[vm] Fix Meteor regression in "[vm] Enable multiple entry-points for unoptimized calls."

Change-Id: I3ffcdd67ae80b05339861a3376a56b0a6ce642c7
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/127462
Commit-Queue: Samir Jindel <sjindel@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>

Author: sjindel-google

runtime/vm/compiler/stub_code_compiler_arm.cc

@@ -2006,7 +2006,10 @@ void StubCodeCompiler::GenerateNArgsCheckInlineCacheStub(
     Optimized optimized,
     CallType type,
     Exactness exactness) {
-  GenerateRecordEntryPoint(assembler);
+  const bool save_entry_point = kind == Token::kILLEGAL;
+  if (save_entry_point) {
+    GenerateRecordEntryPoint(assembler);
+  }
 
   if (optimized == kOptimized) {
     GenerateOptimizedUsageCounterIncrement(assembler);
@@ -2141,8 +2144,12 @@ void StubCodeCompiler::GenerateNArgsCheckInlineCacheStub(
   __ LoadImmediate(R0, 0);
   // Preserve IC data object and arguments descriptor array and
   // setup space on stack for result (target code object).
-  __ SmiTag(R3);
-  __ PushList((1 << R0) | (1 << R4) | (1 << R9) | (1 << R3));
+  RegList regs = (1 << R0) | (1 << R4) | (1 << R9);
+  if (save_entry_point) {
+    __ SmiTag(R3);
+    regs |= 1 << R3;
+  }
+  __ PushList(regs);
   // Push call arguments.
   for (intptr_t i = 0; i < num_args; i++) {
     __ LoadFromOffset(kWord, IP, NOTFP, -i * target::kWordSize);
@@ -2155,8 +2162,10 @@ void StubCodeCompiler::GenerateNArgsCheckInlineCacheStub(
   __ Drop(num_args + 1);
   // Pop returned function object into R0.
   // Restore arguments descriptor array and IC data array.
-  __ PopList((1 << R0) | (1 << R4) | (1 << R9) | (1 << R3));
-  __ SmiUntag(R3);
+  __ PopList(regs);
+  if (save_entry_point) {
+    __ SmiUntag(R3);
+  }
   __ RestoreCodePointer();
   __ LeaveStubFrame();
   Label call_target_function;
@@ -2187,7 +2196,11 @@ void StubCodeCompiler::GenerateNArgsCheckInlineCacheStub(
   // R0: target function.
   __ ldr(CODE_REG, FieldAddress(R0, target::Function::code_offset()));
 
-  __ Branch(Address(R0, R3));
+  if (save_entry_point) {
+    __ Branch(Address(R0, R3));
+  } else {
+    __ Branch(FieldAddress(R0, target::Function::entry_point_offset()));
+  }
 
 #if !defined(PRODUCT)
   if (optimized == kUnoptimized) {
@@ -2196,11 +2209,17 @@ void StubCodeCompiler::GenerateNArgsCheckInlineCacheStub(
     if (type == kInstanceCall) {
       __ Push(R0);  // Preserve receiver.
     }
-    __ SmiTag(R3);                       // Entry-point is not Smi.
-    __ PushList((1 << R3) | (1 << R9));  // Preserve IC data and entry-point.
+    RegList regs = 1 << R9;
+    if (save_entry_point) {
+      regs |= 1 << R3;
+      __ SmiTag(R3);  // Entry-point is not Smi.
+    }
+    __ PushList(regs);  // Preserve IC data and entry-point.
     __ CallRuntime(kSingleStepHandlerRuntimeEntry, 0);
-    __ PopList((1 << R3) | (1 << R9));  // Restore IC data and entry-point
-    __ SmiUntag(R3);
+    __ PopList(regs);  // Restore IC data and entry-point
+    if (save_entry_point) {
+      __ SmiUntag(R3);
+    }
     if (type == kInstanceCall) {
       __ Pop(R0);
     }

runtime/vm/compiler/stub_code_compiler_x64.cc

@@ -2083,7 +2083,10 @@ void StubCodeCompiler::GenerateNArgsCheckInlineCacheStub(
     Optimized optimized,
     CallType type,
     Exactness exactness) {
-  GenerateRecordEntryPoint(assembler);
+  const bool save_entry_point = kind == Token::kILLEGAL;
+  if (save_entry_point) {
+    GenerateRecordEntryPoint(assembler);
+  }
 
   if (optimized == kOptimized) {
     GenerateOptimizedUsageCounterIncrement(assembler);
@@ -2205,8 +2208,10 @@ void StubCodeCompiler::GenerateNArgsCheckInlineCacheStub(
   __ movq(RAX, FieldAddress(R10, target::ArgumentsDescriptor::count_offset()));
   __ leaq(RAX, Address(RSP, RAX, TIMES_4, 0));  // RAX is Smi.
   __ EnterStubFrame();
-  __ SmiTag(R8);           // Entry-point offset is not Smi.
-  __ pushq(R8);            // Preserve entry point.
+  if (save_entry_point) {
+    __ SmiTag(R8);  // Entry-point offset is not Smi.
+    __ pushq(R8);   // Preserve entry point.
+  }
   __ pushq(R10);           // Preserve arguments descriptor array.
   __ pushq(RBX);           // Preserve IC data object.
   __ pushq(Immediate(0));  // Result slot.
@@ -2221,11 +2226,13 @@ void StubCodeCompiler::GenerateNArgsCheckInlineCacheStub(
   for (intptr_t i = 0; i < num_args + 1; i++) {
     __ popq(RAX);
   }
-  __ popq(RAX);     // Pop returned function object into RAX.
-  __ popq(RBX);     // Restore IC data array.
-  __ popq(R10);     // Restore arguments descriptor array.
-  __ popq(R8);      // Restore entry point.
-  __ SmiUntag(R8);  // Entry-point offset is not Smi.
+  __ popq(RAX);  // Pop returned function object into RAX.
+  __ popq(RBX);  // Restore IC data array.
+  __ popq(R10);  // Restore arguments descriptor array.
+  if (save_entry_point) {
+    __ popq(R8);      // Restore entry point.
+    __ SmiUntag(R8);  // Entry-point offset is not Smi.
+  }
   __ RestoreCodePointer();
   __ LeaveStubFrame();
   Label call_target_function;
@@ -2277,8 +2284,12 @@ void StubCodeCompiler::GenerateNArgsCheckInlineCacheStub(
   __ Bind(&call_target_function);
   // RAX: Target function.
   __ movq(CODE_REG, FieldAddress(RAX, target::Function::code_offset()));
-  __ addq(R8, RAX);
-  __ jmp(Address(R8, 0));
+  if (save_entry_point) {
+    __ addq(R8, RAX);
+    __ jmp(Address(R8, 0));
+  } else {
+    __ jmp(FieldAddress(RAX, target::Function::entry_point_offset()));
+  }
 
   if (exactness == kCheckExactness) {
     __ Bind(&call_target_function_through_unchecked_entry);
@@ -2301,11 +2312,15 @@ void StubCodeCompiler::GenerateNArgsCheckInlineCacheStub(
       __ pushq(RDX);  // Preserve receiver.
     }
     __ pushq(RBX);  // Preserve ICData.
-    __ SmiTag(R8);  // Entry-point offset is not Smi.
-    __ pushq(R8);   // Preserve entry point.
+    if (save_entry_point) {
+      __ SmiTag(R8);  // Entry-point offset is not Smi.
+      __ pushq(R8);   // Preserve entry point.
+    }
     __ CallRuntime(kSingleStepHandlerRuntimeEntry, 0);
-    __ popq(R8);  // Restore entry point.
-    __ SmiUntag(R8);
+    if (save_entry_point) {
+      __ popq(R8);  // Restore entry point.
+      __ SmiUntag(R8);
+    }
     __ popq(RBX);  // Restore ICData.
     if (type == kInstanceCall) {
       __ popq(RDX);  // Restore receiver.