PPC/s390: [turbofan] Implement constant folding of string concatenations

Port fef047a4

Original Commit Message:

    This CL implements the following design doc:
    https://docs.google.com/document/d/1h5kdfemMQMpUd15PSKW1lqikJW5hsGwrmOvoqhGFRts/edit?ts=5b978756#heading=h.urs7r34mx9p

R=mslekova@chromium.org, joransiu@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=
LOG=N

Change-Id: Iac369feb7a0bfb1d878a3c0fb4a6efbee6371128
Reviewed-on: https://chromium-review.googlesource.com/1234973Reviewed-by: Joran Siu <joransiu@ca.ibm.com>
Commit-Queue: Junliang Yan <jyan@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#56054}

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

@@ -74,6 +74,9 @@ class PPCOperandConverter final : public InstructionOperandConverter {
         return Operand(constant.ToInt64());
 #endif
       case Constant::kExternalReference:
+      case Constant::kDelayedStringConstant:
+        return Operand::EmbeddedStringConstant(
+            constant.ToDelayedStringConstant());
       case Constant::kHeapObject:
       case Constant::kRpoNumber:
         break;
@@ -2564,6 +2567,10 @@ void CodeGenerator::AssembleMove(InstructionOperand* source,
         case Constant::kExternalReference:
           __ Move(dst, src.ToExternalReference());
           break;
+        case Constant::kDelayedStringConstant:
+          __ mov(dst, Operand::EmbeddedStringConstant(
+                          src.ToDelayedStringConstant()));
+          break;
         case Constant::kHeapObject: {
           Handle<HeapObject> src_object = src.ToHeapObject();
           Heap::RootListIndex index;

src/compiler/s390/code-generator-s390.cc

@@ -67,6 +67,9 @@ class S390OperandConverter final : public InstructionOperandConverter {
         return Operand(constant.ToInt64());
 #endif
       case Constant::kExternalReference:
+      case Constant::kDelayedStringConstant:
+        return Operand::EmbeddedStringConstant(
+            constant.ToDelayedStringConstant());
       case Constant::kHeapObject:
       case Constant::kRpoNumber:
         break;
@@ -3170,6 +3173,10 @@ void CodeGenerator::AssembleMove(InstructionOperand* source,
         case Constant::kExternalReference:
           __ Move(dst, src.ToExternalReference());
           break;
+        case Constant::kDelayedStringConstant:
+          __ mov(dst, Operand::EmbeddedStringConstant(
+                          src.ToDelayedStringConstant()));
+          break;
         case Constant::kHeapObject: {
           Handle<HeapObject> src_object = src.ToHeapObject();
           Heap::RootListIndex index;

src/ppc/assembler-ppc.cc

@@ -44,6 +44,7 @@
 #include "src/deoptimizer.h"
 #include "src/macro-assembler.h"
 #include "src/ppc/assembler-ppc-inl.h"
+#include "src/string-constants.h"
 
 namespace v8 {
 namespace internal {
@@ -211,6 +212,13 @@ Operand Operand::EmbeddedCode(CodeStub* stub) {
   return result;
 }
 
+Operand Operand::EmbeddedStringConstant(const StringConstantBase* str) {
+  Operand result(0, RelocInfo::EMBEDDED_OBJECT);
+  result.is_heap_object_request_ = true;
+  result.value_.heap_object_request = HeapObjectRequest(str);
+  return result;
+}
+
 MemOperand::MemOperand(Register rn, int32_t offset)
     : ra_(rn), offset_(offset), rb_(no_reg) {}
 
@@ -222,19 +230,26 @@ void Assembler::AllocateAndInstallRequestedHeapObjects(Isolate* isolate) {
   for (auto& request : heap_object_requests_) {
     Handle<HeapObject> object;
     switch (request.kind()) {
-      case HeapObjectRequest::kHeapNumber:
+      case HeapObjectRequest::kHeapNumber: {
         object =
             isolate->factory()->NewHeapNumber(request.heap_number(), TENURED);
         break;
-      case HeapObjectRequest::kCodeStub:
+      }
+      case HeapObjectRequest::kCodeStub: {
         request.code_stub()->set_isolate(isolate);
         object = request.code_stub()->GetCode();
         break;
+      }
+      case HeapObjectRequest::kStringConstant: {
+        const StringConstantBase* str = request.string();
+        CHECK_NOT_NULL(str);
+        object = str->AllocateStringConstant(isolate);
+        break;
+      }
     }
     Address pc = reinterpret_cast<Address>(buffer_) + request.offset();
     Address constant_pool = kNullAddress;
-    set_target_address_at(pc, constant_pool,
-                          reinterpret_cast<Address>(object.location()),
+    set_target_address_at(pc, constant_pool, object.address(),
                           SKIP_ICACHE_FLUSH);
   }
 }

src/ppc/assembler-ppc.h

@@ -394,6 +394,7 @@ class Operand {
   V8_INLINE explicit Operand(Register rm);
 
   static Operand EmbeddedNumber(double number);  // Smi or HeapNumber.
+  static Operand EmbeddedStringConstant(const StringConstantBase* str);
   static Operand EmbeddedCode(CodeStub* stub);
 
   // Return true if this is a register operand.

src/s390/assembler-s390.cc

@@ -51,6 +51,7 @@
 #include "src/deoptimizer.h"
 #include "src/macro-assembler.h"
 #include "src/s390/assembler-s390-inl.h"
+#include "src/string-constants.h"
 
 namespace v8 {
 namespace internal {
@@ -316,6 +317,13 @@ Operand Operand::EmbeddedNumber(double value) {
   return result;
 }
 
+Operand Operand::EmbeddedStringConstant(const StringConstantBase* str) {
+  Operand result(0, RelocInfo::EMBEDDED_OBJECT);
+  result.is_heap_object_request_ = true;
+  result.value_.heap_object_request = HeapObjectRequest(str);
+  return result;
+}
+
 MemOperand::MemOperand(Register rn, int32_t offset)
     : baseRegister(rn), indexRegister(r0), offset_(offset) {}
 
@@ -328,20 +336,28 @@ void Assembler::AllocateAndInstallRequestedHeapObjects(Isolate* isolate) {
     Handle<HeapObject> object;
     Address pc = reinterpret_cast<Address>(buffer_ + request.offset());
     switch (request.kind()) {
-      case HeapObjectRequest::kHeapNumber:
+      case HeapObjectRequest::kHeapNumber: {
         object =
             isolate->factory()->NewHeapNumber(request.heap_number(), TENURED);
-        set_target_address_at(pc, kNullAddress,
-                              reinterpret_cast<Address>(object.location()),
+        set_target_address_at(pc, kNullAddress, object.address(),
                               SKIP_ICACHE_FLUSH);
         break;
-      case HeapObjectRequest::kCodeStub:
+      }
+      case HeapObjectRequest::kCodeStub: {
         request.code_stub()->set_isolate(isolate);
         SixByteInstr instr =
             Instruction::InstructionBits(reinterpret_cast<const byte*>(pc));
         int index = instr & 0xFFFFFFFF;
         UpdateCodeTarget(index, request.code_stub()->GetCode());
         break;
+      }
+      case HeapObjectRequest::kStringConstant: {
+        const StringConstantBase* str = request.string();
+        CHECK_NOT_NULL(str);
+        set_target_address_at(pc, kNullAddress,
+                              str->AllocateStringConstant(isolate).address());
+        break;
+      }
     }
   }
 }

src/s390/assembler-s390.h

@@ -368,6 +368,7 @@ class Operand {
   V8_INLINE explicit Operand(Register rm);
 
   static Operand EmbeddedNumber(double value);  // Smi or HeapNumber
+  static Operand EmbeddedStringConstant(const StringConstantBase* str);
 
   // Return true if this is a register operand.
   V8_INLINE bool is_reg() const { return rm_.is_valid(); }