commit 96ba8dc82e7bd859106af837623fe8b2e9e772c3
author Sebastien Hertz <shertz@google.com> Thu Jan 22 18:57:14 2015 +0100
committer Sebastien Hertz <shertz@google.com> Mon Jan 26 16:45:38 2015 +0100
tree d7df58e8a9fb853621700d90ec4864129f6b3a0a
parent 081d27817608c2ea035f2473c4ea1062a79bccef

Refactor register access from StackVisitor

Moves register access checking up to StackVisitor by adding methods
IsAccessibleGPR and IsAccessibleFPR in Context class. It allows to
simplify GetGPR/FPR and SetGPR/FPR methods in the Context class (and
its subclasses).

Also simplifies code in StackVisitor by adding IsAccessibleRegister,
GetRegister and SetRegister methods which then call either GPR or FPR
specific methods in Context depending on the nature of the accessed
register.

Bug: 18547544
Bug: 19106446
Change-Id: I6e707608d935a71571d0e975a6e766053de3763a

runtime/arch/arm64/context_arm64.h

diff --git a/runtime/arch/arm64/context_arm64.h b/runtime/arch/arm64/context_arm64.h
index d9a433b..6a4485b 100644
--- a/runtime/arch/arm64/context_arm64.h
+++ b/runtime/arch/arm64/context_arm64.h
@@ -37,13 +37,16 @@
   void FillCalleeSaves(const StackVisitor& fr) OVERRIDE SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
   void SetSP(uintptr_t new_sp) OVERRIDE {
-    bool success = SetGPR(SP, new_sp);
-    CHECK(success) << "Failed to set SP register";
+    SetGPR(SP, new_sp);
   }
 
   void SetPC(uintptr_t new_lr) OVERRIDE {
-    bool success = SetGPR(LR, new_lr);
-    CHECK(success) << "Failed to set LR register";
+    SetGPR(LR, new_lr);
+  }
+
+  bool IsAccessibleGPR(uint32_t reg) OVERRIDE {
+    DCHECK_LT(reg, static_cast<uint32_t>(kNumberOfXRegisters));
+    return gprs_[reg] != nullptr;
   }
 
   uintptr_t* GetGPRAddress(uint32_t reg) OVERRIDE {
@@ -51,31 +54,26 @@
     return gprs_[reg];
   }
 
-  bool GetGPR(uint32_t reg, uintptr_t* val) OVERRIDE {
+  uintptr_t GetGPR(uint32_t reg) OVERRIDE {
     DCHECK_LT(reg, static_cast<uint32_t>(kNumberOfXRegisters));
-    if (gprs_[reg] == nullptr) {
-      return false;
-    } else {
-      DCHECK(val != nullptr);
-      *val = *gprs_[reg];
-      return true;
-    }
+    DCHECK(IsAccessibleGPR(reg));
+    return *gprs_[reg];
   }
 
-  bool SetGPR(uint32_t reg, uintptr_t value) OVERRIDE;
+  void SetGPR(uint32_t reg, uintptr_t value) OVERRIDE;
 
-  bool GetFPR(uint32_t reg, uintptr_t* val) OVERRIDE {
+  bool IsAccessibleFPR(uint32_t reg) OVERRIDE {
     DCHECK_LT(reg, static_cast<uint32_t>(kNumberOfDRegisters));
-    if (fprs_[reg] == nullptr) {
-      return false;
-    } else {
-      DCHECK(val != nullptr);
-      *val = *fprs_[reg];
-      return true;
-    }
+    return fprs_[reg] != nullptr;
   }
 
-  bool SetFPR(uint32_t reg, uintptr_t value) OVERRIDE;
+  uintptr_t GetFPR(uint32_t reg) OVERRIDE {
+    DCHECK_LT(reg, static_cast<uint32_t>(kNumberOfDRegisters));
+    DCHECK(IsAccessibleFPR(reg));
+    return *fprs_[reg];
+  }
+
+  void SetFPR(uint32_t reg, uintptr_t value) OVERRIDE;
 
   void SmashCallerSaves() OVERRIDE;
   void DoLongJump() OVERRIDE;