commit 94ce9c2f41ea198f5fdcfc09c48b9984c95a9c61
author Vladimir Marko <vmarko@google.com> Fri Sep 30 14:50:51 2016 +0100
committer Vladimir Marko <vmarko@google.com> Wed Oct 19 18:02:48 2016 +0100
tree 8dcaf27e8b34f51f5849b1e8d4366968f9bae849
parent 2f61867045ffbd0c38a4ecec5f59632004f7efff

Change pResolveString entrypoint to kSaveEverything.

Test: Run ART test suite including gcstress on host and Nexus 9.
Test: Run ART test suite including gcstress with baker CC on host and Nexus 9.
Bug: 20323084
Change-Id: I63c21a7d3be8ff7a5765b5003c85b5317635efe6

compiler/optimizing/code_generator_x86_64.cc

diff --git a/compiler/optimizing/code_generator_x86_64.cc b/compiler/optimizing/code_generator_x86_64.cc
index 28638d7..6518c32 100644
--- a/compiler/optimizing/code_generator_x86_64.cc
+++ b/compiler/optimizing/code_generator_x86_64.cc
@@ -299,9 +299,9 @@
     __ Bind(GetEntryLabel());
     SaveLiveRegisters(codegen, locations);
 
-    InvokeRuntimeCallingConvention calling_convention;
     const uint32_t string_index = instruction_->AsLoadString()->GetStringIndex();
-    __ movl(CpuRegister(calling_convention.GetRegisterAt(0)), Immediate(string_index));
+    // Custom calling convention: RAX serves as both input and output.
+    __ movl(CpuRegister(RAX), Immediate(string_index));
     x86_64_codegen->InvokeRuntime(kQuickResolveString,
                                   instruction_,
                                   instruction_->GetDexPc(),
@@ -5450,10 +5450,20 @@
       : LocationSummary::kNoCall;
   LocationSummary* locations = new (GetGraph()->GetArena()) LocationSummary(load, call_kind);
   if (load->GetLoadKind() == HLoadString::LoadKind::kDexCacheViaMethod) {
-    locations->SetInAt(0, Location::RequiresRegister());
     locations->SetOut(Location::RegisterLocation(RAX));
   } else {
     locations->SetOut(Location::RequiresRegister());
+    if (load->GetLoadKind() == HLoadString::LoadKind::kBssEntry) {
+      if (!kUseReadBarrier || kUseBakerReadBarrier) {
+        // Rely on the pResolveString and/or marking to save everything.
+        // Custom calling convention: RAX serves as both input and output.
+        RegisterSet caller_saves = RegisterSet::Empty();
+        caller_saves.Add(Location::RegisterLocation(RAX));
+        locations->SetCustomSlowPathCallerSaves(caller_saves);
+      } else {
+        // For non-Baker read barrier we have a temp-clobbering call.
+      }
+    }
   }
 }
 
@@ -5493,9 +5503,8 @@
   }
 
   // TODO: Re-add the compiler code to do string dex cache lookup again.
-  InvokeRuntimeCallingConvention calling_convention;
-  __ movl(CpuRegister(calling_convention.GetRegisterAt(0)),
-          Immediate(load->GetStringIndex()));
+  // Custom calling convention: RAX serves as both input and output.
+  __ movl(CpuRegister(RAX), Immediate(load->GetStringIndex()));
   codegen_->InvokeRuntime(kQuickResolveString,
                           load,
                           load->GetDexPc());