[llvm-exegesis][NFC] Improve parsing of the YAML files
Summary: sscanf turns out to be slow for reading floating points.
Reviewers: courbet
Subscribers: tschuett, llvm-commits, RKSimon
Differential Revision: https://reviews.llvm.org/D52866
llvm-svn: 343771
diff --git a/llvm/tools/llvm-exegesis/lib/BenchmarkResult.cpp b/llvm/tools/llvm-exegesis/lib/BenchmarkResult.cpp
index c61d869..5d4912e 100644
--- a/llvm/tools/llvm-exegesis/lib/BenchmarkResult.cpp
+++ b/llvm/tools/llvm-exegesis/lib/BenchmarkResult.cpp
@@ -10,6 +10,7 @@
#include "BenchmarkResult.h"
#include "BenchmarkRunner.h"
#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/bit.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ObjectYAML/YAML.h"
#include "llvm/Support/FileOutputBuffer.h"
@@ -17,8 +18,8 @@
#include "llvm/Support/Format.h"
#include "llvm/Support/raw_ostream.h"
-static constexpr const char kIntegerFormat[] = "i_0x%" PRId64 "x";
-static constexpr const char kDoubleFormat[] = "f_%la";
+static constexpr const char kIntegerPrefix[] = "i_0x";
+static constexpr const char kDoublePrefix[] = "f_";
static constexpr const char kInvalidOperand[] = "INVALID";
// A mutable struct holding an LLVMState that can be passed through the
@@ -73,14 +74,37 @@
}
private:
+ void serializeIntegerOperand(llvm::raw_ostream &OS, int64_t Value) {
+ OS << kIntegerPrefix;
+ OS.write_hex(llvm::bit_cast<uint64_t>(Value));
+ }
+
+ bool tryDeserializeIntegerOperand(llvm::StringRef String, int64_t &Value) {
+ if (!String.consume_front(kIntegerPrefix))
+ return false;
+ return !String.consumeInteger(16, Value);
+ }
+
+ void serializeFPOperand(llvm::raw_ostream &OS, double Value) {
+ OS << kDoublePrefix << llvm::format("%la", Value);
+ }
+
+ bool tryDeserializeFPOperand(llvm::StringRef String, double &Value) {
+ if (!String.consume_front(kDoublePrefix))
+ return false;
+ char *EndPointer = nullptr;
+ Value = strtod(String.begin(), &EndPointer);
+ return EndPointer == String.end();
+ }
+
void serializeMCOperand(const llvm::MCOperand &MCOperand,
llvm::raw_ostream &OS) {
if (MCOperand.isReg()) {
OS << getRegName(MCOperand.getReg());
} else if (MCOperand.isImm()) {
- OS << llvm::format(kIntegerFormat, MCOperand.getImm());
+ serializeIntegerOperand(OS, MCOperand.getImm());
} else if (MCOperand.isFPImm()) {
- OS << llvm::format(kDoubleFormat, MCOperand.getFPImm());
+ serializeFPOperand(OS, MCOperand.getFPImm());
} else {
OS << kInvalidOperand;
}
@@ -90,11 +114,9 @@
assert(!String.empty());
int64_t IntValue = 0;
double DoubleValue = 0;
- if (String[0] == kIntegerFormat[0] &&
- sscanf(String.data(), kIntegerFormat, &IntValue) == 1)
+ if (tryDeserializeIntegerOperand(String, IntValue))
return llvm::MCOperand::createImm(IntValue);
- if (String[0] == kDoubleFormat[0] &&
- sscanf(String.data(), kDoubleFormat, &DoubleValue) == 1)
+ if (tryDeserializeFPOperand(String, DoubleValue))
return llvm::MCOperand::createFPImm(DoubleValue);
if (unsigned RegNo = getRegNo(String))
return llvm::MCOperand::createReg(RegNo);