Add compiler support for AVR architecture (Arduino) (#14393)

Co-authored-by: Sijawusz Pur Rahnama <[email protected]>

spec/std/llvm/avr_spec.cr

@@ -0,0 +1,198 @@
+require "spec"
+
+{% if flag?(:interpreted) && !flag?(:win32) %}
+  # TODO: figure out how to link against libstdc++ in interpreted code (#14398)
+  pending LLVM::ABI::AVR
+  {% skip_file %}
+{% end %}
+
+require "llvm"
+
+{% if LibLLVM::BUILT_TARGETS.includes?(:avr) %}
+  LLVM.init_avr
+{% end %}
+
+private def abi
+  triple = "avr-unknown-unknown-atmega328p"
+  target = LLVM::Target.from_triple(triple)
+  machine = target.create_target_machine(triple)
+  machine.enable_global_isel = false
+  LLVM::ABI::AVR.new(machine)
+end
+
+private def test(msg, &block : LLVM::ABI, LLVM::Context ->)
+  it msg do
+    abi = abi()
+    ctx = LLVM::Context.new
+    block.call(abi, ctx)
+  end
+end
+
+class LLVM::ABI
+  describe AVR do
+    {% if LibLLVM::BUILT_TARGETS.includes?(:avr) %}
+      describe "align" do
+        test "for integer" do |abi, ctx|
+          abi.align(ctx.int1).should be_a(::Int32)
+          abi.align(ctx.int1).should eq(1)
+          abi.align(ctx.int8).should eq(1)
+          abi.align(ctx.int16).should eq(1)
+          abi.align(ctx.int32).should eq(1)
+          abi.align(ctx.int64).should eq(1)
+        end
+
+        test "for pointer" do |abi, ctx|
+          abi.align(ctx.int8.pointer).should eq(1)
+        end
+
+        test "for float" do |abi, ctx|
+          abi.align(ctx.float).should eq(1)
+        end
+
+        test "for double" do |abi, ctx|
+          abi.align(ctx.double).should eq(1)
+        end
+
+        test "for struct" do |abi, ctx|
+          abi.align(ctx.struct([ctx.int32, ctx.int64])).should eq(1)
+          abi.align(ctx.struct([ctx.int8, ctx.int16])).should eq(1)
+        end
+
+        test "for packed struct" do |abi, ctx|
+          abi.align(ctx.struct([ctx.int32, ctx.int64], packed: true)).should eq(1)
+        end
+
+        test "for array" do |abi, ctx|
+          abi.align(ctx.int16.array(10)).should eq(1)
+        end
+      end
+
+      describe "size" do
+        test "for integer" do |abi, ctx|
+          abi.size(ctx.int1).should be_a(::Int32)
+          abi.size(ctx.int1).should eq(1)
+          abi.size(ctx.int8).should eq(1)
+          abi.size(ctx.int16).should eq(2)
+          abi.size(ctx.int32).should eq(4)
+          abi.size(ctx.int64).should eq(8)
+        end
+
+        test "for pointer" do |abi, ctx|
+          abi.size(ctx.int8.pointer).should eq(2)
+        end
+
+        test "for float" do |abi, ctx|
+          abi.size(ctx.float).should eq(4)
+        end
+
+        test "for double" do |abi, ctx|
+          abi.size(ctx.double).should eq(8)
+        end
+
+        test "for struct" do |abi, ctx|
+          abi.size(ctx.struct([ctx.int32, ctx.int64])).should eq(12)
+          abi.size(ctx.struct([ctx.int16, ctx.int8])).should eq(3)
+          abi.size(ctx.struct([ctx.int32, ctx.int8, ctx.int8])).should eq(6)
+        end
+
+        test "for packed struct" do |abi, ctx|
+          abi.size(ctx.struct([ctx.int32, ctx.int8], packed: true)).should eq(5)
+        end
+
+        test "for array" do |abi, ctx|
+          abi.size(ctx.int16.array(10)).should eq(20)
+        end
+      end
+
+      describe "abi_info" do
+        {% for bits in [1, 8, 16, 32, 64] %}
+          test "int{{bits}}" do |abi, ctx|
+            arg_type = ArgType.direct(ctx.int{{bits}})
+            info = abi.abi_info([ctx.int{{bits}}], ctx.int{{bits}}, true, ctx)
+            info.arg_types.size.should eq(1)
+            info.arg_types[0].should eq(arg_type)
+            info.arg_types[0].kind.should eq(LLVM::ABI::ArgKind::Direct)
+            info.return_type.should eq(arg_type)
+            info.return_type.kind.should eq(LLVM::ABI::ArgKind::Direct)
+          end
+        {% end %}
+
+        test "float" do |abi, ctx|
+          arg_type = ArgType.direct(ctx.float)
+          info = abi.abi_info([ctx.float], ctx.float, true, ctx)
+          info.arg_types.size.should eq(1)
+          info.arg_types[0].should eq(arg_type)
+          info.arg_types[0].kind.should eq(LLVM::ABI::ArgKind::Direct)
+          info.return_type.should eq(arg_type)
+          info.return_type.kind.should eq(LLVM::ABI::ArgKind::Direct)
+        end
+
+        test "double" do |abi, ctx|
+          arg_type = ArgType.direct(ctx.double)
+          info = abi.abi_info([ctx.double], ctx.double, true, ctx)
+          info.arg_types.size.should eq(1)
+          info.arg_types[0].should eq(arg_type)
+          info.arg_types[0].kind.should eq(LLVM::ABI::ArgKind::Direct)
+          info.return_type.should eq(arg_type)
+          info.return_type.kind.should eq(LLVM::ABI::ArgKind::Direct)
+        end
+
+        test "multiple arguments" do |abi, ctx|
+          args = 9.times.map { ctx.int16 }.to_a
+          info = abi.abi_info(args, ctx.int8, false, ctx)
+          info.arg_types.size.should eq(9)
+          info.arg_types.each(&.kind.should eq(LLVM::ABI::ArgKind::Direct))
+        end
+
+        test "multiple arguments above registers" do |abi, ctx|
+          args = 5.times.map { ctx.int32 }.to_a
+          info = abi.abi_info(args, ctx.int8, false, ctx)
+          info.arg_types.size.should eq(5)
+          info.arg_types[0].kind.should eq(LLVM::ABI::ArgKind::Direct)
+          info.arg_types[1].kind.should eq(LLVM::ABI::ArgKind::Direct)
+          info.arg_types[2].kind.should eq(LLVM::ABI::ArgKind::Direct)
+          info.arg_types[3].kind.should eq(LLVM::ABI::ArgKind::Direct)
+          info.arg_types[4].kind.should eq(LLVM::ABI::ArgKind::Indirect)
+        end
+
+        test "struct args within 18 bytes" do |abi, ctx|
+          args = [
+            ctx.int8,                           # rounded to 2 bytes
+            ctx.struct([ctx.int32, ctx.int32]), # 8 bytes
+            ctx.struct([ctx.int32, ctx.int32]), # 8 bytes
+          ]
+          info = abi.abi_info(args, ctx.void, false, ctx)
+          info.arg_types.size.should eq(3)
+          info.arg_types[0].kind.should eq(LLVM::ABI::ArgKind::Direct)
+          info.arg_types[1].kind.should eq(LLVM::ABI::ArgKind::Direct)
+          info.arg_types[2].kind.should eq(LLVM::ABI::ArgKind::Direct)
+        end
+
+        test "struct args over 18 bytes" do |abi, ctx|
+          args = [
+            ctx.int32,                          # 4 bytes
+            ctx.struct([ctx.int32, ctx.int32]), # 8 bytes
+            ctx.struct([ctx.int32, ctx.int32]), # 8 bytes
+          ]
+          info = abi.abi_info(args, ctx.void, false, ctx)
+          info.arg_types.size.should eq(3)
+          info.arg_types[0].kind.should eq(LLVM::ABI::ArgKind::Direct)
+          info.arg_types[1].kind.should eq(LLVM::ABI::ArgKind::Direct)
+          info.arg_types[2].kind.should eq(LLVM::ABI::ArgKind::Indirect)
+        end
+
+        test "returns struct within 8 bytes" do |abi, ctx|
+          rty = ctx.struct([ctx.int32, ctx.int32])
+          info = abi.abi_info([] of Type, rty, true, ctx)
+          info.return_type.kind.should eq(LLVM::ABI::ArgKind::Direct)
+        end
+
+        test "returns struct over 8 bytes" do |abi, ctx|
+          rty = ctx.struct([ctx.int32, ctx.int32, ctx.int8])
+          info = abi.abi_info([] of Type, rty, true, ctx)
+          info.return_type.kind.should eq(LLVM::ABI::ArgKind::Indirect)
+        end
+      end
+    {% end %}
+  end
+end

src/compiler/crystal/codegen/target.cr

@@ -51,10 +51,14 @@ class Crystal::Codegen::Target
 
   def pointer_bit_width
     case @architecture
-    when "x86_64", "aarch64"
+    when "aarch64", "x86_64"
       64
-    else
+    when "arm", "i386", "wasm32"
       32
+    when "avr"
+      16
+    else
+      raise "BUG: unknown Target#pointer_bit_width for #{@architecture} target architecture"
     end
   end
 
@@ -64,6 +68,8 @@ class Crystal::Codegen::Target
       64
     when "arm", "i386", "wasm32"
       32
+    when "avr"
+      16
     else
       raise "BUG: unknown Target#size_bit_width for #{@architecture} target architecture"
     end
@@ -93,6 +99,7 @@ class Crystal::Codegen::Target
   def executable_extension
     case
     when windows? then ".exe"
+    when avr?     then ".elf"
     else               ""
     end
   end
@@ -181,6 +188,10 @@ class Crystal::Codegen::Target
     environment_parts.any? &.in?("gnueabihf", "musleabihf")
   end
 
+  def avr?
+    @architecture == "avr"
+  end
+
   def to_target_machine(cpu = "", features = "", optimization_mode = Compiler::OptimizationMode::O0,
                         code_model = LLVM::CodeModel::Default) : LLVM::TargetMachine
     case @architecture
@@ -197,6 +208,13 @@ class Crystal::Codegen::Target
       if cpu.empty? && !features.includes?("fp") && armhf?
         features += "+vfp2"
       end
+    when "avr"
+      LLVM.init_avr
+
+      if cpu.blank?
+        # the ABI call convention, codegen and the linker need to known the CPU model
+        raise Target::Error.new("AVR targets must declare a CPU model, for example --mcpu=atmega328p")
+      end
     when "wasm32"
       LLVM.init_webassembly
     else

src/compiler/crystal/compiler.cr

@@ -481,10 +481,13 @@ module Crystal
       elsif program.has_flag? "wasm32"
         link_flags = @link_flags || ""
         {"wasm-ld", %(wasm-ld "${@}" -o #{Process.quote_posix(output_filename)} #{link_flags} -lc #{program.lib_flags}), object_names}
+      elsif program.has_flag? "avr"
+        link_flags = @link_flags || ""
+        link_flags += " --target=avr-unknown-unknown -mmcu=#{@mcpu} -Wl,--gc-sections"
+        {DEFAULT_LINKER, %(#{DEFAULT_LINKER} "${@}" -o #{Process.quote_posix(output_filename)} #{link_flags} #{program.lib_flags}), object_names}
       else
         link_flags = @link_flags || ""
         link_flags += " -rdynamic"
-
         {DEFAULT_LINKER, %(#{DEFAULT_LINKER} "${@}" -o #{Process.quote_posix(output_filename)} #{link_flags} #{program.lib_flags}), object_names}
       end
     end

src/compiler/crystal/semantic/flags.cr

@@ -56,6 +56,10 @@ class Crystal::Program
 
     flags.add "bsd" if target.bsd?
 
+    if target.avr? && (cpu = target_machine.cpu.presence)
+      flags.add cpu
+    end
+
     flags
   end
 end

src/intrinsics.cr

@@ -4,45 +4,57 @@ lib LibIntrinsics
   {% if flag?(:interpreted) %} @[Primitive(:interpreter_intrinsics_debugtrap)] {% end %}
   fun debugtrap = "llvm.debugtrap"
 
-  {% if flag?(:bits64) %}
+  {% if flag?(:avr) %}
     {% if compare_versions(Crystal::LLVM_VERSION, "15.0.0") < 0 %}
-      {% if flag?(:interpreted) %} @[Primitive(:interpreter_intrinsics_memcpy)] {% end %}
-      fun memcpy = "llvm.memcpy.p0i8.p0i8.i64"(dest : Void*, src : Void*, len : UInt64, is_volatile : Bool)
-
-      {% if flag?(:interpreted) %} @[Primitive(:interpreter_intrinsics_memmove)] {% end %}
-      fun memmove = "llvm.memmove.p0i8.p0i8.i64"(dest : Void*, src : Void*, len : UInt64, is_volatile : Bool)
-
-      {% if flag?(:interpreted) %} @[Primitive(:interpreter_intrinsics_memset)] {% end %}
-      fun memset = "llvm.memset.p0i8.i64"(dest : Void*, val : UInt8, len : UInt64, is_volatile : Bool)
+      fun memcpy = "llvm.memcpy.p0i8.p0i8.i16"(dest : Void*, src : Void*, len : UInt16, is_volatile : Bool)
+      fun memmove = "llvm.memmove.p0i8.p0i8.i16"(dest : Void*, src : Void*, len : UInt16, is_volatile : Bool)
+      fun memset = "llvm.memset.p0i8.i16"(dest : Void*, val : UInt8, len : UInt16, is_volatile : Bool)
     {% else %}
-      {% if flag?(:interpreted) %} @[Primitive(:interpreter_intrinsics_memcpy)] {% end %}
-      fun memcpy = "llvm.memcpy.p0.p0.i64"(dest : Void*, src : Void*, len : UInt64, is_volatile : Bool)
-
-      {% if flag?(:interpreted) %} @[Primitive(:interpreter_intrinsics_memmove)] {% end %}
-      fun memmove = "llvm.memmove.p0.p0.i64"(dest : Void*, src : Void*, len : UInt64, is_volatile : Bool)
-
-      {% if flag?(:interpreted) %} @[Primitive(:interpreter_intrinsics_memset)] {% end %}
-      fun memset = "llvm.memset.p0.i64"(dest : Void*, val : UInt8, len : UInt64, is_volatile : Bool)
+      fun memcpy = "llvm.memcpy.p0.p0.i16"(dest : Void*, src : Void*, len : UInt16, is_volatile : Bool)
+      fun memmove = "llvm.memmove.p0.p0.i16"(dest : Void*, src : Void*, len : UInt16, is_volatile : Bool)
+      fun memset = "llvm.memset.p0.i16"(dest : Void*, val : UInt8, len : UInt16, is_volatile : Bool)
     {% end %}
   {% else %}
-    {% if compare_versions(Crystal::LLVM_VERSION, "15.0.0") < 0 %}
-      {% if flag?(:interpreted) %} @[Primitive(:interpreter_intrinsics_memcpy)] {% end %}
-      fun memcpy = "llvm.memcpy.p0i8.p0i8.i32"(dest : Void*, src : Void*, len : UInt32, is_volatile : Bool)
+    {% if flag?(:bits64) %}
+      {% if compare_versions(Crystal::LLVM_VERSION, "15.0.0") < 0 %}
+        {% if flag?(:interpreted) %} @[Primitive(:interpreter_intrinsics_memcpy)] {% end %}
+        fun memcpy = "llvm.memcpy.p0i8.p0i8.i64"(dest : Void*, src : Void*, len : UInt64, is_volatile : Bool)
+
+        {% if flag?(:interpreted) %} @[Primitive(:interpreter_intrinsics_memmove)] {% end %}
+        fun memmove = "llvm.memmove.p0i8.p0i8.i64"(dest : Void*, src : Void*, len : UInt64, is_volatile : Bool)
+
+        {% if flag?(:interpreted) %} @[Primitive(:interpreter_intrinsics_memset)] {% end %}
+        fun memset = "llvm.memset.p0i8.i64"(dest : Void*, val : UInt8, len : UInt64, is_volatile : Bool)
+      {% else %}
+        {% if flag?(:interpreted) %} @[Primitive(:interpreter_intrinsics_memcpy)] {% end %}
+        fun memcpy = "llvm.memcpy.p0.p0.i64"(dest : Void*, src : Void*, len : UInt64, is_volatile : Bool)
+
+        {% if flag?(:interpreted) %} @[Primitive(:interpreter_intrinsics_memmove)] {% end %}
+        fun memmove = "llvm.memmove.p0.p0.i64"(dest : Void*, src : Void*, len : UInt64, is_volatile : Bool)
+
+        {% if flag?(:interpreted) %} @[Primitive(:interpreter_intrinsics_memset)] {% end %}
+        fun memset = "llvm.memset.p0.i64"(dest : Void*, val : UInt8, len : UInt64, is_volatile : Bool)
+      {% end %}
+    {% else %}
+      {% if compare_versions(Crystal::LLVM_VERSION, "15.0.0") < 0 %}
+        {% if flag?(:interpreted) %} @[Primitive(:interpreter_intrinsics_memcpy)] {% end %}
+        fun memcpy = "llvm.memcpy.p0i8.p0i8.i32"(dest : Void*, src : Void*, len : UInt32, is_volatile : Bool)
 
-      {% if flag?(:interpreted) %} @[Primitive(:interpreter_intrinsics_memmove)] {% end %}
-      fun memmove = "llvm.memmove.p0i8.p0i8.i32"(dest : Void*, src : Void*, len : UInt32, is_volatile : Bool)
+        {% if flag?(:interpreted) %} @[Primitive(:interpreter_intrinsics_memmove)] {% end %}
+        fun memmove = "llvm.memmove.p0i8.p0i8.i32"(dest : Void*, src : Void*, len : UInt32, is_volatile : Bool)
 
-      {% if flag?(:interpreted) %} @[Primitive(:interpreter_intrinsics_memset)] {% end %}
-      fun memset = "llvm.memset.p0i8.i32"(dest : Void*, val : UInt8, len : UInt32, is_volatile : Bool)
-    {% else %}
-      {% if flag?(:interpreted) %} @[Primitive(:interpreter_intrinsics_memcpy)] {% end %}
-      fun memcpy = "llvm.memcpy.p0.p0.i32"(dest : Void*, src : Void*, len : UInt32, is_volatile : Bool)
+        {% if flag?(:interpreted) %} @[Primitive(:interpreter_intrinsics_memset)] {% end %}
+        fun memset = "llvm.memset.p0i8.i32"(dest : Void*, val : UInt8, len : UInt32, is_volatile : Bool)
+      {% else %}
+        {% if flag?(:interpreted) %} @[Primitive(:interpreter_intrinsics_memcpy)] {% end %}
+        fun memcpy = "llvm.memcpy.p0.p0.i32"(dest : Void*, src : Void*, len : UInt32, is_volatile : Bool)
 
-      {% if flag?(:interpreted) %} @[Primitive(:interpreter_intrinsics_memmove)] {% end %}
-      fun memmove = "llvm.memmove.p0.p0.i32"(dest : Void*, src : Void*, len : UInt32, is_volatile : Bool)
+        {% if flag?(:interpreted) %} @[Primitive(:interpreter_intrinsics_memmove)] {% end %}
+        fun memmove = "llvm.memmove.p0.p0.i32"(dest : Void*, src : Void*, len : UInt32, is_volatile : Bool)
 
-      {% if flag?(:interpreted) %} @[Primitive(:interpreter_intrinsics_memset)] {% end %}
-      fun memset = "llvm.memset.p0.i32"(dest : Void*, val : UInt8, len : UInt32, is_volatile : Bool)
+        {% if flag?(:interpreted) %} @[Primitive(:interpreter_intrinsics_memset)] {% end %}
+        fun memset = "llvm.memset.p0.i32"(dest : Void*, val : UInt8, len : UInt32, is_volatile : Bool)
+      {% end %}
     {% end %}
   {% end %}
 

src/llvm.cr

@@ -52,6 +52,22 @@ module LLVM
     {% end %}
   end
 
+  def self.init_avr : Nil
+    return if @@initialized_avr
+    @@initialized_avr = true
+
+    {% if LibLLVM::BUILT_TARGETS.includes?(:avr) %}
+      LibLLVM.initialize_avr_target_info
+      LibLLVM.initialize_avr_target
+      LibLLVM.initialize_avr_target_mc
+      LibLLVM.initialize_avr_asm_printer
+      LibLLVM.initialize_avr_asm_parser
+      LibLLVM.link_in_mc_jit
+    {% else %}
+      raise "ERROR: LLVM was built without AVR target"
+    {% end %}
+  end
+
   def self.init_webassembly : Nil
     return if @@initialized_webassembly
     @@initialized_webassembly = true