XPUBackend refactoring to facilitate arch-specific implementations

 - Allow metaclasses injection: use XPUBackendMeta from the .meta submodule as the metaclass, if it exists.
 - Try to find an arch-specific implementation in the .arch.<name> submodule.
 - Create the list of passes in separate methods to allow subclasses to modify it.

Author: AndreyPavlenko

third_party/intel/backend/compiler.py

@@ -1,4 +1,4 @@
-from triton.backends.compiler import BaseBackend, Language
+from triton.backends.compiler import BaseBackend, GPUTarget, Language
 from triton._C.libtriton import ir, passes, llvm, intel
 from triton.backends.intel.driver import compile_module_from_src
 from triton.backends.intel.track import track
@@ -15,6 +15,11 @@
 import subprocess
 from pathlib import Path
 
+try:  # XPUBackend allows metaclasses injection
+    from .meta import XPUBackendMeta
+except ImportError:
+    XPUBackendMeta = type(BaseBackend)
+
 
 @dataclass
 class XPUOptions:
@@ -63,40 +68,41 @@ def hash(self):
         return hashlib.sha256(key.encode("utf-8")).hexdigest()
 
 
-def min_dot_size(device_props: dict):
-    # (M, N, K)
-    # M: repeatCount. 1,2,4,8
-    # N: executionSize. 16 for PVC, 8 for ATS
-    # K: systolicDepth x opsPerChan. systolicDepth must be 8
-    repeat_count = 1
-    sdepth = 8
-    exec_size = min(device_props["sub_group_sizes"])
-
-    def get_ops_per_channel(lhs_type, rhs_type):
-        l_bitwidth = lhs_type.scalar.primitive_bitwidth
-        r_bitwidth = rhs_type.scalar.primitive_bitwidth
-        max_ops_per_chan = 32 / max(l_bitwidth, r_bitwidth)
-        return min(8, max_ops_per_chan)
-
-    return lambda lhs_type, rhs_type: (repeat_count, exec_size, sdepth * get_ops_per_channel(lhs_type, rhs_type))
-
-
-class XPUBackend(BaseBackend):
+class XPUBackend(BaseBackend, metaclass=XPUBackendMeta):
+    arch_to_impl = {}  # Architecture id to backend implementation class mapping
+    binary_ext = "spv"
+    target_arch = "spir64"
     instrumentation = None
 
     @staticmethod
-    def supports_target(target: tuple):
+    def supports_target(target: GPUTarget):
         return target.backend == 'xpu'
 
-    def __init__(self, target: tuple) -> None:
-        super().__init__(target)
+    def __new__(cls, target: GPUTarget):
         if not isinstance(target.arch, dict):
             raise TypeError("target.arch is not a dict")
-        dirname = os.path.dirname(os.path.realpath(__file__))
-        mod = compile_module_from_src(src=Path(os.path.join(dirname, "arch_parser.c")).read_text(), name="arch_utils")
-        self.device_arch = knobs.intel.device_arch or mod.parse_device_arch(target.arch.get('architecture', 0))
+        if cls is not XPUBackend:
+            return super().__new__(cls)
+        arch = target.arch.get("architecture", 0)
+        if (impl := cls.arch_to_impl.get(arch, None)) is None:
+            # Try to find an arch-specific implementation in the .arch.<name> submodule.
+            if not (dev_arch := knobs.intel.device_arch):
+                dirname = os.path.dirname(os.path.realpath(__file__))
+                parser = compile_module_from_src(src=Path(os.path.join(dirname, "arch_parser.c")).read_text(),
+                                                 name="arch_utils")
+                dev_arch = parser.parse_device_arch(target.arch.get('architecture', 0))
+            mod_name = f"{__package__}.arch.{dev_arch}"
+            try:
+                impl = __import__(mod_name, fromlist=["XPUBackendImpl"]).XPUBackendImpl
+            except ImportError:
+                impl = type(f"{mod_name}.XPUBackendImpl", (cls, ), {})
+            impl.device_arch = dev_arch
+            cls.arch_to_impl[arch] = impl
+        return super().__new__(impl)
+
+    def __init__(self, target: GPUTarget) -> None:
+        super().__init__(target)
         self.properties = self.parse_target(target.arch)
-        self.binary_ext = "spv"
 
     def get_target_name(self, options) -> str:
         return f"xpu:{self.device_arch}"
@@ -123,18 +129,36 @@ def parse_target(self, tgt_prop) -> dict:
         return dev_prop
 
     def parse_options(self, opts) -> Any:
-        args = {k: opts[k] for k in XPUOptions.__dataclass_fields__.keys() if k in opts}
+        args = {k: v for k, v in opts.items() if k in XPUOptions.__dataclass_fields__}
         args["allow_fp8e4nv"] = True
         return XPUOptions(**args)
 
     def pack_metadata(self, metadata):
         return metadata
 
+    @staticmethod
+    def min_dot_size(device_props: dict):
+        # (M, N, K)
+        # M: repeatCount. 1,2,4,8
+        # N: executionSize. 16 for PVC, 8 for ATS
+        # K: systolicDepth x opsPerChan. systolicDepth must be 8
+        repeat_count = 1
+        sdepth = 8
+        exec_size = min(device_props["sub_group_sizes"])
+
+        def get_ops_per_channel(lhs_type, rhs_type):
+            l_bitwidth = lhs_type.scalar.primitive_bitwidth
+            r_bitwidth = rhs_type.scalar.primitive_bitwidth
+            max_ops_per_chan = 32 / max(l_bitwidth, r_bitwidth)
+            return min(8, max_ops_per_chan)
+
+        return lambda lhs_type, rhs_type: (repeat_count, exec_size, sdepth * get_ops_per_channel(lhs_type, rhs_type))
+
     def get_codegen_implementation(self, options):
         from triton.language.extra.intel import convert_custom_float8
         codegen_fns = {}
         codegen_fns["convert_custom_types"] = convert_custom_float8
-        codegen_fns["min_dot_size"] = min_dot_size(self.properties)
+        codegen_fns["min_dot_size"] = self.min_dot_size(self.properties)
         return codegen_fns
 
     def get_module_map(self) -> Dict[str, ModuleType]:
@@ -143,8 +167,8 @@ def get_module_map(self) -> Dict[str, ModuleType]:
 
     def load_dialects(self, ctx):
         intel.load_dialects(ctx)
-        if XPUBackend.instrumentation:
-            XPUBackend.instrumentation.load_dialects(ctx)
+        if self.instrumentation:
+            self.instrumentation.load_dialects(ctx)
 
     @staticmethod
     def validate_options(opt, properties):
@@ -158,20 +182,15 @@ def validate_options(opt, properties):
                 f"num_warps={opt.num_warps} is unsupported for the target (limit is {properties['max_num_sub_groups']})"
             )
 
-    @staticmethod
-    def annotate_module(mod, properties, opt, target_arch):
+    @classmethod
+    def annotate_module(cls, module_opts, properties, opt):
         # Annotate module with information required by subsequent transformations.
-        pm = ir.pass_manager(mod.context)
-        pm.enable_debug()
-        module_opts = intel.passes.ttgpuir.AnnotateModuleOptions()
         module_opts.min_sg_size = min(properties["sub_group_sizes"])
         module_opts.support_sg_2d_block = properties["has_subgroup_2d_block_io"]
         module_opts.support_dpas = properties["has_subgroup_matrix_multiply_accumulate"]
         module_opts.support_bf16_conversion = properties["has_bfloat16_conversions"]
         module_opts.threads_per_warp = opt.warp_size
-        module_opts.target_arch = target_arch
-        intel.passes.ttgpuir.add_triton_annotate_module(pm, module_opts)
-        pm.run(mod, 'annotate_module')
+        module_opts.target_arch = cls.target_arch
 
     @staticmethod
     def get_split_barrier_scope(opt):
@@ -182,9 +201,9 @@ def get_split_barrier_scope(opt):
             split_barriers_scope = intel.SplitBarrierScope.Subgroup
         return split_barriers_scope
 
-    @staticmethod
+    @classmethod
     @track
-    def make_ttir(mod, metadata, opt):
+    def make_ttir(cls, mod, metadata, opt):
         pm = ir.pass_manager(mod.context)
         pm.enable_debug()
         passes.common.add_inliner(pm)
@@ -204,21 +223,26 @@ def make_ttir(mod, metadata, opt):
         pm.run(mod, 'make_ttir')
         return mod
 
-    @staticmethod
+    @classmethod
     @track
-    def make_ttgir(mod, metadata, opt, properties):
+    def make_ttgir(cls, mod, metadata, opt, properties):
         cluster_info = intel.ClusterInfo()
         if opt.cluster_dims is not None:
             cluster_info.clusterDimX = opt.cluster_dims[0]
             cluster_info.clusterDimY = opt.cluster_dims[1]
             cluster_info.clusterDimZ = opt.cluster_dims[2]
 
         # Annotate module with information required by subsequent transformations.
-        XPUBackend.annotate_module(mod, properties, opt, "spir64")
+        pm = ir.pass_manager(mod.context)
+        pm.enable_debug()
+        module_opts = intel.passes.ttgpuir.AnnotateModuleOptions()
+        cls.annotate_module(module_opts, properties, opt)
+        intel.passes.ttgpuir.add_triton_annotate_module(pm, module_opts)
+        pm.run(mod, 'annotate_module')
 
         # Overwrite the warp_size option with the module annotation.
         opt.warp_size = intel.get_threads_per_warp(mod)
-        XPUBackend.validate_options(opt, properties)
+        cls.validate_options(opt, properties)
 
         pm = ir.pass_manager(mod.context)
         pm.enable_debug()
@@ -278,9 +302,15 @@ def gluon_to_ttgir(self, src, metadata, options):
         metadata["tensordesc_meta"] = mod.get_tensordesc_metadata()
         return mod
 
-    @staticmethod
+    @classmethod
+    def optimize_llvm_mod(cls, llvm_mod, options):
+        intel.set_spv_target_triple(llvm_mod)
+        with track("optimize_module") as tr:
+            intel.optimize_module(llvm_mod, llvm.OPTIMIZE_O3, tr.callback("passes"))
+
+    @classmethod
     @track
-    def make_llir(src, metadata, options):
+    def make_llir(cls, src, metadata, options):
         mod = src
         # TritonGPU -> LLVM-IR (MLIR)
         pm = ir.pass_manager(mod.context)
@@ -292,8 +322,8 @@ def make_llir(src, metadata, options):
         intel.passes.ttgpuir.add_allocate_shared_memory(pm)
         passes.ttgpuir.add_allocate_global_scratch_memory(pm)
         # instrumentation point here so we can override IRs above (e.g., ttir and ttgir)
-        if XPUBackend.instrumentation:
-            XPUBackend.instrumentation.patch("ttgpuir_to_llvmir", pm, mod.context)
+        if cls.instrumentation:
+            cls.instrumentation.patch("ttgpuir_to_llvmir", pm, mod.context)
         intel.passes.ttgpuir.add_to_llvmir(pm)
         intel.passes.ttgpuir.add_gen_to_llvm(pm)
         passes.common.add_canonicalizer(pm)
@@ -307,8 +337,8 @@ def make_llir(src, metadata, options):
         if not knobs.compilation.disable_line_info and not knobs.compilation.dump_ir_extract_di_local_variables:
             passes.llvmir.add_di_scope(pm)
 
-        if XPUBackend.instrumentation:
-            XPUBackend.instrumentation.patch("llvmir_to_llvm", pm, mod.context)
+        if cls.instrumentation:
+            cls.instrumentation.patch("llvmir_to_llvm", pm, mod.context)
         pm.run(mod, 'make_llir')
 
         if knobs.compilation.dump_ir_extract_di_local_variables:
@@ -333,15 +363,12 @@ def make_llir(src, metadata, options):
         llvm.init_targets()
         context = llvm.context()
         llvm_mod = llvm.to_module(mod, context)
-        intel.set_spv_target_triple(llvm_mod)
         intel.set_fast_math(llvm_mod)
         if options.extern_libs:
             paths = [path for (name, path) in options.extern_libs]
             llvm.link_extern_libs(llvm_mod, paths)
 
-        with track("optimize_module") as tr:
-            intel.optimize_module(llvm_mod, llvm.OPTIMIZE_O3, tr.callback("passes"))
-
+        cls.optimize_llvm_mod(llvm_mod, options)
         intel.post_process_llir(llvm_mod)
 
         # Get some metadata
@@ -359,9 +386,9 @@ def make_llir(src, metadata, options):
         del context
         return ret
 
-    @staticmethod
+    @classmethod
     @track
-    def make_spv(src, metadata, options, device_arch):
+    def make_spv(cls, src, metadata, options):
         spirv, name = intel.translate_to_spirv(src)
         metadata["name"] = name
         metadata.setdefault("build_flags", "")
@@ -380,8 +407,9 @@ def make_spv(src, metadata, options, device_arch):
             metadata["build_flags"] += " -cl-opt-disable"
         return spirv
 
-    @staticmethod
-    def make_zebin(src, metadata, options, device_arch):
+    @classmethod
+    @track
+    def make_zebin(cls, src, metadata, options):
         metadata["binary_ext"] = "zebin"
 
         shader_dump_opt = ""
@@ -398,8 +426,8 @@ def make_zebin(src, metadata, options, device_arch):
             fbin = fsrc.name + '.o'
 
             ocloc_cmd = [
-                'ocloc', 'compile', '-file', fsrc.name, '-o', fbin, '-spirv_input', '-device', device_arch, '-options',
-                metadata["build_flags"] + shader_dump_opt
+                'ocloc', 'compile', '-file', fsrc.name, '-o', fbin, '-spirv_input', '-device', cls.device_arch,
+                '-options', metadata["build_flags"] + shader_dump_opt
             ]
 
             try:
@@ -437,9 +465,9 @@ def add_stages(self, stages, options, language):
         elif language == Language.GLUON:
             stages["ttgir"] = lambda src, metadata: self.gluon_to_ttgir(src, metadata, options)
         stages["llir"] = lambda src, metadata: self.make_llir(src, metadata, options)
-        stages["spv"] = lambda src, metadata: self.make_spv(src, metadata, options, self.device_arch)
+        stages["spv"] = lambda src, metadata: self.make_spv(src, metadata, options)
         if options.generate_native_code:
-            stages["zebin"] = lambda src, metadata: self.make_zebin(src, metadata, options, self.device_arch)
+            stages["zebin"] = lambda src, metadata: self.make_zebin(src, metadata, options)
         if knobs.runtime.add_stages_inspection_hook is not None:
             knobs.runtime.add_stages_inspection_hook(self, stages, options, language, None)