Add CHEDDAR GPU backend/emitter

BUILD.bazel

@@ -70,6 +70,21 @@ config_setting(
     },
 )
 
+# CHEDDAR GPU FHE backend (opt-in, requires CUDA)
+# use by passing `--//:enable_cheddar=1` to `bazel build`
+string_flag(
+    name = "enable_cheddar",
+    build_setting_default = "0",
+)
+
+config_setting(
+    name = "config_enable_cheddar",
+    flag_values = {
+        ":enable_cheddar": "1",
+    },
+    visibility = ["//visibility:public"],
+)
+
 # OpenFHE interpreter
 string_flag(
     name = "openfhe_enable_timing",

MODULE.bazel

@@ -25,6 +25,8 @@ bazel_dep(name = "bazel_skylib_gazelle_plugin", version = "1.8.2", dev_dependenc
 # implicitly depends upon the target '//:license'. How bizarre.
 bazel_dep(name = "rules_license", version = "1.0.0")
 bazel_dep(name = "platforms", version = "1.0.0")
+bazel_dep(name = "rules_cuda", version = "0.3.0")
+bazel_dep(name = "rules_foreign_cc", version = "0.15.1")
 bazel_dep(name = "rules_go", version = "0.53.0")
 bazel_dep(name = "rules_python", version = "1.5.1")
 bazel_dep(name = "googletest", version = "1.17.0")
@@ -64,6 +66,18 @@ use_repo(
     "llvm_zstd",
 )
 
+# CHEDDAR GPU FHE library (opt-in, requires CUDA)
+cheddar_extensions = use_extension("//bazel:extensions.bzl", "cheddar_deps")
+use_repo(cheddar_extensions, "cheddar")
+
+# CUDA toolkit (for CHEDDAR and other GPU backends)
+cuda = use_extension("@rules_cuda//cuda:extensions.bzl", "toolchain")
+cuda.toolkit(
+    name = "cuda",
+    toolkit_path = "",
+)
+use_repo(cuda, "cuda")
+
 # The subset of LLVM backend targets that should be compiled
 _LLVM_TARGETS = [
     "X86",

bazel/cheddar/BUILD

@@ -0,0 +1,7 @@
+# This build file is necessary to mark this directory as a subpackage for bazel
+# to have access to the files.
+
+package(
+    default_applicable_licenses = ["@heir//:license"],
+    default_visibility = ["//visibility:public"],
+)

bazel/cheddar/cheddar.BUILD

@@ -0,0 +1,56 @@
+load("@rules_cc//cc:cc_library.bzl", "cc_library")
+load("@rules_foreign_cc//foreign_cc:defs.bzl", "cmake")
+
+package(
+    default_visibility = ["//visibility:public"],
+)
+
+filegroup(
+    name = "all_srcs",
+    srcs = glob(
+        ["**"],
+        exclude = [
+            "bazel-*/**",
+            "build/**",
+            "cmake-build*/**",
+        ],
+    ),
+)
+
+cmake(
+    name = "cheddar_cmake",
+    cache_entries = {
+        "CMAKE_BUILD_TYPE": "Release",
+        "BUILD_UNITTEST": "OFF",
+        "ENABLE_EXTENSION": "ON",
+        "USE_GMP": "OFF",
+        # Build for the local GPU architecture to keep build times manageable.
+        "CMAKE_CUDA_ARCHITECTURES": "native",
+        # Assumes conventional CUDA toolkit location and configuration.
+        "CMAKE_CUDA_COMPILER": "/usr/local/cuda/bin/nvcc",
+        "CUDAToolkit_ROOT": "/usr/local/cuda",
+        "CMAKE_CUDA_HOST_COMPILER:FILEPATH": "/usr/bin/g++",
+        "CMAKE_CUDA_FLAGS": "-ccbin=/usr/bin/g++",
+        # Wipe toolchain-provided linker flags that can inject unsupported host options.
+        "CMAKE_EXE_LINKER_FLAGS": "",
+        "CMAKE_MODULE_LINKER_FLAGS": "",
+        "CMAKE_SHARED_LINKER_FLAGS": "",
+    },
+    generate_crosstool_file = False,
+    lib_source = ":all_srcs",
+    out_include_dir = "include",
+    out_shared_libs = [
+        "libcheddar.so",
+    ],
+    targets = ["cheddar"],
+)
+
+# Wrap the cmake output with CUDA Thrust headers so downstream consumers
+# can resolve cheddar's public #include <thrust/...> directives.
+cc_library(
+    name = "cheddar",
+    deps = [
+        ":cheddar_cmake",
+        "@cuda//:thrust",
+    ],
+)

bazel/cheddar/config.bzl

@@ -0,0 +1,21 @@
+"""Helper macros for CHEDDAR opt-in build configuration."""
+
+def if_cheddar_enabled(if_true, if_false = []):
+    """Select based on whether CHEDDAR is enabled."""
+    return select({
+        "@heir//:config_enable_cheddar": if_true,
+        "//conditions:default": if_false,
+    })
+
+def requires_cheddar():
+    """Returns target_compatible_with for CHEDDAR-requiring targets."""
+    return select({
+        "@heir//:config_enable_cheddar": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    })
+
+def cheddar_deps(extra = []):
+    """Returns CHEDDAR library deps, empty when disabled."""
+    return if_cheddar_enabled(
+        ["@cheddar//:cheddar"] + extra,
+    )

bazel/extensions.bzl

@@ -53,3 +53,19 @@ def _llvm_deps_impl(_):
 llvm_deps = module_extension(
     implementation = _llvm_deps_impl,
 )
+
+# CHEDDAR GPU FHE library
+CHEDDAR_COMMIT = "307b49cbe03e7f8f14bf31485f716c1090c9ec9d"
+
+def _cheddar_deps_impl(_):
+    maybe(
+        new_git_repository,
+        name = "cheddar",
+        build_file = "@heir//bazel/cheddar:cheddar.BUILD",
+        commit = CHEDDAR_COMMIT,
+        remote = "https://github.com/scale-snu/cheddar-fhe.git",
+        patches = ["@heir//patches:cheddar.patch"],
+        patch_args = ["-p1"],
+    )
+
+cheddar_deps = module_extension(implementation = _cheddar_deps_impl)

lib/Dialect/Cheddar/IR/BUILD

@@ -0,0 +1,156 @@
+# Cheddar dialect implementation
+
+load("@heir//lib/Dialect:dialect.bzl", "add_heir_dialect_library")
+load("@llvm-project//mlir:tblgen.bzl", "td_library")
+load("@rules_cc//cc:cc_library.bzl", "cc_library")
+
+package(
+    default_applicable_licenses = ["@heir//:license"],
+    default_visibility = ["//visibility:public"],
+)
+
+cc_library(
+    name = "Dialect",
+    srcs = [
+        "CheddarDialect.cpp",
+    ],
+    hdrs = [
+        "CheddarAttributes.h",
+        "CheddarDialect.h",
+        "CheddarOps.h",
+        "CheddarTypes.h",
+    ],
+    deps = [
+        ":CheddarAttributes",
+        ":CheddarOps",
+        ":CheddarTypes",
+        ":attributes_inc_gen",
+        ":dialect_inc_gen",
+        ":ops_inc_gen",
+        ":types_inc_gen",
+        "@heir//lib/Dialect:HEIRInterfaces",
+        "@llvm-project//llvm:Support",
+        "@llvm-project//mlir:IR",
+        "@llvm-project//mlir:InferTypeOpInterface",
+    ],
+)
+
+cc_library(
+    name = "CheddarAttributes",
+    srcs = [
+        "CheddarAttributes.cpp",
+    ],
+    hdrs = [
+        "CheddarAttributes.h",
+        "CheddarDialect.h",
+    ],
+    deps = [
+        ":attributes_inc_gen",
+        ":dialect_inc_gen",
+        "@llvm-project//mlir:IR",
+    ],
+)
+
+cc_library(
+    name = "CheddarTypes",
+    srcs = [
+        "CheddarTypes.cpp",
+    ],
+    hdrs = [
+        "CheddarAttributes.h",
+        "CheddarDialect.h",
+        "CheddarTypes.h",
+    ],
+    deps = [
+        ":CheddarAttributes",
+        ":attributes_inc_gen",
+        ":dialect_inc_gen",
+        ":types_inc_gen",
+        "@heir//lib/Dialect:HEIRInterfaces",
+        "@llvm-project//mlir:IR",
+    ],
+)
+
+cc_library(
+    name = "CheddarOps",
+    srcs = [
+        "CheddarOps.cpp",
+    ],
+    hdrs = [
+        "CheddarDialect.h",
+        "CheddarOps.h",
+        "CheddarTypes.h",
+    ],
+    deps = [
+        ":CheddarAttributes",
+        ":CheddarTypes",
+        ":dialect_inc_gen",
+        ":ops_inc_gen",
+        ":types_inc_gen",
+        "@heir//lib/Dialect:HEIRInterfaces",
+        "@heir//lib/Utils",
+        "@heir//lib/Utils:RotationUtils",
+        "@llvm-project//mlir:IR",
+        "@llvm-project//mlir:InferTypeOpInterface",
+        "@llvm-project//mlir:Support",
+    ],
+)
+
+td_library(
+    name = "td_files",
+    srcs = [
+        "CheddarAttributes.td",
+        "CheddarDialect.td",
+        "CheddarOps.td",
+        "CheddarTypes.td",
+    ],
+    # include from the heir-root to enable fully-qualified include-paths
+    includes = ["../../../.."],
+    deps = [
+        "@heir//lib/Dialect:td_files",
+        "@llvm-project//mlir:BuiltinDialectTdFiles",
+        "@llvm-project//mlir:InferTypeOpInterfaceTdFiles",
+        "@llvm-project//mlir:OpBaseTdFiles",
+    ],
+)
+
+add_heir_dialect_library(
+    name = "dialect_inc_gen",
+    dialect = "Cheddar",
+    kind = "dialect",
+    td_file = "CheddarDialect.td",
+    deps = [
+        ":td_files",
+    ],
+)
+
+add_heir_dialect_library(
+    name = "attributes_inc_gen",
+    dialect = "Cheddar",
+    kind = "attribute",
+    td_file = "CheddarAttributes.td",
+    deps = [
+        ":td_files",
+    ],
+)
+
+add_heir_dialect_library(
+    name = "types_inc_gen",
+    dialect = "Cheddar",
+    kind = "type",
+    td_file = "CheddarTypes.td",
+    deps = [
+        ":td_files",
+    ],
+)
+
+add_heir_dialect_library(
+    name = "ops_inc_gen",
+    dialect = "Cheddar",
+    kind = "op",
+    td_file = "CheddarOps.td",
+    deps = [
+        ":td_files",
+        "@heir//lib/Dialect:td_files",
+    ],
+)

lib/Dialect/Cheddar/IR/CheddarAttributes.cpp

@@ -0,0 +1,7 @@
+#include "lib/Dialect/Cheddar/IR/CheddarAttributes.h"
+
+namespace mlir {
+namespace heir {
+namespace cheddar {}  // namespace cheddar
+}  // namespace heir
+}  // namespace mlir

lib/Dialect/Cheddar/IR/CheddarAttributes.h

@@ -0,0 +1,9 @@
+#ifndef LIB_DIALECT_CHEDDAR_IR_CHEDDARATTRIBUTES_H_
+#define LIB_DIALECT_CHEDDAR_IR_CHEDDARATTRIBUTES_H_
+
+#include "lib/Dialect/Cheddar/IR/CheddarDialect.h"
+
+#define GET_ATTRDEF_CLASSES
+#include "lib/Dialect/Cheddar/IR/CheddarAttributes.h.inc"
+
+#endif  // LIB_DIALECT_CHEDDAR_IR_CHEDDARATTRIBUTES_H_

lib/Dialect/Cheddar/IR/CheddarAttributes.td

@@ -0,0 +1,30 @@
+#ifndef LIB_DIALECT_CHEDDAR_IR_CHEDDARATTRIBUTES_TD_
+#define LIB_DIALECT_CHEDDAR_IR_CHEDDARATTRIBUTES_TD_
+
+include "CheddarDialect.td"
+
+include "mlir/IR/AttrTypeBase.td"
+include "mlir/IR/DialectBase.td"
+
+class Cheddar_Attribute<string attrName, string attrMnemonic>
+    : AttrDef<Cheddar_Dialect, attrName> {
+    let mnemonic = attrMnemonic;
+    let assemblyFormat = "`<` struct(params) `>`";
+}
+
+def Cheddar_ParameterFileAttr
+    : Cheddar_Attribute<"ParameterFile", "parameter_file"> {
+    let summary = "Path to a CHEDDAR parameter JSON file";
+    let description = [{
+        This attribute holds the path to a CHEDDAR parameter JSON file.
+
+        CHEDDAR parameters are loaded from pre-built JSON files that specify
+        ring dimension, prime chains, scale, and other CKKS parameters.
+    }];
+    let parameters = (ins
+      StringRefParameter<"path to JSON parameter file">:$path,
+      DefaultValuedParameter<"bool", "false", "use 64-bit word type">:$use64Bit
+    );
+}
+
+#endif  // LIB_DIALECT_CHEDDAR_IR_CHEDDARATTRIBUTES_TD_