-module RubyVM::RJIT

- class ExitCompiler

- def initialize = freeze

-

- # Used for invalidating a block on entry.

- # @param pc [Integer]

- # @param asm [RubyVM::RJIT::Assembler]

- def compile_entry_exit(pc, ctx, asm, cause:)

- # Fix pc/sp offsets for the interpreter

- save_pc_and_sp(pc, ctx, asm, reset_sp_offset: false)

-

- # Increment per-insn exit counter

- count_insn_exit(pc, asm)

-

- # Restore callee-saved registers

- asm.comment("#{cause}: entry exit")

- asm.pop(SP)

- asm.pop(EC)

- asm.pop(CFP)

-

- asm.mov(C_RET, Qundef)

- asm.ret

- end

-

- # Set to cfp->jit_return by default for leave insn

- # @param asm [RubyVM::RJIT::Assembler]

- def compile_leave_exit(asm)

- asm.comment('default cfp->jit_return')

-

- # Restore callee-saved registers

- asm.pop(SP)

- asm.pop(EC)

- asm.pop(CFP)

-

- # :rax is written by #leave

- asm.ret

- end

-

- # Fire cfunc events on invalidation by TracePoint

- # @param asm [RubyVM::RJIT::Assembler]

- def compile_full_cfunc_return(asm)

- # This chunk of code expects REG_EC to be filled properly and

- # RAX to contain the return value of the C method.

-

- asm.comment('full cfunc return')

- asm.mov(C_ARGS[0], EC)

- asm.mov(C_ARGS[1], :rax)

- asm.call(C.rjit_full_cfunc_return)

-

- # TODO: count the exit

-

- # Restore callee-saved registers

- asm.pop(SP)

- asm.pop(EC)

- asm.pop(CFP)

-

- asm.mov(C_RET, Qundef)

- asm.ret

- end

-

- # @param jit [RubyVM::RJIT::JITState]

- # @param ctx [RubyVM::RJIT::Context]

- # @param asm [RubyVM::RJIT::Assembler]

- def compile_side_exit(pc, ctx, asm)

- # Fix pc/sp offsets for the interpreter

- save_pc_and_sp(pc, ctx.dup, asm) # dup to avoid sp_offset update

-

- # Increment per-insn exit counter

- count_insn_exit(pc, asm)

-

- # Restore callee-saved registers

- asm.comment("exit to interpreter on #{pc_to_insn(pc).name}")

- asm.pop(SP)

- asm.pop(EC)

- asm.pop(CFP)

-

- asm.mov(C_RET, Qundef)

- asm.ret

- end

-

- # @param asm [RubyVM::RJIT::Assembler]

- # @param entry_stub [RubyVM::RJIT::EntryStub]

- def compile_entry_stub(asm, entry_stub)

- # Call rb_rjit_entry_stub_hit

- asm.comment('entry stub hit')

- asm.mov(C_ARGS[0], to_value(entry_stub))

- asm.call(C.rb_rjit_entry_stub_hit)

-

- # Jump to the address returned by rb_rjit_entry_stub_hit

- asm.jmp(:rax)

- end

-

- # @param ctx [RubyVM::RJIT::Context]

- # @param asm [RubyVM::RJIT::Assembler]

- # @param branch_stub [RubyVM::RJIT::BranchStub]

- # @param target0_p [TrueClass,FalseClass]

- def compile_branch_stub(ctx, asm, branch_stub, target0_p)

- # Call rb_rjit_branch_stub_hit

- iseq = branch_stub.iseq

- if C.rjit_opts.dump_disasm && C.imemo_type_p(iseq, C.imemo_iseq) # Guard against ISEQ GC at random moments

- asm.comment("branch stub hit: #{iseq.body.location.label}@#{C.rb_iseq_path(iseq)}:#{iseq_lineno(iseq, target0_p ? branch_stub.target0.pc : branch_stub.target1.pc)}")

- end

- asm.mov(:rdi, to_value(branch_stub))

- asm.mov(:esi, ctx.sp_offset)

- asm.mov(:edx, target0_p ? 1 : 0)

- asm.call(C.rb_rjit_branch_stub_hit)

-

- # Jump to the address returned by rb_rjit_branch_stub_hit

- asm.jmp(:rax)

- end

-

- private

-

- def pc_to_insn(pc)

- Compiler.decode_insn(C.VALUE.new(pc).*)

- end

-

- # @param pc [Integer]

- # @param asm [RubyVM::RJIT::Assembler]

- def count_insn_exit(pc, asm)

- if C.rjit_opts.stats

- insn = Compiler.decode_insn(C.VALUE.new(pc).*)

- asm.comment("increment insn exit: #{insn.name}")

- asm.mov(:rax, (C.rjit_insn_exits + insn.bin).to_i)

- asm.add([:rax], 1) # TODO: lock

- end

- if C.rjit_opts.trace_exits

- asm.comment('rjit_record_exit_stack')

- asm.mov(C_ARGS[0], pc)

- asm.call(C.rjit_record_exit_stack)

- end

- end

-

- # @param jit [RubyVM::RJIT::JITState]

- # @param ctx [RubyVM::RJIT::Context]

- # @param asm [RubyVM::RJIT::Assembler]

- def save_pc_and_sp(pc, ctx, asm, reset_sp_offset: true)

- # Update pc (TODO: manage PC offset?)

- asm.comment("save PC#{' and SP' if ctx.sp_offset != 0} to CFP")

- asm.mov(:rax, pc) # rax = jit.pc

- asm.mov([CFP, C.rb_control_frame_t.offsetof(:pc)], :rax) # cfp->pc = rax

-

- # Update sp

- if ctx.sp_offset != 0

- asm.add(SP, C.VALUE.size * ctx.sp_offset) # sp += stack_size

- asm.mov([CFP, C.rb_control_frame_t.offsetof(:sp)], SP) # cfp->sp = sp

- if reset_sp_offset

- ctx.sp_offset = 0

- end

- end

- end

-

- def to_value(obj)

- GC_REFS << obj

- C.to_value(obj)

- end

-

- def iseq_lineno(iseq, pc)

- C.rb_iseq_line_no(iseq, (pc - iseq.body.iseq_encoded.to_i) / C.VALUE.size)

- rescue RangeError # bignum too big to convert into `unsigned long long' (RangeError)

- -1

- end

- end

-end