Use IC register definitions in platform files.

src/ia32/ic-ia32.cc

Index: src/ia32/ic-ia32.cc
diff --git a/src/ia32/ic-ia32.cc b/src/ia32/ic-ia32.cc
index 0b3d110d1148948a7c5a4f0cc8234d2cfd4a3c5d..4ad3cf645d8cb8b07807f37a61c047c5835a8fe8 100644
--- a/src/ia32/ic-ia32.cc
+++ b/src/ia32/ic-ia32.cc
@@ -388,6 +388,8 @@ void KeyedLoadIC::GenerateGeneric(MacroAssembler* masm) {
   //  -- edx    : receiver
   //  -- esp[0] : return address
   // -----------------------------------
+  ASSERT(edx.is(ReceiverRegister()));
+  ASSERT(ecx.is(NameRegister()));
   Label slow, check_name, index_smi, index_name, property_array_property;
   Label probe_dictionary, check_number_dictionary;
 
@@ -566,6 +568,8 @@ void KeyedLoadIC::GenerateString(MacroAssembler* masm) {
   //  -- edx    : receiver
   //  -- esp[0] : return address
   // -----------------------------------
+  ASSERT(edx.is(ReceiverRegister()));
+  ASSERT(ecx.is(NameRegister()));
   Label miss;
 
   Register receiver = edx;
@@ -598,6 +602,8 @@ void KeyedLoadIC::GenerateIndexedInterceptor(MacroAssembler* masm) {
   //  -- edx    : receiver
   //  -- esp[0] : return address
   // -----------------------------------
+  ASSERT(edx.is(ReceiverRegister()));
+  ASSERT(ecx.is(NameRegister()));
   Label slow;
 
   // Check that the receiver isn't a smi.
@@ -640,6 +646,8 @@ void KeyedLoadIC::GenerateSloppyArguments(MacroAssembler* masm) {
   //  -- edx    : receiver
   //  -- esp[0] : return address
   // -----------------------------------
+  ASSERT(edx.is(ReceiverRegister()));
+  ASSERT(ecx.is(NameRegister()));
   Label slow, notin;
   Factory* factory = masm->isolate()->factory();
   Operand mapped_location =
@@ -930,6 +938,8 @@ void LoadIC::GenerateMegamorphic(MacroAssembler* masm) {
   //  -- edx    : receiver
   //  -- esp[0] : return address
   // -----------------------------------
+  ASSERT(edx.is(ReceiverRegister()));
+  ASSERT(ecx.is(NameRegister()));
 
   // Probe the stub cache.
   Code::Flags flags = Code::ComputeHandlerFlags(Code::LOAD_IC);
@@ -947,6 +957,9 @@ void LoadIC::GenerateNormal(MacroAssembler* masm) {
   //  -- edx    : receiver
   //  -- esp[0] : return address
   // -----------------------------------
+  ASSERT(edx.is(ReceiverRegister()));

[Jakob Kummerow, 2014/06/25 10:59:12]

I'm not too happy with these ASSERTs, as opposed to using ReceiverRegister()
instead of raw "edx" below. But I concede that it's hard to decide where to draw
the line. I can live with the ASSERT, at least for now.

[mvstanton, 2014/06/25 15:10:27]

Okay, yep. I'm cautious because when code starts mentioned 4, 5 or 6 registers 
within a few lines I feel like the reader is best served by knowing what those
registers are. It's extra cognitive load to remember "which one is
ReceiverRegister()? Oh yeah." That is, the reader will actually turn it back
into a register.

Plus when you consider that one of the IC spec registers plays another role
(say, it's the accumulator and a call is made), then you really have to be
careful against obscuring the plain old register name.

At any rate, I'll be back in this code in order to unify LoadIC and KeyedLoadIC
register specs. I'll pay the price for any failure to fully push through a
useful abstraction! And in doing that work I'll push the abstraction deeper
wherever possible.

+  ASSERT(ecx.is(NameRegister()));
+
   Label miss, slow;
 
   GenerateNameDictionaryReceiverCheck(masm, edx, eax, ebx, &miss);
@@ -966,19 +979,22 @@ void LoadIC::GenerateNormal(MacroAssembler* masm) {
 }
 
 
-void LoadIC::GenerateMiss(MacroAssembler* masm) {
-  // ----------- S t a t e -------------
-  //  -- ecx    : name
-  //  -- edx    : receiver
-  //  -- esp[0] : return address
-  // -----------------------------------
+// A register that isn't one of the parameters to the load ic.
+static const Register LoadIC_TempRegister() { return ebx; }

[Jakob Kummerow, 2014/06/25 10:59:12]

As discussed, I think medium-term we want to define this globally like
ReceiverRegister() and friends. But for now this is OK.

[mvstanton, 2014/06/25 15:10:27]

Okay, thanks. I will keep it this way for now. I'm reluctant to elevate temp
registers as a concept for the platform independent file to be concerned with.
Lets keep playing the refactoring out and the right home for these will become
clearer.

+
 
+void LoadIC::GenerateMiss(MacroAssembler* masm) {
+  // ----------- S t a t e ------------------
+  //  -- ReceiverRegister()  : receiver

[Jakob Kummerow, 2014/06/25 10:59:12]

Arguably this entire comment block could now be reduced to:
// Return address is on the stack (esp[0]).
But I'm fine with keeping it.

[mvstanton, 2014/06/25 15:10:27]

It's a super-redundant comment, so I'll take it out. :D

+  //  -- NameRegister()      : name
+  //  -- esp[0]              : return address
+  // ----------------------------------------
   __ IncrementCounter(masm->isolate()->counters()->load_miss(), 1);
 
-  __ pop(ebx);
-  __ push(edx);  // receiver
-  __ push(ecx);  // name
-  __ push(ebx);  // return address
+  __ pop(LoadIC_TempRegister());
+  __ push(ReceiverRegister());  // receiver
+  __ push(NameRegister());  // name
+  __ push(LoadIC_TempRegister());  // return address
 
   // Perform tail call to the entry.
   ExternalReference ref =
@@ -988,35 +1004,39 @@ void LoadIC::GenerateMiss(MacroAssembler* masm) {
 
 
 void LoadIC::GenerateRuntimeGetProperty(MacroAssembler* masm) {
-  // ----------- S t a t e -------------
-  //  -- ecx    : key
-  //  -- edx    : receiver
-  //  -- esp[0] : return address
-  // -----------------------------------
-
-  __ pop(ebx);
-  __ push(edx);  // receiver
-  __ push(ecx);  // name
-  __ push(ebx);  // return address
+  // ----------- S t a t e ------------------
+  //  -- ReceiverRegister()  : receiver
+  //  -- NameRegister()      : name
+  //  -- esp[0]              : return address
+  // ----------------------------------------
+  __ pop(LoadIC_TempRegister());
+  __ push(ReceiverRegister());   // receiver
+  __ push(NameRegister());       // name
+  __ push(LoadIC_TempRegister());  // return address
 
   // Perform tail call to the entry.
   __ TailCallRuntime(Runtime::kGetProperty, 2, 1);
 }
 
 
-void KeyedLoadIC::GenerateMiss(MacroAssembler* masm) {
-  // ----------- S t a t e -------------
-  //  -- ecx    : key
-  //  -- edx    : receiver
-  //  -- esp[0] : return address
-  // -----------------------------------
+// A register that isn't one of the parameters to the load ic.
+static const Register KeyedLoadIC_TempRegister() {
+  return LoadIC_TempRegister();
+}
+
 
+void KeyedLoadIC::GenerateMiss(MacroAssembler* masm) {
+  // ----------- S t a t e ------------------
+  //  -- ReceiverRegister()  : receiver
+  //  -- NameRegister()      : name
+  //  -- esp[0]              : return address
+  // ----------------------------------------
   __ IncrementCounter(masm->isolate()->counters()->keyed_load_miss(), 1);
 
-  __ pop(ebx);
-  __ push(edx);  // receiver
-  __ push(ecx);  // name
-  __ push(ebx);  // return address
+  __ pop(KeyedLoadIC_TempRegister());
+  __ push(ReceiverRegister());  // receiver
+  __ push(NameRegister());  // name
+  __ push(KeyedLoadIC_TempRegister());  // return address
 
   // Perform tail call to the entry.
   ExternalReference ref =
@@ -1039,16 +1059,15 @@ const Register KeyedLoadIC::NameRegister() { return LoadIC::NameRegister(); }
 
 
 void KeyedLoadIC::GenerateRuntimeGetProperty(MacroAssembler* masm) {
-  // ----------- S t a t e -------------
-  //  -- ecx    : key
-  //  -- edx    : receiver
-  //  -- esp[0] : return address
-  // -----------------------------------
-
-  __ pop(ebx);
-  __ push(edx);  // receiver
-  __ push(ecx);  // name
-  __ push(ebx);  // return address
+  // ----------- S t a t e ------------------
+  //  -- ReceiverRegister()  : receiver
+  //  -- NameRegister()      : name
+  //  -- esp[0]              : return address
+  // ----------------------------------------
+  __ pop(KeyedLoadIC_TempRegister());
+  __ push(ReceiverRegister());  // receiver
+  __ push(NameRegister());  // name
+  __ push(KeyedLoadIC_TempRegister());  // return address
 
   // Perform tail call to the entry.
   __ TailCallRuntime(Runtime::kKeyedGetProperty, 2, 1);