Implements shifted offset register addressing mode for arm.

runtime/vm/assembler_arm.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"
 #if defined(TARGET_ARCH_ARM)
 
 #include "vm/assembler.h"
 
 #include "vm/stub_code.h"
@@ skipping 46 matching lines @@
   // ldrex/strex register field encodings.
   kLdExRnShift = 16,
   kLdExRtShift = 12,
   kStrExRnShift = 16,
   kStrExRdShift = 12,
   kStrExRtShift = 0,
 };
 
 
 uint32_t Address::encoding3() const {
+  ASSERT(kind_ == Immediate);
   const uint32_t offset_mask = (1 << 12) - 1;
   uint32_t offset = encoding_ & offset_mask;
   ASSERT(offset < 256);
   return (encoding_ & ~offset_mask) | ((offset & 0xf0) << 4) | (offset & 0xf);
 }
 
 
 uint32_t Address::vencoding() const {
+  ASSERT(kind_ == Immediate);
   const uint32_t offset_mask = (1 << 12) - 1;
   uint32_t offset = encoding_ & offset_mask;
   ASSERT(offset < (1 << 10));  // In the range 0 to +1020.
   ASSERT(Utils::IsAligned(offset, 4));  // Multiple of 4.
   int mode = encoding_ & ((8|4|1) << 21);
   ASSERT((mode == Offset) || (mode == NegOffset));
   uint32_t vencoding = (encoding_ & (0xf << kRnShift)) | (offset >> 2);
   if (mode == Offset) {
     vencoding |= 1 << 23;
   }
@@ skipping 48 matching lines @@
 
 
 void Assembler::EmitMemOp(Condition cond,
                           bool load,
                           bool byte,
                           Register rd,
                           Address ad) {
   ASSERT(rd != kNoRegister);
   ASSERT(cond != kNoCondition);
   int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
-                     B26 |
+                     B26 | (ad.kind() == Address::Immediate ? 0 : B25) |
                      (load ? L : 0) |
                      (byte ? B : 0) |
                      (static_cast<int32_t>(rd) << kRdShift) |
                      ad.encoding();
   Emit(encoding);
 }
 
 
 void Assembler::EmitMemOpAddressMode3(Condition cond,
                                       int32_t mode,
@@ skipping 1420 matching lines @@
   // Do not reuse an existing entry, since each reference may be patched
   // independently.
   object_pool_.Add(smi);
   return object_pool_.Length() - 1;
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM