Increase coverage of global loads in optimized code...

src/arm/full-codegen-arm.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1586 matching lines @@
           __ mov(r0, Operand(property->key()->AsLiteral()->handle()));
           __ Push(r1, r0);
         } else {
           VisitForStackValue(property->obj());
           VisitForStackValue(property->key());
         }
       }
       break;
   }
 
+  // For compound assignments we need another deoptimization point after the
+  // variable/property load.
   if (expr->is_compound()) {
     { AccumulatorValueContext context(this);
       switch (assign_type) {
         case VARIABLE:
           EmitVariableLoad(expr->target()->AsVariableProxy()->var());
+          PrepareForBailout(expr->target(), TOS_REG);
           break;
         case NAMED_PROPERTY:
           EmitNamedPropertyLoad(property);
+          PrepareForBailoutForId(expr->CompoundLoadId(), TOS_REG);
           break;
         case KEYED_PROPERTY:
           EmitKeyedPropertyLoad(property);
+          PrepareForBailoutForId(expr->CompoundLoadId(), TOS_REG);
           break;
       }
     }
 
-    // For property compound assignments we need another deoptimization
-    // point after the property load.
-    if (property != NULL) {
-      PrepareForBailoutForId(expr->CompoundLoadId(), TOS_REG);
-    }
-
     Token::Value op = expr->binary_op();
     __ push(r0);  // Left operand goes on the stack.
     VisitForAccumulatorValue(expr->value());
 
     OverwriteMode mode = expr->value()->ResultOverwriteAllowed()
         ? OVERWRITE_RIGHT
         : NO_OVERWRITE;
     SetSourcePosition(expr->position() + 1);
     AccumulatorValueContext context(this);
     if (ShouldInlineSmiCase(op)) {
@@ skipping 2131 matching lines @@
   if (prop != NULL) {
     assign_type =
         (prop->key()->IsPropertyName()) ? NAMED_PROPERTY : KEYED_PROPERTY;
   }
 
   // Evaluate expression and get value.
   if (assign_type == VARIABLE) {
     ASSERT(expr->expression()->AsVariableProxy()->var() != NULL);
     AccumulatorValueContext context(this);
     EmitVariableLoad(expr->expression()->AsVariableProxy()->var());
+    PrepareForBailout(expr->expression(), TOS_REG);
   } else {
     // Reserve space for result of postfix operation.
     if (expr->is_postfix() && !context()->IsEffect()) {
       __ mov(ip, Operand(Smi::FromInt(0)));
       __ push(ip);
     }
     if (assign_type == NAMED_PROPERTY) {
       // Put the object both on the stack and in the accumulator.
       VisitForAccumulatorValue(prop->obj());
       __ push(r0);
       EmitNamedPropertyLoad(prop);
     } else {
       if (prop->is_arguments_access()) {
         VariableProxy* obj_proxy = prop->obj()->AsVariableProxy();
         __ ldr(r0, EmitSlotSearch(obj_proxy->var()->AsSlot(), r0));
         __ push(r0);
         __ mov(r0, Operand(prop->key()->AsLiteral()->handle()));
       } else {
         VisitForStackValue(prop->obj());
         VisitForAccumulatorValue(prop->key());
       }
       __ ldr(r1, MemOperand(sp, 0));
       __ push(r0);
       EmitKeyedPropertyLoad(prop);
     }
   }
 
   // We need a second deoptimization point after loading the value
   // in case evaluating the property load my have a side effect.
   PrepareForBailout(expr->increment(), TOS_REG);

[fschneider, 2011/03/16 10:28:18]

I think it does not hurt here, but shouldn't this bailout be prepared only for
named and keyed properties then?

[Søren Thygesen Gjesse, 2011/03/17 07:52:27]

That looks right, done (on all platforms).

 
   // Call ToNumber only if operand is not a smi.
   Label no_conversion;
   __ JumpIfSmi(r0, &no_conversion);
   ToNumberStub convert_stub;
   __ CallStub(&convert_stub);
   __ bind(&no_conversion);
 
   // Save result for postfix expressions.
   if (expr->is_postfix()) {
@@ skipping 463 matching lines @@
   __ mov(r1, Operand(r1, ASR, 1));  // Un-smi-tag value.
   __ add(pc, r1, Operand(masm_->CodeObject()));
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM