ARM assembly parsing for ASR(immediate).

Start of rdar://9704684

llvm-svn: 144293

llvm/lib/Target/ARM/ARMInstrFormats.td

@@ -293,21 +293,27 @@ class InstThumb<AddrMode am, int sz, IndexMode im,
 // Pseudo-instructions for alternate assembly syntax (never used by codegen).
 // These are aliases that require C++ handling to convert to the target
 // instruction, while InstAliases can be handled directly by tblgen.
-class AsmPseudoInst<dag iops>
+class AsmPseudoInst<string asm, dag iops>
   : InstTemplate<AddrModeNone, 0, IndexModeNone, Pseudo, GenericDomain,
                  "", NoItinerary> {
-  let OutOperandList = (ops);
+  let OutOperandList = (outs);
   let InOperandList = iops;
   let Pattern = [];
   let isCodeGenOnly = 0; // So we get asm matcher for it.
+  let AsmString = asm;
   let isPseudo = 1;
 }
 
-class ARMAsmPseudo<dag iops> : AsmPseudoInst<iops>, Requires<[IsARM]>;
-class tAsmPseudo<dag iops> : AsmPseudoInst<iops>, Requires<[IsThumb]>;
-class t2AsmPseudo<dag iops> : AsmPseudoInst<iops>, Requires<[IsThumb2]>;
-class VFP2AsmPseudo<dag iops> : AsmPseudoInst<iops>, Requires<[HasVFP2]>;
-class NEONAsmPseudo<dag iops> : AsmPseudoInst<iops>, Requires<[HasNEON]>;
+class ARMAsmPseudo<string asm, dag iops> : AsmPseudoInst<asm, iops>,
+        Requires<[IsARM]>;
+class tAsmPseudo<string asm, dag iops> : AsmPseudoInst<asm, iops>,
+        Requires<[IsThumb]>;
+class t2AsmPseudo<string asm, dag iops> : AsmPseudoInst<asm, iops>,
+        Requires<[IsThumb2]>;
+class VFP2AsmPseudo<string asm, dag iops> : AsmPseudoInst<asm, iops>,
+        Requires<[HasVFP2]>;
+class NEONAsmPseudo<string asm, dag iops> : AsmPseudoInst<asm, iops>,
+        Requires<[HasNEON]>;
 
 // Pseudo instructions for the code generator.
 class PseudoInst<dag oops, dag iops, InstrItinClass itin, list<dag> pattern>

llvm/lib/Target/ARM/ARMInstrInfo.td

@@ -4994,3 +4994,12 @@ def : MnemonicAlias<"usubaddx", "usax">;
 // for isel.
 def : ARMInstAlias<"mov${s}${p} $Rd, $imm",
                    (MVNi rGPR:$Rd, so_imm_not:$imm, pred:$p, cc_out:$s)>;
+
+// The shifter forms of the MOV instruction are aliased to the ASR, LSL,
+// LSR, ROR, and RRX instructions.
+// FIXME: We need C++ parser hooks to map the alias to the MOV
+//        encoding. It seems we should be able to do that sort of thing
+//        in tblgen, but it could get ugly.
+def ASRi : ARMAsmPseudo<"asr${s}${p} $Rd, $Rm, $imm",
+                        (ins GPR:$Rd, GPR:$Rm, imm1_32:$imm, pred:$p,
+                             cc_out:$s)>;

llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp

@@ -4541,6 +4541,21 @@ void ARMAsmParser::
 processInstruction(MCInst &Inst,
                    const SmallVectorImpl<MCParsedAsmOperand*> &Operands) {
   switch (Inst.getOpcode()) {
+  // Handle the MOV complex aliases.
+  case ARM::ASRi: {
+    unsigned Amt = Inst.getOperand(2).getImm() + 1;
+    unsigned ShiftOp = ARM_AM::getSORegOpc(ARM_AM::asr, Amt);
+    MCInst TmpInst;
+    TmpInst.setOpcode(ARM::MOVsi);
+    TmpInst.addOperand(Inst.getOperand(0)); // Rd
+    TmpInst.addOperand(Inst.getOperand(1)); // Rn
+    TmpInst.addOperand(MCOperand::CreateImm(ShiftOp)); // Shift value and ty
+    TmpInst.addOperand(Inst.getOperand(3)); // CondCode
+    TmpInst.addOperand(Inst.getOperand(4));
+    TmpInst.addOperand(Inst.getOperand(5)); // cc_out
+    Inst = TmpInst;
+    break;
+  }
   case ARM::LDMIA_UPD:
     // If this is a load of a single register via a 'pop', then we should use
     // a post-indexed LDR instruction instead, per the ARM ARM.

llvm/test/MC/ARM/basic-arm-instructions.s

@@ -257,8 +257,15 @@ Lforward:
 @ CHECK: and	r10, r10, r1, rrx       @ encoding: [0x61,0xa0,0x0a,0xe0]
 
 @------------------------------------------------------------------------------
-@ FIXME: ASR
+@ ASR
 @------------------------------------------------------------------------------
+	asr r2, r4, #32
+	asr r2, r4, #2
+
+@ CHECK: asr	r2, r4, #32             @ encoding: [0x44,0x20,0xa0,0xe1]
+@ CHECK: asr	r2, r4, #2              @ encoding: [0x44,0x21,0xa0,0xe1]
+
+
 @------------------------------------------------------------------------------
 @ B
 @------------------------------------------------------------------------------