X64 Crankshaft: Port TaggedToI to X64.

src/x64/lithium-codegen-x64.cc

Index: src/x64/lithium-codegen-x64.cc
===================================================================
--- src/x64/lithium-codegen-x64.cc	(revision 6635)
+++ src/x64/lithium-codegen-x64.cc	(working copy)
@@ -1954,13 +1954,108 @@
 }
 
 
+class DeferredTaggedToI: public LDeferredCode {
+ public:
+  DeferredTaggedToI(LCodeGen* codegen, LTaggedToI* instr)
+      : LDeferredCode(codegen), instr_(instr) { }
+  virtual void Generate() { codegen()->DoDeferredTaggedToI(instr_); }
+ private:
+  LTaggedToI* instr_;
+};
+
+
 void LCodeGen::DoDeferredTaggedToI(LTaggedToI* instr) {
-  Abort("Unimplemented: %s", "DoDeferredTaggedToI");
+  NearLabel done, heap_number;
+  Register input_reg = ToRegister(instr->InputAt(0));
+
+  // Heap number map check.
+  __ CompareRoot(FieldOperand(input_reg, HeapObject::kMapOffset),
+                   Heap::kHeapNumberMapRootIndex);

[Lasse Reichstein, 2011/02/04 12:57:55]

indentation.

[William Hesse, 2011/02/04 13:16:39]

Done.

+
+  if (instr->truncating()) {
+    __ j(equal, &heap_number);
+    // Check for undefined. Undefined is converted to zero for truncating
+    // conversions.
+    __ CompareRoot(input_reg, Heap::kUndefinedValueRootIndex);
+    DeoptimizeIf(not_equal, instr->environment());
+    __ movl(input_reg, Immediate(0));
+    __ jmp(&done);
+
+    __ bind(&heap_number);
+    if (CpuFeatures::IsSupported(SSE3)) {
+      CpuFeatures::Scope scope(SSE3);

[Lasse Reichstein, 2011/02/04 12:57:55]

Fisttp isn't any "more powerful" than cvttsd2si in X64 mode, since we have a
64-bit version of that too. I.e., the valid ranges are the same. Use the 64-bit
cvttsd2si in all cases, and avoid the FPU stack.

[William Hesse, 2011/02/04 13:16:39]

Done.

+      NearLabel convert;
+      // Use more powerful conversion when sse3 is available.
+      // Load x87 register with heap number.
+      __ fld_d(FieldOperand(input_reg, HeapNumber::kValueOffset));
+      // Get exponent alone and check for too-big exponent.
+      __ movl(input_reg, FieldOperand(input_reg, HeapNumber::kExponentOffset));
+      __ andl(input_reg, Immediate(HeapNumber::kExponentMask));
+      const uint32_t kTooBigExponent =
+          (HeapNumber::kExponentBias + 63) << HeapNumber::kExponentShift;
+      __ cmpl(input_reg, Immediate(kTooBigExponent));
+      __ j(less, &convert);
+      // Pop FPU stack before deoptimizing.
+      __ ffree(0);
+      __ fincstp();

[Lasse Reichstein, 2011/02/04 12:57:55]

Use
  __ fstp(0);
to drop the top of the FPU stack.

[William Hesse, 2011/02/04 13:16:39]

Entire block of code deleted.
On 2011/02/04 12:57:55, Lasse Reichstein wrote:

+      DeoptimizeIf(no_condition, instr->environment());
+
+      // Reserve space for 64 bit answer.
+      __ bind(&convert);
+      __ subq(rsp, Immediate(kDoubleSize));
+      // Do conversion, which cannot fail because we checked the exponent.
+      __ fisttp_d(Operand(rsp, 0));
+      __ movl(input_reg, Operand(rsp, 0));  // Low word of answer is the result.
+      __ addq(rsp, Immediate(kDoubleSize));
+    } else {
+      NearLabel deopt;
+      XMMRegister xmm_temp = ToDoubleRegister(instr->TempAt(0));
+      __ movsd(xmm0, FieldOperand(input_reg, HeapNumber::kValueOffset));
+      __ cvttsd2si(input_reg, xmm0);

[Lasse Reichstein, 2011/02/04 12:57:55]

Use the 64-bit version and compare to 0x8000000000000000 instead.

[William Hesse, 2011/02/04 13:16:39]

Done.

+      __ cmpl(input_reg, Immediate(0x80000000u));
+      __ j(not_equal, &done);
+      // Check if the input was 0x8000000 (kMinInt).
+      // If no, then we got an overflow and we deoptimize.
+      ExternalReference min_int = ExternalReference::address_of_min_int();
+      __ movq(kScratchRegister, min_int);
+      __ movsd(xmm_temp, Operand(kScratchRegister, 0));
+      __ ucomisd(xmm_temp, xmm0);
+      DeoptimizeIf(not_equal, instr->environment());
+      DeoptimizeIf(parity_even, instr->environment());  // NaN.
+    }
+  } else {
+    // Deoptimize if we don't have a heap number.
+    DeoptimizeIf(not_equal, instr->environment());
+
+    XMMRegister xmm_temp = ToDoubleRegister(instr->TempAt(0));
+    __ movsd(xmm0, FieldOperand(input_reg, HeapNumber::kValueOffset));
+    __ cvttsd2si(input_reg, xmm0);
+    __ cvtlsi2sd(xmm_temp, input_reg);
+    __ ucomisd(xmm0, xmm_temp);
+    DeoptimizeIf(not_equal, instr->environment());
+    DeoptimizeIf(parity_even, instr->environment());  // NaN.
+    if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
+      __ testl(input_reg, input_reg);
+      __ j(not_zero, &done);
+      __ movmskpd(input_reg, xmm0);
+      __ andl(input_reg, Immediate(1));
+      DeoptimizeIf(not_zero, instr->environment());
+    }
+  }
+  __ bind(&done);
 }
 
 
 void LCodeGen::DoTaggedToI(LTaggedToI* instr) {
-  Abort("Unimplemented: %s", "DoTaggedToI");
+  LOperand* input = instr->InputAt(0);
+  ASSERT(input->IsRegister());
+  ASSERT(input->Equals(instr->result()));
+
+  Register input_reg = ToRegister(input);
+  DeferredTaggedToI* deferred = new DeferredTaggedToI(this, instr);
+  __ JumpIfNotSmi(input_reg, deferred->entry());
+  __ SmiToInteger32(input_reg, input_reg);
+  __ bind(deferred->exit());
 }
 
 
@@ -2217,7 +2312,6 @@
 void LCodeGen::DoStackCheck(LStackCheck* instr) {
   // Perform stack overflow check.
   NearLabel done;
-  ExternalReference stack_limit = ExternalReference::address_of_stack_limit();
   __ CompareRoot(rsp, Heap::kStackLimitRootIndex);
   __ j(above_equal, &done);