Author: [email protected]
Date: Mon Jul 6 06:21:39 2009
New Revision: 2364
Modified:
branches/bleeding_edge/src/x64/assembler-x64.cc
branches/bleeding_edge/src/x64/assembler-x64.h
branches/bleeding_edge/src/x64/codegen-x64.cc
Log:
X64: Make comparisons work on zero-extended smis.
Review URL: http://codereview.chromium.org/155083
Modified: branches/bleeding_edge/src/x64/assembler-x64.cc
==============================================================================
--- branches/bleeding_edge/src/x64/assembler-x64.cc (original)
+++ branches/bleeding_edge/src/x64/assembler-x64.cc Mon Jul 6 06:21:39 2009
@@ -1449,7 +1449,7 @@
last_pc_ = pc_;
if (reg.is(rax)) {
emit(0xA8);
- emit(mask);
+ emit(mask.value_); // Low byte emitted.
} else {
if (reg.code() > 3) {
// Register is not one of al, bl, cl, dl. Its encoding needs REX.
@@ -1470,6 +1470,15 @@
emit(0xF6);
emit_operand(rax, op); // Operation code 0
emit(mask.value_); // Low byte emitted.
+}
+
+
+void Assembler::testl(Register dst, Register src) {
+ EnsureSpace ensure_space(this);
+ last_pc_ = pc_;
+ emit_optional_rex_32(dst, src);
+ emit(0x85);
+ emit_modrm(dst, src);
}
Modified: branches/bleeding_edge/src/x64/assembler-x64.h
==============================================================================
--- branches/bleeding_edge/src/x64/assembler-x64.h (original)
+++ branches/bleeding_edge/src/x64/assembler-x64.h Mon Jul 6 06:21:39 2009
@@ -562,6 +562,14 @@
immediate_arithmetic_op_8(0x7, dst, src);
}
+ void cmpl(Register dst, Register src) {
+ arithmetic_op_32(0x3B, dst, src);
+ }
+
+ void cmpl(Register dst, Immediate src) {
+ immediate_arithmetic_op_32(0x7, dst, src);
+ }
+
void cmpq(Register dst, Register src) {
arithmetic_op(0x3B, dst, src);
}
@@ -578,10 +586,6 @@
immediate_arithmetic_op(0x7, dst, src);
}
- void cmpl(Register dst, Immediate src) {
- immediate_arithmetic_op_32(0x7, dst, src);
- }
-
void cmpq(const Operand& dst, Immediate src) {
immediate_arithmetic_op(0x7, dst, src);
}
@@ -740,6 +744,7 @@
void testb(Register reg, Immediate mask);
void testb(const Operand& op, Immediate mask);
+ void testl(Register dst, Register src);
void testl(Register reg, Immediate mask);
void testl(const Operand& op, Immediate mask);
void testq(const Operand& op, Register reg);
Modified: branches/bleeding_edge/src/x64/codegen-x64.cc
==============================================================================
--- branches/bleeding_edge/src/x64/codegen-x64.cc (original)
+++ branches/bleeding_edge/src/x64/codegen-x64.cc Mon Jul 6 06:21:39 2009
@@ -2459,13 +2459,13 @@
// receiver. Use a scratch register to avoid destroying the result.
Result scratch = allocator_->Allocate();
ASSERT(scratch.is_valid());
- __ movl(scratch.reg(),
+ __ movq(scratch.reg(),
FieldOperand(result.reg(), FixedArray::OffsetOfElementAt(0)));
frame_->SetElementAt(arg_count + 1, &scratch);
// We can reuse the result register now.
frame_->Spill(result.reg());
- __ movl(result.reg(),
+ __ movq(result.reg(),
FieldOperand(result.reg(), FixedArray::OffsetOfElementAt(1)));
frame_->SetElementAt(arg_count, &result);
@@ -4316,12 +4316,8 @@
left_side = Result(left_reg);
right_side = Result(right_val);
// Test smi equality and comparison by signed int comparison.
- if (IsUnsafeSmi(right_side.handle())) {
- right_side.ToRegister();
- __ cmpq(left_side.reg(), right_side.reg());
- } else {
- __ Cmp(left_side.reg(), right_side.handle());
- }
+ // Both sides are smis, so we can use an Immediate.
+ __ cmpl(left_side.reg(), Immediate(Smi::cast(*right_side.handle())));
left_side.Unuse();
right_side.Unuse();
dest->Split(cc);
@@ -4373,7 +4369,8 @@
// When non-smi, call out to the compare stub.
CompareStub stub(cc, strict);
Result answer = frame_->CallStub(&stub, &left_side, &right_side);
- __ testq(answer.reg(), answer.reg()); // Both zero and sign flag
right.
+ // The result is a Smi, which is negative, zero, or positive.
+ __ testl(answer.reg(), answer.reg()); // Both zero and sign flag
right.
answer.Unuse();
dest->Split(cc);
} else {
@@ -4393,11 +4390,7 @@
// When non-smi, call out to the compare stub.
CompareStub stub(cc, strict);
Result answer = frame_->CallStub(&stub, &left_side, &right_side);
- if (cc == equal) {
- __ testq(answer.reg(), answer.reg());
- } else {
- __ cmpq(answer.reg(), Immediate(0));
- }
+ __ testl(answer.reg(), answer.reg()); // Sets both zero and sign
flags.
answer.Unuse();
dest->true_target()->Branch(cc);
dest->false_target()->Jump();
@@ -4405,7 +4398,7 @@
is_smi.Bind();
left_side = Result(left_reg);
right_side = Result(right_reg);
- __ cmpq(left_side.reg(), right_side.reg());
+ __ cmpl(left_side.reg(), right_side.reg());
right_side.Unuse();
left_side.Unuse();
dest->Split(cc);
@@ -5446,6 +5439,7 @@
__ bind(¬_string);
// HeapNumber => false iff +0, -0, or NaN.
+ // These three cases set C3 when compared to zero in the FPU.
__ Cmp(rdx, Factory::heap_number_map());
__ j(not_equal, &true_result);
// TODO(x64): Don't use fp stack, use MMX registers?
@@ -5455,9 +5449,9 @@
__ fucompp(); // Compare and pop both values.
__ movq(kScratchRegister, rax);
__ fnstsw_ax(); // Store fp status word in ax, no checking for
exceptions.
- __ testb(rax, Immediate(0x08)); // Test FP condition flag C3.
+ __ testl(rax, Immediate(0x4000)); // Test FP condition flag C3, bit 16.
__ movq(rax, kScratchRegister);
- __ j(zero, &false_result);
+ __ j(not_zero, &false_result);
// Fall through to |true_result|.
// Return 1/0 for true/false in rax.
@@ -5627,7 +5621,11 @@
__ shl(rax, Immediate(12));
// If all bits in the mantissa are zero the number is Infinity, and
// we return zero. Otherwise it is a NaN, and we return non-zero.
- // So just return rax.
+ // We cannot just return rax because only eax is tested on return.
+ // TODO(X64): Solve this using movcc, when implemented.
+ __ movq(kScratchRegister, rax);
+ __ shr(kScratchRegister, Immediate(32));
+ __ or_(rax, kScratchRegister);
__ ret(0);
__ bind(¬_identical);
@@ -5665,7 +5663,7 @@
Factory::heap_number_map());
// If heap number, handle it in the slow case.
__ j(equal, &slow);
- // Return non-equal (ebx is not zero)
+ // Return non-equal. ebx (the lower half of rbx) is not zero.
__ movq(rax, rbx);
__ ret(0);
@@ -5681,7 +5679,7 @@
Label first_non_object;
__ CmpObjectType(rax, FIRST_JS_OBJECT_TYPE, rcx);
__ j(below, &first_non_object);
- // Return non-zero (rax is not zero)
+ // Return non-zero (eax (not rax) is not zero)
Label return_not_equal;
ASSERT(kHeapObjectTag != 0);
__ bind(&return_not_equal);
@@ -5745,7 +5743,7 @@
BranchIfNonSymbol(masm, &call_builtin, rdx, kScratchRegister);
// We've already checked for object identity, so if both operands
- // are symbols they aren't equal. Register rax already holds a
+ // are symbols they aren't equal. Register eax (not rax) already holds
a
// non-zero value, which indicates not equal, so just return.
__ ret(2 * kPointerSize);
}
--~--~---------~--~----~------------~-------~--~----~
v8-dev mailing list
[email protected]
http://groups.google.com/group/v8-dev
-~----------~----~----~----~------~----~------~--~---
