Introduce Signature type to avoid string comparisons.

Method resolution currently creates strings to then compare with strings formed
from methods in other dex files. The temporary strings are purely created for
the sake of comparisons. This change creates a new Signature type that
represents a method signature but not as a string. This type supports
comparisons and so can be used when searching for methods in resolution.

With this change malloc is no longer the hottest method during dex2oat (now its
memset) and allocations during verification have been reduced. The verifier is
commonly what is populating the dex cache for methods and fields not declared
in the dex file itself.

Change-Id: I5ef0542823fbcae868aaa4a2457e8da7df0e9dae

1 files changed, 6 insertions, 6 deletions

diff --git a/compiler/dex/quick/codegen_util.cc b/compiler/dex/quick/codegen_util.cc
index 4ce752fb39..6e49f0bc54 100644
--- a/compiler/dex/quick/codegen_util.cc
+++ b/compiler/dex/quick/codegen_util.cc
@@ -248,12 +248,12 @@ void Mir2Lir::DumpPromotionMap() {
 }
 
 /* Dump a mapping table */
-void Mir2Lir::DumpMappingTable(const char* table_name, const std::string& descriptor,
-                               const std::string& name, const std::string& signature,
+void Mir2Lir::DumpMappingTable(const char* table_name, const char* descriptor,
+                               const char* name, const Signature& signature,
                                const std::vector<uint32_t>& v) {
   if (v.size() > 0) {
     std::string line(StringPrintf("\n  %s %s%s_%s_table[%zu] = {", table_name,
-                     descriptor.c_str(), name.c_str(), signature.c_str(), v.size()));
+                     descriptor, name, signature.ToString().c_str(), v.size()));
     std::replace(line.begin(), line.end(), ';', '_');
     LOG(INFO) << line;
     for (uint32_t i = 0; i < v.size(); i+=2) {
@@ -293,9 +293,9 @@ void Mir2Lir::CodegenDump() {
 
   const DexFile::MethodId& method_id =
       cu_->dex_file->GetMethodId(cu_->method_idx);
-  std::string signature(cu_->dex_file->GetMethodSignature(method_id));
-  std::string name(cu_->dex_file->GetMethodName(method_id));
-  std::string descriptor(cu_->dex_file->GetMethodDeclaringClassDescriptor(method_id));
+  const Signature signature = cu_->dex_file->GetMethodSignature(method_id);
+  const char* name = cu_->dex_file->GetMethodName(method_id);
+  const char* descriptor(cu_->dex_file->GetMethodDeclaringClassDescriptor(method_id));
 
   // Dump mapping tables
   DumpMappingTable("PC2Dex_MappingTable", descriptor, name, signature, pc2dex_mapping_table_);