Merge r4254 to trunk.

src/ia32/codegen-ia32.cc

Index: src/ia32/codegen-ia32.cc
diff --git a/src/ia32/codegen-ia32.cc b/src/ia32/codegen-ia32.cc
index 7c115c5846219c06550ecccf2d1c18a33ac859a5..d71b63988d43b4380a2e952feb0ba4c9a69e006e 100644
--- a/src/ia32/codegen-ia32.cc
+++ b/src/ia32/codegen-ia32.cc
@@ -911,7 +911,6 @@ class FloatingPointHelper : public AllStatic {
   // operand in register number. Returns operand as floating point number
   // on FPU stack.
   static void LoadFloatOperand(MacroAssembler* masm, Register number);
-
   // Code pattern for loading floating point values. Input values must
   // be either smi or heap number objects (fp values). Requirements:
   // operand_1 on TOS+1 or in edx, operand_2 on TOS+2 or in eax.
@@ -930,7 +929,6 @@ class FloatingPointHelper : public AllStatic {
   static void CheckFloatOperands(MacroAssembler* masm,
                                  Label* non_float,
                                  Register scratch);
-
   // Takes the operands in edx and eax and loads them as integers in eax
   // and ecx.
   static void LoadAsIntegers(MacroAssembler* masm,
@@ -949,7 +947,6 @@ class FloatingPointHelper : public AllStatic {
   // into xmm0 and xmm1 if they are. Operands are in edx and eax.
   // Leaves operands unchanged.
   static void LoadSSE2Operands(MacroAssembler* masm);
-
   // Test if operands are numbers (smi or HeapNumber objects), and load
   // them into xmm0 and xmm1 if they are.  Jump to label not_numbers if
   // either operand is not a number.  Operands are in edx and eax.
@@ -2364,22 +2361,6 @@ static bool CouldBeNaN(const Result& result) {
 }
 
 
-// Convert from signed to unsigned comparison to match the way EFLAGS are set
-// by FPU and XMM compare instructions.
-static Condition DoubleCondition(Condition cc) {
-  switch (cc) {
-    case less:          return below;
-    case equal:         return equal;
-    case less_equal:    return below_equal;
-    case greater:       return above;
-    case greater_equal: return above_equal;
-    default:            UNREACHABLE();
-  }
-  UNREACHABLE();
-  return equal;
-}
-
-
 void CodeGenerator::Comparison(AstNode* node,
                                Condition cc,
                                bool strict,
@@ -2450,7 +2431,7 @@ void CodeGenerator::Comparison(AstNode* node,
         left_side = right_side;
         right_side = temp;
         cc = ReverseCondition(cc);
-        // This may re-introduce greater or less_equal as the value of cc.
+        // This may reintroduce greater or less_equal as the value of cc.
         // CompareStub and the inline code both support all values of cc.
       }
       // Implement comparison against a constant Smi, inlining the case
@@ -2499,7 +2480,16 @@ void CodeGenerator::Comparison(AstNode* node,
           // Jump to builtin for NaN.
           not_number.Branch(parity_even, &left_side);
           left_side.Unuse();
-          dest->true_target()->Branch(DoubleCondition(cc));
+          Condition double_cc = cc;
+          switch (cc) {
+            case less:          double_cc = below;       break;
+            case equal:         double_cc = equal;       break;
+            case less_equal:    double_cc = below_equal; break;
+            case greater:       double_cc = above;       break;
+            case greater_equal: double_cc = above_equal; break;
+            default: UNREACHABLE();
+          }
+          dest->true_target()->Branch(double_cc);
           dest->false_target()->Jump();
           not_number.Bind(&left_side);
         }
@@ -2698,53 +2688,21 @@ void CodeGenerator::Comparison(AstNode* node,
       dest->Split(cc);
     }
   } else {
-    // Neither side is a constant Smi, constant 1-char string or constant null.
-    // If either side is a non-smi constant, or known to be a heap number skip
-    // the smi check.
+    // Neither side is a constant Smi or null.
+    // If either side is a non-smi constant, skip the smi check.
     bool known_non_smi =
         (left_side.is_constant() && !left_side.handle()->IsSmi()) ||
-        (right_side.is_constant() && !right_side.handle()->IsSmi()) ||
-        left_side.number_info().IsHeapNumber() ||
-        right_side.number_info().IsHeapNumber();
+        (right_side.is_constant() && !right_side.handle()->IsSmi());
     NaNInformation nan_info =
         (CouldBeNaN(left_side) && CouldBeNaN(right_side)) ?
         kBothCouldBeNaN :
         kCantBothBeNaN;
-
-    // Inline number comparison handling any combination of smi's and heap
-    // numbers if:
-    //   code is in a loop
-    //   the compare operation is different from equal
-    //   compare is not a for-loop comparison
-    // The reason for excluding equal is that it will most likely be done
-    // with smi's (not heap numbers) and the code to comparing smi's is inlined
-    // separately. The same reason applies for for-loop comparison which will
-    // also most likely be smi comparisons.
-    bool is_loop_condition = (node->AsExpression() != NULL)
-        && node->AsExpression()->is_loop_condition();
-    bool inline_number_compare =
-        loop_nesting() > 0 && cc != equal && !is_loop_condition;
-
-    // Left and right needed in registers for the following code.
     left_side.ToRegister();
     right_side.ToRegister();
 
     if (known_non_smi) {
-      // Inline the equality check if both operands can't be a NaN. If both
-      // objects are the same they are equal.
-      if (nan_info == kCantBothBeNaN && cc == equal) {
-        __ cmp(left_side.reg(), Operand(right_side.reg()));
-        dest->true_target()->Branch(equal);
-      }
-
-      // Inline number comparison.
-      if (inline_number_compare) {
-        GenerateInlineNumberComparison(&left_side, &right_side, cc, dest);
-      }
-
-      // End of in-line compare, call out to the compare stub. Don't include
-      // number comparison in the stub if it was inlined.
-      CompareStub stub(cc, strict, nan_info, !inline_number_compare);
+      // When non-smi, call out to the compare stub.
+      CompareStub stub(cc, strict, nan_info);
       Result answer = frame_->CallStub(&stub, &left_side, &right_side);
       if (cc == equal) {
         __ test(answer.reg(), Operand(answer.reg()));
@@ -2763,7 +2721,6 @@ void CodeGenerator::Comparison(AstNode* node,
       Register left_reg = left_side.reg();
       Register right_reg = right_side.reg();
 
-      // In-line check for comparing two smis.
       Result temp = allocator_->Allocate();
       ASSERT(temp.is_valid());
       __ mov(temp.reg(), left_side.reg());
@@ -2771,22 +2728,8 @@ void CodeGenerator::Comparison(AstNode* node,
       __ test(temp.reg(), Immediate(kSmiTagMask));
       temp.Unuse();
       is_smi.Branch(zero, taken);
-
-      // Inline the equality check if both operands can't be a NaN. If both
-      // objects are the same they are equal.
-      if (nan_info == kCantBothBeNaN && cc == equal) {
-        __ cmp(left_side.reg(), Operand(right_side.reg()));
-        dest->true_target()->Branch(equal);
-      }
-
-      // Inline number comparison.
-      if (inline_number_compare) {
-        GenerateInlineNumberComparison(&left_side, &right_side, cc, dest);
-      }
-
-      // End of in-line compare, call out to the compare stub. Don't include
-      // number comparison in the stub if it was inlined.
-      CompareStub stub(cc, strict, nan_info, !inline_number_compare);
+      // When non-smi, call out to the compare stub.
+      CompareStub stub(cc, strict, nan_info);
       Result answer = frame_->CallStub(&stub, &left_side, &right_side);
       if (cc == equal) {
         __ test(answer.reg(), Operand(answer.reg()));
@@ -2809,150 +2752,6 @@ void CodeGenerator::Comparison(AstNode* node,
 }
 
 
-// Check that the comparison operand is a number. Jump to not_numbers jump
-// target passing the left and right result if the operand is not a number.
-static void CheckComparisonOperand(MacroAssembler* masm_,
-                                   Result* operand,
-                                   Result* left_side,
-                                   Result* right_side,
-                                   JumpTarget* not_numbers) {
-  // Perform check if operand is not known to be a number.
-  if (!operand->number_info().IsNumber()) {
-    Label done;
-    __ test(operand->reg(), Immediate(kSmiTagMask));
-    __ j(zero, &done);
-    __ cmp(FieldOperand(operand->reg(), HeapObject::kMapOffset),
-           Immediate(Factory::heap_number_map()));
-    not_numbers->Branch(not_equal, left_side, right_side, not_taken);
-    __ bind(&done);
-  }
-}
-
-
-// Load a comparison operand to the FPU stack. This assumes that the operand has
-// already been checked and is a number.
-static void LoadComparisonOperand(MacroAssembler* masm_,
-                                  Result* operand,
-                                  Result* left_side,
-                                  Result* right_side) {
-  Label done;
-  if (operand->number_info().IsHeapNumber()) {
-    // Operand is known to be a heap number, just load it.
-    __ fld_d(FieldOperand(operand->reg(), HeapNumber::kValueOffset));
-  } else if (operand->number_info().IsSmi()) {
-    // Operand is known to be a smi. Convert it to double and keep the original
-    // smi.
-    __ SmiUntag(operand->reg());
-    __ push(operand->reg());
-    __ fild_s(Operand(esp, 0));
-    __ pop(operand->reg());
-    __ SmiTag(operand->reg());
-  } else {
-    // Operand type not known, check for smi otherwise assume heap number.
-    Label smi;
-    __ test(operand->reg(), Immediate(kSmiTagMask));
-    __ j(zero, &smi);
-    __ fld_d(FieldOperand(operand->reg(), HeapNumber::kValueOffset));
-    __ jmp(&done);
-    __ bind(&smi);
-    __ SmiUntag(operand->reg());
-    __ push(operand->reg());
-    __ fild_s(Operand(esp, 0));
-    __ pop(operand->reg());
-    __ SmiTag(operand->reg());
-    __ jmp(&done);
-  }
-  __ bind(&done);
-}
-
-
-// Load a comparison operand into into a XMM register. Jump to not_numbers jump
-// target passing the left and right result if the operand is not a number.
-static void LoadComparisonOperandSSE2(MacroAssembler* masm_,
-                                      Result* operand,
-                                      XMMRegister reg,
-                                      Result* left_side,
-                                      Result* right_side,
-                                      JumpTarget* not_numbers) {
-  Label done;
-  if (operand->number_info().IsHeapNumber()) {
-    // Operand is known to be a heap number, just load it.
-    __ movdbl(reg, FieldOperand(operand->reg(), HeapNumber::kValueOffset));
-  } else if (operand->number_info().IsSmi()) {
-    // Operand is known to be a smi. Convert it to double and keep the original
-    // smi.
-    __ SmiUntag(operand->reg());
-    __ cvtsi2sd(reg, Operand(operand->reg()));
-    __ SmiTag(left_side->reg());
-  } else {
-    // Operand type not known, check for smi or heap number.
-    Label smi;
-    __ test(operand->reg(), Immediate(kSmiTagMask));
-    __ j(zero, &smi);
-    if (!operand->number_info().IsNumber()) {
-      __ cmp(FieldOperand(operand->reg(), HeapObject::kMapOffset),
-             Immediate(Factory::heap_number_map()));
-      not_numbers->Branch(not_equal, left_side, right_side, taken);
-    }
-    __ movdbl(reg, FieldOperand(operand->reg(), HeapNumber::kValueOffset));
-    __ jmp(&done);
-
-    __ bind(&smi);
-    // Comvert smi to float and keep the original smi.
-    __ SmiUntag(operand->reg());
-    __ cvtsi2sd(reg, Operand(operand->reg()));
-    __ SmiTag(operand->reg());
-    __ jmp(&done);
-  }
-  __ bind(&done);
-}
-
-
-void CodeGenerator::GenerateInlineNumberComparison(Result* left_side,
-                                                   Result* right_side,
-                                                   Condition cc,
-                                                   ControlDestination* dest) {
-  ASSERT(left_side->is_register());
-  ASSERT(right_side->is_register());
-
-  JumpTarget not_numbers;
-  if (CpuFeatures::IsSupported(SSE2)) {
-    CpuFeatures::Scope use_sse2(SSE2);
-
-    // Load left and right operand into registers xmm0 and xmm1 and compare.
-    LoadComparisonOperandSSE2(masm_, left_side, xmm0, left_side, right_side,
-                              &not_numbers);
-    LoadComparisonOperandSSE2(masm_, right_side, xmm1, left_side, right_side,
-                              &not_numbers);
-    __ comisd(xmm0, xmm1);
-  } else {
-    Label check_right, compare;
-
-    // Make sure that both comparison operands are numbers.
-    CheckComparisonOperand(masm_, left_side, left_side, right_side,
-                           &not_numbers);
-    CheckComparisonOperand(masm_, right_side, left_side, right_side,
-                           &not_numbers);
-
-    // Load right and left operand to FPU stack and compare.
-    LoadComparisonOperand(masm_, right_side, left_side, right_side);
-    LoadComparisonOperand(masm_, left_side, left_side, right_side);
-    __ FCmp();
-  }
-
-  // Bail out if a NaN is involved.
-  not_numbers.Branch(parity_even, left_side, right_side, not_taken);
-
-  // Split to destination targets based on comparison.
-  left_side->Unuse();
-  right_side->Unuse();
-  dest->true_target()->Branch(DoubleCondition(cc));
-  dest->false_target()->Jump();
-
-  not_numbers.Bind(left_side, right_side);
-}
-
-
 // Call the function just below TOS on the stack with the given
 // arguments. The receiver is the TOS.
 void CodeGenerator::CallWithArguments(ZoneList<Expression*>* args,
@@ -11078,70 +10877,63 @@ void CompareStub::Generate(MacroAssembler* masm) {
   __ push(edx);
   __ push(ecx);
 
-  // Generate the number comparison code.
-  if (include_number_compare_) {
-    Label non_number_comparison;
-    Label unordered;
-    if (CpuFeatures::IsSupported(SSE2)) {
-      CpuFeatures::Scope use_sse2(SSE2);
-      CpuFeatures::Scope use_cmov(CMOV);
-
-      FloatingPointHelper::LoadSSE2Operands(masm, &non_number_comparison);
-      __ comisd(xmm0, xmm1);
-
-      // Don't base result on EFLAGS when a NaN is involved.
-      __ j(parity_even, &unordered, not_taken);
-      // Return a result of -1, 0, or 1, based on EFLAGS.
-      __ mov(eax, 0);  // equal
-      __ mov(ecx, Immediate(Smi::FromInt(1)));
-      __ cmov(above, eax, Operand(ecx));
-      __ mov(ecx, Immediate(Smi::FromInt(-1)));
-      __ cmov(below, eax, Operand(ecx));
-      __ ret(2 * kPointerSize);
-    } else {
-      FloatingPointHelper::CheckFloatOperands(
-          masm, &non_number_comparison, ebx);
-      FloatingPointHelper::LoadFloatOperands(masm, ecx);
-      __ FCmp();
+  // Inlined floating point compare.
+  // Call builtin if operands are not floating point or smi.
+  Label check_for_symbols;
+  Label unordered;
+  if (CpuFeatures::IsSupported(SSE2)) {
+    CpuFeatures::Scope use_sse2(SSE2);
+    CpuFeatures::Scope use_cmov(CMOV);
 
-      // Don't base result on EFLAGS when a NaN is involved.
-      __ j(parity_even, &unordered, not_taken);
+    FloatingPointHelper::LoadSSE2Operands(masm, &check_for_symbols);
+    __ comisd(xmm0, xmm1);
 
-      Label below_label, above_label;
-      // Return a result of -1, 0, or 1, based on EFLAGS. In all cases remove
-      // two arguments from the stack as they have been pushed in preparation
-      // of a possible runtime call.
-      __ j(below, &below_label, not_taken);
-      __ j(above, &above_label, not_taken);
+    // Jump to builtin for NaN.
+    __ j(parity_even, &unordered, not_taken);
+    __ mov(eax, 0);  // equal
+    __ mov(ecx, Immediate(Smi::FromInt(1)));
+    __ cmov(above, eax, Operand(ecx));
+    __ mov(ecx, Immediate(Smi::FromInt(-1)));
+    __ cmov(below, eax, Operand(ecx));
+    __ ret(2 * kPointerSize);
+  } else {
+    FloatingPointHelper::CheckFloatOperands(masm, &check_for_symbols, ebx);
+    FloatingPointHelper::LoadFloatOperands(masm, ecx);
+    __ FCmp();
 
-      __ xor_(eax, Operand(eax));
-      __ ret(2 * kPointerSize);
+    // Jump to builtin for NaN.
+    __ j(parity_even, &unordered, not_taken);
 
-      __ bind(&below_label);
-      __ mov(eax, Immediate(Smi::FromInt(-1)));
-      __ ret(2 * kPointerSize);
+    Label below_lbl, above_lbl;
+    // Return a result of -1, 0, or 1, to indicate result of comparison.
+    __ j(below, &below_lbl, not_taken);
+    __ j(above, &above_lbl, not_taken);
 
-      __ bind(&above_label);
-      __ mov(eax, Immediate(Smi::FromInt(1)));
-      __ ret(2 * kPointerSize);
-    }
+    __ xor_(eax, Operand(eax));  // equal
+    // Both arguments were pushed in case a runtime call was needed.
+    __ ret(2 * kPointerSize);
 
-    // If one of the numbers was NaN, then the result is always false.
-    // The cc is never not-equal.
-    __ bind(&unordered);
-    ASSERT(cc_ != not_equal);
-    if (cc_ == less || cc_ == less_equal) {
-      __ mov(eax, Immediate(Smi::FromInt(1)));
-    } else {
-      __ mov(eax, Immediate(Smi::FromInt(-1)));
-    }
-    __ ret(2 * kPointerSize);  // eax, edx were pushed
+    __ bind(&below_lbl);
+    __ mov(eax, Immediate(Smi::FromInt(-1)));
+    __ ret(2 * kPointerSize);
 
-    // The number comparison code did not provide a valid result.
-    __ bind(&non_number_comparison);
+    __ bind(&above_lbl);
+    __ mov(eax, Immediate(Smi::FromInt(1)));
+    __ ret(2 * kPointerSize);  // eax, edx were pushed
+  }
+  // If one of the numbers was NaN, then the result is always false.
+  // The cc is never not-equal.
+  __ bind(&unordered);
+  ASSERT(cc_ != not_equal);
+  if (cc_ == less || cc_ == less_equal) {
+    __ mov(eax, Immediate(Smi::FromInt(1)));
+  } else {
+    __ mov(eax, Immediate(Smi::FromInt(-1)));
   }
+  __ ret(2 * kPointerSize);  // eax, edx were pushed
 
   // Fast negative check for symbol-to-symbol equality.
+  __ bind(&check_for_symbols);
   Label check_for_strings;
   if (cc_ == equal) {
     BranchIfNonSymbol(masm, &check_for_strings, eax, ecx);
@@ -11751,59 +11543,57 @@ void InstanceofStub::Generate(MacroAssembler* masm) {
 }
 
 
-int CompareStub::MinorKey() {
-  // Encode the three parameters in a unique 16 bit value. To avoid duplicate
-  // stubs the never NaN NaN condition is only taken into account if the
-  // condition is equals.
-  ASSERT(static_cast<unsigned>(cc_) < (1 << 13));
-  return ConditionField::encode(static_cast<unsigned>(cc_))
-         | StrictField::encode(strict_)
-         | NeverNanNanField::encode(cc_ == equal ? never_nan_nan_ : false)
-         | IncludeNumberCompareField::encode(include_number_compare_);
-}
-
-
 // Unfortunately you have to run without snapshots to see most of these
 // names in the profile since most compare stubs end up in the snapshot.
 const char* CompareStub::GetName() {
-  if (name_ != NULL) return name_;
-  const int kMaxNameLength = 100;
-  name_ = Bootstrapper::AllocateAutoDeletedArray(kMaxNameLength);
-  if (name_ == NULL) return "OOM";
-
-  const char* cc_name;
   switch (cc_) {
-    case less: cc_name = "LT"; break;
-    case greater: cc_name = "GT"; break;
-    case less_equal: cc_name = "LE"; break;
-    case greater_equal: cc_name = "GE"; break;
-    case equal: cc_name = "EQ"; break;
-    case not_equal: cc_name = "NE"; break;
-    default: cc_name = "UnknownCondition"; break;
-  }
-
-  const char* strict_name = "";
-  if (strict_ && (cc_ == equal || cc_ == not_equal)) {
-    strict_name = "_STRICT";
-  }
-
-  const char* never_nan_nan_name = "";
-  if (never_nan_nan_ && (cc_ == equal || cc_ == not_equal)) {
-    never_nan_nan_name = "_NO_NAN";
+    case less: return "CompareStub_LT";
+    case greater: return "CompareStub_GT";
+    case less_equal: return "CompareStub_LE";
+    case greater_equal: return "CompareStub_GE";
+    case not_equal: {
+      if (strict_) {
+        if (never_nan_nan_) {
+          return "CompareStub_NE_STRICT_NO_NAN";
+        } else {
+          return "CompareStub_NE_STRICT";
+        }
+      } else {
+        if (never_nan_nan_) {
+          return "CompareStub_NE_NO_NAN";
+        } else {
+          return "CompareStub_NE";
+        }
+      }
+    }
+    case equal: {
+      if (strict_) {
+        if (never_nan_nan_) {
+          return "CompareStub_EQ_STRICT_NO_NAN";
+        } else {
+          return "CompareStub_EQ_STRICT";
+        }
+      } else {
+        if (never_nan_nan_) {
+          return "CompareStub_EQ_NO_NAN";
+        } else {
+          return "CompareStub_EQ";
+        }
+      }
+    }
+    default: return "CompareStub";
   }
+}
 
-  const char* include_number_compare_name = "";
-  if (!include_number_compare_) {
-    include_number_compare_name = "_NO_NUMBER";
-  }
 
-  OS::SNPrintF(Vector<char>(name_, kMaxNameLength),
-               "CompareStub_%s%s%s%s",
-               cc_name,
-               strict_name,
-               never_nan_nan_name,
-               include_number_compare_name);
-  return name_;
+int CompareStub::MinorKey() {
+  // Encode the three parameters in a unique 16 bit value. To avoid duplicate
+  // stubs the never NaN NaN condition is only taken into account if the
+  // condition is equals.
+  ASSERT(static_cast<unsigned>(cc_) < (1 << 14));
+  return ConditionField::encode(static_cast<unsigned>(cc_))
+         | StrictField::encode(strict_)
+         | NeverNanNanField::encode(cc_ == equal ? never_nan_nan_ : false);
 }
 
 
@@ -12437,9 +12227,6 @@ void StringCompareStub::GenerateCompareFlatAsciiStrings(MacroAssembler* masm,
   Label result_not_equal;
   Label result_greater;
   Label compare_lengths;
-
-  __ IncrementCounter(&Counters::string_compare_native, 1);
-
   // Find minimum length.
   Label left_shorter;
   __ mov(scratch1, FieldOperand(left, String::kLengthOffset));
@@ -12537,6 +12324,7 @@ void StringCompareStub::Generate(MacroAssembler* masm) {
   __ JumpIfNotBothSequentialAsciiStrings(edx, eax, ecx, ebx, &runtime);
 
   // Compare flat ascii strings.
+  __ IncrementCounter(&Counters::string_compare_native, 1);
   GenerateCompareFlatAsciiStrings(masm, edx, eax, ecx, ebx, edi);
 
   // Call the runtime; it returns -1 (less), 0 (equal), or 1 (greater)