Add movw and movt support for ARMv7. This includes some code from...

src/arm/disasm-arm.cc

Index: src/arm/disasm-arm.cc
===================================================================
--- src/arm/disasm-arm.cc	(revision 4906)
+++ src/arm/disasm-arm.cc	(working copy)
@@ -101,6 +101,7 @@
   void PrintSRegister(int reg);
   void PrintDRegister(int reg);
   int FormatVFPRegister(Instr* instr, const char* format);
+  void PrintMovwMovt(Instr* instr);
   int FormatVFPinstruction(Instr* instr, const char* format);
   void PrintCondition(Instr* instr);
   void PrintShiftRm(Instr* instr);
@@ -375,6 +376,23 @@
 }
 
 
+// Print the movw or movt instruction.
+void Decoder::PrintMovwMovt(Instr* instr) {
+  int imm = instr->ImmedMovwMovtField();
+  int rd = instr->RdField();
+  PrintRegister(rd);
+  if (instr->Bit(22) == 1) {
+    // Movt instruction.
+    out_buffer_pos_ += v8i::OS::SNPrintF(out_buffer_ + out_buffer_pos_,

[Søren Thygesen Gjesse, 2010/06/21 21:39:26]

According to the ARM reference manual the assembler syntax is

  MOVT<c><q> <Rd>, #<imm16>

(without the trailing 0's)

+                                         ", #0x%04x0000", imm);
+  } else {
+    // Movw instruction
+    out_buffer_pos_ += v8i::OS::SNPrintF(out_buffer_ + out_buffer_pos_,
+                                         ", #0x%04x", imm);
+  }
+}
+
+
 // FormatOption takes a formatting string and interprets it based on
 // the current instructions. The format string points to the first
 // character of the option string (the option escape has already been
@@ -430,7 +448,12 @@
       return 1;
     }
     case 'm': {
-      if (format[1] == 'e') {  // 'memop: load/store instructions
+      if ((format[1] == 't') || (format[1] == 'w')) {
+        // 't and 'w: movt/movw instructions.
+        PrintMovwMovt(instr);
+        return 2;
+      }
+      if (format[1] == 'e') {  // 'memop: load/store instructions.
         ASSERT(STRING_STARTS_WITH(format, "memop"));
         if (instr->HasL()) {
           Print("ldr");
@@ -776,7 +799,7 @@
         if (instr->HasS()) {
           Format(instr, "tst'cond 'rn, 'shift_op");
         } else {
-          Unknown(instr);  // not used by V8
+          Format(instr, "movw'cond 'mw");
         }
         break;
       }
@@ -794,7 +817,7 @@
         if (instr->HasS()) {
           Format(instr, "cmp'cond 'rn, 'shift_op");
         } else {
-          Unknown(instr);  // not used by V8
+          Format(instr, "movt'cond 'mt");
         }
         break;
       }