Restrict immediate operands to smi where only smis are supported.

runtime/vm/intermediate_language_ia32.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_IA32.
 #if defined(TARGET_ARCH_IA32)
 
 #include "vm/intermediate_language.h"
 
 #include "lib/error.h"
@@ skipping 266 matching lines @@
     locs->set_in(0, Location::RequiresXmmRegister());
     locs->set_in(1, Location::RequiresXmmRegister());
     locs->set_out(Location::RequiresRegister());
     return locs;
   }
   if (receiver_class_id() == kSmiCid) {
     const intptr_t kNumTemps = 0;
     LocationSummary* locs =
         new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
     locs->set_in(0, Location::RegisterOrConstant(left()));
-    locs->set_in(1, Location::RegisterOrConstant(right()));
+    // Only one input can be a constant operand.
+    locs->set_in(1, locs->in(0).IsConstant()
+                        ? Location::RequiresRegister()
+                        : Location::RegisterOrConstant(right()));
     locs->set_out(Location::RequiresRegister());
     return locs;
   }
   if (is_checked_strict_equal) {
     const intptr_t kNumTemps = 1;
     LocationSummary* locs =
         new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
     locs->set_in(0, Location::RequiresRegister());
     locs->set_in(1, Location::RequiresRegister());
     locs->set_temp(0, Location::RequiresRegister());
@@ skipping 303 matching lines @@
   __ Bind(&done);
 }
 
 
 static void EmitSmiComparisonOp(FlowGraphCompiler* compiler,
                                 const LocationSummary& locs,
                                 Token::Kind kind,
                                 BranchInstr* branch) {
   Location left = locs.in(0);
   Location right = locs.in(1);
+  ASSERT(!left.IsConstant() || !right.IsConstant());
 
   Condition true_condition = TokenKindToSmiCondition(kind);
 
-  if (left.IsConstant() && right.IsConstant()) {
-    bool result = false;
-    // One of them could be NULL (for equality only).
-    if (left.constant().IsNull() || right.constant().IsNull()) {
-      ASSERT((kind == Token::kEQ) || (kind == Token::kNE));
-      result = left.constant().IsNull() && right.constant().IsNull();
-      if (kind == Token::kNE) {
-        result = !result;
-      }
-    } else {
-    // TODO(vegorov): should be eliminated earlier by constant propagation.
-      result = FlowGraphCompiler::EvaluateCondition(
-          true_condition,
-          Smi::Cast(left.constant()).Value(),
-          Smi::Cast(right.constant()).Value());
-    }
-
-    if (branch != NULL) {
-      branch->EmitBranchOnValue(compiler, result);
-    } else {
-      __ LoadObject(locs.out().reg(), result ? compiler->bool_true()
-                                             : compiler->bool_false());
-    }
-
-    return;
-  }
-
   if (left.IsConstant()) {
     __ CompareObject(right.reg(), left.constant());
     true_condition = FlowGraphCompiler::FlipCondition(true_condition);
   } else if (right.IsConstant()) {
     __ CompareObject(left.reg(), right.constant());
   } else {
     __ cmpl(left.reg(), right.reg());
   }
 
   if (branch != NULL) {
@@ skipping 261 matching lines @@
     LocationSummary* summary =
         new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
     summary->set_in(0, Location::RequiresXmmRegister());
     summary->set_in(1, Location::RequiresXmmRegister());
     summary->set_out(Location::RequiresRegister());
     return summary;
   } else if (operands_class_id() == kSmiCid) {
     LocationSummary* summary =
         new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
     summary->set_in(0, Location::RegisterOrConstant(left()));
-    summary->set_in(1, Location::RegisterOrConstant(right()));
+    // Only one input can be a constant operand.

[srdjan, 2012/11/12 20:48:18]

Why don't you allow both to be constant? You expect that to be handled in the
optimizer instead? (please add comment).

[Florian Schneider, 2012/11/12 22:43:45]

Done.

+    summary->set_in(1, summary->in(0).IsConstant()
+                           ? Location::RequiresRegister()
+                           : Location::RegisterOrConstant(right()));
     summary->set_out(Location::RequiresRegister());
     return summary;
   }
   LocationSummary* locs =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kCall);
   // Pick arbitrary fixed input registers because this is a call.
   locs->set_in(0, Location::RegisterLocation(EAX));
   locs->set_in(1, Location::RegisterLocation(ECX));
   locs->set_out(Location::RegisterLocation(EAX));
   return locs;
@@ skipping 777 matching lines @@
     summary->set_temp(0, Location::RegisterLocation(EBX));
     // Will be used for for sign extension.
     summary->set_temp(1, Location::RegisterLocation(EDX));
     summary->set_temp(2, Location::RequiresRegister());
     return summary;
   } else if (op_kind() == Token::kSHR) {
     const intptr_t kNumTemps = 0;
     LocationSummary* summary =
         new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
     summary->set_in(0, Location::RequiresRegister());
-    summary->set_in(1, Location::FixedRegisterOrConstant(right(), ECX));
+    summary->set_in(1, Location::FixedRegisterOrSmiConstant(right(), ECX));
     summary->set_out(Location::SameAsFirstInput());
     return summary;
   } else if (op_kind() == Token::kSHL) {
     const intptr_t kNumTemps = 1;
     LocationSummary* summary =
         new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
     summary->set_in(0, Location::RequiresRegister());
-    summary->set_in(1, Location::FixedRegisterOrConstant(right(), ECX));
+    summary->set_in(1, Location::FixedRegisterOrSmiConstant(right(), ECX));
     summary->set_temp(0, Location::RequiresRegister());
     summary->set_out(Location::SameAsFirstInput());
     return summary;
   } else {
     const intptr_t kNumTemps = 0;
     LocationSummary* summary =
         new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
     summary->set_in(0, Location::RequiresRegister());
-    summary->set_in(1, Location::RegisterOrConstant(right()));
+    summary->set_in(1, Location::RegisterOrSmiConstant(right()));
     summary->set_out(Location::SameAsFirstInput());
     return summary;
   }
 }
 
 
 void BinarySmiOpInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   Register left = locs()->in(0).reg();
   Register result = locs()->out().reg();
   ASSERT(left == result);
@@ skipping 614 matching lines @@
   __ testl(value, Immediate(kSmiTagMask));
   __ j(NOT_ZERO, deopt);
 }
 
 
 LocationSummary* CheckArrayBoundInstr::MakeLocationSummary() const {
   const intptr_t kNumInputs = 2;
   const intptr_t kNumTemps = 0;
   LocationSummary* locs =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
-  locs->set_in(0, Location::RegisterOrConstant(array()));
-  locs->set_in(1, Location::RegisterOrConstant(index()));
+  locs->set_in(0, Location::RegisterOrSmiConstant(array()));
+  locs->set_in(1, Location::RegisterOrSmiConstant(index()));
   return locs;
 }
 
 
 void CheckArrayBoundInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   Label* deopt = compiler->AddDeoptStub(deopt_id(),
                                         kDeoptCheckArrayBound);
   if (locs()->in(0).IsConstant() && locs()->in(1).IsConstant()) {
     // Unconditionally deoptimize for constant bounds checks because they
     // only occur only when index is out-of-bounds.
@@ skipping 325 matching lines @@
   __ pcmpeqq(XMM0, XMM0);  // Generate all 1's.
   __ pxor(value, XMM0);
 }
 
 
 }  // namespace dart
 
 #undef __
 
 #endif  // defined TARGET_ARCH_X64