Collect type feedback on result of Math.[round|ceil|floor]

src/ia32/code-stubs-ia32.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_IA32
 
 #include "src/base/bits.h"
 #include "src/bootstrapper.h"
@@ skipping 2247 matching lines @@
   CallFunctionNoFeedback(masm,
                          arg_count(),
                          true,
                          CallAsMethod());
 
   // Unreachable.
   __ int3();
 }
 
 
+void CallIC_RoundStub::Generate(MacroAssembler* masm) {
+  Register function = edi;
+  Register vector = ebx;
+  Register slot = edx;
+
+  Register temp = eax;
+  XMMRegister xmm_temp1 = xmm0;
+  XMMRegister xmm_temp2 = xmm1;
+  Label tail, miss;
+
+  // Ensure nobody has snuck in another function.
+  __ BranchIfNotBuiltin(function, temp, kMathRound, &miss);
+
+  if (arg_count() > 0) {
+    ExternalReference minus_one_half =
+        ExternalReference::address_of_minus_one_half();
+
+    __ mov(temp, Operand(esp, arg_count() * kPointerSize));
+    Handle<Map> map = isolate()->factory()->heap_number_map();
+    __ CheckMap(temp, map, &tail, DO_SMI_CHECK);
+
+    // If the number is positive, it doesn't round to -0
+    __ movsd(xmm_temp1, FieldOperand(eax, HeapNumber::kValueOffset));
+
+    // If the number is >0, it doesn't round to -0
+    __ xorps(xmm_temp2, xmm_temp2);
+    __ ucomisd(xmm_temp1, xmm_temp2);
+    __ j(above, &tail, Label::kNear);
+
+    // If the number is <-.5, it doesn't round to -0
+    __ movsd(xmm_temp2, Operand::StaticVariable(minus_one_half));
+    __ ucomisd(xmm_temp1, xmm_temp2);
+    __ j(below, &tail, Label::kNear);
+
+    // The only positive result remaining is 0, it doesn't round to -0..
+    __ movmskpd(temp, xmm_temp1);
+    __ test(temp, Immediate(1));
+    __ j(zero, &tail, Label::kNear);
+
+    __ mov(FieldOperand(vector, slot, times_half_pointer_size,
+                        FixedArray::kHeaderSize + kPointerSize),
+           Immediate(Smi::FromInt(kHasReturnedMinusZeroSentinel)));
+  }
+
+  __ bind(&tail);
+  CallFunctionNoFeedback(masm, arg_count(), true, CallAsMethod());
+
+  // Unreachable.
+  __ int3();
+
+  __ bind(&miss);
+  GenerateMiss(masm);
+  __ jmp(&tail);
+}
+
+
+void CallIC_FloorStub::Generate(MacroAssembler* masm) {
+  Register function = edi;
+  Register vector = ebx;
+  Register slot = edx;
+
+  Register temp = eax;
+  Label tail, miss;
+
+  // Ensure nobody has snuck in another function.
+  __ BranchIfNotBuiltin(function, temp, kMathFloor, &miss);
+
+  if (arg_count() > 0) {
+    __ mov(temp, Operand(esp, arg_count() * kPointerSize));
+    Handle<Map> map = isolate()->factory()->heap_number_map();
+    __ CheckMap(temp, map, &tail, DO_SMI_CHECK);
+
+    // The only number that floors to -0 is -0.
+    __ cmp(FieldOperand(temp, HeapNumber::kExponentOffset),
+           Immediate(0x80000000));
+    __ j(not_equal, &tail);
+
+    __ cmp(FieldOperand(temp, HeapNumber::kMantissaOffset), Immediate(0));
+    __ j(not_equal, &tail);
+
+    __ mov(FieldOperand(vector, slot, times_half_pointer_size,
+                        FixedArray::kHeaderSize + kPointerSize),
+           Immediate(Smi::FromInt(kHasReturnedMinusZeroSentinel)));
+  }
+
+  __ bind(&tail);
+  CallFunctionNoFeedback(masm, arg_count(), true, CallAsMethod());
+
+  // Unreachable.
+  __ int3();
+
+  __ bind(&miss);
+  GenerateMiss(masm);
+  __ jmp(&tail);
+}
+
+
+void CallIC_CeilStub::Generate(MacroAssembler* masm) {
+  Register function = edi;
+  Register vector = ebx;
+  Register slot = edx;
+
+  Register temp = eax;
+  XMMRegister xmm_temp1 = xmm0;
+  XMMRegister xmm_temp2 = xmm1;
+  Label tail, miss;
+
+  // Ensure nobody has snuck in another function.
+  __ BranchIfNotBuiltin(function, temp, kMathCeil, &miss);
+
+  if (arg_count() > 0) {
+    ExternalReference minus_one = ExternalReference::address_of_minus_one();
+
+    __ mov(temp, Operand(esp, arg_count() * kPointerSize));
+    Handle<Map> map = isolate()->factory()->heap_number_map();
+    __ CheckMap(temp, map, &tail, DO_SMI_CHECK);
+
+    __ movsd(xmm_temp1, FieldOperand(eax, HeapNumber::kValueOffset));
+
+    // If the number is >0, it doesn't round to -0
+    __ xorps(xmm_temp2, xmm_temp2);
+    __ ucomisd(xmm_temp1, xmm_temp2);
+    __ j(greater, &tail, Label::kNear);
+
+    // If the number is <=-1, it doesn't round to -0
+    __ movsd(xmm_temp2, Operand::StaticVariable(minus_one));
+    __ ucomisd(xmm_temp1, xmm_temp2);
+    __ j(less_equal, &tail, Label::kNear);
+
+    // The only positive result remaining is 0, it doesn't round to -0..
+    __ movmskpd(temp, xmm_temp1);
+    __ test(temp, Immediate(1));
+    __ j(zero, &tail, Label::kNear);
+
+    __ mov(FieldOperand(vector, slot, times_half_pointer_size,
+                        FixedArray::kHeaderSize + kPointerSize),
+           Immediate(Smi::FromInt(kHasReturnedMinusZeroSentinel)));
+  }
+
+  __ bind(&tail);
+  CallFunctionNoFeedback(masm, arg_count(), true, CallAsMethod());
+
+  // Unreachable.
+  __ int3();
+
+  __ bind(&miss);
+  GenerateMiss(masm);
+  __ jmp(&tail);
+}
+
+
 void CallICStub::Generate(MacroAssembler* masm) {
   // edi - function
   // edx - slot id
   // ebx - vector
   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;
@@ skipping 88 matching lines @@
   // 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);
 
+  // Make sure that the function is not Math.floor, Math.round or Math.ceil
+  // which have special CallICs to handle -0.0.
+  __ mov(eax, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset));
+  __ mov(eax, FieldOperand(eax, SharedFunctionInfo::kFunctionDataOffset));
+  __ cmp(eax, Immediate(Smi::FromInt(kMathRound)));

[mvstanton, 2015/05/04 09:41:22]

Make this look like the other platforms, where you just compare against 0
instead of each interesting builtin id..

[danno, 2015/05/04 14:31:56]

Done.

+  __ j(equal, &miss);
+  __ cmp(eax, Immediate(Smi::FromInt(kMathFloor)));
+  __ j(equal, &miss);
+  __ cmp(eax, Immediate(Smi::FromInt(kMathCeil)));
+  __ j(equal, &miss);
+
   // Update stats.
   __ add(FieldOperand(ebx, with_types_offset), Immediate(Smi::FromInt(1)));
 
   // Store the function. Use a stub since we need a frame for allocation.
   // ebx - vector
   // edx - slot
   // edi - function
   {
     FrameScope scope(masm, StackFrame::INTERNAL);
     CreateWeakCellStub create_stub(isolate);
@@ skipping 2255 matching lines @@
 }
 
 
 void CallIC_ArrayTrampolineStub::Generate(MacroAssembler* masm) {
   EmitLoadTypeFeedbackVector(masm, ebx);
   CallIC_ArrayStub stub(isolate(), state());
   __ jmp(stub.GetCode(), RelocInfo::CODE_TARGET);
 }
 
 
+void CallIC_RoundTrampolineStub::Generate(MacroAssembler* masm) {
+  EmitLoadTypeFeedbackVector(masm, ebx);
+  CallIC_RoundStub stub(isolate(), state());
+  __ jmp(stub.GetCode(), RelocInfo::CODE_TARGET);
+}
+
+
+void CallIC_FloorTrampolineStub::Generate(MacroAssembler* masm) {
+  EmitLoadTypeFeedbackVector(masm, ebx);
+  CallIC_FloorStub stub(isolate(), state());
+  __ jmp(stub.GetCode(), RelocInfo::CODE_TARGET);
+}
+
+
+void CallIC_CeilTrampolineStub::Generate(MacroAssembler* masm) {
+  EmitLoadTypeFeedbackVector(masm, ebx);
+  CallIC_CeilStub stub(isolate(), state());
+  __ jmp(stub.GetCode(), RelocInfo::CODE_TARGET);
+}
+
+
 void ProfileEntryHookStub::MaybeCallEntryHook(MacroAssembler* masm) {
   if (masm->isolate()->function_entry_hook() != NULL) {
     ProfileEntryHookStub stub(masm->isolate());
     masm->CallStub(&stub);
   }
 }
 
 
 void ProfileEntryHookStub::Generate(MacroAssembler* masm) {
   // Save volatile registers.
@@ skipping 746 matching lines @@
                            ApiParameterOperand(2), kStackSpace, nullptr,
                            Operand(ebp, 7 * kPointerSize), NULL);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32