PPC: [turbofan] Fewer gap moves for tail calls

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

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/code-generator.h"
 
 #include "src/ast/scopes.h"
 #include "src/compiler/code-generator-impl.h"
 #include "src/compiler/gap-resolver.h"
 #include "src/compiler/node-matchers.h"
@@ skipping 592 matching lines @@
     __ bind(&done);                                           \
     DCHECK_EQ(LeaveRC, i.OutputRCBit());                      \
   } while (0)
 
 
 void CodeGenerator::AssembleDeconstructActivationRecord(int stack_param_delta) {
   int sp_slot_delta = TailCallFrameStackSlotDelta(stack_param_delta);
   if (sp_slot_delta > 0) {
     __ Add(sp, sp, sp_slot_delta * kPointerSize, r0);
   }
-  if (frame()->needs_frame()) {
-    if (FLAG_enable_embedded_constant_pool) {
-      __ Pop(r0, fp, kConstantPoolRegister);
-    } else {
-      __ Pop(r0, fp);
-    }
-    __ mtlr(r0);
-  }
   frame_access_state()->SetFrameAccessToDefault();
 }
 
 
 void CodeGenerator::AssemblePrepareTailCall(int stack_param_delta) {
   int sp_slot_delta = TailCallFrameStackSlotDelta(stack_param_delta);
   if (sp_slot_delta < 0) {
     __ Add(sp, sp, sp_slot_delta * kPointerSize, r0);
     frame_access_state()->IncreaseSPDelta(-sp_slot_delta);
   }
+  if (frame()->needs_frame()) {
+    if (FLAG_enable_embedded_constant_pool) {
+      __ LoadP(kConstantPoolRegister,
+               MemOperand(fp, StandardFrameConstants::kConstantPoolOffset));
+    }
+    __ LoadP(r0, MemOperand(fp, StandardFrameConstants::kCallerPCOffset));
+    __ LoadP(fp, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
+    __ mtlr(r0);
+  }
   frame_access_state()->SetFrameAccessToSP();
 }
 
 
 // Assembles an instruction after register allocation, producing machine code.
 void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
   PPCOperandConverter i(this, instr);
   ArchOpcode opcode = ArchOpcodeField::decode(instr->opcode());
 
   switch (opcode) {
@@ skipping 1128 matching lines @@
       padding_size -= v8::internal::Assembler::kInstrSize;
     }
   }
 }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8