[arm, arm64] Implemented unaligned scalar float access.

runtime/vm/disassembler_arm64.cc

 // Copyright (c) 2014, 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/disassembler.h"
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_ARM64.
 #if defined(TARGET_ARCH_ARM64)
 #include "platform/assert.h"
 #include "vm/instructions.h"
@@ skipping 1301 matching lines @@
     // Double.
     Format(instr, "fmovd 'vd, 'immd");
   } else {
     // Single.
     Unknown(instr);
   }
 }
 
 
 void ARM64Decoder::DecodeFPIntCvt(Instr* instr) {
-  if ((instr->Bit(29) != 0) || (instr->Bits(22, 2) != 1)) {
+  if ((instr->Bit(29) != 0)) {
     Unknown(instr);
     return;
   }
-  if (instr->Bits(16, 5) == 2) {
-    Format(instr, "scvtfd'sf 'vd, 'rn");
-  } else if (instr->Bits(16, 5) == 6) {
-    Format(instr, "fmovrd'sf 'rd, 'vn");
-  } else if (instr->Bits(16, 5) == 7) {
-    Format(instr, "fmovdr'sf 'vd, 'rn");
-  } else if (instr->Bits(16, 5) == 24) {
-    Format(instr, "fcvtzds'sf 'rd, 'vn");
+
+  if ((instr->SFField() == 0) && (instr->Bits(22, 2) == 0)) {
+    if (instr->Bits(16, 5) == 6) {
+      Format(instr, "fmovrs'sf 'rd, 'vn");
+    } else if (instr->Bits(16, 5) == 7) {
+      Format(instr, "fmovsr'sf 'vd, 'rn");
+    } else {
+      Unknown(instr);
+    }
+  } else if (instr->Bits(22, 2) == 1) {
+    if (instr->Bits(16, 5) == 2) {
+      Format(instr, "scvtfd'sf 'vd, 'rn");
+    } else if (instr->Bits(16, 5) == 6) {
+      Format(instr, "fmovrd'sf 'rd, 'vn");
+    } else if (instr->Bits(16, 5) == 7) {
+      Format(instr, "fmovdr'sf 'vd, 'rn");
+    } else if (instr->Bits(16, 5) == 24) {
+      Format(instr, "fcvtzds'sf 'rd, 'vn");
+    } else {
+      Unknown(instr);
+    }
   } else {
     Unknown(instr);
   }
 }
 
 
 void ARM64Decoder::DecodeFPOneSource(Instr* instr) {
   const int opc = instr->Bits(15, 6);
 
   if ((opc != 5) && (instr->Bit(22) != 1)) {
@@ skipping 141 matching lines @@
       *object = NULL;
     }
   }
 }
 
 #endif  // !PRODUCT
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM