PPC: Make base register containing prologue address explicit.

No functional change.  This is prep for fixing test failures in wasm tests.

R=joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=

Review URL: https://codereview.chromium.org/1583523002

Cr-Commit-Position: refs/heads/master@{#33248}

src/compiler/ppc/code-generator-ppc.cc

@@ -1543,9 +1543,9 @@ void CodeGenerator::AssemblePrologue() {
       __ mr(fp, sp);
     }
   } else if (descriptor->IsJSFunctionCall()) {
-    __ Prologue(this->info()->GeneratePreagedPrologue());
+    __ Prologue(this->info()->GeneratePreagedPrologue(), ip);
   } else if (frame()->needs_frame()) {
-    __ StubPrologue();
+    __ StubPrologue(ip);
   } else {
     frame()->SetElidedFrameSizeInSlots(0);
   }

src/crankshaft/ppc/lithium-codegen-ppc.cc

@@ -130,9 +130,9 @@ bool LCodeGen::GeneratePrologue() {
   info()->set_prologue_offset(prologue_offset);
   if (NeedsEagerFrame()) {
     if (info()->IsStub()) {
-      __ StubPrologue(prologue_offset);
+      __ StubPrologue(ip, prologue_offset);
     } else {
-      __ Prologue(info()->GeneratePreagedPrologue(), prologue_offset);
+      __ Prologue(info()->GeneratePreagedPrologue(), ip, prologue_offset);
     }
     frame_is_built_ = true;
   }

src/full-codegen/ppc/full-codegen-ppc.cc

@@ -135,7 +135,7 @@ void FullCodeGenerator::Generate() {
     __ addi(ip, ip, Operand(prologue_offset));
   }
   info->set_prologue_offset(prologue_offset);
-  __ Prologue(info->GeneratePreagedPrologue(), prologue_offset);
+  __ Prologue(info->GeneratePreagedPrologue(), ip, prologue_offset);
 
   {
     Comment cmnt(masm_, "[ Allocate locals");

src/ppc/macro-assembler-ppc.cc

@@ -753,20 +753,26 @@ void MacroAssembler::LoadConstantPoolPointerRegister() {
 }
 
 
-void MacroAssembler::StubPrologue(int prologue_offset) {
+void MacroAssembler::StubPrologue(Register base, int prologue_offset) {
   LoadSmiLiteral(r11, Smi::FromInt(StackFrame::STUB));
   PushFixedFrame(r11);
   // Adjust FP to point to saved FP.
   addi(fp, sp, Operand(StandardFrameConstants::kFixedFrameSizeFromFp));
   if (FLAG_enable_embedded_constant_pool) {
-    // ip contains prologue address
-    LoadConstantPoolPointerRegister(ip, -prologue_offset);
+    if (!base.is(no_reg)) {
+      // base contains prologue address
+      LoadConstantPoolPointerRegister(base, -prologue_offset);
+    } else {
+      LoadConstantPoolPointerRegister();
+    }
     set_constant_pool_available(true);
   }
 }
 
 
-void MacroAssembler::Prologue(bool code_pre_aging, int prologue_offset) {
+void MacroAssembler::Prologue(bool code_pre_aging, Register base,
+                              int prologue_offset) {
+  DCHECK(!base.is(no_reg));
   {
     PredictableCodeSizeScope predictible_code_size_scope(
         this, kNoCodeAgeSequenceLength);
@@ -796,8 +802,8 @@ void MacroAssembler::Prologue(bool code_pre_aging, int prologue_offset) {
     }
   }
   if (FLAG_enable_embedded_constant_pool) {
-    // ip contains prologue address
-    LoadConstantPoolPointerRegister(ip, -prologue_offset);
+    // base contains prologue address
+    LoadConstantPoolPointerRegister(base, -prologue_offset);
     set_constant_pool_available(true);
   }
 }

src/ppc/macro-assembler-ppc.h

@@ -403,8 +403,8 @@ class MacroAssembler : public Assembler {
 #endif
 
   // Generates function and stub prologue code.
-  void StubPrologue(int prologue_offset = 0);
-  void Prologue(bool code_pre_aging, int prologue_offset = 0);
+  void StubPrologue(Register base = no_reg, int prologue_offset = 0);
+  void Prologue(bool code_pre_aging, Register base, int prologue_offset = 0);
 
   // Enter exit frame.
   // stack_space - extra stack space, used for parameters before call to C.