[v8-dev] X87: [date] Refactor the %_DateField intrinsic to be optimizable. (issue 1174913002 by [email protected])

Thu, 11 Jun 2015 01:41:23 -0700 

Reviewers: Weiliang,

Message:
PTAL

Description:
X87: [date] Refactor the %_DateField intrinsic to be optimizable.

port e4782a9b468258344d512a5f7dadbf1584928849 (r28782)

original commit message:

    Previously the %_DateField intrinsic would also check the object and
    throw an exception if you happen to pass something that is not a valid
    JSDate, which (a) violates our policy for instrinsics and (b) is hard to
    optimize in TurboFan (even Crankshaft has a hard time, but there we will
    never inline the relevant builtins, so it doesn't show up). The throwing
    part is now a separate intrinsics %_ThrowIfNotADate that throws an
    exception in full codegen and deoptimizes in Crankshaft, which means the
    code for the current use cases is roughly the same (modulo some register
    renamings/gap moves).

BUG=

Please review this at https://codereview.chromium.org/1174913002/

Base URL: https://chromium.googlesource.com/v8/v8.git@master

Affected files (+27, -18 lines):
  M src/x87/full-codegen-x87.cc
  M src/x87/lithium-codegen-x87.cc
  M src/x87/lithium-x87.cc


Index: src/x87/full-codegen-x87.cc
diff --git a/src/x87/full-codegen-x87.cc b/src/x87/full-codegen-x87.cc
index 2cb448ae2beb7f7284dadbf257c1b938e3b09c9d..7390de3ee1b956d5579bd234da120a3d79d66b36 100644 
--- a/src/x87/full-codegen-x87.cc
+++ b/src/x87/full-codegen-x87.cc
@@ -3776,6 +3776,28 @@ void FullCodeGenerator::EmitValueOf(CallRuntime* expr) { 
 }


+void FullCodeGenerator::EmitThrowIfNotADate(CallRuntime* expr) {
+  ZoneList<Expression*>* args = expr->arguments();
+  DCHECK_EQ(1, args->length());
+
+  VisitForAccumulatorValue(args->at(0));  // Load the object.
+
+  Label done, not_date_object;
+  Register object = eax;
+  Register result = eax;
+  Register scratch = ecx;
+
+  __ JumpIfSmi(object, &not_date_object, Label::kNear);
+  __ CmpObjectType(object, JS_DATE_TYPE, scratch);
+  __ j(equal, &done, Label::kNear);
+  __ bind(&not_date_object);
+  __ CallRuntime(Runtime::kThrowNotDateError, 0);
+
+  __ bind(&done);
+  context()->Plug(result);
+}
+
+
 void FullCodeGenerator::EmitDateField(CallRuntime* expr) {
   ZoneList<Expression*>* args = expr->arguments();
   DCHECK(args->length() == 2);
@@ -3784,19 +3806,14 @@ void FullCodeGenerator::EmitDateField(CallRuntime* expr) { 

   VisitForAccumulatorValue(args->at(0));  // Load the object.

-  Label runtime, done, not_date_object;
   Register object = eax;
   Register result = eax;
   Register scratch = ecx;

-  __ JumpIfSmi(object, &not_date_object);
-  __ CmpObjectType(object, JS_DATE_TYPE, scratch);
-  __ j(not_equal, &not_date_object);
-
   if (index->value() == 0) {
     __ mov(result, FieldOperand(object, JSDate::kValueOffset));
-    __ jmp(&done);
   } else {
+    Label runtime, done;
     if (index->value() < JSDate::kFirstUncachedField) {
ExternalReference stamp = ExternalReference::date_cache_stamp(isolate()); 
       __ mov(scratch, Operand::StaticVariable(stamp));
@@ -3804,19 +3821,16 @@ void FullCodeGenerator::EmitDateField(CallRuntime* expr) { 
       __ j(not_equal, &runtime, Label::kNear);
       __ mov(result, FieldOperand(object, JSDate::kValueOffset +
                                           kPointerSize * index->value()));
-      __ jmp(&done);
+      __ jmp(&done, Label::kNear);
     }
     __ bind(&runtime);
     __ PrepareCallCFunction(2, scratch);
     __ mov(Operand(esp, 0), object);
     __ mov(Operand(esp, 1 * kPointerSize), Immediate(index));
__ CallCFunction(ExternalReference::get_date_field_function(isolate()), 2); 
-    __ jmp(&done);
+    __ bind(&done);
   }

-  __ bind(&not_date_object);
-  __ CallRuntime(Runtime::kThrowNotDateError, 0);
-  __ bind(&done);
   context()->Plug(result);
 }

Index: src/x87/lithium-codegen-x87.cc
diff --git a/src/x87/lithium-codegen-x87.cc b/src/x87/lithium-codegen-x87.cc
index 58925cd1cf4c1398e0e96e866723961c2b176d9c..51193c9af1b7b0e083cadb5fe80d1200d514a5d9 100644 
--- a/src/x87/lithium-codegen-x87.cc
+++ b/src/x87/lithium-codegen-x87.cc
@@ -2061,18 +2061,13 @@ void LCodeGen::DoDateField(LDateField* instr) {
   Register result = ToRegister(instr->result());
   Register scratch = ToRegister(instr->temp());
   Smi* index = instr->index();
-  Label runtime, done;
   DCHECK(object.is(result));
   DCHECK(object.is(eax));

-  __ test(object, Immediate(kSmiTagMask));
-  DeoptimizeIf(zero, instr, Deoptimizer::kSmi);
-  __ CmpObjectType(object, JS_DATE_TYPE, scratch);
-  DeoptimizeIf(not_equal, instr, Deoptimizer::kNotADateObject);
-
   if (index->value() == 0) {
     __ mov(result, FieldOperand(object, JSDate::kValueOffset));
   } else {
+    Label runtime, done;
     if (index->value() < JSDate::kFirstUncachedField) {
ExternalReference stamp = ExternalReference::date_cache_stamp(isolate()); 
       __ mov(scratch, Operand::StaticVariable(stamp));
Index: src/x87/lithium-x87.cc
diff --git a/src/x87/lithium-x87.cc b/src/x87/lithium-x87.cc
index 889df6164cac818d1b40487c6cae8dc33f5613f8..c0424e74312fbc844d1da1e6a779437fa7ead7de 100644 
--- a/src/x87/lithium-x87.cc
+++ b/src/x87/lithium-x87.cc
@@ -1821,7 +1821,7 @@ LInstruction* LChunkBuilder::DoDateField(HDateField* instr) { 
   LOperand* date = UseFixed(instr->value(), eax);
   LDateField* result =
       new(zone()) LDateField(date, FixedTemp(ecx), instr->index());
- return MarkAsCall(DefineFixed(result, eax), instr, CAN_DEOPTIMIZE_EAGERLY); + return MarkAsCall(DefineFixed(result, eax), instr, CANNOT_DEOPTIMIZE_EAGERLY); 
 }




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