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Unified Diff: src/x64/stub-cache-x64.cc

Issue 6315004: Truncate rather than round to nearest when performing float-to-integer... (Closed) Base URL: http://v8.googlecode.com/svn/branches/bleeding_edge/
Patch Set: '' Created 9 years, 11 months ago
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Index: src/x64/stub-cache-x64.cc
===================================================================
--- src/x64/stub-cache-x64.cc (revision 6336)
+++ src/x64/stub-cache-x64.cc (working copy)
@@ -3115,6 +3115,306 @@
}
+MaybeObject* ExternalArrayStubCompiler::CompileKeyedLoadStub(
+ ExternalArrayType array_type, Code::Flags flags) {
+ // ----------- S t a t e -------------
+ // -- rax : key
+ // -- rdx : receiver
+ // -- rsp[0] : return address
+ // -----------------------------------
+ Label slow;
+
+ // Check that the object isn't a smi.
+ __ JumpIfSmi(rdx, &slow);
+
+ // Check that the key is a smi.
+ __ JumpIfNotSmi(rax, &slow);
+
+ // Check that the object is a JS object.
+ __ CmpObjectType(rdx, JS_OBJECT_TYPE, rcx);
+ __ j(not_equal, &slow);
+ // Check that the receiver does not require access checks. We need
+ // to check this explicitly since this generic stub does not perform
+ // map checks. The map is already in rdx.
+ __ testb(FieldOperand(rcx, Map::kBitFieldOffset),
+ Immediate(1 << Map::kIsAccessCheckNeeded));
+ __ j(not_zero, &slow);
+
+ // Check that the elements array is the appropriate type of
+ // ExternalArray.
+ // rax: index (as a smi)
+ // rdx: JSObject
+ __ movq(rbx, FieldOperand(rdx, JSObject::kElementsOffset));
+ __ CompareRoot(FieldOperand(rbx, HeapObject::kMapOffset),
+ Heap::RootIndexForExternalArrayType(array_type));
+ __ j(not_equal, &slow);
+
+ // Check that the index is in range.
+ __ SmiToInteger32(rcx, rax);
+ __ cmpl(rcx, FieldOperand(rbx, ExternalArray::kLengthOffset));
+ // Unsigned comparison catches both negative and too-large values.
+ __ j(above_equal, &slow);
+
+ // rax: index (as a smi)
+ // rdx: receiver (JSObject)
+ // rcx: untagged index
+ // rbx: elements array
+ __ movq(rbx, FieldOperand(rbx, ExternalArray::kExternalPointerOffset));
+ // rbx: base pointer of external storage
+ switch (array_type) {
+ case kExternalByteArray:
+ __ movsxbq(rcx, Operand(rbx, rcx, times_1, 0));
+ break;
+ case kExternalUnsignedByteArray:
+ __ movzxbq(rcx, Operand(rbx, rcx, times_1, 0));
+ break;
+ case kExternalShortArray:
+ __ movsxwq(rcx, Operand(rbx, rcx, times_2, 0));
+ break;
+ case kExternalUnsignedShortArray:
+ __ movzxwq(rcx, Operand(rbx, rcx, times_2, 0));
+ break;
+ case kExternalIntArray:
+ __ movsxlq(rcx, Operand(rbx, rcx, times_4, 0));
+ break;
+ case kExternalUnsignedIntArray:
+ __ movl(rcx, Operand(rbx, rcx, times_4, 0));
+ break;
+ case kExternalFloatArray:
+ __ cvtss2sd(xmm0, Operand(rbx, rcx, times_4, 0));
+ break;
+ default:
+ UNREACHABLE();
+ break;
+ }
+
+ // rax: index
+ // rdx: receiver
+ // For integer array types:
+ // rcx: value
+ // For floating-point array type:
+ // xmm0: value as double.
+
+ ASSERT(kSmiValueSize == 32);
+ if (array_type == kExternalUnsignedIntArray) {
+ // For the UnsignedInt array type, we need to see whether
+ // the value can be represented in a Smi. If not, we need to convert
+ // it to a HeapNumber.
+ NearLabel box_int;
+
+ __ JumpIfUIntNotValidSmiValue(rcx, &box_int);
+
+ __ Integer32ToSmi(rax, rcx);
+ __ ret(0);
+
+ __ bind(&box_int);
+
+ // Allocate a HeapNumber for the int and perform int-to-double
+ // conversion.
+ // The value is zero-extended since we loaded the value from memory
+ // with movl.
+ __ cvtqsi2sd(xmm0, rcx);
+
+ __ AllocateHeapNumber(rcx, rbx, &slow);
+ // Set the value.
+ __ movsd(FieldOperand(rcx, HeapNumber::kValueOffset), xmm0);
+ __ movq(rax, rcx);
+ __ ret(0);
+ } else if (array_type == kExternalFloatArray) {
+ // For the floating-point array type, we need to always allocate a
+ // HeapNumber.
+ __ AllocateHeapNumber(rcx, rbx, &slow);
+ // Set the value.
+ __ movsd(FieldOperand(rcx, HeapNumber::kValueOffset), xmm0);
+ __ movq(rax, rcx);
+ __ ret(0);
+ } else {
+ __ Integer32ToSmi(rax, rcx);
+ __ ret(0);
+ }
+
+ // Slow case: Jump to runtime.
+ __ bind(&slow);
+ __ IncrementCounter(&Counters::keyed_load_external_array_slow, 1);
+
+ // ----------- S t a t e -------------
+ // -- rax : key
+ // -- rdx : receiver
+ // -- rsp[0] : return address
+ // -----------------------------------
+
+ __ pop(rbx);
+ __ push(rdx); // receiver
+ __ push(rax); // name
+ __ push(rbx); // return address
+
+ // Perform tail call to the entry.
+ __ TailCallRuntime(Runtime::kKeyedGetProperty, 2, 1);
+
+ // Return the generated code.
+ return GetCode(flags);
+}
+
+
+MaybeObject* ExternalArrayStubCompiler::CompileKeyedStoreStub(
+ ExternalArrayType array_type, Code::Flags flags) {
+ // ----------- S t a t e -------------
+ // -- rax : value
+ // -- rcx : key
+ // -- rdx : receiver
+ // -- rsp[0] : return address
+ // -----------------------------------
+ Label slow;
+
+ // Check that the object isn't a smi.
+ __ JumpIfSmi(rdx, &slow);
+ // Get the map from the receiver.
+ __ movq(rbx, FieldOperand(rdx, 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.
+ __ testb(FieldOperand(rbx, Map::kBitFieldOffset),
+ Immediate(1 << Map::kIsAccessCheckNeeded));
+ __ j(not_zero, &slow);
+ // Check that the key is a smi.
+ __ JumpIfNotSmi(rcx, &slow);
+
+ // Check that the object is a JS object.
+ __ CmpInstanceType(rbx, JS_OBJECT_TYPE);
+ __ j(not_equal, &slow);
+
+ // Check that the elements array is the appropriate type of
+ // ExternalArray.
+ // rax: value
+ // rcx: key (a smi)
+ // rdx: receiver (a JSObject)
+ __ movq(rbx, FieldOperand(rdx, JSObject::kElementsOffset));
+ __ CompareRoot(FieldOperand(rbx, HeapObject::kMapOffset),
+ Heap::RootIndexForExternalArrayType(array_type));
+ __ j(not_equal, &slow);
+
+ // Check that the index is in range.
+ __ SmiToInteger32(rdi, rcx); // Untag the index.
+ __ cmpl(rdi, FieldOperand(rbx, 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.
+ // rax: value
+ // rcx: key (a smi)
+ // rdx: receiver (a JSObject)
+ // rbx: elements array
+ // rdi: untagged key
+ NearLabel check_heap_number;
+ __ JumpIfNotSmi(rax, &check_heap_number);
+ // No more branches to slow case on this path. Key and receiver not needed.
+ __ SmiToInteger32(rdx, rax);
+ __ movq(rbx, FieldOperand(rbx, ExternalArray::kExternalPointerOffset));
+ // rbx: base pointer of external storage
+ switch (array_type) {
+ case kExternalByteArray:
+ case kExternalUnsignedByteArray:
+ __ movb(Operand(rbx, rdi, times_1, 0), rdx);
+ break;
+ case kExternalShortArray:
+ case kExternalUnsignedShortArray:
+ __ movw(Operand(rbx, rdi, times_2, 0), rdx);
+ break;
+ case kExternalIntArray:
+ case kExternalUnsignedIntArray:
+ __ movl(Operand(rbx, rdi, times_4, 0), rdx);
+ break;
+ case kExternalFloatArray:
+ // Need to perform int-to-float conversion.
+ __ cvtlsi2ss(xmm0, rdx);
+ __ movss(Operand(rbx, rdi, times_4, 0), xmm0);
+ break;
+ default:
+ UNREACHABLE();
+ break;
+ }
+ __ ret(0);
+
+ __ bind(&check_heap_number);
+ // rax: value
+ // rcx: key (a smi)
+ // rdx: receiver (a JSObject)
+ // rbx: elements array
+ // rdi: untagged key
+ __ CmpObjectType(rax, HEAP_NUMBER_TYPE, kScratchRegister);
+ __ j(not_equal, &slow);
+ // No more branches to slow case on this path.
+
+ // The WebGL specification leaves the behavior of storing NaN and
+ // +/-Infinity into integer arrays basically undefined. For more
+ // reproducible behavior, convert these to zero.
+ __ movsd(xmm0, FieldOperand(rax, HeapNumber::kValueOffset));
+ __ movq(rbx, FieldOperand(rbx, ExternalArray::kExternalPointerOffset));
+ // rdi: untagged index
+ // rbx: base pointer of external storage
+ // top of FPU stack: value
+ if (array_type == kExternalFloatArray) {
+ __ cvtsd2ss(xmm0, xmm0);
+ __ movss(Operand(rbx, rdi, times_4, 0), xmm0);
+ __ ret(0);
+ } else {
+ // Perform float-to-int conversion with truncation (round-to-zero)
+ // behavior.
+
+ // Convert to int32 and store the low byte/word.
+ // If the value is NaN or +/-infinity, the result is 0x80000000,
+ // which is automatically zero when taken mod 2^n, n < 32.
+ // rdx: value (converted to an untagged integer)
+ // rdi: untagged index
+ // rbx: base pointer of external storage
+ switch (array_type) {
+ case kExternalByteArray:
+ case kExternalUnsignedByteArray:
+ __ cvttsd2si(rdx, xmm0);
+ __ movb(Operand(rbx, rdi, times_1, 0), rdx);
+ break;
+ case kExternalShortArray:
+ case kExternalUnsignedShortArray:
+ __ cvttsd2si(rdx, xmm0);
+ __ movw(Operand(rbx, rdi, times_2, 0), rdx);
+ break;
+ case kExternalIntArray:
+ case kExternalUnsignedIntArray: {
+ // Convert to int64, so that NaN and infinities become
+ // 0x8000000000000000, which is zero mod 2^32.
+ __ cvttsd2siq(rdx, xmm0);
+ __ movl(Operand(rbx, rdi, times_4, 0), rdx);
+ break;
+ }
+ default:
+ UNREACHABLE();
+ break;
+ }
+ __ ret(0);
+ }
+
+ // Slow case: call runtime.
+ __ bind(&slow);
+
+ // ----------- S t a t e -------------
+ // -- rax : value
+ // -- rcx : key
+ // -- rdx : receiver
+ // -- rsp[0] : return address
+ // -----------------------------------
+
+ __ pop(rbx);
+ __ push(rdx); // receiver
+ __ push(rcx); // key
+ __ push(rax); // value
+ __ push(rbx); // return address
+
+ // Do tail-call to runtime routine.
+ __ TailCallRuntime(Runtime::kSetProperty, 3, 1);
+
+ return GetCode(flags);
+}
+
#undef __
} } // namespace v8::internal
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