Implement loop invariant code motion for check instructions.

runtime/vm/object.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/object.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/bigint_operations.h"
@@ skipping 6658 matching lines @@
   UNREACHABLE();
   return "";
 }
 
 
 void PcDescriptors::PrintHeaderString() {
   // 4 bits per hex digit + 2 for "0x".
   const int addr_width = (kBitsPerWord / 4) + 2;
   // "*" in a printf format specifier tells it to read the field width from
   // the printf argument list.
-  OS::Print("%-*s\tkind    \ttid\ttok-ix\ttry/deopt-ix\n", addr_width, "pc");
+  OS::Print("%-*s\tkind    \tdeopt-id\ttok-ix\ttry/deopt-ix\n",
+            addr_width, "pc");
 }
 
 
 const char* PcDescriptors::ToCString() const {
   if (Length() == 0) {
     return "No pc descriptors\n";
   }
   // 4 bits per hex digit.
   const int addr_width = kBitsPerWord / 4;
   // "*" in a printf format specifier tells it to read the field width from
@@ skipping 30 matching lines @@
         token_pos_or_deopt_reason,
         multi_purpose_index);
   }
   return buffer;
 }
 
 
 // Verify assumptions (in debug mode only).
 // - No two deopt descriptors have the same deoptimization id.
 // - No two ic-call descriptors have the same deoptimization id (type feedback).
-// - No two descriptors of same kind have the same PC.
 // A function without unique ids is marked as non-optimizable (e.g., because of

[srdjan, 2012/09/06 13:44:26]

Maybe replace removed comment with what you said in the CL.

[Florian Schneider, 2012/09/06 13:49:30]

Done.

 // finally blocks).
 void PcDescriptors::Verify(bool check_ids) const {
 #if defined(DEBUG)
   // TODO(srdjan): Implement a more efficient way to check, currently drop
   // the check for too large number of descriptors.
   if (Length() > 3000) {
     if (FLAG_trace_compiler) {
       OS::Print("Not checking pc decriptors, length %"Pd"\n", Length());
     }
     return;
   }
   for (intptr_t i = 0; i < Length(); i++) {
-    uword pc = PC(i);
     PcDescriptors::Kind kind = DescriptorKind(i);
     // 'deopt_id' is set for kDeopt and kIcCall and must be unique for one kind.
     intptr_t deopt_id = Isolate::kNoDeoptId;
     if (check_ids) {
       if ((DescriptorKind(i) == PcDescriptors::kDeoptBefore) ||
           (DescriptorKind(i) == PcDescriptors::kIcCall)) {
         deopt_id = DeoptId(i);
       }
     }
     for (intptr_t k = i + 1; k < Length(); k++) {
       if (kind == DescriptorKind(k)) {
         if (deopt_id != Isolate::kNoDeoptId) {
           ASSERT(DeoptId(k) != deopt_id);
         }
-        ASSERT(pc != PC(k));
       }
     }
   }
 #endif  // DEBUG
 }
 
 
 void Stackmap::SetCode(const dart::Code& code) const {
   StorePointer(&raw_ptr()->code_, code.raw());
 }
@@ skipping 4429 matching lines @@
   }
   return result.raw();
 }
 
 
 const char* WeakProperty::ToCString() const {
   return "_WeakProperty";
 }
 
 }  // namespace dart