[TableGen] Add support for DefaultMode in per-HwMode encode/decode.

llvm/test/TableGen/HwModeEncodeDecode3.td

@@ -0,0 +1,168 @@
+// RUN: llvm-tblgen -gen-emitter -I %p/../../include %s | \
+// RUN:     FileCheck %s --check-prefix=ENCODER
+// RUN: llvm-tblgen -gen-disassembler -I %p/../../include %s | \
+// RUN:     FileCheck %s --check-prefix=DECODER
+// RUN: llvm-tblgen -gen-disassembler --suppress-per-hwmode-duplicates -I \
+// RUN:     %p/../../include %s | FileCheck %s --check-prefix=DECODER-SUPPRESS
+
+include "llvm/Target/Target.td"
+
+def archInstrInfo : InstrInfo { }
+
+def arch : Target {
+  let InstructionSet = archInstrInfo;
+}
+
+def Myi32 : Operand<i32> {
+  let DecoderMethod = "DecodeMyi32";
+}
+
+def HasA : Predicate<"Subtarget->hasA()">;
+def HasB : Predicate<"Subtarget->hasB()">;
+
+def ModeA : HwMode<"+a", [HasA]>;
+def ModeB : HwMode<"+b", [HasB]>;
+
+
+def fooTypeEncDefault : InstructionEncoding {
+  let Size = 8;
+  field bits<64> SoftFail = 0;
+  bits<64> Inst;
+  bits<8> factor;
+  let Inst{7...0} = factor;
+  let Inst{3...2} = 0b10;
+  let Inst{1...0} = 0b00;
+}
+
+def fooTypeEncA : InstructionEncoding {
+  let Size = 4;
+  field bits<32> SoftFail = 0;
+  bits<32> Inst;
+  bits<8> factor;
+  let Inst{7...0} = factor;
+  let Inst{3...2} = 0b11;
+  let Inst{1...0} = 0b00;
+}
+
+def fooTypeEncB : InstructionEncoding {
+  let Size = 4;
+  field bits<32> SoftFail = 0;
+  bits<32> Inst;
+  bits<8> factor;
+  let Inst{15...8} = factor;
+  let Inst{1...0} = 0b11;
+}
+
+// Test for DefaultMode as a selector.
+def foo : Instruction {
+  let OutOperandList = (outs);
+  let InOperandList = (ins i32imm:$factor);
+  let EncodingInfos = EncodingByHwMode<
+    [ModeA, ModeB, DefaultMode], [fooTypeEncA, fooTypeEncB, fooTypeEncDefault]
+  >;
+  let AsmString = "foo  $factor";
+}
+
+def bar: Instruction {
+  let OutOperandList = (outs);
+  let InOperandList = (ins i32imm:$factor);
+  let Size = 4;
+  bits<32> Inst;
+  bits<32> SoftFail;
+  bits<8> factor;
+  let Inst{31...24} = factor;
+  let Inst{1...0} = 0b10;
+  let AsmString = "bar  $factor";
+}
+
+def baz : Instruction {
+  let OutOperandList = (outs);
+  let InOperandList = (ins i32imm:$factor);
+  bits<32> Inst;
+  let EncodingInfos = EncodingByHwMode<
+    [ModeB], [fooTypeEncA]
+  >;
+  let AsmString = "foo  $factor";
+}
+
+def unrelated: Instruction {
+  let OutOperandList = (outs);
+  let DecoderNamespace = "Alt";
+  let InOperandList = (ins i32imm:$factor);
+  let Size = 4;
+  bits<32> Inst;
+  bits<32> SoftFail;
+  bits<8> factor;
+  let Inst{31...24} = factor;
+  let Inst{1...0} = 0b10;
+  let AsmString = "unrelated  $factor";
+}
+
+
+// DECODER-LABEL: DecoderTableAlt_DefaultMode32[] =
+// DECODER-DAG: Opcode: unrelated
+// DECODER-LABEL: DecoderTableAlt_ModeA32[] =
+// DECODER-DAG: Opcode: unrelated
+// DECODER-LABEL: DecoderTableAlt_ModeB32[] =
+// DECODER-DAG: Opcode: unrelated
+// DECODER-LABEL: DecoderTable_DefaultMode32[] =
+// DECODER-DAG: Opcode: bar
+// DECODER-LABEL: DecoderTable_DefaultMode64[] =
+// DECODER-DAG: Opcode: fooTypeEncDefault:foo
+// DECODER-LABEL: DecoderTable_ModeA32[] =
+// DECODER-DAG: Opcode: fooTypeEncA:foo
+// DECODER-DAG: Opcode: bar
+// DECODER-LABEL: DecoderTable_ModeB32[] =
+// DECODER-DAG: Opcode: fooTypeEncB:foo
+// DECODER-DAG: Opcode: fooTypeEncA:baz
+// DECODER-DAG: Opcode: bar
+
+
+// DECODER-SUPPRESS-LABEL: DecoderTableAlt_AllModes32[] =
+// DECODER-SUPPRESS-DAG: Opcode: unrelated
+// DECODER-SUPPRESS-LABEL: DecoderTable_AllModes32[] =
+// DECODER-SUPPRESS-DAG: Opcode: bar
+// DECODER-SUPPRESS-LABEL: DecoderTable_DefaultMode64[] =
+// DECODER-SUPPRESS-NOT: Opcode: bar
+// DECODER-SUPPRESS-DAG: Opcode: fooTypeEncDefault:foo
+// DECODER-SUPPRESS-LABEL: DecoderTable_ModeA32[] =
+// DECODER-SUPPRESS-DAG: Opcode: fooTypeEncA:foo
+// DECODER-SUPPRESS-NOT: Opcode: bar
+// DECODER-SUPPRESS-LABEL: DecoderTable_ModeB32[] =
+// DECODER-SUPPRESS-DAG: Opcode: fooTypeEncB:foo
+// DECODER-SUPPRESS-DAG: Opcode: fooTypeEncA:baz
+// DECODER-SUPPRESS-NOT: Opcode: bar
+
+// ENCODER-LABEL:   static const uint64_t InstBits_DefaultMode[] = {
+// ENCODER:         UINT64_C(2),        // bar
+// ENCODER:         UINT64_C(0),        // baz
+// ENCODER:         UINT64_C(8),        // foo
+// ENCODER:         UINT64_C(2),        // unrelated
+
+// ENCODER-LABEL:   static const uint64_t InstBits_ModeA[] = {
+// ENCODER:         UINT64_C(2),        // bar
+// ENCODER:         UINT64_C(0),        // baz
+// ENCODER:         UINT64_C(12),       // foo
+// ENCODER:         UINT64_C(2),        // unrelated
+
+// ENCODER-LABEL:   static const uint64_t InstBits_ModeB[] = {
+// ENCODER:         UINT64_C(2),        // bar
+// ENCODER:         UINT64_C(12),       // baz
+// ENCODER:         UINT64_C(3),        // foo
+// ENCODER:         UINT64_C(2),        // unrelated
+
+// ENCODER:  unsigned HwMode = STI.getHwMode();
+// ENCODER:  switch (HwMode) {
+// ENCODER:  default: llvm_unreachable("Unknown hardware mode!"); break;
+// ENCODER:  case 0: InstBits = InstBits_DefaultMode; break;
+// ENCODER:  case 1: InstBits = InstBits_ModeA; break;
+// ENCODER:  case 2: InstBits = InstBits_ModeB; break;
+// ENCODER:  };
+
+// ENCODER:     case ::foo: {
+// ENCODER:      switch (HwMode) {
+// ENCODER:      default: llvm_unreachable("Unhandled HwMode");
+// ENCODER:      case 0: {
+// ENCODER:      case 1: {
+// ENCODER:      case 2: {
+

llvm/utils/TableGen/CodeEmitterGen.cpp

@@ -365,8 +365,8 @@ void CodeEmitterGen::emitInstructionBaseValues(
   if (HwMode == -1)
     o << "  static const uint64_t InstBits[] = {\n";
   else
-    o << "  static const uint64_t InstBits_" << HWM.getMode(HwMode).Name
-      << "[] = {\n";
+    o << "  static const uint64_t InstBits_"
+      << HWM.getModeName(HwMode, /*IncludeDefault=*/true) << "[] = {\n";
 
   for (const CodeGenInstruction *CGI : NumberedInstructions) {
     Record *R = CGI->TheDef;
@@ -495,8 +495,8 @@ void CodeEmitterGen::run(raw_ostream &o) {
       o << "  switch (HwMode) {\n";
       o << "  default: llvm_unreachable(\"Unknown hardware mode!\"); break;\n";
       for (unsigned I : HwModes) {
-        o << "  case " << I << ": InstBits = InstBits_" << HWM.getMode(I).Name
-          << "; break;\n";
+        o << "  case " << I << ": InstBits = InstBits_"
+          << HWM.getModeName(I, /*IncludeDefault=*/true) << "; break;\n";
       }
       o << "  };\n";
     }

llvm/utils/TableGen/CodeGenHwModes.h

@@ -52,6 +52,11 @@ struct CodeGenHwModes {
     assert(Id != 0 && "Mode id of 0 is reserved for the default mode");
     return Modes[Id - 1];
   }
+  const StringRef getModeName(unsigned Id, bool IncludeDefault = false) const {
+    if (IncludeDefault && Id == CodeGenHwModes::DefaultMode)
+      return DefaultModeName;
+    return getMode(Id).Name;
+  }
   const HwModeSelect &getHwModeSelect(Record *R) const;
   const std::map<Record *, HwModeSelect> &getHwModeSelects() const {
     return ModeSelects;

llvm/utils/TableGen/DecoderEmitter.cpp

@@ -2461,8 +2461,9 @@ collectHwModesReferencedForEncodings(const CodeGenHwModes &HWM,
         BV.set(P.first);
     }
   }
-  transform(BV.set_bits(), std::back_inserter(Names),
-            [&HWM](const int &M) { return HWM.getMode(M).Name; });
+  transform(BV.set_bits(), std::back_inserter(Names), [&HWM](const int &M) {
+    return HWM.getModeName(M, /*IncludeDefault=*/true);
+  });
 }
 
 // Emits disassembler code for instruction decoding.
@@ -2503,8 +2504,9 @@ void DecoderEmitter::run(raw_ostream &o) {
       if (DefInit *DI = dyn_cast_or_null<DefInit>(RV->getValue())) {
         EncodingInfoByHwMode EBM(DI->getDef(), HWM);
         for (auto &KV : EBM)
-          NumberedEncodings.emplace_back(KV.second, NumberedInstruction,
-                                         HWM.getMode(KV.first).Name);
+          NumberedEncodings.emplace_back(
+              KV.second, NumberedInstruction,
+              HWM.getModeName(KV.first, /*IncludeDefault=*/true));
         continue;
       }
     }