[MSP430] Print add x,x as rla x

Author: chbessonova

src/llvm/lib/Target/MSP430/InstPrinter/MSP430InstPrinter.cpp

@@ -27,10 +27,47 @@ using namespace llvm;
 #define PRINT_ALIAS_INSTR
 #include "MSP430GenAsmWriter.inc"
 
+static bool isRLAmInstruction(const MCInst *MI) {
+  // add x,x == rla x
+  unsigned Opc = MI->getOpcode();
+  if (Opc != MSP430::ADD8mm && Opc != MSP430::ADD16mm &&
+      Opc != MSP430::ADDC8mm && Opc != MSP430::ADDC16mm)
+    return false;
+
+  // Check operands pairs are equal
+  const MCOperand &Op1 = MI->getOperand(0);
+  const MCOperand &Op2 = MI->getOperand(1);
+  const MCOperand &Op3 = MI->getOperand(2);
+  const MCOperand &Op4 = MI->getOperand(3);
+
+  if (Op1.isReg() && Op3.isReg() && Op1.getReg() == Op3.getReg() &&
+      Op2.isImm() && Op4.isImm() && Op2.getImm() == Op4.getImm())
+      return true;
+  // TODO: Is it possible to check if two MCExpr are equal?
+  return false;
+}
+
 void MSP430InstPrinter::printInst(const MCInst *MI, raw_ostream &O,
                                   StringRef Annot, const MCSubtargetInfo &STI) {
+  // Print add x,x -> rla x (only mm case here, rr is handled by tablegen)
+  // TODO: Is it possible to resolve this by tablegen as well?
+  if (isRLAmInstruction(MI)) {
+    switch (MI->getOpcode()) {
+    case MSP430::ADD8mm:     O << "\trla.b\t";        break;
+    case MSP430::ADD16mm:    O << "\trla\t";          break;
+    case MSP430::ADDC8mm:    O << "\trlc.b\t";        break;
+    case MSP430::ADDC16mm:   O << "\trlc\t";          break;
+    default:
+      llvm_unreachable("Unexpected instruction");
+    }
+    printSrcMemOperand(MI, 0, O);
+    printAnnotation(O, Annot);
+    return;
+  }
+
   if (!printAliasInstr(MI, O))
     printInstruction(MI, O);
+
   printAnnotation(O, Annot);
 }
 

src/llvm/lib/Target/MSP430/MSP430InstrInfo.td

@@ -586,16 +586,16 @@ def INV16r  : InstAlias<"inv\t$dst",    (XOR16rc   GR16:$dst,   -1)>;
 def INV8m   : InstAlias<"inv.b\t$dst",  (XOR8mc    memdst:$dst, -1)>;
 def INV16m  : InstAlias<"inv\t$dst",    (XOR16mc   memdst:$dst, -1)>;
 
-// printAliasInstr() doesn't check $dst operands are actually equal
+// printAliasInstr() doesn't check non-register operands are actually equal
 // for RLA and RLC aliases below, so disable printing aliases.
 
-def RLA8r   : InstAlias<"rla.b\t$dst",  (ADD8rr    GR8:$dst,     GR8:$dst),    0>;
-def RLA16r  : InstAlias<"rla\t$dst",    (ADD16rr   GR16:$dst,    GR16:$dst),   0>;
+def RLA8r   : InstAlias<"rla.b\t$dst",  (ADD8rr    GR8:$dst,     GR8:$dst),    1>;
+def RLA16r  : InstAlias<"rla\t$dst",    (ADD16rr   GR16:$dst,    GR16:$dst),   1>;
 def RLA8m   : InstAlias<"rla.b\t$dst",  (ADD8mm    memdst:$dst,  memdst:$dst), 0>;
 def RLA16m  : InstAlias<"rla\t$dst",    (ADD16mm   memdst:$dst,  memdst:$dst), 0>;
 
-def RLC8r   : InstAlias<"rlc.b\t$dst",  (ADDC8rr   GR8:$dst,     GR8:$dst),    0>;
-def RLC16r  : InstAlias<"rlc\t$dst",    (ADDC16rr  GR16:$dst,    GR16:$dst),   0>;
+def RLC8r   : InstAlias<"rlc.b\t$dst",  (ADDC8rr   GR8:$dst,     GR8:$dst),    1>;
+def RLC16r  : InstAlias<"rlc\t$dst",    (ADDC16rr  GR16:$dst,    GR16:$dst),   1>;
 def RLC8m   : InstAlias<"rlc.b\t$dst",  (ADDC8mm   memdst:$dst,  memdst:$dst), 0>;
 def RLC16m  : InstAlias<"rlc\t$dst",    (ADDC16mm  memdst:$dst,  memdst:$dst), 0>;
 

src/llvm/test/CodeGen/MSP430/jumptable.ll

@@ -15,7 +15,7 @@ entry:
   %i.addr = alloca i16, align 2
   store i16 %i, i16* %i.addr, align 2
   %0 = load i16, i16* %i.addr, align 2
-; CHECK:      add   r12, r12
+; CHECK:      rla   r12
 ; CHECK-NEXT: br .LJTI0_0(r12)
   switch i16 %0, label %sw.default [
     i16 0, label %sw.bb

src/llvm/test/CodeGen/MSP430/shifts.ll

@@ -22,7 +22,7 @@ entry:
 define zeroext i8 @shl8(i8 zeroext %a, i8 zeroext %cnt) nounwind readnone {
 entry:
 ; CHECK: shl8
-; CHECK: add.b
+; CHECK: rla.b
   %shl = shl i8 %a, %cnt
   ret i8 %shl
 }
@@ -47,7 +47,7 @@ entry:
 define zeroext i16 @shl16(i16 zeroext %a, i16 zeroext %cnt) nounwind readnone {
 entry:
 ; CHECK-LABEL: shl16:
-; CHECK: add
+; CHECK: rla
   %shl = shl i16 %a, %cnt
   ret i16 %shl
 }

src/llvm/test/MC/MSP430/opcode.s

@@ -125,9 +125,9 @@
   ;; Emulated logical instructions
   inv    r7     ; CHECK-INST: inv    r7
                 ; CHECK: encoding: [0x37,0xe3]
-  rla    r7     ; CHECK-INST: add    r7, r7
+  rla    r7     ; CHECK-INST: rla    r7
                 ; CHECK: encoding: [0x07,0x57]
-  rlc    r7     ; CHECK-INST: addc   r7, r7
+  rlc    r7     ; CHECK-INST: rlc    r7
                 ; CHECK: encoding: [0x07,0x67]
 
   ;; Emulated program flow control instructions