Revert "Revert "Introduce a NearLabel in thumb2.""

This reverts commit 1f277e3cef6c33cd35e91123978491d83338d2ad.

- Fix CompareAndBranch to not use cbz/cbnz with high registers.
- Add a test for CompareAndBranch with the *inc file, as the
  other assembler test infrastructure does not handle labels.

Change-Id: If552bf1112b96caa3b9bb6c73c4b40bb90a33db7

1 files changed, 16 insertions, 0 deletions

diff --git a/compiler/utils/arm/assembler_arm.h b/compiler/utils/arm/assembler_arm.h
index dee8287e67..52a69ca487 100644
--- a/compiler/utils/arm/assembler_arm.h
+++ b/compiler/utils/arm/assembler_arm.h
@@ -33,6 +33,16 @@ namespace arm {
 class Arm32Assembler;
 class Thumb2Assembler;
 
+// This class indicates that the label and its uses
+// will fall into a range that is encodable in 16bits on thumb2.
+class NearLabel : public Label {
+ public:
+  NearLabel() {}
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(NearLabel);
+};
+
 class ShifterOperand {
  public:
   ShifterOperand() : type_(kUnknown), rm_(kNoRegister), rs_(kNoRegister),
@@ -519,6 +529,9 @@ class ArmAssembler : public Assembler {
 
   // Branch instructions.
   virtual void b(Label* label, Condition cond = AL) = 0;
+  virtual void b(NearLabel* label, Condition cond = AL) {
+    b(static_cast<Label*>(label), cond);
+  }
   virtual void bl(Label* label, Condition cond = AL) = 0;
   virtual void blx(Register rm, Condition cond = AL) = 0;
   virtual void bx(Register rm, Condition cond = AL) = 0;
@@ -654,6 +667,9 @@ class ArmAssembler : public Assembler {
   virtual void Bind(Label* label) = 0;
 
   virtual void CompareAndBranchIfZero(Register r, Label* label) = 0;
+  virtual void CompareAndBranchIfZero(Register r, NearLabel* label) {
+    CompareAndBranchIfZero(r, static_cast<Label*>(label));
+  }
   virtual void CompareAndBranchIfNonZero(Register r, Label* label) = 0;
 
   //