Truncate rather than round to nearest when performing float-to-integer...

src/ia32/ic-ia32.cc

 // Copyright 2010 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 700 matching lines @@
   __ ret(0);
 
   StubRuntimeCallHelper call_helper;
   char_at_generator.GenerateSlow(masm, call_helper);
 
   __ bind(&miss);
   GenerateMiss(masm);
 }
 
 
-void KeyedLoadIC::GenerateExternalArray(MacroAssembler* masm,
-                                        ExternalArrayType array_type) {
-  // ----------- S t a t e -------------
-  //  -- eax    : key
-  //  -- edx    : receiver
-  //  -- esp[0] : return address
-  // -----------------------------------
-  Label slow, failed_allocation;
-
-  // Check that the object isn't a smi.
-  __ test(edx, Immediate(kSmiTagMask));
-  __ j(zero, &slow, not_taken);
-
-  // Check that the key is a smi.
-  __ test(eax, Immediate(kSmiTagMask));
-  __ j(not_zero, &slow, not_taken);
-
-  // Get the map of the receiver.
-  __ mov(ecx, FieldOperand(edx, HeapObject::kMapOffset));
-  // Check that the receiver does not require access checks.  We need
-  // to check this explicitly since this generic stub does not perform
-  // map checks.
-  __ test_b(FieldOperand(ecx, Map::kBitFieldOffset),
-            1 << Map::kIsAccessCheckNeeded);
-  __ j(not_zero, &slow, not_taken);
-
-  __ CmpInstanceType(ecx, JS_OBJECT_TYPE);
-  __ j(not_equal, &slow, not_taken);
-
-  // Check that the elements array is the appropriate type of
-  // ExternalArray.
-  __ mov(ebx, FieldOperand(edx, JSObject::kElementsOffset));
-  Handle<Map> map(Heap::MapForExternalArrayType(array_type));
-  __ cmp(FieldOperand(ebx, HeapObject::kMapOffset),
-         Immediate(map));
-  __ j(not_equal, &slow, not_taken);
-
-  // eax: key, known to be a smi.
-  // edx: receiver, known to be a JSObject.
-  // ebx: elements object, known to be an external array.
-  // Check that the index is in range.
-  __ mov(ecx, eax);
-  __ SmiUntag(ecx);  // Untag the index.
-  __ cmp(ecx, FieldOperand(ebx, ExternalArray::kLengthOffset));
-  // Unsigned comparison catches both negative and too-large values.
-  __ j(above_equal, &slow);
-
-  __ mov(ebx, FieldOperand(ebx, ExternalArray::kExternalPointerOffset));
-  // ebx: base pointer of external storage
-  switch (array_type) {
-    case kExternalByteArray:
-      __ movsx_b(ecx, Operand(ebx, ecx, times_1, 0));
-      break;
-    case kExternalUnsignedByteArray:
-      __ movzx_b(ecx, Operand(ebx, ecx, times_1, 0));
-      break;
-    case kExternalShortArray:
-      __ movsx_w(ecx, Operand(ebx, ecx, times_2, 0));
-      break;
-    case kExternalUnsignedShortArray:
-      __ movzx_w(ecx, Operand(ebx, ecx, times_2, 0));
-      break;
-    case kExternalIntArray:
-    case kExternalUnsignedIntArray:
-      __ mov(ecx, Operand(ebx, ecx, times_4, 0));
-      break;
-    case kExternalFloatArray:
-      __ fld_s(Operand(ebx, ecx, times_4, 0));
-      break;
-    default:
-      UNREACHABLE();
-      break;
-  }
-
-  // For integer array types:
-  // ecx: value
-  // For floating-point array type:
-  // FP(0): value
-
-  if (array_type == kExternalIntArray ||
-      array_type == kExternalUnsignedIntArray) {
-    // For the Int and UnsignedInt array types, we need to see whether
-    // the value can be represented in a Smi. If not, we need to convert
-    // it to a HeapNumber.
-    Label box_int;
-    if (array_type == kExternalIntArray) {
-      __ cmp(ecx, 0xC0000000);
-      __ j(sign, &box_int);
-    } else {
-      ASSERT_EQ(array_type, kExternalUnsignedIntArray);
-      // The test is different for unsigned int values. Since we need
-      // the value to be in the range of a positive smi, we can't
-      // handle either of the top two bits being set in the value.
-      __ test(ecx, Immediate(0xC0000000));
-      __ j(not_zero, &box_int);
-    }
-
-    __ mov(eax, ecx);
-    __ SmiTag(eax);
-    __ ret(0);
-
-    __ bind(&box_int);
-
-    // Allocate a HeapNumber for the int and perform int-to-double
-    // conversion.
-    if (array_type == kExternalIntArray) {
-      __ push(ecx);
-      __ fild_s(Operand(esp, 0));
-      __ pop(ecx);
-    } else {
-      ASSERT(array_type == kExternalUnsignedIntArray);
-      // Need to zero-extend the value.
-      // There's no fild variant for unsigned values, so zero-extend
-      // to a 64-bit int manually.
-      __ push(Immediate(0));
-      __ push(ecx);
-      __ fild_d(Operand(esp, 0));
-      __ pop(ecx);
-      __ pop(ecx);
-    }
-    // FP(0): value
-    __ AllocateHeapNumber(ecx, ebx, edi, &failed_allocation);
-    // Set the value.
-    __ mov(eax, ecx);
-    __ fstp_d(FieldOperand(eax, HeapNumber::kValueOffset));
-    __ ret(0);
-  } else if (array_type == kExternalFloatArray) {
-    // For the floating-point array type, we need to always allocate a
-    // HeapNumber.
-    __ AllocateHeapNumber(ecx, ebx, edi, &failed_allocation);
-    // Set the value.
-    __ mov(eax, ecx);
-    __ fstp_d(FieldOperand(eax, HeapNumber::kValueOffset));
-    __ ret(0);
-  } else {
-    __ mov(eax, ecx);
-    __ SmiTag(eax);
-    __ ret(0);
-  }
-
-  // If we fail allocation of the HeapNumber, we still have a value on
-  // top of the FPU stack. Remove it.
-  __ bind(&failed_allocation);
-  __ ffree();
-  __ fincstp();
-  // Fall through to slow case.
-
-  // Slow case: Jump to runtime.
-  __ bind(&slow);
-  __ IncrementCounter(&Counters::keyed_load_external_array_slow, 1);
-  GenerateRuntimeGetProperty(masm);
-}
-
-
 void KeyedLoadIC::GenerateIndexedInterceptor(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- eax    : key
   //  -- edx    : receiver
   //  -- esp[0] : return address
   // -----------------------------------
   Label slow;
 
   // Check that the receiver isn't a smi.
   __ test(edx, Immediate(kSmiTagMask));
@@ skipping 139 matching lines @@
   // edx: receiver
   // edi: FixedArray receiver->elements
   __ mov(CodeGenerator::FixedArrayElementOperand(edi, ecx), eax);
   // Update write barrier for the elements array address.
   __ mov(edx, Operand(eax));
   __ RecordWrite(edi, 0, edx, ecx);
   __ ret(0);
 }
 
 
-void KeyedStoreIC::GenerateExternalArray(MacroAssembler* masm,
-                                         ExternalArrayType array_type) {
-  // ----------- S t a t e -------------
-  //  -- eax    : value
-  //  -- ecx    : key
-  //  -- edx    : receiver
-  //  -- esp[0] : return address
-  // -----------------------------------
-  Label slow, check_heap_number;
-
-  // Check that the object isn't a smi.
-  __ test(edx, Immediate(kSmiTagMask));
-  __ j(zero, &slow);
-  // Get the map from the receiver.
-  __ mov(edi, FieldOperand(edx, HeapObject::kMapOffset));
-  // Check that the receiver does not require access checks.  We need
-  // to do this because this generic stub does not perform map checks.
-  __ test_b(FieldOperand(edi, Map::kBitFieldOffset),
-            1 << Map::kIsAccessCheckNeeded);
-  __ j(not_zero, &slow);
-  // Check that the key is a smi.
-  __ test(ecx, Immediate(kSmiTagMask));
-  __ j(not_zero, &slow);
-  // Get the instance type from the map of the receiver.
-  __ CmpInstanceType(edi, JS_OBJECT_TYPE);
-  __ j(not_equal, &slow);
-
-  // Check that the elements array is the appropriate type of
-  // ExternalArray.
-  // eax: value
-  // edx: receiver, a JSObject
-  // ecx: key, a smi
-  __ mov(edi, FieldOperand(edx, JSObject::kElementsOffset));
-  __ CheckMap(edi, Handle<Map>(Heap::MapForExternalArrayType(array_type)),
-              &slow, true);
-
-  // Check that the index is in range.
-  __ mov(ebx, ecx);
-  __ SmiUntag(ebx);
-  __ cmp(ebx, FieldOperand(edi, ExternalArray::kLengthOffset));
-  // Unsigned comparison catches both negative and too-large values.
-  __ j(above_equal, &slow);
-
-  // Handle both smis and HeapNumbers in the fast path. Go to the
-  // runtime for all other kinds of values.
-  // eax: value
-  // edx: receiver
-  // ecx: key
-  // edi: elements array
-  // ebx: untagged index
-  __ test(eax, Immediate(kSmiTagMask));
-  __ j(not_equal, &check_heap_number);
-  // smi case
-  __ mov(ecx, eax);  // Preserve the value in eax.  Key is no longer needed.
-  __ SmiUntag(ecx);
-  __ mov(edi, FieldOperand(edi, ExternalArray::kExternalPointerOffset));
-  // ecx: base pointer of external storage
-  switch (array_type) {
-    case kExternalByteArray:
-    case kExternalUnsignedByteArray:
-      __ mov_b(Operand(edi, ebx, times_1, 0), ecx);
-      break;
-    case kExternalShortArray:
-    case kExternalUnsignedShortArray:
-      __ mov_w(Operand(edi, ebx, times_2, 0), ecx);
-      break;
-    case kExternalIntArray:
-    case kExternalUnsignedIntArray:
-      __ mov(Operand(edi, ebx, times_4, 0), ecx);
-      break;
-    case kExternalFloatArray:
-      // Need to perform int-to-float conversion.
-      __ push(ecx);
-      __ fild_s(Operand(esp, 0));
-      __ pop(ecx);
-      __ fstp_s(Operand(edi, ebx, times_4, 0));
-      break;
-    default:
-      UNREACHABLE();
-      break;
-  }
-  __ ret(0);  // Return the original value.
-
-  __ bind(&check_heap_number);
-  // eax: value
-  // edx: receiver
-  // ecx: key
-  // edi: elements array
-  // ebx: untagged index
-  __ cmp(FieldOperand(eax, HeapObject::kMapOffset),
-         Immediate(Factory::heap_number_map()));
-  __ j(not_equal, &slow);
-
-  // The WebGL specification leaves the behavior of storing NaN and
-  // +/-Infinity into integer arrays basically undefined. For more
-  // reproducible behavior, convert these to zero.
-  __ fld_d(FieldOperand(eax, HeapNumber::kValueOffset));
-  __ mov(edi, FieldOperand(edi, ExternalArray::kExternalPointerOffset));
-  // ebx: untagged index
-  // edi: base pointer of external storage
-  // top of FPU stack: value
-  if (array_type == kExternalFloatArray) {
-    __ fstp_s(Operand(edi, ebx, times_4, 0));
-    __ ret(0);
-  } else {
-    // Need to perform float-to-int conversion.
-    // Test the top of the FP stack for NaN.
-    Label is_nan;
-    __ fucomi(0);
-    __ j(parity_even, &is_nan);
-
-    if (array_type != kExternalUnsignedIntArray) {
-      __ push(ecx);  // Make room on stack
-      __ fistp_s(Operand(esp, 0));
-      __ pop(ecx);
-    } else {
-      // fistp stores values as signed integers.
-      // To represent the entire range, we need to store as a 64-bit
-      // int and discard the high 32 bits.
-      __ sub(Operand(esp), Immediate(2 * kPointerSize));
-      __ fistp_d(Operand(esp, 0));
-      __ pop(ecx);
-      __ add(Operand(esp), Immediate(kPointerSize));
-    }
-    // ecx: untagged integer value
-    switch (array_type) {
-      case kExternalByteArray:
-      case kExternalUnsignedByteArray:
-        __ mov_b(Operand(edi, ebx, times_1, 0), ecx);
-        break;
-      case kExternalShortArray:
-      case kExternalUnsignedShortArray:
-        __ mov_w(Operand(edi, ebx, times_2, 0), ecx);
-        break;
-      case kExternalIntArray:
-      case kExternalUnsignedIntArray: {
-        // We also need to explicitly check for +/-Infinity. These are
-        // converted to MIN_INT, but we need to be careful not to
-        // confuse with legal uses of MIN_INT.
-        Label not_infinity;
-        // This test would apparently detect both NaN and Infinity,
-        // but we've already checked for NaN using the FPU hardware
-        // above.
-        __ mov_w(edx, FieldOperand(eax, HeapNumber::kValueOffset + 6));
-        __ and_(edx, 0x7FF0);
-        __ cmp(edx, 0x7FF0);
-        __ j(not_equal, &not_infinity);
-        __ mov(ecx, 0);
-        __ bind(&not_infinity);
-        __ mov(Operand(edi, ebx, times_4, 0), ecx);
-        break;
-      }
-      default:
-        UNREACHABLE();
-        break;
-    }
-    __ ret(0);  // Return original value.
-
-    __ bind(&is_nan);
-    __ ffree();
-    __ fincstp();
-    switch (array_type) {
-      case kExternalByteArray:
-      case kExternalUnsignedByteArray:
-        __ mov_b(Operand(edi, ebx, times_1, 0), 0);
-        break;
-      case kExternalShortArray:
-      case kExternalUnsignedShortArray:
-        __ Set(ecx, Immediate(0));
-        __ mov_w(Operand(edi, ebx, times_2, 0), ecx);
-        break;
-      case kExternalIntArray:
-      case kExternalUnsignedIntArray:
-        __ mov(Operand(edi, ebx, times_4, 0), Immediate(0));
-        break;
-      default:
-        UNREACHABLE();
-        break;
-    }
-    __ ret(0);  // Return the original value.
-  }
-
-  // Slow case: call runtime.
-  __ bind(&slow);
-  GenerateRuntimeSetProperty(masm);
-}
-
-
 // The generated code does not accept smi keys.
 // The generated code falls through if both probes miss.
 static void GenerateMonomorphicCacheProbe(MacroAssembler* masm,
                                           int argc,
                                           Code::Kind kind) {
   // ----------- S t a t e -------------
   //  -- ecx                 : name
   //  -- edx                 : receiver
   // -----------------------------------
   Label number, non_number, non_string, boolean, probe, miss;
@@ skipping 875 matching lines @@
   Condition cc = *jmp_address == Assembler::kJncShortOpcode
       ? not_zero
       : zero;
   *jmp_address = static_cast<byte>(Assembler::kJccShortPrefix | cc);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32