[GlobalISel] Generate prelegalizer combiner rules

1 files changed, 56 insertions, 0 deletions

diff --git a/backend/lib/Target/RISCV/GISel/RISCVGISelCombiner.cpp b/backend/lib/Target/RISCV/GISel/RISCVGISelCombiner.cpp
new file mode 100644
index 0000000..bf67c0a
--- /dev/null
+++ b/backend/lib/Target/RISCV/GISel/RISCVGISelCombiner.cpp
@@ -0,0 +1,56 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "RISCV.h"
+#include "rcc/CodeGen/GlobalISel/GIMatchTableExecutor.h"
+#include "rcc/CodeGen/MachineFunction.h"
+#include "rcc/CodeGen/MachineInstr.h"
+#include "rcc/CodeGen/MachineRegisterInfo.h"
+#include "rcc/CodeGen/TargetDescription.h"
+
+#include <string>
+
+namespace rcc::riscv {
+namespace {
+
+#define GET_GLOBALISEL_COMBINER_TABLE
+#include "RISCVGenGlobalISelCombiner.inc"
+#undef GET_GLOBALISEL_COMBINER_TABLE
+
+class RISCVGISelCombinerExecutor final : public GIMatchTableExecutor {
+protected:
+  [[nodiscard]] Expected<bool>
+  matchesTargetPredicate(std::string_view Name, const MachineInstr &Instruction,
+                         const MachineFunction &Function,
+                         const TargetDescription &Target) const override {
+    if (Name != "sext_cheaper_than_zext")
+      return GIMatchTableExecutor::matchesTargetPredicate(Name, Instruction, Function, Target);
+    const MachineOperand *Destination = Instruction.operandAt(0);
+    const MachineOperand *Source = Instruction.operandAt(1);
+    const Register *DestinationReg =
+        Destination == nullptr ? nullptr : Destination->getIf<Register>();
+    const Register *SourceReg = Source == nullptr ? nullptr : Source->getIf<Register>();
+    if (DestinationReg == nullptr || SourceReg == nullptr || !DestinationReg->isVirtual() ||
+        !SourceReg->isVirtual())
+      return false;
+    auto DestinationType = Function.registerInfo().getType(*DestinationReg);
+    auto SourceType = Function.registerInfo().getType(*SourceReg);
+    if (!DestinationType || !SourceType)
+      return false;
+    return DestinationType->isCategoryNeutralScalar() && SourceType->isCategoryNeutralScalar() &&
+           DestinationType->scalarBitWidth() == 64 && SourceType->scalarBitWidth() == 32;
+  }
+};
+
+} // namespace
+
+const GIMatchTable &giselCombinerTable() noexcept {
+  static constexpr GIMatchTable Table = generatedGlobalISelCombinerMatchTable();
+  return Table;
+}
+
+const GIMatchTableExecutor &giselCombinerExecutor() noexcept {
+  static const RISCVGISelCombinerExecutor Executor;
+  return Executor;
+}
+
+} // namespace rcc::riscv