Update double_conversion to 9df6272fefd846401afbf839cbe7d0f9e319fe08

9df6272 Move buffer and buffer_pos down (#125)
43c6826 Fix strtod.cc undefined constants (#123)
1dce44c Add full license to test .cc files missing it. (#121)
8857767 Add wasm32 as supported platform (#120)
a54561b Pseiderer/add nios2 and xtensa 001 (#119)
5cc233e Add support for microblaze.
4a51e73 Add support for e2k architecture. (#118)
7da5db9 Add min exponent width option in double-to-string conversion (#116)

Bug: 977230
Change-Id: I89fbe9295172df16ae2668b750aeac6293e7b361
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2023865Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Robert Sesek <rsesek@chromium.org>
Commit-Queue: Vitaly Buka <vitalybuka@chromium.org>
Cr-Commit-Position: refs/heads/master@{#735656}

base/third_party/double_conversion/README.chromium

@@ -2,8 +2,8 @@ Name: Google Double Conversion
 Short Name: double-conversion
 URL: https://github.com/google/double-conversion
 Version: 0
-Date: 2019-06-22
-Revision: 3f9cd30e1bca91c0a036ad8b2b7eb8e2d2290dd2
+Date: 2020-01-27
+Revision: 9df6272fefd846401afbf839cbe7d0f9e319fe08
 License: BSD
 License File: LICENSE
 Security Critical: yes

base/third_party/double_conversion/double-conversion/double-to-string.cc

@@ -97,6 +97,7 @@ void DoubleToStringConverter::CreateExponentialRepresentation(
     return;
   }
   DOUBLE_CONVERSION_ASSERT(exponent < 1e4);
+  // Changing this constant requires updating the comment of DoubleToStringConverter constructor
   const int kMaxExponentLength = 5;
   char buffer[kMaxExponentLength + 1];
   buffer[kMaxExponentLength] = '\0';
@@ -105,6 +106,11 @@ void DoubleToStringConverter::CreateExponentialRepresentation(
     buffer[--first_char_pos] = '0' + (exponent % 10);
     exponent /= 10;
   }
+  // Add prefix '0' to make exponent width >= min(min_exponent_with_, kMaxExponentLength)
+  // For example: convert 1e+9 -> 1e+09, if min_exponent_with_ is set to 2
+  while(kMaxExponentLength - first_char_pos < std::min(min_exponent_width_, kMaxExponentLength)) {
+    buffer[--first_char_pos] = '0';
+  }
   result_builder->AddSubstring(&buffer[first_char_pos],
                                kMaxExponentLength - first_char_pos);
 }

base/third_party/double_conversion/double-conversion/double-to-string.h

@@ -104,6 +104,12 @@ class DoubleToStringConverter {
   //   ToPrecision(230.0, 2) -> "230"
   //   ToPrecision(230.0, 2) -> "230."  with EMIT_TRAILING_DECIMAL_POINT.
   //   ToPrecision(230.0, 2) -> "2.3e2" with EMIT_TRAILING_ZERO_AFTER_POINT.
+  //
+  // The min_exponent_width is used for exponential representations.
+  // The converter adds leading '0's to the exponent until the exponent
+  // is at least min_exponent_width digits long.
+  // The min_exponent_width is clamped to 5.
+  // As such, the exponent may never have more than 5 digits in total.
   DoubleToStringConverter(int flags,
                           const char* infinity_symbol,
                           const char* nan_symbol,
@@ -111,7 +117,8 @@ class DoubleToStringConverter {
                           int decimal_in_shortest_low,
                           int decimal_in_shortest_high,
                           int max_leading_padding_zeroes_in_precision_mode,
-                          int max_trailing_padding_zeroes_in_precision_mode)
+                          int max_trailing_padding_zeroes_in_precision_mode,
+                          int min_exponent_width = 0)
       : flags_(flags),
         infinity_symbol_(infinity_symbol),
         nan_symbol_(nan_symbol),
@@ -121,7 +128,8 @@ class DoubleToStringConverter {
         max_leading_padding_zeroes_in_precision_mode_(
             max_leading_padding_zeroes_in_precision_mode),
         max_trailing_padding_zeroes_in_precision_mode_(
-            max_trailing_padding_zeroes_in_precision_mode) {
+            max_trailing_padding_zeroes_in_precision_mode),
+        min_exponent_width_(min_exponent_width) {
     // When 'trailing zero after the point' is set, then 'trailing point'
     // must be set too.
     DOUBLE_CONVERSION_ASSERT(((flags & EMIT_TRAILING_DECIMAL_POINT) != 0) ||
@@ -378,6 +386,7 @@ class DoubleToStringConverter {
   const int decimal_in_shortest_high_;
   const int max_leading_padding_zeroes_in_precision_mode_;
   const int max_trailing_padding_zeroes_in_precision_mode_;
+  const int min_exponent_width_;
 
   DOUBLE_CONVERSION_DISALLOW_IMPLICIT_CONSTRUCTORS(DoubleToStringConverter);
 };

base/third_party/double_conversion/double-conversion/string-to-double.cc

@@ -441,11 +441,6 @@ double StringToDoubleConverter::StringToIeee(
     }
   }
 
-  // The longest form of simplified number is: "-<significant digits>.1eXXX\0".
-  const int kBufferSize = kMaxSignificantDigits + 10;
-  char buffer[kBufferSize];  // NOLINT: size is known at compile time.
-  int buffer_pos = 0;
-
   // Exponent will be adjusted if insignificant digits of the integer part
   // or insignificant leading zeros of the fractional part are dropped.
   int exponent = 0;
@@ -480,7 +475,6 @@ double StringToDoubleConverter::StringToIeee(
         return junk_string_value_;
       }
 
-      DOUBLE_CONVERSION_ASSERT(buffer_pos == 0);
       *processed_characters_count = static_cast<int>(current - input);
       return sign ? -Double::Infinity() : Double::Infinity();
     }
@@ -499,7 +493,6 @@ double StringToDoubleConverter::StringToIeee(
         return junk_string_value_;
       }
 
-      DOUBLE_CONVERSION_ASSERT(buffer_pos == 0);
       *processed_characters_count = static_cast<int>(current - input);
       return sign ? -Double::NaN() : Double::NaN();
     }
@@ -556,6 +549,12 @@ double StringToDoubleConverter::StringToIeee(
 
   bool octal = leading_zero && (flags_ & ALLOW_OCTALS) != 0;
 
+  // The longest form of simplified number is: "-<significant digits>.1eXXX\0".
+  const int kBufferSize = kMaxSignificantDigits + 10;
+  DOUBLE_CONVERSION_STACK_UNINITIALIZED char
+      buffer[kBufferSize];  // NOLINT: size is known at compile time.
+  int buffer_pos = 0;
+
   // Copy significant digits of the integer part (if any) to the buffer.
   while (*current >= '0' && *current <= '9') {
     if (significant_digits < kMaxSignificantDigits) {

base/third_party/double_conversion/double-conversion/strtod.cc

@@ -35,10 +35,12 @@
 
 namespace double_conversion {
 
+#if defined(DOUBLE_CONVERSION_CORRECT_DOUBLE_OPERATIONS)
 // 2^53 = 9007199254740992.
 // Any integer with at most 15 decimal digits will hence fit into a double
 // (which has a 53bit significand) without loss of precision.
 static const int kMaxExactDoubleIntegerDecimalDigits = 15;
+#endif // #if defined(DOUBLE_CONVERSION_CORRECT_DOUBLE_OPERATIONS)
 // 2^64 = 18446744073709551616 > 10^19
 static const int kMaxUint64DecimalDigits = 19;
 
@@ -55,6 +57,7 @@ static const int kMinDecimalPower = -324;
 static const uint64_t kMaxUint64 = DOUBLE_CONVERSION_UINT64_2PART_C(0xFFFFFFFF, FFFFFFFF);
 
 
+#if defined(DOUBLE_CONVERSION_CORRECT_DOUBLE_OPERATIONS)
 static const double exact_powers_of_ten[] = {
   1.0,  // 10^0
   10.0,
@@ -82,6 +85,7 @@ static const double exact_powers_of_ten[] = {
   10000000000000000000000.0
 };
 static const int kExactPowersOfTenSize = DOUBLE_CONVERSION_ARRAY_SIZE(exact_powers_of_ten);
+#endif // #if defined(DOUBLE_CONVERSION_CORRECT_DOUBLE_OPERATIONS)
 
 // Maximum number of significant digits in the decimal representation.
 // In fact the value is 772 (see conversions.cc), but to give us some margin

base/third_party/double_conversion/double-conversion/utils.h

@@ -64,6 +64,12 @@ inline void abort_noreturn() { abort(); }
 #endif
 #endif
 
+#if defined(__clang__) && __has_attribute(uninitialized)
+#define DOUBLE_CONVERSION_STACK_UNINITIALIZED __attribute__((uninitialized))
+#else
+#define DOUBLE_CONVERSION_STACK_UNINITIALIZED
+#endif
+
 // Double operations detection based on target architecture.
 // Linux uses a 80bit wide floating point stack on x86. This induces double
 // rounding, which in turn leads to wrong results.
@@ -94,15 +100,17 @@ int main(int argc, char** argv) {
     defined(__ARMEL__) || defined(__avr32__) || defined(_M_ARM) || defined(_M_ARM64) || \
     defined(__hppa__) || defined(__ia64__) || \
     defined(__mips__) || \
+    defined(__nios2__) || \
     defined(__powerpc__) || defined(__ppc__) || defined(__ppc64__) || \
     defined(_POWER) || defined(_ARCH_PPC) || defined(_ARCH_PPC64) || \
     defined(__sparc__) || defined(__sparc) || defined(__s390__) || \
     defined(__SH4__) || defined(__alpha__) || \
     defined(_MIPS_ARCH_MIPS32R2) || defined(__ARMEB__) ||\
     defined(__AARCH64EL__) || defined(__aarch64__) || defined(__AARCH64EB__) || \
-    defined(__riscv) || \
+    defined(__riscv) || defined(__e2k__) || \
     defined(__or1k__) || defined(__arc__) || \
-    defined(__EMSCRIPTEN__)
+    defined(__microblaze__) || defined(__XTENSA__) || \
+    defined(__EMSCRIPTEN__) || defined(__wasm32__)
 #define DOUBLE_CONVERSION_CORRECT_DOUBLE_OPERATIONS 1
 #elif defined(__mc68000__) || \
     defined(__pnacl__) || defined(__native_client__)