Optimizing/ARM: Implement kDexCachePcRelative dispatch.

Change-Id: I0fe2da50a30a3f62bec8ea01688dd1fec84b1831
diff --git a/compiler/utils/arm/assembler_thumb2.cc b/compiler/utils/arm/assembler_thumb2.cc
index 7ad5b44..cdeb443 100644
--- a/compiler/utils/arm/assembler_thumb2.cc
+++ b/compiler/utils/arm/assembler_thumb2.cc
@@ -2569,30 +2569,19 @@
 
 void Thumb2Assembler::movw(Register rd, uint16_t imm16, Condition cond) {
   CheckCondition(cond);
-  bool must_be_32bit = force_32bit_;
-  if (IsHighRegister(rd)|| imm16 >= 256u) {
-    must_be_32bit = true;
-  }
-
-  if (must_be_32bit) {
-    // Use encoding T3.
-    uint32_t imm4 = (imm16 >> 12) & 15U /* 0b1111 */;
-    uint32_t i = (imm16 >> 11) & 1U /* 0b1 */;
-    uint32_t imm3 = (imm16 >> 8) & 7U /* 0b111 */;
-    uint32_t imm8 = imm16 & 0xff;
-    int32_t encoding = B31 | B30 | B29 | B28 |
-                    B25 | B22 |
-                    static_cast<uint32_t>(rd) << 8 |
-                    i << 26 |
-                    imm4 << 16 |
-                    imm3 << 12 |
-                    imm8;
-    Emit32(encoding);
-  } else {
-    int16_t encoding = B13 | static_cast<uint16_t>(rd) << 8 |
-                imm16;
-    Emit16(encoding);
-  }
+  // Always 32 bits, encoding T3. (Other encondings are called MOV, not MOVW.)
+  uint32_t imm4 = (imm16 >> 12) & 15U /* 0b1111 */;
+  uint32_t i = (imm16 >> 11) & 1U /* 0b1 */;
+  uint32_t imm3 = (imm16 >> 8) & 7U /* 0b111 */;
+  uint32_t imm8 = imm16 & 0xff;
+  int32_t encoding = B31 | B30 | B29 | B28 |
+                  B25 | B22 |
+                  static_cast<uint32_t>(rd) << 8 |
+                  i << 26 |
+                  imm4 << 16 |
+                  imm3 << 12 |
+                  imm8;
+  Emit32(encoding);
 }
 
 
diff --git a/compiler/utils/assembler_thumb_test.cc b/compiler/utils/assembler_thumb_test.cc
index 1de51a2..5ae2cc2 100644
--- a/compiler/utils/assembler_thumb_test.cc
+++ b/compiler/utils/assembler_thumb_test.cc
@@ -832,11 +832,12 @@
 TEST(Thumb2AssemblerTest, MovWMovT) {
   arm::Thumb2Assembler assembler;
 
-  __ movw(R4, 0);         // 16 bit.
-  __ movw(R4, 0x34);      // 16 bit.
-  __ movw(R9, 0x34);      // 32 bit due to high register.
-  __ movw(R3, 0x1234);    // 32 bit due to large value.
-  __ movw(R9, 0xffff);    // 32 bit due to large value and high register.
+  // Always 32 bit.
+  __ movw(R4, 0);
+  __ movw(R4, 0x34);
+  __ movw(R9, 0x34);
+  __ movw(R3, 0x1234);
+  __ movw(R9, 0xffff);
 
   // Always 32 bit.
   __ movt(R0, 0);
diff --git a/compiler/utils/assembler_thumb_test_expected.cc.inc b/compiler/utils/assembler_thumb_test_expected.cc.inc
index 9246c82..886295e 100644
--- a/compiler/utils/assembler_thumb_test_expected.cc.inc
+++ b/compiler/utils/assembler_thumb_test_expected.cc.inc
@@ -439,14 +439,14 @@
   nullptr
 };
 const char* MovWMovTResults[] = {
-  "   0:	2400      	movs	r4, #0\n",
-  "   2:	2434      	movs	r4, #52	; 0x34\n",
-  "   4:	f240 0934 	movw	r9, #52	; 0x34\n",
-  "   8:	f241 2334 	movw	r3, #4660	; 0x1234\n",
-  "   c:	f64f 79ff 	movw	r9, #65535	; 0xffff\n",
-  "  10:	f2c0 0000 	movt	r0, #0\n",
-  "  14:	f2c1 2034 	movt	r0, #4660	; 0x1234\n",
-  "  18:	f6cf 71ff 	movt	r1, #65535	; 0xffff\n",
+  "   0:	f240 0400 	movw  r4, #0\n",
+  "   4:	f240 0434 	movw  r4, #52 ; 0x34\n",
+  "   8:	f240 0934 	movw	r9, #52	; 0x34\n",
+  "   c:	f241 2334 	movw	r3, #4660	; 0x1234\n",
+  "  10:	f64f 79ff 	movw	r9, #65535	; 0xffff\n",
+  "  14:	f2c0 0000 	movt	r0, #0\n",
+  "  18:	f2c1 2034 	movt	r0, #4660	; 0x1234\n",
+  "  1c:	f6cf 71ff 	movt	r1, #65535	; 0xffff\n",
   nullptr
 };
 const char* SpecialAddSubResults[] = {