Store arguments descriptor in ICData. Remove loading of arguments descriptor at unoptimized call si…

runtime/vm/stub_code_arm.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"
 #if defined(TARGET_ARCH_ARM)
 
 #include "vm/assembler.h"
 #include "vm/code_generator.h"
 #include "vm/compiler.h"
@@ skipping 1296 matching lines @@
   // Remove arguments.
   __ Drop(4);
   __ Pop(R0);  // Get result into R0.
   __ LeaveStubFrame();
   __ Ret();
 }
 
 
 //  R6: function object.
 //  R5: inline cache data object.
-//  R4: arguments descriptor array.
+// Cannot use function object from ICData as it may be the inlined
+// function and not the top-scope function.
 void StubCode::GenerateOptimizedUsageCounterIncrement(Assembler* assembler) {
   Register ic_reg = R5;
   Register func_reg = R6;
   if (FLAG_trace_optimized_ic_calls) {
     __ EnterStubFrame();
-    __ PushList((1 << R4) | (1 << R5) | (1 << R6));  // Preserve.
+    __ PushList((1 << R5) | (1 << R6));  // Preserve.
     __ Push(ic_reg);  // Argument.
     __ Push(func_reg);  // Argument.
     __ CallRuntime(kTraceICCallRuntimeEntry);
     __ Drop(2);  // Discard argument;
-    __ PushList((1 << R4) | (1 << R5) | (1 << R6));  // Restore.
+    __ PopList((1 << R5) | (1 << R6));  // Restore.
     __ LeaveStubFrame();
   }
   __ ldr(R7, FieldAddress(func_reg, Function::usage_counter_offset()));
   Label is_hot;
   if (FlowGraphCompiler::CanOptimize()) {
     ASSERT(FLAG_optimization_counter_threshold > 1);
     __ CompareImmediate(R7, FLAG_optimization_counter_threshold);
     __ b(&is_hot, GE);
     // As long as VM has no OSR do not optimize in the middle of the function
     // but only at exit so that we have collected all type feedback before
@@ skipping 26 matching lines @@
   }
   __ add(R7, R7, ShifterOperand(1));
   __ str(R7, FieldAddress(func_reg, Function::usage_counter_offset()));
   __ Bind(&is_hot);
 }
 
 
 // Generate inline cache check for 'num_args'.
 //  LR: return address.
 //  R5: inline cache data object.
-//  R4: arguments descriptor array.
 // Control flow:
 // - If receiver is null -> jump to IC miss.
 // - If receiver is Smi -> load Smi class.
 // - If receiver is not-Smi -> load receiver's class.
 // - Check if 'num_args' (including receiver) match any IC data group.
 // - Match found -> jump to target.
 // - Match not found -> jump to IC miss.
 void StubCode::GenerateNArgsCheckInlineCacheStub(Assembler* assembler,
                                                  intptr_t num_args) {
   ASSERT(num_args > 0);
 #if defined(DEBUG)
   { Label ok;
     // Check that the IC data array has NumberOfArgumentsChecked() == num_args.
     // 'num_args_tested' is stored as an untagged int.
     __ ldr(R6, FieldAddress(R5, ICData::num_args_tested_offset()));
     __ CompareImmediate(R6, num_args);
     __ b(&ok, EQ);
     __ Stop("Incorrect stub for IC data");
     __ Bind(&ok);
   }
 #endif  // DEBUG
 
+  // Load arguments descriptor into R4.
+  __ ldr(R4, FieldAddress(R5, ICData::arguments_descriptor_offset()));
   // Preserve return address, since LR is needed for subroutine call.
   __ mov(R8, ShifterOperand(LR));
   // Loop that checks if there is an IC data match.
   Label loop, update, test, found, get_class_id_as_smi;
   // R5: IC data object (preserved).
   __ ldr(R6, FieldAddress(R5, ICData::ic_data_offset()));
   // R6: ic_data_array with check entries: classes and target functions.
   __ AddImmediate(R6, R6, Array::data_offset() - kHeapObjectTag);
   // R6: points directly to the first ic data array element.
 
@@ skipping 121 matching lines @@
   __ LoadClassId(R0, R0);
   __ SmiTag(R0);
   __ bx(LR);
 }
 
 
 // Use inline cache data array to invoke the target or continue in inline
 // cache miss handler. Stub for 1-argument check (receiver class).
 //  LR: return address.
 //  R5: inline cache data object.
-//  R4: arguments descriptor array.
 // Inline cache data object structure:
 // 0: function-name
 // 1: N, number of arguments checked.
 // 2 .. (length - 1): group of checks, each check containing:
 //   - N classes.
 //   - 1 target function.
 void StubCode::GenerateOneArgCheckInlineCacheStub(Assembler* assembler) {
   GenerateUsageCounterIncrement(assembler, R6);
   GenerateNArgsCheckInlineCacheStub(assembler, 1);
 }
@@ skipping 81 matching lines @@
 
   // Instead of returning to the patched Dart function, emulate the
   // smashed return code pattern and return to the function's caller.
   __ LeaveDartFrame();
   __ Ret();
 }
 
 
 //  LR: return address (Dart code).
 //  R5: inline cache data array.
-//  R4: arguments descriptor array.
 void StubCode::GenerateBreakpointDynamicStub(Assembler* assembler) {
   // Create a stub frame as we are pushing some objects on the stack before
   // calling into the runtime.
   __ EnterStubFrame();
-  __ PushList((1 << R4) | (1 << R5));
+  __ Push(R5);
   __ CallRuntime(kBreakpointDynamicHandlerRuntimeEntry);
-  __ PopList((1 << R4) | (1 << R5));
+  __ Pop(R5);
   __ LeaveStubFrame();
 
   // Find out which dispatch stub to call.
   __ ldr(IP, FieldAddress(R5, ICData::num_args_tested_offset()));
   __ cmp(IP, ShifterOperand(1));
   __ Branch(&StubCode::OneArgCheckInlineCacheLabel(), EQ);
   __ cmp(IP, ShifterOperand(2));
   __ Branch(&StubCode::TwoArgsCheckInlineCacheLabel(), EQ);
   __ cmp(IP, ShifterOperand(3));
   __ Branch(&StubCode::ThreeArgsCheckInlineCacheLabel(), EQ);
@@ skipping 321 matching lines @@
   __ Bind(&reference_compare);
   __ cmp(left, ShifterOperand(right));
   __ Bind(&done);
   __ PopList((1 << R0) | (1 << R1) | (1 << R2));
   __ Ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM