Restrict immediate operands to smi where only smis are supported.

runtime/vm/intermediate_language_ia32.cc

Index: runtime/vm/intermediate_language_ia32.cc
===================================================================
--- runtime/vm/intermediate_language_ia32.cc	(revision 14796)
+++ runtime/vm/intermediate_language_ia32.cc	(working copy)
@@ -284,7 +284,10 @@
     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;
   }
@@ -608,36 +611,10 @@
                                 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);
@@ -919,7 +896,10 @@
     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;
   }
@@ -1717,7 +1697,7 @@
     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) {
@@ -1725,7 +1705,7 @@
     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;
@@ -1734,7 +1714,7 @@
     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;
   }
@@ -2369,8 +2349,8 @@
   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;
 }