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

runtime/vm/intermediate_language_ia32.cc

 // Copyright (c) 2013, 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 1296 matching lines @@
     case kInt8ArrayCid:
     case kUint8ArrayCid:
     case kExternalUint8ArrayCid:
     case kUint8ClampedArrayCid:
     case kExternalUint8ClampedArrayCid:
     case kInt16ArrayCid:
     case kUint16ArrayCid:
       return kTagged;
     case kInt32ArrayCid:
     case kUint32ArrayCid:
-      return kUnboxedMint;
+      return (value()->Type()->ToCid() == kSmiCid) ? kTagged : kUnboxedMint;
     case kFloat32ArrayCid :
     case kFloat64ArrayCid :
       return kUnboxedDouble;
     default:
       UNIMPLEMENTED();
       return kTagged;
   }
 }
 
 
@@ skipping 33 matching lines @@
     case kUint8ClampedArrayCid:
       // TODO(fschneider): Add location constraint for byte registers (EAX,
       // EBX, ECX, EDX) instead of using a fixed register.
       locs->set_in(2, Location::FixedRegisterOrSmiConstant(value(), EAX));
       break;
     case kInt16ArrayCid:
     case kUint16ArrayCid:
       // 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());
       break;
     default:
       UNREACHABLE();
       return NULL;
   }
   return locs;
 }
@@ skipping 89 matching lines @@
     }
     case kInt16ArrayCid:
     case kUint16ArrayCid: {
       Register value = locs()->in(2).reg();
       __ SmiUntag(value);
       __ movw(element_address, value);
       break;
     }
     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.
       __ cvtsd2ss(locs()->temp(0).fpu_reg(), locs()->in(2).fpu_reg());
       // Store.
       __ movss(element_address, locs()->temp(0).fpu_reg());
       break;
     case kFloat64ArrayCid:
       __ movsd(element_address, locs()->in(2).fpu_reg());
       break;
@@ skipping 1983 matching lines @@
                          PcDescriptors::kOther,
                          locs());
   __ Drop(2);  // Discard type arguments and receiver.
 }
 
 }  // namespace dart
 
 #undef __
 
 #endif  // defined TARGET_ARCH_IA32