MIR Serialization: Serialize the sub register indices.

This commit serializes the sub register indices from the register machine
operands.

Reviewers: Duncan P. N. Exon Smith
llvm-svn: 242084

lib/CodeGen/MIRParser/MILexer.cpp

@@ -179,6 +179,8 @@ static MIToken::TokenKind symbolToken(char C) {
     return MIToken::comma;
   case '=':
     return MIToken::equal;
+  case ':':
+    return MIToken::colon;
   default:
     return MIToken::Error;
   }

lib/CodeGen/MIRParser/MILexer.h

@@ -35,6 +35,7 @@ struct MIToken {
     comma,
     equal,
     underscore,
+    colon,
 
     // Keywords
     kw_implicit,

lib/CodeGen/MIRParser/MIParser.cpp

@@ -56,6 +56,8 @@ class MIParser {
   StringMap<unsigned> Names2Regs;
   /// Maps from register mask names to register masks.
   StringMap<const uint32_t *> Names2RegMasks;
+  /// Maps from subregister names to subregister indices.
+  StringMap<unsigned> Names2SubRegIndices;
 
 public:
   MIParser(SourceMgr &SM, MachineFunction &MF, SMDiagnostic &Error,
@@ -79,6 +81,7 @@ public:
 
   bool parseRegister(unsigned &Reg);
   bool parseRegisterFlag(unsigned &Flags);
+  bool parseSubRegisterIndex(unsigned &SubReg);
   bool parseRegisterOperand(MachineOperand &Dest, bool IsDef = false);
   bool parseImmediateOperand(MachineOperand &Dest);
   bool parseMBBReference(MachineBasicBlock *&MBB);
@@ -115,6 +118,13 @@ private:
   ///
   /// Return null if the identifier isn't a register mask.
   const uint32_t *getRegMask(StringRef Identifier);
+
+  void initNames2SubRegIndices();
+
+  /// Check if the given identifier is a name of a subregister index.
+  ///
+  /// Return 0 if the name isn't a subregister index class.
+  unsigned getSubRegIndex(StringRef Name);
 };
 
 } // end anonymous namespace
@@ -332,6 +342,19 @@ bool MIParser::parseRegisterFlag(unsigned &Flags) {
   return false;
 }
 
+bool MIParser::parseSubRegisterIndex(unsigned &SubReg) {
+  assert(Token.is(MIToken::colon));
+  lex();
+  if (Token.isNot(MIToken::Identifier))
+    return error("expected a subregister index after ':'");
+  auto Name = Token.stringValue();
+  SubReg = getSubRegIndex(Name);
+  if (!SubReg)
+    return error(Twine("use of unknown subregister index '") + Name + "'");
+  lex();
+  return false;
+}
+
 bool MIParser::parseRegisterOperand(MachineOperand &Dest, bool IsDef) {
   unsigned Reg;
   unsigned Flags = IsDef ? RegState::Define : 0;
@@ -344,10 +367,15 @@ bool MIParser::parseRegisterOperand(MachineOperand &Dest, bool IsDef) {
   if (parseRegister(Reg))
     return true;
   lex();
-  // TODO: Parse subregister.
+  unsigned SubReg = 0;
+  if (Token.is(MIToken::colon)) {
+    if (parseSubRegisterIndex(SubReg))
+      return true;
+  }
   Dest = MachineOperand::CreateReg(
       Reg, Flags & RegState::Define, Flags & RegState::Implicit,
-      Flags & RegState::Kill, Flags & RegState::Dead, Flags & RegState::Undef);
+      Flags & RegState::Kill, Flags & RegState::Dead, Flags & RegState::Undef,
+      /*isEarlyClobber=*/false, SubReg);
   return false;
 }
 
@@ -525,6 +553,23 @@ const uint32_t *MIParser::getRegMask(StringRef Identifier) {
   return RegMaskInfo->getValue();
 }
 
+void MIParser::initNames2SubRegIndices() {
+  if (!Names2SubRegIndices.empty())
+    return;
+  const TargetRegisterInfo *TRI = MF.getSubtarget().getRegisterInfo();
+  for (unsigned I = 1, E = TRI->getNumSubRegIndices(); I < E; ++I)
+    Names2SubRegIndices.insert(
+        std::make_pair(StringRef(TRI->getSubRegIndexName(I)).lower(), I));
+}
+
+unsigned MIParser::getSubRegIndex(StringRef Name) {
+  initNames2SubRegIndices();
+  auto SubRegInfo = Names2SubRegIndices.find(Name);
+  if (SubRegInfo == Names2SubRegIndices.end())
+    return 0;
+  return SubRegInfo->getValue();
+}
+
 bool llvm::parseMachineInstr(MachineInstr *&MI, SourceMgr &SM,
                              MachineFunction &MF, StringRef Src,
                              const PerFunctionMIParsingState &PFS,

lib/CodeGen/MIRPrinter.cpp

@@ -303,7 +303,9 @@ void MIPrinter::print(const MachineOperand &Op, const TargetRegisterInfo *TRI) {
     if (Op.isUndef())
       OS << "undef ";
     printReg(Op.getReg(), OS, TRI);
-    // TODO: Print sub register.
+    // Print the sub register.
+    if (Op.getSubReg() != 0)
+      OS << ':' << TRI->getSubRegIndexName(Op.getSubReg());
     break;
   case MachineOperand::MO_Immediate:
     OS << Op.getImm();

test/CodeGen/MIR/X86/expected-subregister-after-colon.mir

@@ -0,0 +1,29 @@
+# RUN: not llc -march=x86-64 -start-after machine-sink -stop-after machine-sink -o /dev/null %s 2>&1 | FileCheck %s
+
+--- |
+
+  define zeroext i1 @t(i1 %c) {
+  entry:
+    ret i1 %c
+  }
+
+...
+---
+name:            t
+isSSA:           true
+tracksRegLiveness: true
+registers:
+  - { id: 0, class: gr32 }
+  - { id: 1, class: gr8 }
+  - { id: 2, class: gr8 }
+body:
+  - name:        entry
+    id:          0
+    instructions:
+      - '%0 = COPY %edi'
+      # CHECK: [[@LINE+1]]:25: expected a subregister index after ':'
+      - '%1 = COPY %0 : 42'
+      - '%2 = AND8ri %1, 1, implicit-def %eflags'
+      - '%al = COPY %2'
+      - 'RETQ %al'
+...

test/CodeGen/MIR/X86/subregister-operands.mir

@@ -0,0 +1,33 @@
+# RUN: llc -march=x86-64 -start-after machine-sink -stop-after machine-sink -o /dev/null %s | FileCheck %s
+# This test ensures that the MIR parser parses subregisters in register operands
+# correctly.
+
+--- |
+
+  define zeroext i1 @t(i1 %c) {
+  entry:
+    ret i1 %c
+  }
+
+...
+---
+name:            t
+isSSA:           true
+tracksRegLiveness: true
+registers:
+  - { id: 0, class: gr32 }
+  - { id: 1, class: gr8 }
+  - { id: 2, class: gr8 }
+body:
+  - name:        entry
+    id:          0
+    instructions:
+      # CHECK:      %0 = COPY %edi
+      # CHECK-NEXT: %1 = COPY %0:sub_8bit
+      - '%0 = COPY %edi'
+      - '%1 = COPY %0:sub_8bit'
+      - '%2 = AND8ri %1, 1, implicit-def %eflags'
+      - '%al = COPY %2'
+      - 'RETQ %al'
+...
+

test/CodeGen/MIR/X86/unknown-subregister-index.mir

@@ -0,0 +1,31 @@
+# RUN: not llc -march=x86-64 -start-after machine-sink -stop-after machine-sink -o /dev/null %s 2>&1 | FileCheck %s
+# This test ensures that an error is reported when an unknown subregister index
+# is encountered.
+
+--- |
+
+  define zeroext i1 @t(i1 %c) {
+  entry:
+    ret i1 %c
+  }
+
+...
+---
+name:            t
+isSSA:           true
+tracksRegLiveness: true
+registers:
+  - { id: 0, class: gr32 }
+  - { id: 1, class: gr8 }
+  - { id: 2, class: gr8 }
+body:
+  - name:        entry
+    id:          0
+    instructions:
+      - '%0 = COPY %edi'
+      # CHECK: [[@LINE+1]]:23: use of unknown subregister index 'bit8'
+      - '%1 = COPY %0:bit8'
+      - '%2 = AND8ri %1, 1, implicit-def %eflags'
+      - '%al = COPY %2'
+      - 'RETQ %al'
+...