Use compile type to improve stores to Int32List and Uint32List on ia32.

runtime/vm/intermediate_language_ia32.cc

Index: runtime/vm/intermediate_language_ia32.cc
===================================================================
--- runtime/vm/intermediate_language_ia32.cc	(revision 18616)
+++ runtime/vm/intermediate_language_ia32.cc	(working copy)
@@ -1314,7 +1314,7 @@
       return kTagged;
     case kInt32ArrayCid:
     case kUint32ArrayCid:
-      return kUnboxedMint;
+      return (value()->Type()->ToCid() == kSmiCid) ? kTagged : kUnboxedMint;
     case kFloat32ArrayCid :
     case kFloat64ArrayCid :
       return kUnboxedDouble;
@@ -1368,12 +1368,18 @@
       // Writable register because the value must be untagged before storing.
       locs->set_in(2, Location::WritableRegister());
       break;
+    case kInt32ArrayCid:
+    case kUint32ArrayCid:
+      // Mints are stored in XMM registers. For smis, use a writable register
+      // because the value must be untagged before storing.
+      locs->set_in(2, (RequiredInputRepresentation(2) == kUnboxedMint)
+                      ? Location::RequiresFpuRegister()
+                      : Location::WritableRegister());
+      break;
     case kFloat32ArrayCid:
       // Need temp register for float-to-double conversion.
       locs->AddTemp(Location::RequiresFpuRegister());
       // Fall through.
-    case kInt32ArrayCid:
-    case kUint32ArrayCid:
     case kFloat64ArrayCid:
       // TODO(srdjan): Support Float64 constants.
       locs->set_in(2, Location::RequiresFpuRegister());
@@ -1483,7 +1489,14 @@
     }
     case kInt32ArrayCid:
     case kUint32ArrayCid:
+      if (RequiredInputRepresentation(2) == kTagged) {

[Vyacheslav Egorov (Google), 2013/02/18 16:21:44]

I suggest you encapsulate this check (and two above) in a function called
IsSmiValue() or similar. 

[Florian Schneider, 2013/02/18 16:33:31]

Done.

+        Register value = locs()->in(2).reg();
+        __ SmiUntag(value);
+        __ movl(element_address, value);
+      } else {
+        ASSERT(RequiredInputRepresentation(2) == kUnboxedMint);
       __ movss(element_address, locs()->in(2).fpu_reg());
+      }
       break;
     case kFloat32ArrayCid:
       // Convert to single precision.