[llvm] [GlobalISel] Add GIM_CheckMachineOperandType for matching metadata operands (PR #191389)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-tablegen

Author: Sameer Sahasrabuddhe (ssahasra)

<details>
<summary>Changes</summary>

Add a new match table opcode GIM_CheckMachineOperandType and a corresponding MachineOperandTypeMatcher class to support matching operands by their MachineOperand type. This enables GlobalISel pattern matching for intrinsics that have metadata operands (MVT::Metadata), which previously could not be matched in the generated selector.

This is patch was extracted from #<!-- -->172090.

Co-authored-by: macurtis-amd <macurtis@<!-- -->amd.com>
Assisted-by: Claude Opus 4.6

---
Full diff: https://github.com/llvm/llvm-project/pull/191389.diff


4 Files Affected:

- (modified) llvm/include/llvm/CodeGen/GlobalISel/GIMatchTableExecutor.h (+6) 
- (modified) llvm/include/llvm/CodeGen/GlobalISel/GIMatchTableExecutorImpl.h (+9) 
- (modified) llvm/utils/TableGen/Common/GlobalISel/GlobalISelMatchTable.cpp (+17) 
- (modified) llvm/utils/TableGen/Common/GlobalISel/GlobalISelMatchTable.h (+18) 


``````````diff
diff --git a/llvm/include/llvm/CodeGen/GlobalISel/GIMatchTableExecutor.h b/llvm/include/llvm/CodeGen/GlobalISel/GIMatchTableExecutor.h
index 3a2509345b776..f21923827039c 100644
--- a/llvm/include/llvm/CodeGen/GlobalISel/GIMatchTableExecutor.h
+++ b/llvm/include/llvm/CodeGen/GlobalISel/GIMatchTableExecutor.h
@@ -246,6 +246,12 @@ enum {
   /// - SizeInBits(ULEB128) - The size of the pointer value in bits.
   GIM_CheckPointerToAny,
 
+  /// Check the machine type of the specified operand
+  /// - InsnID(ULEB128) - Instruction ID
+  /// - OpIdx(ULEB128) - Operand index
+  /// - MachineOperandType(ULEB128) - Expected type
+  GIM_CheckMachineOperandType,
+
   /// Check the register bank for the specified operand
   /// - InsnID(ULEB128) - Instruction ID
   /// - OpIdx(ULEB128) - Operand index
diff --git a/llvm/include/llvm/CodeGen/GlobalISel/GIMatchTableExecutorImpl.h b/llvm/include/llvm/CodeGen/GlobalISel/GIMatchTableExecutorImpl.h
index 8f6586e79d78a..3d6dd9e62f963 100644
--- a/llvm/include/llvm/CodeGen/GlobalISel/GIMatchTableExecutorImpl.h
+++ b/llvm/include/llvm/CodeGen/GlobalISel/GIMatchTableExecutorImpl.h
@@ -768,6 +768,15 @@ bool GIMatchTableExecutor::executeMatchTable(
 
       break;
     }
+    case GIM_CheckMachineOperandType: {
+      uint64_t InsnID = readULEB();
+      uint64_t OpIdx = readULEB();
+      uint64_t MOTy = readULEB();
+      MachineOperand &MO = State.MIs[InsnID]->getOperand(OpIdx);
+      if (MO.getType() != MOTy)
+        return false;
+      break;
+    }
     case GIM_RecordNamedOperand: {
       uint64_t InsnID = readULEB();
       uint64_t OpIdx = readULEB();
diff --git a/llvm/utils/TableGen/Common/GlobalISel/GlobalISelMatchTable.cpp b/llvm/utils/TableGen/Common/GlobalISel/GlobalISelMatchTable.cpp
index 1968097f91983..b642a5fe70d63 100644
--- a/llvm/utils/TableGen/Common/GlobalISel/GlobalISelMatchTable.cpp
+++ b/llvm/utils/TableGen/Common/GlobalISel/GlobalISelMatchTable.cpp
@@ -1493,6 +1493,12 @@ Error OperandMatcher::addTypeCheckPredicate(const TypeSetByHwMode &VTy,
     return Error::success();
   }
 
+  llvm::MVT::SimpleValueType STy = VTy.getMachineValueType().SimpleTy;
+  if (STy == MVT::Metadata) {
+    addPredicate<MachineOperandTypeMatcher>(MachineOperand::MO_Metadata);
+    return Error::success();
+  }
+
   auto OpTyOrNone = MVTToLLT(VTy.getMachineValueType().SimpleTy);
   if (!OpTyOrNone)
     return failUnsupported("unsupported type");
@@ -1958,6 +1964,17 @@ bool InstructionOperandMatcher::isHigherPriorityThan(
   return false;
 }
 
+//===- MachineOperandTypeMatcher -----------------------------------------===//
+
+void MachineOperandTypeMatcher::emitPredicateOpcodes(MatchTable &Table,
+                                                     RuleMatcher &Rule) const {
+  Table << MatchTable::Opcode("GIM_CheckMachineOperandType")
+        << MatchTable::Comment("MI") << MatchTable::ULEB128Value(InsnVarID)
+        << MatchTable::Comment("Op") << MatchTable::ULEB128Value(OpIdx)
+        << MatchTable::Comment("Ty") << MatchTable::ULEB128Value(MOTy)
+        << MatchTable::LineBreak;
+}
+
 //===- OperandRenderer ----------------------------------------------------===//
 
 OperandRenderer::~OperandRenderer() = default;
diff --git a/llvm/utils/TableGen/Common/GlobalISel/GlobalISelMatchTable.h b/llvm/utils/TableGen/Common/GlobalISel/GlobalISelMatchTable.h
index 4749139049861..d58e7a603f651 100644
--- a/llvm/utils/TableGen/Common/GlobalISel/GlobalISelMatchTable.h
+++ b/llvm/utils/TableGen/Common/GlobalISel/GlobalISelMatchTable.h
@@ -23,6 +23,7 @@
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/StringRef.h"
+#include "llvm/CodeGen/MachineOperand.h"
 #include "llvm/CodeGenTypes/LowLevelType.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/SaveAndRestore.h"
@@ -860,6 +861,7 @@ class PredicateMatcher {
     OPM_MBB,
     OPM_RecordNamedOperand,
     OPM_RecordRegType,
+    OPM_MOType,
   };
 
 protected:
@@ -1963,6 +1965,22 @@ class InstructionOperandMatcher : public OperandPredicateMatcher {
   }
 };
 
+class MachineOperandTypeMatcher : public OperandPredicateMatcher {
+  const MachineOperand::MachineOperandType MOTy;
+
+public:
+  MachineOperandTypeMatcher(unsigned InsnVarID, unsigned OpIdx,
+                            MachineOperand::MachineOperandType MOTy)
+      : OperandPredicateMatcher(OPM_MOType, InsnVarID, OpIdx), MOTy(MOTy) {}
+
+  static bool classof(const PredicateMatcher *P) {
+    return P->getKind() == OPM_MOType;
+  }
+
+  void emitPredicateOpcodes(MatchTable &Table,
+                            RuleMatcher &Rule) const override;
+};
+
 //===- Actions ------------------------------------------------------------===//
 class OperandRenderer {
 public:

``````````

</details>


https://github.com/llvm/llvm-project/pull/191389