diff options
Diffstat (limited to 'llvm/tools/llvm-exegesis/lib/Analysis.cpp')
| -rw-r--r-- | llvm/tools/llvm-exegesis/lib/Analysis.cpp | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/llvm/tools/llvm-exegesis/lib/Analysis.cpp b/llvm/tools/llvm-exegesis/lib/Analysis.cpp index 3d7bffd..0a91679 100644 --- a/llvm/tools/llvm-exegesis/lib/Analysis.cpp +++ b/llvm/tools/llvm-exegesis/lib/Analysis.cpp @@ -12,6 +12,7 @@ #include "llvm/ADT/STLExtras.h" #include "llvm/MC/MCAsmInfo.h" #include "llvm/Support/FormatVariadic.h" +#include <limits> #include <unordered_set> #include <vector> @@ -95,7 +96,21 @@ writeClusterId(llvm::raw_ostream &OS, template <EscapeTag Tag> static void writeMeasurementValue(llvm::raw_ostream &OS, const double Value) { - writeEscaped<Tag>(OS, llvm::formatv("{0:F}", Value).str()); + // Given Value, if we wanted to serialize it to a string, + // how many base-10 digits will we need to store, max? + static constexpr auto MaxDigitCount = + std::numeric_limits<decltype(Value)>::max_digits10; + // Also, we will need a decimal separator. + static constexpr auto DecimalSeparatorLen = 1; // '.' e.g. + // So how long of a string will the serialization produce, max? + static constexpr auto SerializationLen = MaxDigitCount + DecimalSeparatorLen; + + // WARNING: when changing the format, also adjust the small-size estimate ^. + static constexpr StringLiteral SimpleFloatFormat = StringLiteral("{0:F}"); + + writeEscaped<Tag>( + OS, + llvm::formatv(SimpleFloatFormat.data(), Value).sstr<SerializationLen>()); } template <typename EscapeTag, EscapeTag Tag> |