[ia32] Unalias kRootRegister in IC, Construct and ArgumentsAdaptor descriptors

This replaces ebx usage in several more interface descriptors.

- IC descriptors already passed most arguments on the stack (updated
  their Register accessors to reflect that).
- The allocation site argument appears to be unused in the
  ConstructStub descriptor. It can probably be removed in a follow-up.

Drive-by: Rename ArgumentAdaptorDescriptor to
ArgumentsAdaptorDescriptor to match the builtin name.

Bug: v8:6666
Change-Id: I4cdf1775a5b4b74491d6d303c49a8af9b6cd3c03
Reviewed-on: https://chromium-review.googlesource.com/1195367
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55495}

src/arm/interface-descriptors-arm.cc

@@ -193,7 +193,7 @@ void BinaryOpDescriptor::InitializePlatformSpecific(
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
-void ArgumentAdaptorDescriptor::InitializePlatformSpecific(
+void ArgumentsAdaptorDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {
       r1,  // JSFunction

src/arm64/interface-descriptors-arm64.cc

@@ -198,7 +198,7 @@ void BinaryOpDescriptor::InitializePlatformSpecific(
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
-void ArgumentAdaptorDescriptor::InitializePlatformSpecific(
+void ArgumentsAdaptorDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {
       x1,  // JSFunction

src/builtins/builtins-definitions.h

@@ -1208,7 +1208,7 @@ namespace internal {
   /* Wasm */                                                                   \
   ASM(WasmCompileLazy)                                                         \
   TFC(WasmAllocateHeapNumber, AllocateHeapNumber, 1)                           \
-  TFC(WasmArgumentsAdaptor, ArgumentAdaptor, 1)                                \
+  TFC(WasmArgumentsAdaptor, ArgumentsAdaptor, 1)                               \
   TFC(WasmCallJavaScript, CallTrampoline, 1)                                   \
   TFC(WasmGrowMemory, WasmGrowMemory, 1)                                       \
   TFC(WasmStackGuard, NoContext, 1)                                            \

src/builtins/builtins-wasm-gen.cc

@@ -63,7 +63,7 @@ TF_BUILTIN(WasmArgumentsAdaptor, WasmBuiltinsAssembler) {
   TNode<Object> argc2 = UncheckedParameter(Descriptor::kExpectedArgumentsCount);
   TNode<Code> target =
       LoadBuiltinFromFrame(Builtins::kArgumentsAdaptorTrampoline);
-  TailCallStub(ArgumentAdaptorDescriptor{}, target, context, function,
+  TailCallStub(ArgumentsAdaptorDescriptor{}, target, context, function,
                new_target, argc1, argc2);
 }
 

src/builtins/ia32/builtins-ia32.cc

@@ -2116,10 +2116,6 @@ void Builtins::Generate_ConstructFunction(MacroAssembler* masm) {
   __ AssertConstructor(edi);
   __ AssertFunction(edi);
 
-  // Calling convention for function specific ConstructStubs require
-  // ebx to contain either an AllocationSite or undefined.
-  __ LoadRoot(ebx, Heap::kUndefinedValueRootIndex);
-
   Label call_generic_stub;
 
   // Jump to JSBuiltinsConstructStub or JSConstructStubGeneric.
@@ -2128,10 +2124,16 @@ void Builtins::Generate_ConstructFunction(MacroAssembler* masm) {
           Immediate(SharedFunctionInfo::ConstructAsBuiltinBit::kMask));
   __ j(zero, &call_generic_stub, Label::kNear);
 
+  // Calling convention for function specific ConstructStubs require
+  // ecx to contain either an AllocationSite or undefined.
+  __ LoadRoot(ecx, Heap::kUndefinedValueRootIndex);
   __ Jump(BUILTIN_CODE(masm->isolate(), JSBuiltinsConstructStub),
           RelocInfo::CODE_TARGET);
 
   __ bind(&call_generic_stub);
+  // Calling convention for function specific ConstructStubs require
+  // ecx to contain either an AllocationSite or undefined.
+  __ LoadRoot(ecx, Heap::kUndefinedValueRootIndex);
   __ Jump(BUILTIN_CODE(masm->isolate(), JSConstructStubGeneric),
           RelocInfo::CODE_TARGET);
 }
@@ -2220,28 +2222,32 @@ void Builtins::Generate_Construct(MacroAssembler* masm) {
 void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- eax : actual number of arguments
-  //  -- ebx : expected number of arguments
+  //  -- ecx : expected number of arguments
   //  -- edx : new target (passed through to callee)
   //  -- edi : function (passed through to callee)
   // -----------------------------------
 
+  const Register kExpectedNumberOfArgumentsRegister = ecx;
+
   Label invoke, dont_adapt_arguments, stack_overflow;
   __ IncrementCounter(masm->isolate()->counters()->arguments_adaptors(), 1);
 
   Label enough, too_few;
-  __ cmp(ebx, SharedFunctionInfo::kDontAdaptArgumentsSentinel);
+  __ cmp(kExpectedNumberOfArgumentsRegister,
+         SharedFunctionInfo::kDontAdaptArgumentsSentinel);
   __ j(equal, &dont_adapt_arguments);
-  __ cmp(eax, ebx);
+  __ cmp(eax, kExpectedNumberOfArgumentsRegister);
   __ j(less, &too_few);
 
   {  // Enough parameters: Actual >= expected.
     __ bind(&enough);
     EnterArgumentsAdaptorFrame(masm);
-    // edi is used as a scratch register. It should be restored from the frame
-    // when needed.
-    Generate_StackOverflowCheck(masm, ebx, ecx, &stack_overflow);
+    Generate_StackOverflowCheck(masm, kExpectedNumberOfArgumentsRegister, ebx,
+                                &stack_overflow);
 
     // Copy receiver and all expected arguments.
+    // edi is used as a scratch register. It should be restored from the frame
+    // when needed.
     const int offset = StandardFrameConstants::kCallerSPOffset;
     __ lea(edi, Operand(ebp, eax, times_4, offset));
     __ mov(eax, -1);  // account for receiver
@@ -2251,7 +2257,7 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
     __ inc(eax);
     __ push(Operand(edi, 0));
     __ sub(edi, Immediate(kPointerSize));
-    __ cmp(eax, ebx);
+    __ cmp(eax, kExpectedNumberOfArgumentsRegister);
     __ j(less, &copy);
     // eax now contains the expected number of arguments.
     __ jmp(&invoke);
@@ -2262,16 +2268,17 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
     EnterArgumentsAdaptorFrame(masm);
     // edi is used as a scratch register. It should be restored from the frame
     // when needed.
-    Generate_StackOverflowCheck(masm, ebx, ecx, &stack_overflow);
+    Generate_StackOverflowCheck(masm, kExpectedNumberOfArgumentsRegister, ebx,
+                                &stack_overflow);
 
-    // Remember expected arguments in ecx.
-    __ mov(ecx, ebx);
+    // Remember expected arguments in ebx.
+    __ mov(ebx, kExpectedNumberOfArgumentsRegister);
 
     // Copy receiver and all actual arguments.
     const int offset = StandardFrameConstants::kCallerSPOffset;
     __ lea(edi, Operand(ebp, eax, times_4, offset));
-    // ebx = expected - actual.
-    __ sub(ebx, eax);
+    // ecx = expected - actual.
+    __ sub(kExpectedNumberOfArgumentsRegister, eax);
     // eax = -actual - 1
     __ neg(eax);
     __ sub(eax, Immediate(1));
@@ -2289,11 +2296,11 @@ void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
     __ bind(&fill);
     __ inc(eax);
     __ push(Immediate(masm->isolate()->factory()->undefined_value()));
-    __ cmp(eax, ebx);
+    __ cmp(eax, kExpectedNumberOfArgumentsRegister);
     __ j(less, &fill);
 
     // Restore expected arguments.
-    __ mov(eax, ecx);
+    __ mov(eax, ebx);
   }
 
   // Call the entry point.

src/code-factory.cc

@@ -218,7 +218,7 @@ Callable CodeFactory::FastNewFunctionContext(Isolate* isolate,
 // static
 Callable CodeFactory::ArgumentAdaptor(Isolate* isolate) {
   return Callable(BUILTIN_CODE(isolate, ArgumentsAdaptorTrampoline),
-                  ArgumentAdaptorDescriptor{});
+                  ArgumentsAdaptorDescriptor{});
 }
 
 // static

src/compiler/wasm-compiler.cc

@@ -4533,7 +4533,7 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
           }
 
           call_descriptor = Linkage::GetStubCallDescriptor(
-              mcgraph()->zone(), ArgumentAdaptorDescriptor{}, 1 + wasm_count,
+              mcgraph()->zone(), ArgumentsAdaptorDescriptor{}, 1 + wasm_count,
               CallDescriptor::kNoFlags, Operator::kNoProperties,
               StubCallMode::kCallWasmRuntimeStub);
 

src/ia32/interface-descriptors-ia32.cc

@@ -172,8 +172,9 @@ void ConstructStubDescriptor::InitializePlatformSpecific(
   // eax : number of arguments
   // edx : the new target
   // edi : the target to call
-  // ebx : allocation site or undefined
-  Register registers[] = {edi, edx, eax, ebx};
+  // ecx : allocation site or undefined
+  // TODO(jgruber): Remove the unused allocation site parameter.
+  Register registers[] = {edi, edx, eax, ecx};
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
@@ -201,13 +202,13 @@ void BinaryOpDescriptor::InitializePlatformSpecific(
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
-void ArgumentAdaptorDescriptor::InitializePlatformSpecific(
+void ArgumentsAdaptorDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {
       edi,  // JSFunction
       edx,  // the new target
       eax,  // actual number of arguments
-      ebx,  // expected number of arguments
+      ecx,  // expected number of arguments
   };
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }

src/ia32/macro-assembler-ia32.cc

@@ -1079,6 +1079,9 @@ void MacroAssembler::InvokePrologue(const ParameterCount& expected,
   }
 
   if (!definitely_matches) {
+    // TODO(v8:6666): All call-sites should be updated to pass in ecx as the
+    // expected register to avoid this useless move.
+    MoveForRootRegisterRefactoring(ecx, ebx);
     Handle<Code> adaptor = BUILTIN_CODE(isolate(), ArgumentsAdaptorTrampoline);
     if (flag == CALL_FUNCTION) {
       Call(adaptor, RelocInfo::CODE_TARGET);

src/interface-descriptors.h

@@ -60,7 +60,7 @@ namespace internal {
   V(StringAt)                         \
   V(StringSubstring)                  \
   V(GetProperty)                      \
-  V(ArgumentAdaptor)                  \
+  V(ArgumentsAdaptor)                 \
   V(ApiCallback)                      \
   V(ApiGetter)                        \
   V(GrowArrayElements)                \
@@ -775,6 +775,7 @@ class ConstructWithArrayLikeDescriptor : public CallInterfaceDescriptor {
 // TODO(ishell): consider merging this with ArrayConstructorDescriptor
 class ConstructStubDescriptor : public CallInterfaceDescriptor {
  public:
+  // TODO(jgruber): Remove the unused allocation site parameter.
   DEFINE_JS_PARAMETERS(kAllocationSite)
   DEFINE_JS_PARAMETER_TYPES(MachineType::AnyTagged());
 
@@ -895,11 +896,11 @@ class StringSubstringDescriptor final : public CallInterfaceDescriptor {
   DECLARE_DESCRIPTOR(StringSubstringDescriptor, CallInterfaceDescriptor)
 };
 
-class ArgumentAdaptorDescriptor : public CallInterfaceDescriptor {
+class ArgumentsAdaptorDescriptor : public CallInterfaceDescriptor {
  public:
   DEFINE_JS_PARAMETERS(kExpectedArgumentsCount)
   DEFINE_JS_PARAMETER_TYPES(MachineType::Int32())
-  DECLARE_DESCRIPTOR(ArgumentAdaptorDescriptor, CallInterfaceDescriptor)
+  DECLARE_DESCRIPTOR(ArgumentsAdaptorDescriptor, CallInterfaceDescriptor)
 };
 
 class CppBuiltinAdaptorDescriptor : public CallInterfaceDescriptor {

src/mips/interface-descriptors-mips.cc

@@ -194,7 +194,7 @@ void BinaryOpDescriptor::InitializePlatformSpecific(
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
-void ArgumentAdaptorDescriptor::InitializePlatformSpecific(
+void ArgumentsAdaptorDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {
       a1,  // JSFunction

src/mips64/interface-descriptors-mips64.cc

@@ -194,7 +194,7 @@ void BinaryOpDescriptor::InitializePlatformSpecific(
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
-void ArgumentAdaptorDescriptor::InitializePlatformSpecific(
+void ArgumentsAdaptorDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {
       a1,  // JSFunction

src/ppc/interface-descriptors-ppc.cc

@@ -194,7 +194,7 @@ void BinaryOpDescriptor::InitializePlatformSpecific(
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
-void ArgumentAdaptorDescriptor::InitializePlatformSpecific(
+void ArgumentsAdaptorDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {
       r4,  // JSFunction

src/s390/interface-descriptors-s390.cc

@@ -192,7 +192,7 @@ void BinaryOpDescriptor::InitializePlatformSpecific(
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
-void ArgumentAdaptorDescriptor::InitializePlatformSpecific(
+void ArgumentsAdaptorDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {
       r3,  // JSFunction

src/x64/interface-descriptors-x64.cc

@@ -195,7 +195,7 @@ void BinaryOpDescriptor::InitializePlatformSpecific(
   data->InitializePlatformSpecific(arraysize(registers), registers);
 }
 
-void ArgumentAdaptorDescriptor::InitializePlatformSpecific(
+void ArgumentsAdaptorDescriptor::InitializePlatformSpecific(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {
       rdi,  // JSFunction