commit 5ef93b0c4ceb0c6ace49227fb0631d9cafbfbc15
author Alex Lorenz <arphaman@gmail.com> Wed Aug 19 19:05:34 2015 +0000
committer Alex Lorenz <arphaman@gmail.com> Wed Aug 19 19:05:34 2015 +0000
tree 2b5c862c434a5fd2ab52c032aa9fd7d8f9e776f0
parent 5f1cea414123eff634d3d7e0320cdb3f0a825e57

MIR Serialization: Serialize instruction's register ties.

This commit serializes the machine instruction's register operand ties.
The ties are printed out only when the instructon has register ties that are
different from the ties that are specified in the instruction's description.

llvm-svn: 245482

llvm/lib/CodeGen/MIRPrinter.cpp

diff --git a/llvm/lib/CodeGen/MIRPrinter.cpp b/llvm/lib/CodeGen/MIRPrinter.cpp
index 5d3c299..759a8d3 100644
--- a/llvm/lib/CodeGen/MIRPrinter.cpp
+++ b/llvm/lib/CodeGen/MIRPrinter.cpp
@@ -117,7 +117,7 @@
   void printOffset(int64_t Offset);
   void printTargetFlags(const MachineOperand &Op);
   void print(const MachineOperand &Op, const TargetRegisterInfo *TRI,
-             bool IsDef = false);
+             unsigned I, bool ShouldPrintRegisterTies, bool IsDef = false);
   void print(const MachineMemOperand &Op);
 
   void print(const MCCFIInstruction &CFI, const TargetRegisterInfo *TRI);
@@ -502,6 +502,23 @@
     OS.indent(2) << "}\n";
 }
 
+/// Return true when an instruction has tied register that can't be determined
+/// by the instruction's descriptor.
+static bool hasComplexRegisterTies(const MachineInstr &MI) {
+  const MCInstrDesc &MCID = MI.getDesc();
+  for (unsigned I = 0, E = MI.getNumOperands(); I < E; ++I) {
+    const auto &Operand = MI.getOperand(I);
+    if (!Operand.isReg() || Operand.isDef())
+      // Ignore the defined registers as MCID marks only the uses as tied.
+      continue;
+    int ExpectedTiedIdx = MCID.getOperandConstraint(I, MCOI::TIED_TO);
+    int TiedIdx = Operand.isTied() ? int(MI.findTiedOperandIdx(I)) : -1;
+    if (ExpectedTiedIdx != TiedIdx)
+      return true;
+  }
+  return false;
+}
+
 void MIPrinter::print(const MachineInstr &MI) {
   const auto &SubTarget = MI.getParent()->getParent()->getSubtarget();
   const auto *TRI = SubTarget.getRegisterInfo();
@@ -511,13 +528,14 @@
   if (MI.isCFIInstruction())
     assert(MI.getNumOperands() == 1 && "Expected 1 operand in CFI instruction");
 
+  bool ShouldPrintRegisterTies = hasComplexRegisterTies(MI);
   unsigned I = 0, E = MI.getNumOperands();
   for (; I < E && MI.getOperand(I).isReg() && MI.getOperand(I).isDef() &&
          !MI.getOperand(I).isImplicit();
        ++I) {
     if (I)
       OS << ", ";
-    print(MI.getOperand(I), TRI, /*IsDef=*/true);
+    print(MI.getOperand(I), TRI, I, ShouldPrintRegisterTies, /*IsDef=*/true);
   }
 
   if (I)
@@ -532,7 +550,7 @@
   for (; I < E; ++I) {
     if (NeedComma)
       OS << ", ";
-    print(MI.getOperand(I), TRI);
+    print(MI.getOperand(I), TRI, I, ShouldPrintRegisterTies);
     NeedComma = true;
   }
 
@@ -690,11 +708,10 @@
 }
 
 void MIPrinter::print(const MachineOperand &Op, const TargetRegisterInfo *TRI,
-                      bool IsDef) {
+                      unsigned I, bool ShouldPrintRegisterTies, bool IsDef) {
   printTargetFlags(Op);
   switch (Op.getType()) {
   case MachineOperand::MO_Register:
-    // FIXME: Serialize the tied register.
     if (Op.isImplicit())
       OS << (Op.isDef() ? "implicit-def " : "implicit ");
     else if (!IsDef && Op.isDef())
@@ -716,6 +733,8 @@
     // Print the sub register.
     if (Op.getSubReg() != 0)
       OS << ':' << TRI->getSubRegIndexName(Op.getSubReg());
+    if (ShouldPrintRegisterTies && Op.isTied() && !Op.isDef())
+      OS << "(tied-def " << Op.getParent()->findTiedOperandIdx(I) << ")";
     break;
   case MachineOperand::MO_Immediate:
     OS << Op.getImm();