Improve performance of keyed loads/stores which have a HeapNumber index.

src/x64/stub-cache-x64.cc

 // Copyright 2012 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 3094 matching lines @@
   // ----------- S t a t e -------------
   //  -- rax    : key
   //  -- rdx    : receiver
   //  -- rsp[0]  : return address
   // -----------------------------------
   Handle<Code> miss_ic =
       masm->isolate()->builtins()->KeyedLoadIC_MissForceGeneric();
   __ jmp(miss_ic, RelocInfo::CODE_TARGET);
 }
 
+
+static void GenerateSmiKeyCheck(MacroAssembler* masm,
+                                Register key,
+                                Register scratch,
+                                XMMRegister xmm_scratch0,
+                                XMMRegister xmm_scratch1,
+                                Label* fail) {
+  // Check that key is a smi or a heap number containing a smi and branch
+  // if the check fails.
+  Label key_ok;
+  __ JumpIfSmi(key, &key_ok);
+  __ CheckMap(key,
+              masm->isolate()->factory()->heap_number_map(),
+              fail,
+              DONT_DO_SMI_CHECK);
+  __ movsd(xmm_scratch0, FieldOperand(key, HeapNumber::kValueOffset));
+  __ cvttsd2si(scratch, xmm_scratch0);
+  __ cvtlsi2sd(xmm_scratch1, scratch);
+  __ ucomisd(xmm_scratch1, xmm_scratch0);
+  __ j(not_equal, fail);
+  __ j(parity_even, fail);  // NaN.
+  __ Integer32ToSmi(key, scratch);
+  __ bind(&key_ok);
+}
+
+
 void KeyedLoadStubCompiler::GenerateLoadExternalArray(
     MacroAssembler* masm,
     ElementsKind elements_kind) {
   // ----------- S t a t e -------------
   //  -- rax    : key
   //  -- rdx    : receiver
   //  -- rsp[0] : return address
   // -----------------------------------
   Label slow, miss_force_generic;
 
   // This stub is meant to be tail-jumped to, the receiver must already
   // have been verified by the caller to not be a smi.
 
-  // Check that the key is a smi.
-  __ JumpIfNotSmi(rax, &miss_force_generic);
+  // Check that the key is a smi or a heap number convertible to a smi.
+  GenerateSmiKeyCheck(masm, rax, rcx, xmm0, xmm1, &miss_force_generic);
 
   // Check that the index is in range.
   __ movq(rbx, FieldOperand(rdx, JSObject::kElementsOffset));
   __ SmiToInteger32(rcx, rax);
   __ cmpq(rax, FieldOperand(rbx, ExternalArray::kLengthOffset));
   // Unsigned comparison catches both negative and too-large values.
   __ j(above_equal, &miss_force_generic);
 
   // rax: index (as a smi)
   // rdx: receiver (JSObject)
@@ skipping 113 matching lines @@
   //  -- rax     : value
   //  -- rcx     : key
   //  -- rdx     : receiver
   //  -- rsp[0]  : return address
   // -----------------------------------
   Label slow, miss_force_generic;
 
   // This stub is meant to be tail-jumped to, the receiver must already
   // have been verified by the caller to not be a smi.
 
-  // Check that the key is a smi.
-  __ JumpIfNotSmi(rcx, &miss_force_generic);
+  // Check that the key is a smi or a heap number convertible to a smi.
+  GenerateSmiKeyCheck(masm, rcx, rbx, xmm0, xmm1, &miss_force_generic);
 
   // Check that the index is in range.
   __ movq(rbx, FieldOperand(rdx, JSObject::kElementsOffset));
   __ SmiToInteger32(rdi, rcx);  // Untag the index.
   __ cmpq(rcx, FieldOperand(rbx, ExternalArray::kLengthOffset));
   // Unsigned comparison catches both negative and too-large values.
   __ j(above_equal, &miss_force_generic);
 
   // Handle both smis and HeapNumbers in the fast path. Go to the
   // runtime for all other kinds of values.
@@ skipping 160 matching lines @@
   // ----------- S t a t e -------------
   //  -- rax    : key
   //  -- rdx    : receiver
   //  -- rsp[0] : return address
   // -----------------------------------
   Label miss_force_generic;
 
   // This stub is meant to be tail-jumped to, the receiver must already
   // have been verified by the caller to not be a smi.
 
-  // Check that the key is a smi.
-  __ JumpIfNotSmi(rax, &miss_force_generic);
+  // Check that the key is a smi or a heap number convertible to a smi.
+  GenerateSmiKeyCheck(masm, rax, rcx, xmm0, xmm1, &miss_force_generic);
 
   // Get the elements array.
   __ movq(rcx, FieldOperand(rdx, JSObject::kElementsOffset));
   __ AssertFastElements(rcx);
 
   // Check that the key is within bounds.
   __ SmiCompare(rax, FieldOperand(rcx, FixedArray::kLengthOffset));
   __ j(above_equal, &miss_force_generic);
 
   // Load the result and make sure it's not the hole.
@@ skipping 20 matching lines @@
   // ----------- S t a t e -------------
   //  -- rax    : key
   //  -- rdx    : receiver
   //  -- rsp[0] : return address
   // -----------------------------------
   Label miss_force_generic, slow_allocate_heapnumber;
 
   // This stub is meant to be tail-jumped to, the receiver must already
   // have been verified by the caller to not be a smi.
 
-  // Check that the key is a smi.
-  __ JumpIfNotSmi(rax, &miss_force_generic);
+  // Check that the key is a smi or a heap number convertible to a smi.
+  GenerateSmiKeyCheck(masm, rax, rcx, xmm0, xmm1, &miss_force_generic);
 
   // Get the elements array.
   __ movq(rcx, FieldOperand(rdx, JSObject::kElementsOffset));
   __ AssertFastElements(rcx);
 
   // Check that the key is within bounds.
   __ SmiCompare(rax, FieldOperand(rcx, FixedArray::kLengthOffset));
   __ j(above_equal, &miss_force_generic);
 
   // Check for the hole
@@ skipping 34 matching lines @@
   //  -- rcx    : key
   //  -- rdx    : receiver
   //  -- rsp[0] : return address
   // -----------------------------------
   Label miss_force_generic, transition_elements_kind, finish_store, grow;
   Label check_capacity, slow;
 
   // This stub is meant to be tail-jumped to, the receiver must already
   // have been verified by the caller to not be a smi.
 
-  // Check that the key is a smi.
-  __ JumpIfNotSmi(rcx, &miss_force_generic);
+  // Check that the key is a smi or a heap number convertible to a smi.
+  GenerateSmiKeyCheck(masm, rcx, rbx, xmm0, xmm1, &miss_force_generic);
 
   if (elements_kind == FAST_SMI_ONLY_ELEMENTS) {
     __ JumpIfNotSmi(rax, &transition_elements_kind);
   }
 
   // Get the elements array and make sure it is a fast element array, not 'cow'.
   __ movq(rdi, FieldOperand(rdx, JSObject::kElementsOffset));
   // Check that the key is within bounds.
   if (is_js_array) {
     __ SmiCompare(rcx, FieldOperand(rdx, JSArray::kLengthOffset));
@@ skipping 120 matching lines @@
   //  -- rcx    : key
   //  -- rdx    : receiver
   //  -- rsp[0] : return address
   // -----------------------------------
   Label miss_force_generic, transition_elements_kind, finish_store;
   Label grow, slow, check_capacity;
 
   // This stub is meant to be tail-jumped to, the receiver must already
   // have been verified by the caller to not be a smi.
 
-  // Check that the key is a smi.
-  __ JumpIfNotSmi(rcx, &miss_force_generic);
+  // Check that the key is a smi or a heap number convertible to a smi.
+  GenerateSmiKeyCheck(masm, rcx, rbx, xmm0, xmm1, &miss_force_generic);
 
   // Get the elements array.
   __ movq(rdi, FieldOperand(rdx, JSObject::kElementsOffset));
   __ AssertFastElements(rdi);
 
   // Check that the key is within bounds.
   if (is_js_array) {
       __ SmiCompare(rcx, FieldOperand(rdx, JSArray::kLengthOffset));
       if (grow_mode == ALLOW_JSARRAY_GROWTH) {
         __ j(above_equal, &grow);
@@ skipping 89 matching lines @@
     __ jmp(ic_slow, RelocInfo::CODE_TARGET);
   }
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64