PPC: use pc-relative address to init constpool reg

R=joransiu@ca.ibm.com

Change-Id: I67364f29d494b09786a14b13743f73bef4b64582
Reviewed-on: https://chromium-review.googlesource.com/950242
Commit-Queue: Junliang Yan <jyan@ca.ibm.com>
Reviewed-by: Joran Siu <joransiu@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#51750}

src/ppc/macro-assembler-ppc.cc

@@ -168,7 +168,7 @@ void TurboAssembler::Call(Register target) {
 }
 
 void MacroAssembler::CallJSEntry(Register target) {
-  DCHECK(target == ip);
+  CHECK(target == r5);
   Call(target);
 }
 
@@ -825,7 +825,7 @@ void TurboAssembler::ShiftRightAlgPair(Register dst_low, Register dst_high,
 }
 #endif
 
-void MacroAssembler::LoadConstantPoolPointerRegisterFromCodeTargetAddress(
+void TurboAssembler::LoadConstantPoolPointerRegisterFromCodeTargetAddress(
     Register code_target_address) {
   lwz(kConstantPoolRegister,
       MemOperand(code_target_address,
@@ -833,8 +833,15 @@ void MacroAssembler::LoadConstantPoolPointerRegisterFromCodeTargetAddress(
   add(kConstantPoolRegister, kConstantPoolRegister, code_target_address);
 }
 
+void TurboAssembler::LoadPC(Register dst) {
+  b(4, SetLK);
+  mflr(dst);
+}
+
 void TurboAssembler::LoadConstantPoolPointerRegister() {
-  mov_label_addr(kConstantPoolRegister, ConstantPoolPosition());
+  LoadPC(kConstantPoolRegister);
+  add_label_offset(kConstantPoolRegister, kConstantPoolRegister,
+                   ConstantPoolPosition(), -pc_offset() + 4);
 }
 
 void TurboAssembler::StubPrologue(StackFrame::Type type) {
@@ -850,7 +857,6 @@ void TurboAssembler::StubPrologue(StackFrame::Type type) {
 }
 
 void TurboAssembler::Prologue() {
-  DCHECK(base != no_reg);
   PushStandardFrame(r4);
   if (FLAG_enable_embedded_constant_pool) {
     // base contains prologue address

src/ppc/macro-assembler-ppc.h

@@ -216,6 +216,7 @@ class TurboAssembler : public Assembler {
                   Register scratch = no_reg);
   void LoadSingleU(DoubleRegister dst, const MemOperand& mem,
                    Register scratch = no_reg);
+  void LoadPC(Register dst);
 
   void StoreDouble(DoubleRegister src, const MemOperand& mem,
                    Register scratch = no_reg);
@@ -641,6 +642,10 @@ class TurboAssembler : public Assembler {
   void CallStubDelayed(CodeStub* stub);
 
   void LoadConstantPoolPointerRegister();
+
+  // Loads the constant pool pointer (kConstantPoolRegister).
+  void LoadConstantPoolPointerRegisterFromCodeTargetAddress(
+      Register code_target_address);
   void AbortConstantPoolBuilding() {
 #ifdef DEBUG
     // Avoid DCHECK(!is_linked()) failure in ~Label()
@@ -735,10 +740,6 @@ class MacroAssembler : public TurboAssembler {
   void PushSafepointRegisters();
   void PopSafepointRegisters();
 
-  // Loads the constant pool pointer (kConstantPoolRegister).
-  void LoadConstantPoolPointerRegisterFromCodeTargetAddress(
-      Register code_target_address);
-
   // Flush the I-cache from asm code. You should use CpuFeatures::FlushICache
   // from C.
   // Does not handle errors.