[mips] Port `[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 `

Change-Id: Ib34a2e18c56bc7ccf3cbfa0f1baa07dcc8ed0cd4
Reviewed-on: https://chromium-review.googlesource.com/1235974Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Sreten Kovacevic <skovacevic@wavecomp.com>
Cr-Commit-Position: refs/heads/master@{#56097}

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

@@ -84,6 +84,9 @@ class MipsOperandConverter final : public InstructionOperandConverter {
         // TODO(plind): Maybe we should handle ExtRef & HeapObj here?
         //    maybe not done on arm due to const pool ??
         break;
+      case Constant::kDelayedStringConstant:
+        return Operand::EmbeddedStringConstant(
+            constant.ToDelayedStringConstant());
       case Constant::kRpoNumber:
         UNREACHABLE();  // TODO(titzer): RPO immediates on mips?
         break;
@@ -3371,6 +3374,9 @@ void CodeGenerator::AssembleMove(InstructionOperand* source,
         case Constant::kExternalReference:
           __ li(dst, src.ToExternalReference());
           break;
+        case Constant::kDelayedStringConstant:
+          __ li(dst, src.ToDelayedStringConstant());
+          break;
         case Constant::kHeapObject: {
           Handle<HeapObject> src_object = src.ToHeapObject();
           RootIndex index;

src/compiler/mips64/code-generator-mips64.cc

@@ -87,6 +87,9 @@ class MipsOperandConverter final : public InstructionOperandConverter {
         // TODO(plind): Maybe we should handle ExtRef & HeapObj here?
         //    maybe not done on arm due to const pool ??
         break;
+      case Constant::kDelayedStringConstant:
+        return Operand::EmbeddedStringConstant(
+            constant.ToDelayedStringConstant());
       case Constant::kRpoNumber:
         UNREACHABLE();  // TODO(titzer): RPO immediates on mips?
         break;
@@ -2496,7 +2499,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       Label all_false;
       __ BranchMSA(&all_false, MSA_BRANCH_V, all_zero,
                    i.InputSimd128Register(0), USE_DELAY_SLOT);
-      __ li(dst, 0);  // branch delay slot
+      __ li(dst, 0l);  // branch delay slot
       __ li(dst, -1);
       __ bind(&all_false);
       break;
@@ -2508,7 +2511,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ BranchMSA(&all_true, MSA_BRANCH_W, all_not_zero,
                    i.InputSimd128Register(0), USE_DELAY_SLOT);
       __ li(dst, -1);  // branch delay slot
-      __ li(dst, 0);
+      __ li(dst, 0l);
       __ bind(&all_true);
       break;
     }
@@ -2519,7 +2522,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ BranchMSA(&all_true, MSA_BRANCH_H, all_not_zero,
                    i.InputSimd128Register(0), USE_DELAY_SLOT);
       __ li(dst, -1);  // branch delay slot
-      __ li(dst, 0);
+      __ li(dst, 0l);
       __ bind(&all_true);
       break;
     }
@@ -2530,7 +2533,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ BranchMSA(&all_true, MSA_BRANCH_B, all_not_zero,
                    i.InputSimd128Register(0), USE_DELAY_SLOT);
       __ li(dst, -1);  // branch delay slot
-      __ li(dst, 0);
+      __ li(dst, 0l);
       __ bind(&all_true);
       break;
     }
@@ -3621,6 +3624,9 @@ void CodeGenerator::AssembleMove(InstructionOperand* source,
         case Constant::kExternalReference:
           __ li(dst, src.ToExternalReference());
           break;
+        case Constant::kDelayedStringConstant:
+          __ li(dst, src.ToDelayedStringConstant());
+          break;
         case Constant::kHeapObject: {
           Handle<HeapObject> src_object = src.ToHeapObject();
           RootIndex index;

src/mips/assembler-mips.cc

@@ -41,6 +41,7 @@
 #include "src/code-stubs.h"
 #include "src/deoptimizer.h"
 #include "src/mips/assembler-mips-inl.h"
+#include "src/string-constants.h"
 
 namespace v8 {
 namespace internal {
@@ -248,6 +249,13 @@ 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 rm, int32_t offset) : Operand(rm) {
   offset_ = offset;
 }
@@ -271,6 +279,11 @@ void Assembler::AllocateAndInstallRequestedHeapObjects(Isolate* isolate) {
         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();
     set_target_value_at(pc, reinterpret_cast<uint32_t>(object.location()));

src/mips/assembler-mips.h

@@ -408,6 +408,7 @@ class Operand {
 
   static Operand EmbeddedNumber(double number);  // Smi or HeapNumber.
   static Operand EmbeddedCode(CodeStub* stub);
+  static Operand EmbeddedStringConstant(const StringConstantBase* str);
 
   // Register.
   V8_INLINE explicit Operand(Register rm) : rm_(rm) {}

src/mips/macro-assembler-mips.cc

@@ -1344,6 +1344,11 @@ void TurboAssembler::li(Register dst, ExternalReference value, LiFlags mode) {
   li(dst, Operand(value), mode);
 }
 
+void TurboAssembler::li(Register dst, const StringConstantBase* string,
+                        LiFlags mode) {
+  li(dst, Operand::EmbeddedStringConstant(string), mode);
+}
+
 void TurboAssembler::li(Register rd, Operand j, LiFlags mode) {
   DCHECK(!j.is_reg());
   BlockTrampolinePoolScope block_trampoline_pool(this);

src/mips/macro-assembler-mips.h

@@ -236,6 +236,8 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   }
   void li(Register dst, Handle<HeapObject> value, LiFlags mode = OPTIMIZE_SIZE);
   void li(Register dst, ExternalReference value, LiFlags mode = OPTIMIZE_SIZE);
+  void li(Register dst, const StringConstantBase* string,
+          LiFlags mode = OPTIMIZE_SIZE);
 
   void LoadFromConstantsTable(Register destination,
                               int constant_index) override;

src/mips64/assembler-mips64.cc

@@ -40,6 +40,7 @@
 #include "src/code-stubs.h"
 #include "src/deoptimizer.h"
 #include "src/mips64/assembler-mips64-inl.h"
+#include "src/string-constants.h"
 
 namespace v8 {
 namespace internal {
@@ -226,6 +227,13 @@ 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 rm, int32_t offset) : Operand(rm) {
   offset_ = offset;
 }
@@ -250,6 +258,11 @@ void Assembler::AllocateAndInstallRequestedHeapObjects(Isolate* isolate) {
         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();
     set_target_value_at(pc, reinterpret_cast<uint64_t>(object.location()));

src/mips64/assembler-mips64.h

@@ -415,6 +415,7 @@ class Operand {
 
   static Operand EmbeddedNumber(double number);  // Smi or HeapNumber.
   static Operand EmbeddedCode(CodeStub* stub);
+  static Operand EmbeddedStringConstant(const StringConstantBase* str);
 
   // Register.
   V8_INLINE explicit Operand(Register rm) : rm_(rm) {}

src/mips64/macro-assembler-mips64.cc

@@ -1570,6 +1570,11 @@ void TurboAssembler::li(Register dst, ExternalReference value, LiFlags mode) {
   li(dst, Operand(value), mode);
 }
 
+void TurboAssembler::li(Register dst, const StringConstantBase* string,
+                        LiFlags mode) {
+  li(dst, Operand::EmbeddedStringConstant(string), mode);
+}
+
 static inline int InstrCountForLiLower32Bit(int64_t value) {
   if (!is_int16(static_cast<int32_t>(value)) && (value & kUpper16MaskOf64) &&
       (value & kImm16Mask)) {

src/mips64/macro-assembler-mips64.h

@@ -254,8 +254,13 @@ class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
   inline void li(Register rd, int64_t j, LiFlags mode = OPTIMIZE_SIZE) {
     li(rd, Operand(j), mode);
   }
+  // inline void li(Register rd, int32_t j, LiFlags mode = OPTIMIZE_SIZE) {
+  //   li(rd, Operand(static_cast<int64_t>(j)), mode);
+  // }
   void li(Register dst, Handle<HeapObject> value, LiFlags mode = OPTIMIZE_SIZE);
   void li(Register dst, ExternalReference value, LiFlags mode = OPTIMIZE_SIZE);
+  void li(Register dst, const StringConstantBase* string,
+          LiFlags mode = OPTIMIZE_SIZE);
 
   void LoadFromConstantsTable(Register destination,
                               int constant_index) override;

test/cctest/test-assembler-mips64.cc

@@ -85,7 +85,7 @@ TEST(MIPS1) {
   Label L, C;
 
   __ mov(a1, a0);
-  __ li(v0, 0);
+  __ li(v0, 0l);
   __ b(&C);
   __ nop();
 
@@ -2316,7 +2316,7 @@ TEST(movt_movd) {
         __ Lw(t1, MemOperand(a0, offsetof(TestFloat, fcsr)));
         __ cfc1(t0, FCSR);
         __ ctc1(t1, FCSR);
-        __ li(t2, 0x0);
+        __ li(t2, 0x0l);
         __ mtc1(t2, f12);
         __ mtc1(t2, f10);
         __ Sdc1(f10, MemOperand(a0, offsetof(TestFloat, dstdold)));
@@ -5421,7 +5421,7 @@ uint64_t run_jic(int16_t offset) {
 
   Label get_program_counter, stop_execution;
   __ push(ra);
-  __ li(v0, 0);
+  __ li(v0, 0l);
   __ li(t1, 0x66);
 
   __ addiu(v0, v0, 0x1);        // <-- offset = -32
@@ -5496,7 +5496,7 @@ uint64_t run_beqzc(int32_t value, int32_t offset) {
                       v8::internal::CodeObjectRequired::kYes);
 
   Label stop_execution;
-  __ li(v0, 0);
+  __ li(v0, 0l);
   __ li(t1, 0x66);
 
   __ addiu(v0, v0, 0x1);        // <-- offset = -8
@@ -5755,7 +5755,7 @@ uint64_t run_jialc(int16_t offset) {
 
   Label main_block, get_program_counter;
   __ push(ra);
-  __ li(v0, 0);
+  __ li(v0, 0l);
   __ beq(v0, v0, &main_block);
   __ nop();
 
@@ -5980,8 +5980,8 @@ int64_t run_bc(int32_t offset) {
 
   Label continue_1, stop_execution;
   __ push(ra);
-  __ li(v0, 0);
-  __ li(t8, 0);
+  __ li(v0, 0l);
+  __ li(t8, 0l);
   __ li(t9, 2);   // Condition for the stopping execution.
 
   for (int32_t i = -100; i <= -11; ++i) {
@@ -6060,8 +6060,8 @@ int64_t run_balc(int32_t offset) {
 
   Label continue_1, stop_execution;
   __ push(ra);
-  __ li(v0, 0);
-  __ li(t8, 0);
+  __ li(v0, 0l);
+  __ li(t8, 0l);
   __ li(t9, 2);   // Condition for stopping execution.
 
   __ beq(t8, t8, &continue_1);
@@ -7072,7 +7072,7 @@ void run_msa_ctc_cfc(uint64_t value) {
 
   MSAControlRegister msareg = {kMSACSRRegister};
   __ li(t0, value);
-  __ li(t2, 0);
+  __ li(t2, 0l);
   __ cfcmsa(t1, msareg);
   __ ctcmsa(msareg, t0);
   __ cfcmsa(t2, msareg);