Make "mov" work for all Thumb2 MOV encodings

According to the ARM specification, "mov" is a valid mnemonic for all Thumb2 MOV encodings.
To achieve this, the patch adds one instruction alias with a special range condition to avoid collision with the Thumb1 MOV.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188901 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/ARM/ARMInstrInfo.td

@@ -710,6 +710,11 @@ def imm0_65535_expr : Operand<i32> {
   let ParserMatchClass = Imm0_65535ExprAsmOperand;
 }
 
+def Imm256_65535ExprAsmOperand: ImmAsmOperand { let Name = "Imm256_65535Expr"; }
+def imm256_65535_expr : Operand<i32> {
+  let ParserMatchClass = Imm256_65535ExprAsmOperand;
+}
+
 /// imm24b - True if the 32-bit immediate is encodable in 24 bits.
 def Imm24bitAsmOperand: ImmAsmOperand { let Name = "Imm24bit"; }
 def imm24b : Operand<i32>, ImmLeaf<i32, [{

lib/Target/ARM/ARMInstrThumb2.td

@@ -1855,6 +1855,9 @@ def t2MOVi16 : T2I<(outs rGPR:$Rd), (ins imm0_65535_expr:$imm), IIC_iMOVi,
   let DecoderMethod = "DecodeT2MOVTWInstruction";
 }
 
+def : t2InstAlias<"mov${p} $Rd, $imm", 
+                  (t2MOVi16 rGPR:$Rd, imm256_65535_expr:$imm, pred:$p)>;
+
 def t2MOVi16_ga_pcrel : PseudoInst<(outs rGPR:$Rd),
                                 (ins i32imm:$addr, pclabel:$id), IIC_iMOVi, []>;
 

lib/Target/ARM/AsmParser/ARMAsmParser.cpp

@@ -867,6 +867,15 @@ class ARMOperand : public MCParsedAsmOperand {
     int64_t Value = CE->getValue();
     return Value >= 0 && Value < 65536;
   }
+  bool isImm256_65535Expr() const {
+    if (!isImm()) return false;
+    const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(getImm());
+    // If it's not a constant expression, it'll generate a fixup and be
+    // handled later.
+    if (!CE) return true;
+    int64_t Value = CE->getValue();
+    return Value >= 256 && Value < 65536;
+  }
   bool isImm0_65535Expr() const {
     if (!isImm()) return false;
     const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(getImm());

test/MC/ARM/basic-thumb2-instructions.s

@@ -1323,8 +1323,15 @@ _func:
         movlo r1, #-1
 
         @ alias for mvn
-	mov r3, #-3
+        mov r3, #-3
+        mov r11, #0xabcd
+        movs r0, #1
+        it ne
+        movne r3, #15
 
+        itt eq
+        moveq r0, #255
+        moveq r1, #256
 
 @ CHECK: movs	r1, #21                 @ encoding: [0x15,0x21]
 @ CHECK: movs.w	r1, #21                 @ encoding: [0x5f,0xf0,0x15,0x01]
@@ -1343,6 +1350,14 @@ _func:
 @ CHECK: it	lo                      @ encoding: [0x38,0xbf]
 @ CHECK: movlo.w	r1, #-1         @ encoding: [0x4f,0xf0,0xff,0x31]
 @ CHECK: mvn	r3, #2                  @ encoding: [0x6f,0xf0,0x02,0x03]
+@ CHECK: movw	r11, #43981             @ encoding: [0x4a,0xf6,0xcd,0x3b]
+@ CHECK: movs	r0, #1                  @ encoding: [0x01,0x20]
+@ CHECK: it	ne                      @ encoding: [0x18,0xbf]
+@ CHECK: movne	r3, #15                 @ encoding: [0x0f,0x23]
+
+@ CHECK: itt    eq                      @ encoding: [0x04,0xbf]
+@ CHECK: moveq  r0, #255                @ encoding: [0xff,0x20]
+@ CHECK: movweq r1, #256                @ encoding: [0x40,0xf2,0x00,0x11]
 
 @------------------------------------------------------------------------------
 @ MOV(shifted register)