From 50a829b3cfe8ec0b7ccd1b7e154e632c9a73e5f0 Mon Sep 17 00:00:00 2001
From: "weiliang.lin@intel.com" <weiliang.lin@intel.com>
Date: Mon, 10 Nov 2014 05:50:51 +0000
Subject: [PATCH] X87: Try avoiding MISS for callic monomorphic case.

port 6412c8ba70f2331aae0f21b968dd051b2320b947 (r25207)

original commit message:

  Try avoiding MISS for callic monomorphic case.

BUG=
R=weiliang.lin@intel.com

Review URL: https://codereview.chromium.org/713743003

Patch from Chunyang Dai <chunyang.dai@intel.com>.

Cr-Commit-Position: refs/heads/master@{#25230}
git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@25230 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
---
 src/x87/code-stubs-x87.cc | 77 ++++++++++++++++++++++++++++-----------
 1 file changed, 56 insertions(+), 21 deletions(-)

diff --git a/src/x87/code-stubs-x87.cc b/src/x87/code-stubs-x87.cc
index 5d38d75455..8925d4ffb3 100644
--- a/src/x87/code-stubs-x87.cc
+++ b/src/x87/code-stubs-x87.cc
@@ -1900,6 +1900,10 @@ void CallICStub::Generate(MacroAssembler* masm) {
   // edi - function
   // edx - slot id
   Isolate* isolate = masm->isolate();
+  const int with_types_offset =
+      FixedArray::OffsetOfElementAt(TypeFeedbackVector::kWithTypesIndex);
+  const int generic_offset =
+      FixedArray::OffsetOfElementAt(TypeFeedbackVector::kGenericCountIndex);
   Label extra_checks_or_miss, slow_start;
   Label slow, non_function, wrap, cont;
   Label have_js_function;
@@ -1939,35 +1943,66 @@ void CallICStub::Generate(MacroAssembler* masm) {
   }
 
   __ bind(&extra_checks_or_miss);
-  Label miss;
+  Label uninitialized, miss;
 
   __ mov(ecx, FieldOperand(ebx, edx, times_half_pointer_size,
                            FixedArray::kHeaderSize));
   __ cmp(ecx, Immediate(TypeFeedbackVector::MegamorphicSentinel(isolate)));
   __ j(equal, &slow_start);
-  __ cmp(ecx, Immediate(TypeFeedbackVector::UninitializedSentinel(isolate)));
-  __ j(equal, &miss);
 
-  if (!FLAG_trace_ic) {
-    // We are going megamorphic. If the feedback is a JSFunction, it is fine
-    // to handle it here. More complex cases are dealt with in the runtime.
-    __ AssertNotSmi(ecx);
-    __ CmpObjectType(ecx, JS_FUNCTION_TYPE, ecx);
-    __ j(not_equal, &miss);
-    __ mov(FieldOperand(ebx, edx, times_half_pointer_size,
-                        FixedArray::kHeaderSize),
-           Immediate(TypeFeedbackVector::MegamorphicSentinel(isolate)));
-    // We have to update statistics for runtime profiling.
-    const int with_types_offset =
-        FixedArray::OffsetOfElementAt(TypeFeedbackVector::kWithTypesIndex);
-    __ sub(FieldOperand(ebx, with_types_offset), Immediate(Smi::FromInt(1)));
-    const int generic_offset =
-        FixedArray::OffsetOfElementAt(TypeFeedbackVector::kGenericCountIndex);
-    __ add(FieldOperand(ebx, generic_offset), Immediate(Smi::FromInt(1)));
-    __ jmp(&slow_start);
+  // The following cases attempt to handle MISS cases without going to the
+  // runtime.
+  if (FLAG_trace_ic) {
+    __ jmp(&miss);
   }
 
-  // We are here because tracing is on or we are going monomorphic.
+  __ cmp(ecx, Immediate(TypeFeedbackVector::UninitializedSentinel(isolate)));
+  __ j(equal, &uninitialized);
+
+  // We are going megamorphic. If the feedback is a JSFunction, it is fine
+  // to handle it here. More complex cases are dealt with in the runtime.
+  __ AssertNotSmi(ecx);
+  __ CmpObjectType(ecx, JS_FUNCTION_TYPE, ecx);
+  __ j(not_equal, &miss);
+  __ mov(
+      FieldOperand(ebx, edx, times_half_pointer_size, FixedArray::kHeaderSize),
+      Immediate(TypeFeedbackVector::MegamorphicSentinel(isolate)));
+  // We have to update statistics for runtime profiling.
+  __ sub(FieldOperand(ebx, with_types_offset), Immediate(Smi::FromInt(1)));
+  __ add(FieldOperand(ebx, generic_offset), Immediate(Smi::FromInt(1)));
+  __ jmp(&slow_start);
+
+  __ bind(&uninitialized);
+
+  // We are going monomorphic, provided we actually have a JSFunction.
+  __ JumpIfSmi(edi, &miss);
+
+  // Goto miss case if we do not have a function.
+  __ CmpObjectType(edi, JS_FUNCTION_TYPE, ecx);
+  __ j(not_equal, &miss);
+
+  // Make sure the function is not the Array() function, which requires special
+  // behavior on MISS.
+  __ LoadGlobalFunction(Context::ARRAY_FUNCTION_INDEX, ecx);
+  __ cmp(edi, ecx);
+  __ j(equal, &miss);
+
+  // Update stats.
+  __ add(FieldOperand(ebx, with_types_offset), Immediate(Smi::FromInt(1)));
+
+  // Store the function.
+  __ mov(
+      FieldOperand(ebx, edx, times_half_pointer_size, FixedArray::kHeaderSize),
+      edi);
+
+  // Update the write barrier.
+  __ mov(eax, edi);
+  __ RecordWriteArray(ebx, eax, edx, kDontSaveFPRegs, EMIT_REMEMBERED_SET,
+                      OMIT_SMI_CHECK);
+  __ jmp(&have_js_function);
+
+  // We are here because tracing is on or we encountered a MISS case we can't
+  // handle here.
   __ bind(&miss);
   GenerateMiss(masm);