+}  // namespace Internals
+}  // namespace ArduinoJson