Hydrogen code stubs for vector-based ICs.

src/ic/handler-compiler.cc

Index: src/ic/handler-compiler.cc
diff --git a/src/ic/handler-compiler.cc b/src/ic/handler-compiler.cc
index 22135735f32fdca0639856c2d0a20563612d4da4..7f9ac67c03085ddef523e332d54bda5c64ae8496 100644
--- a/src/ic/handler-compiler.cc
+++ b/src/ic/handler-compiler.cc
@@ -132,8 +132,27 @@ Register NamedStoreHandlerCompiler::FrontendHeader(Register object_reg,
 Register PropertyHandlerCompiler::Frontend(Register object_reg,
                                            Handle<Name> name) {
   Label miss;
+  if (FLAG_vector_ics &&

[Jakob Kummerow, 2014/12/02 08:43:07]

Can we re-use IC::ICUseVector here and below?

[mvstanton, 2014/12/03 11:48:30]

Done.

+      (kind() == Code::LOAD_IC || kind() == Code::KEYED_LOAD_IC)) {
+    if (object_reg.is(VectorLoadICDescriptor::VectorRegister())) {
+      PushVectorAndSlot(scratch2(), scratch3());
+    } else {
+      PushVectorAndSlot();
+    }
+  }
   Register reg = FrontendHeader(object_reg, name, &miss);
   FrontendFooter(name, &miss);
+  // The footer consumes the vector and slot from the stack if
+  // miss occurs

[Jakob Kummerow, 2014/12/02 08:43:07]

nit: Trailing full stop.

[mvstanton, 2014/12/03 11:48:30]

Done.

+  if (FLAG_vector_ics &&
+      (kind() == Code::LOAD_IC || kind() == Code::KEYED_LOAD_IC)) {
+    if (reg.is(VectorLoadICDescriptor::VectorRegister()) &&
+        !reg.is(object_reg)) {

[Jakob Kummerow, 2014/12/02 08:43:07]

Uhm... you've pushed scratch2/scratch3 if object_reg == vector_reg. Now you're
popping them if object_reg != vector_reg. If that's intentional, then it's
confusing and deserves a comment.

[mvstanton, 2014/12/03 11:48:30]

Okay, I've refactored this. The problem is that Frontend() is usually used in a
simple way, with object_reg == receiver(). But the interceptor case plays some
tricks with it. I removed all these contortions here in favor of confining them
to interceptor handler compilation, where they've been reformulated to make more
sense.

The general idea is that the interceptor wants to store the holder in the vector
register, but MISS can still occur during that period. So code that maintains
the vector and slot may need to shift where it stores them to scratch2() and
scratch3() during that time.

This story can now be read in a straight line as a part of interceptor handler
compilation.

+      PopVectorAndSlot(scratch2(), scratch3());
+    } else {
+      DiscardVectorAndSlot();
+    }
+  }
   return reg;
 }
 
@@ -200,7 +219,15 @@ Handle<Code> NamedLoadHandlerCompiler::CompileLoadConstant(Handle<Name> name,
 Handle<Code> NamedLoadHandlerCompiler::CompileLoadNonexistent(
     Handle<Name> name) {
   Label miss;
+  if (FLAG_vector_ics) {
+    DCHECK(kind() == Code::LOAD_IC);
+    PushVectorAndSlot();
+  }
   NonexistentFrontendHeader(name, &miss, scratch2(), scratch3());
+  if (FLAG_vector_ics &&
+      (kind() == Code::LOAD_IC || kind() == Code::KEYED_LOAD_IC)) {
+    DiscardVectorAndSlot();
+  }
   GenerateLoadConstant(isolate()->factory()->undefined_value());
   FrontendFooter(name, &miss);
   return GetCode(kind(), Code::FAST, name);