diff options
Diffstat (limited to 'debian/patches/ppc-float-conversion.diff')
| -rw-r--r-- | debian/patches/ppc-float-conversion.diff | 268 |
1 files changed, 0 insertions, 268 deletions
diff --git a/debian/patches/ppc-float-conversion.diff b/debian/patches/ppc-float-conversion.diff deleted file mode 100644 index f0ff9595..00000000 --- a/debian/patches/ppc-float-conversion.diff +++ /dev/null @@ -1,268 +0,0 @@ -From: Samuel Benzaquen <sbenza@google.com> -Subject: Fix float conversion for PPC. -Origin: backport, https://github.com/abseil/abseil-cpp/commit/c36d825d9a5443f81d2656685ae021d6326da90c - -In PPC `long double` is a double-double representation which behaves weirdly -wrt numeric_limits. Don't take `long double` into account when we are not -handling `long double` natively anyway. - -Fix the convert test to always run the conversion even if we are not going to -compare against libc's printf result. This allows exercising the code itself to -make sure we don't trigger assertions or UB found by sanitizers. - -The author works at Google. Upstream applied this patch as Piper revision -355857729 and exported it to GitHub; the Applied-Upstream URL above points to -the exported commit. - ---- a/absl/strings/internal/str_format/convert_test.cc -+++ b/absl/strings/internal/str_format/convert_test.cc -@@ -540,7 +540,8 @@ - } - - template <typename Floating> --void TestWithMultipleFormatsHelper(const std::vector<Floating> &floats) { -+void TestWithMultipleFormatsHelper(const std::vector<Floating> &floats, -+ const std::set<Floating> &skip_verify) { - const NativePrintfTraits &native_traits = VerifyNativeImplementation(); - // Reserve the space to ensure we don't allocate memory in the output itself. - std::string str_format_result; -@@ -588,7 +589,16 @@ - AppendPack(&str_format_result, format, absl::MakeSpan(args)); - } - -- if (string_printf_result != str_format_result) { -+#ifdef _MSC_VER -+ // MSVC has a different rounding policy than us so we can't test our -+ // implementation against the native one there. -+ continue; -+#elif defined(__APPLE__) -+ // Apple formats NaN differently (+nan) vs. (nan) -+ if (std::isnan(d)) continue; -+#endif -+ if (string_printf_result != str_format_result && -+ skip_verify.find(d) == skip_verify.end()) { - // We use ASSERT_EQ here because failures are usually correlated and a - // bug would print way too many failed expectations causing the test - // to time out. -@@ -602,12 +612,6 @@ - } - - TEST_F(FormatConvertTest, Float) { --#ifdef _MSC_VER -- // MSVC has a different rounding policy than us so we can't test our -- // implementation against the native one there. -- return; --#endif // _MSC_VER -- - std::vector<float> floats = {0.0f, - -0.0f, - .9999999f, -@@ -621,7 +625,8 @@ - std::numeric_limits<float>::epsilon(), - std::numeric_limits<float>::epsilon() + 1.0f, - std::numeric_limits<float>::infinity(), -- -std::numeric_limits<float>::infinity()}; -+ -std::numeric_limits<float>::infinity(), -+ std::nanf("")}; - - // Some regression tests. - floats.push_back(0.999999989f); -@@ -650,21 +655,14 @@ - std::sort(floats.begin(), floats.end()); - floats.erase(std::unique(floats.begin(), floats.end()), floats.end()); - --#ifndef __APPLE__ -- // Apple formats NaN differently (+nan) vs. (nan) -- floats.push_back(std::nan("")); --#endif -- -- TestWithMultipleFormatsHelper(floats); -+ TestWithMultipleFormatsHelper(floats, {}); - } - - TEST_F(FormatConvertTest, Double) { --#ifdef _MSC_VER -- // MSVC has a different rounding policy than us so we can't test our -- // implementation against the native one there. -- return; --#endif // _MSC_VER -- -+ // For values that we know won't match the standard library implementation we -+ // skip verification, but still run the algorithm to catch asserts/sanitizer -+ // bugs. -+ std::set<double> skip_verify; - std::vector<double> doubles = {0.0, - -0.0, - .99999999999999, -@@ -678,7 +676,8 @@ - std::numeric_limits<double>::epsilon(), - std::numeric_limits<double>::epsilon() + 1, - std::numeric_limits<double>::infinity(), -- -std::numeric_limits<double>::infinity()}; -+ -std::numeric_limits<double>::infinity(), -+ std::nan("")}; - - // Some regression tests. - doubles.push_back(0.99999999999999989); -@@ -708,33 +707,29 @@ - "5084551339423045832369032229481658085593321233482747978262041447231" - "68738177180919299881250404026184124858368.000000"; - -- if (!gcc_bug_22142) { -- for (int exp = -300; exp <= 300; ++exp) { -- const double all_ones_mantissa = 0x1fffffffffffff; -- doubles.push_back(std::ldexp(all_ones_mantissa, exp)); -+ for (int exp = -300; exp <= 300; ++exp) { -+ const double all_ones_mantissa = 0x1fffffffffffff; -+ doubles.push_back(std::ldexp(all_ones_mantissa, exp)); -+ if (gcc_bug_22142) { -+ skip_verify.insert(doubles.back()); - } - } - - if (gcc_bug_22142) { -- for (auto &d : doubles) { -- using L = std::numeric_limits<double>; -- double d2 = std::abs(d); -- if (d2 == L::max() || d2 == L::min() || d2 == L::denorm_min()) { -- d = 0; -- } -- } -+ using L = std::numeric_limits<double>; -+ skip_verify.insert(L::max()); -+ skip_verify.insert(L::min()); // NOLINT -+ skip_verify.insert(L::denorm_min()); -+ skip_verify.insert(-L::max()); -+ skip_verify.insert(-L::min()); // NOLINT -+ skip_verify.insert(-L::denorm_min()); - } - - // Remove duplicates to speed up the logic below. - std::sort(doubles.begin(), doubles.end()); - doubles.erase(std::unique(doubles.begin(), doubles.end()), doubles.end()); - --#ifndef __APPLE__ -- // Apple formats NaN differently (+nan) vs. (nan) -- doubles.push_back(std::nan("")); --#endif -- -- TestWithMultipleFormatsHelper(doubles); -+ TestWithMultipleFormatsHelper(doubles, skip_verify); - } - - TEST_F(FormatConvertTest, DoubleRound) { -@@ -1055,11 +1050,6 @@ - } - - TEST_F(FormatConvertTest, LongDouble) { --#ifdef _MSC_VER -- // MSVC has a different rounding policy than us so we can't test our -- // implementation against the native one there. -- return; --#endif // _MSC_VER - const NativePrintfTraits &native_traits = VerifyNativeImplementation(); - const char *const kFormats[] = {"%", "%.3", "%8.5", "%9", "%.5000", - "%.60", "%+", "% ", "%-10"}; -@@ -1120,10 +1110,18 @@ - for (auto d : doubles) { - FormatArgImpl arg(d); - UntypedFormatSpecImpl format(fmt_str); -+ std::string result = FormatPack(format, {&arg, 1}); -+ -+#ifdef _MSC_VER -+ // MSVC has a different rounding policy than us so we can't test our -+ // implementation against the native one there. -+ continue; -+#endif // _MSC_VER -+ - // We use ASSERT_EQ here because failures are usually correlated and a - // bug would print way too many failed expectations causing the test to - // time out. -- ASSERT_EQ(StrPrint(fmt_str.c_str(), d), FormatPack(format, {&arg, 1})) -+ ASSERT_EQ(StrPrint(fmt_str.c_str(), d), result) - << fmt_str << " " << StrPrint("%.18Lg", d) << " " - << StrPrint("%La", d) << " " << StrPrint("%.1080Lf", d); - } ---- a/absl/strings/internal/str_format/float_conversion.cc -+++ b/absl/strings/internal/str_format/float_conversion.cc -@@ -98,12 +98,22 @@ - return next_carry % divisor; - } - -+constexpr bool IsDoubleDouble() { -+ // This is the `double-double` representation of `long double`. -+ // We do not handle it natively. Fallback to snprintf. -+ return std::numeric_limits<long double>::digits == -+ 2 * std::numeric_limits<double>::digits; -+} -+ -+using MaxFloatType = -+ typename std::conditional<IsDoubleDouble(), double, long double>::type; -+ - // Generates the decimal representation for an integer of the form `v * 2^exp`, - // where `v` and `exp` are both positive integers. - // It generates the digits from the left (ie the most significant digit first) - // to allow for direct printing into the sink. - // --// Requires `0 <= exp` and `exp <= numeric_limits<long double>::max_exponent`. -+// Requires `0 <= exp` and `exp <= numeric_limits<MaxFloatType>::max_exponent`. - class BinaryToDecimal { - static constexpr int ChunksNeeded(int exp) { - // We will left shift a uint128 by `exp` bits, so we need `128+exp` total -@@ -118,10 +128,10 @@ - static void RunConversion(uint128 v, int exp, - absl::FunctionRef<void(BinaryToDecimal)> f) { - assert(exp > 0); -- assert(exp <= std::numeric_limits<long double>::max_exponent); -+ assert(exp <= std::numeric_limits<MaxFloatType>::max_exponent); - static_assert( - StackArray::kMaxCapacity >= -- ChunksNeeded(std::numeric_limits<long double>::max_exponent), -+ ChunksNeeded(std::numeric_limits<MaxFloatType>::max_exponent), - ""); - - StackArray::RunWithCapacity( -@@ -218,14 +228,14 @@ - - // Converts a value of the form `x * 2^-exp` into a sequence of decimal digits. - // Requires `-exp < 0` and --// `-exp >= limits<long double>::min_exponent - limits<long double>::digits`. -+// `-exp >= limits<MaxFloatType>::min_exponent - limits<MaxFloatType>::digits`. - class FractionalDigitGenerator { - public: - // Run the conversion for `v * 2^exp` and call `f(generator)`. - // This function will allocate enough stack space to perform the conversion. - static void RunConversion( - uint128 v, int exp, absl::FunctionRef<void(FractionalDigitGenerator)> f) { -- using Limits = std::numeric_limits<long double>; -+ using Limits = std::numeric_limits<MaxFloatType>; - assert(-exp < 0); - assert(-exp >= Limits::min_exponent - 128); - static_assert(StackArray::kMaxCapacity >= -@@ -858,10 +868,10 @@ - // This buffer holds the "0x1.ab1de3" portion of "0x1.ab1de3pe+2". Compute the - // size with long double which is the largest of the floats. - constexpr size_t kBufSizeForHexFloatRepr = -- 2 // 0x -- + std::numeric_limits<long double>::digits / 4 // number of hex digits -- + 1 // round up -- + 1; // "." (dot) -+ 2 // 0x -+ + std::numeric_limits<MaxFloatType>::digits / 4 // number of hex digits -+ + 1 // round up -+ + 1; // "." (dot) - char digits_buffer[kBufSizeForHexFloatRepr]; - char *digits_iter = digits_buffer; - const char *const digits = -@@ -1380,10 +1390,7 @@ - - bool ConvertFloatImpl(long double v, const FormatConversionSpecImpl &conv, - FormatSinkImpl *sink) { -- if (std::numeric_limits<long double>::digits == -- 2 * std::numeric_limits<double>::digits) { -- // This is the `double-double` representation of `long double`. -- // We do not handle it natively. Fallback to snprintf. -+ if (IsDoubleDouble()) { - return FallbackToSnprintf(v, conv, sink); - } - |