diff options
Diffstat (limited to 'yjit/src/codegen.rs')
-rw-r--r-- | yjit/src/codegen.rs | 230 |
1 files changed, 210 insertions, 20 deletions
diff --git a/yjit/src/codegen.rs b/yjit/src/codegen.rs index 7c2c0dbe87..6686a41a8c 100644 --- a/yjit/src/codegen.rs +++ b/yjit/src/codegen.rs @@ -1886,6 +1886,9 @@ fn jit_chain_guard( // up to 5 different classes, and embedded or not for each pub const GET_IVAR_MAX_DEPTH: i32 = 10; +// up to 5 different classes, and embedded or not for each +pub const SET_IVAR_MAX_DEPTH: i32 = 10; + // hashes and arrays pub const OPT_AREF_MAX_CHAIN_DEPTH: i32 = 2; @@ -2010,7 +2013,7 @@ fn gen_get_ivar( } let ivar_index = unsafe { - let shape_id = comptime_receiver.shape_of(); + let shape_id = comptime_receiver.shape_id_of(); let shape = rb_shape_get_shape_by_id(shape_id); let mut ivar_index: u32 = 0; if rb_shape_get_iv_index(shape, ivar_name, &mut ivar_index) { @@ -2134,33 +2137,220 @@ fn gen_getinstancevariable( ) } +// Generate an IV write. +// This function doesn't deal with writing the shape, or expanding an object +// to use an IV buffer if necessary. That is the callers responsibility +fn gen_write_iv( + ctx: &mut Context, + asm: &mut Assembler, + comptime_receiver: VALUE, + recv: Opnd, + ivar_index: usize, + extension_needed: bool) +{ + // Compile time self is embedded and the ivar index lands within the object + let embed_test_result = comptime_receiver.embedded_p() && !extension_needed; + + if embed_test_result { + // Find the IV offset + let offs = ROBJECT_OFFSET_AS_ARY + (ivar_index * SIZEOF_VALUE) as i32; + let ivar_opnd = Opnd::mem(64, recv, offs); + + // Write the IV + asm.comment("write IV"); + asm.mov(ivar_opnd, ctx.stack_pop(0)); + } else { + // Compile time value is *not* embedded. + + // Get a pointer to the extended table + let tbl_opnd = asm.load(Opnd::mem(64, recv, ROBJECT_OFFSET_AS_HEAP_IVPTR)); + + // Write the ivar in to the extended table + let ivar_opnd = Opnd::mem(64, tbl_opnd, (SIZEOF_VALUE * ivar_index) as i32); + + asm.comment("write IV"); + asm.mov(ivar_opnd, ctx.stack_pop(0)); + } +} + fn gen_setinstancevariable( jit: &mut JITState, ctx: &mut Context, asm: &mut Assembler, - _ocb: &mut OutlinedCb, + ocb: &mut OutlinedCb, ) -> CodegenStatus { - let id = jit_get_arg(jit, 0).as_usize(); - let ic = jit_get_arg(jit, 1).as_u64(); // type IVC + let starting_context = *ctx; // make a copy for use with jit_chain_guard - // Save the PC and SP because the callee may allocate - // Note that this modifies REG_SP, which is why we do it first - jit_prepare_routine_call(jit, ctx, asm); + // Defer compilation so we can specialize on a runtime `self` + if !jit_at_current_insn(jit) { + defer_compilation(jit, ctx, asm, ocb); + return EndBlock; + } - // Get the operands from the stack - let val_opnd = ctx.stack_pop(1); + let ivar_name = jit_get_arg(jit, 0).as_u64(); + let comptime_receiver = jit_peek_at_self(jit); + let comptime_val_klass = comptime_receiver.class_of(); - // Call rb_vm_setinstancevariable(iseq, obj, id, val, ic); - asm.ccall( - rb_vm_setinstancevariable as *const u8, - vec![ - Opnd::const_ptr(jit.iseq as *const u8), - Opnd::mem(64, CFP, RUBY_OFFSET_CFP_SELF), - id.into(), - val_opnd, - Opnd::const_ptr(ic as *const u8), - ] - ); + // Check if the comptime class uses a custom allocator + let custom_allocator = unsafe { rb_get_alloc_func(comptime_val_klass) }; + let uses_custom_allocator = match custom_allocator { + Some(alloc_fun) => { + let allocate_instance = rb_class_allocate_instance as *const u8; + alloc_fun as *const u8 != allocate_instance + } + None => false, + }; + + // Check if the comptime receiver is a T_OBJECT + let receiver_t_object = unsafe { RB_TYPE_P(comptime_receiver, RUBY_T_OBJECT) }; + + // If the receiver isn't a T_OBJECT, or uses a custom allocator, + // then just write out the IV write as a function call + if !receiver_t_object || uses_custom_allocator { + asm.comment("call rb_vm_setinstancevariable()"); + + let ic = jit_get_arg(jit, 1).as_u64(); // type IVC + + // The function could raise exceptions. + jit_prepare_routine_call(jit, ctx, asm); + + // Save the PC and SP because the callee may allocate + // Note that this modifies REG_SP, which is why we do it first + jit_prepare_routine_call(jit, ctx, asm); + + // Get the operands from the stack + let val_opnd = ctx.stack_pop(1); + + // Call rb_vm_setinstancevariable(iseq, obj, id, val, ic); + asm.ccall( + rb_vm_setinstancevariable as *const u8, + vec![ + Opnd::const_ptr(jit.iseq as *const u8), + Opnd::mem(64, CFP, RUBY_OFFSET_CFP_SELF), + ivar_name.into(), + val_opnd, + Opnd::const_ptr(ic as *const u8), + ] + ); + } else { + // Get the iv index + let ivar_index = unsafe { + let shape_id = comptime_receiver.shape_id_of(); + let shape = rb_shape_get_shape_by_id(shape_id); + let mut ivar_index: u32 = 0; + if rb_shape_get_iv_index(shape, ivar_name, &mut ivar_index) { + Some(ivar_index as usize) + } else { + None + } + }; + + // Get the receiver + let mut recv = asm.load(Opnd::mem(64, CFP, RUBY_OFFSET_CFP_SELF)); + + let recv_opnd = SelfOpnd; + let recv_type = ctx.get_opnd_type(recv_opnd); + + // Generate a side exit + let side_exit = get_side_exit(jit, ocb, ctx); + + // Upgrade type + if !recv_type.is_heap() { // Must be a heap type + ctx.upgrade_opnd_type(recv_opnd, Type::UnknownHeap); + guard_object_is_heap(asm, recv, side_exit); + } + + let expected_shape = unsafe { rb_shape_get_shape_id(comptime_receiver) }; + let shape_bit_size = unsafe { rb_shape_id_num_bits() }; // either 16 or 32 depending on RUBY_DEBUG + let shape_byte_size = shape_bit_size / 8; + let shape_opnd = Opnd::mem(shape_bit_size, recv, RUBY_OFFSET_RBASIC_FLAGS + (8 - shape_byte_size as i32)); + + asm.comment("guard shape"); + asm.cmp(shape_opnd, Opnd::UImm(expected_shape as u64)); + let megamorphic_side_exit = counted_exit!(ocb, side_exit, getivar_megamorphic).into(); + jit_chain_guard( + JCC_JNE, + jit, + &starting_context, + asm, + ocb, + SET_IVAR_MAX_DEPTH, + megamorphic_side_exit, + ); + + match ivar_index { + // If we don't have an instance variable index, then we need to + // transition out of the current shape. + None => { + let mut shape = comptime_receiver.shape_of(); + + // If the object doesn't have the capacity to store the IV, + // then we'll need to allocate it. + let needs_extension = unsafe { (*shape).next_iv_index >= (*shape).capacity }; + + // We can write to the object, but we need to transition the shape + let ivar_index = unsafe { (*shape).next_iv_index } as usize; + + if needs_extension { + let current_capacity = unsafe { (*shape).capacity }; + let newsize = current_capacity * 2; + + // We need to add an extended table to the object + // First, create an outgoing transition that increases the + // capacity + shape = unsafe { + rb_shape_transition_shape_capa(shape, newsize) + }; + + // Generate the C call so that runtime code will increase + // the capacity and set the buffer. + asm.ccall(rb_ensure_iv_list_size as *const u8, + vec![ + recv, + Opnd::UImm(current_capacity.into()), + Opnd::UImm(newsize.into()) + ] + ); + + // Load the receiver again after the function call + recv = asm.load(Opnd::mem(64, CFP, RUBY_OFFSET_CFP_SELF)) + } + + let new_shape_id = unsafe { + rb_shape_id(rb_shape_get_next(shape, comptime_receiver, ivar_name)) + }; + + gen_write_iv(ctx, asm, comptime_receiver, recv, ivar_index, needs_extension); + + asm.comment("write shape"); + let cleared_flags = asm.and( + Opnd::mem(64, recv, RUBY_OFFSET_RBASIC_FLAGS), + Opnd::UImm(unsafe { rb_shape_flag_mask() }.into())); + + let new_flags = asm.or(cleared_flags, Opnd::UImm((new_shape_id as u64) << unsafe { rb_shape_flag_shift() })); + + asm.store(Opnd::mem(64, recv, RUBY_OFFSET_RBASIC_FLAGS), new_flags); + }, + + Some(ivar_index) => { + // If the iv index already exists, then we don't need to + // transition to a new shape. The reason is because we find + // the iv index by searching up the shape tree. If we've + // made the transition already, then there's no reason to + // update the shape on the object. Just set the IV. + gen_write_iv(ctx, asm, comptime_receiver, recv, ivar_index, false); + }, + } + + asm.comment("write barrier"); + asm.ccall( + rb_gc_writebarrier as *const u8, + vec![ + recv, + ctx.stack_pop(1), + ] + ); + } KeepCompiling } |