commit 44b819e8d2ac48f1f66915ec1fab36ad247eb4d9
author Nicolas Geoffray <ngeoffray@google.com> Thu Nov 06 12:00:54 2014 +0000
committer Nicolas Geoffray <ngeoffray@google.com> Thu Nov 06 12:14:21 2014 +0000
tree 40710d90f3ae82e14e6acb376f6a0d78069c97be
parent 508368cc013f146b4348793d72d66d4f0e96f07c

Don't use R4 for suspend check.

Change-Id: I57ccfaa527e2676f21339860b28955468a87adfe

compiler/optimizing/code_generator_arm.cc

diff --git a/compiler/optimizing/code_generator_arm.cc b/compiler/optimizing/code_generator_arm.cc
index 39e564a..fe8a96f 100644
--- a/compiler/optimizing/code_generator_arm.cc
+++ b/compiler/optimizing/code_generator_arm.cc
@@ -373,9 +373,6 @@
   blocked_core_registers_[LR] = true;
   blocked_core_registers_[PC] = true;
 
-  // Reserve R4 for suspend check.
-  blocked_core_registers_[R4] = true;
-
   // Reserve thread register.
   blocked_core_registers_[TR] = true;
 
@@ -385,6 +382,7 @@
   // TODO: We currently don't use Quick's callee saved registers.
   // We always save and restore R6 and R7 to make sure we can use three
   // register pairs for long operations.
+  blocked_core_registers_[R4] = true;
   blocked_core_registers_[R5] = true;
   blocked_core_registers_[R8] = true;
   blocked_core_registers_[R10] = true;
@@ -2157,12 +2155,15 @@
       new (GetGraph()->GetArena()) SuspendCheckSlowPathARM(instruction, successor);
   codegen_->AddSlowPath(slow_path);
 
-  __ subs(R4, R4, ShifterOperand(1));
+  __ LoadFromOffset(
+      kLoadUnsignedHalfword, IP, TR, Thread::ThreadFlagsOffset<kArmWordSize>().Int32Value());
+  __ cmp(IP, ShifterOperand(0));
+  // TODO: Figure out the branch offsets and use cbz/cbnz.
   if (successor == nullptr) {
-    __ b(slow_path->GetEntryLabel(), EQ);
+    __ b(slow_path->GetEntryLabel(), NE);
     __ Bind(slow_path->GetReturnLabel());
   } else {
-    __ b(codegen_->GetLabelOf(successor), NE);
+    __ b(codegen_->GetLabelOf(successor), EQ);
     __ b(slow_path->GetEntryLabel());
   }
 }