#include #include "insns.inc" #include "internal.h" #include "vm_core.h" #include "vm_sync.h" #include "vm_callinfo.h" #include "builtin.h" #include "internal/compile.h" #include "insns_info.inc" #include "ujit_compile.h" #include "ujit_asm.h" #include "ujit_utils.h" // TODO: give ujit_examples.inc some more meaningful file name // eg ujit_hook.h #include "ujit_examples.inc" #ifdef _WIN32 #define PLATFORM_SUPPORTED_P 0 #else #define PLATFORM_SUPPORTED_P 1 #endif bool rb_ujit_enabled; // Hash table of encoded instructions extern st_table *rb_encoded_insn_data; // Code generation context typedef struct ctx_struct { // Current PC VALUE *pc; // Difference between the current stack pointer and actual stack top int32_t stack_diff; const rb_iseq_t *iseq; } ctx_t; // MicroJIT code generation function signature typedef bool (*codegen_fn)(codeblock_t* cb, codeblock_t* ocb, ctx_t* ctx); // Map from YARV opcodes to code generation functions static st_table *gen_fns; // Code block into which we write machine code static codeblock_t block; static codeblock_t* cb = NULL; // Code block into which we write out-of-line machine code static codeblock_t outline_block; static codeblock_t* ocb = NULL; // Keep track of mapping from instructions to generated code // See comment for rb_encoded_insn_data in iseq.c static void addr2insn_bookkeeping(void *code_ptr, int insn) { const void * const *table = rb_vm_get_insns_address_table(); const void * const translated_address = table[insn]; st_data_t encoded_insn_data; if (st_lookup(rb_encoded_insn_data, (st_data_t)translated_address, &encoded_insn_data)) { st_insert(rb_encoded_insn_data, (st_data_t)code_ptr, encoded_insn_data); } else { rb_bug("ujit: failed to find info for original instruction while dealing with addr2insn"); } } static int opcode_at_pc(const rb_iseq_t *iseq, const VALUE *pc) { const VALUE at_pc = *pc; if (FL_TEST_RAW((VALUE)iseq, ISEQ_TRANSLATED)) { return rb_vm_insn_addr2insn((const void *)at_pc); } else { return (int)at_pc; } } // Get the current instruction opcode from the context object int ctx_get_opcode(ctx_t *ctx) { return opcode_at_pc(ctx->iseq, ctx->pc); } // Get an instruction argument from the context object VALUE ctx_get_arg(ctx_t* ctx, size_t arg_idx) { assert (arg_idx + 1 < insn_len(ctx_get_opcode(ctx))); return *(ctx->pc + arg_idx + 1); } /* Get an operand for the adjusted stack pointer address */ x86opnd_t ctx_sp_opnd(ctx_t* ctx, size_t n) { int32_t offset = (ctx->stack_diff) * 8; return mem_opnd(64, RSI, offset); } /* Make space on the stack for N values Return a pointer to the new stack top */ x86opnd_t ctx_stack_push(ctx_t* ctx, size_t n) { ctx->stack_diff += n; // SP points just above the topmost value int32_t offset = (ctx->stack_diff - 1) * 8; return mem_opnd(64, RSI, offset); } /* Pop N values off the stack Return a pointer to the stack top before the pop operation */ x86opnd_t ctx_stack_pop(ctx_t* ctx, size_t n) { // SP points just above the topmost value int32_t offset = (ctx->stack_diff - 1) * 8; x86opnd_t top = mem_opnd(64, RSI, offset); ctx->stack_diff -= n; return top; } x86opnd_t ctx_stack_opnd(ctx_t* ctx, int32_t idx) { // SP points just above the topmost value int32_t offset = (ctx->stack_diff - 1 - idx) * 8; x86opnd_t opnd = mem_opnd(64, RSI, offset); return opnd; } // Ruby instruction entry static void ujit_gen_entry(codeblock_t* cb) { for (size_t i = 0; i < sizeof(ujit_pre_call_bytes); ++i) cb_write_byte(cb, ujit_pre_call_bytes[i]); } /** Generate an inline exit to return to the interpreter */ static void ujit_gen_exit(codeblock_t* cb, ctx_t* ctx, VALUE* exit_pc) { // Write the adjusted SP back into the CFP if (ctx->stack_diff != 0) { x86opnd_t stack_pointer = ctx_sp_opnd(ctx, 1); lea(cb, RSI, stack_pointer); mov(cb, mem_opnd(64, RDI, 8), RSI); } // Directly return the next PC, which is a constant mov(cb, RAX, const_ptr_opnd(exit_pc)); // Write PC back into the CFP mov(cb, mem_opnd(64, RDI, 0), RAX); // Write the post call bytes for (size_t i = 0; i < sizeof(ujit_post_call_bytes); ++i) cb_write_byte(cb, ujit_post_call_bytes[i]); } /** Generate an out-of-line exit to return to the interpreter */ uint8_t* ujit_side_exit(codeblock_t* cb, ctx_t* ctx, VALUE* exit_pc) { uint8_t* code_ptr = cb_get_ptr(cb, cb->write_pos); // Write back the old instruction at the exit PC // Otherwise the interpreter may jump right back to the // JITted code we're trying to exit const void * const *table = rb_vm_get_insns_address_table(); int opcode = opcode_at_pc(ctx->iseq, exit_pc); void* old_instr = (void*)table[opcode]; mov(cb, RAX, const_ptr_opnd(exit_pc)); mov(cb, RCX, const_ptr_opnd(old_instr)); mov(cb, mem_opnd(64, RAX, 0), RCX); // Generate the code to exit to the interpreters ujit_gen_exit(cb, ctx, exit_pc); return code_ptr; } /* Generate a chunk of machine code for one individual bytecode instruction Eventually, this will handle multiple instructions in a sequence MicroJIT code gets a pointer to the cfp as the first argument in RDI See rb_ujit_empty_func(rb_control_frame_t *cfp) in iseq.c Throughout the generated code, we store the current stack pointer in RSI System V ABI reference: https://wiki.osdev.org/System_V_ABI#x86-64 */ uint8_t * ujit_compile_insn(const rb_iseq_t *iseq, unsigned int insn_idx, unsigned int* next_ujit_idx) { if (!cb) { return NULL; } VALUE *encoded = iseq->body->iseq_encoded; // NOTE: if we are ever deployed in production, we // should probably just log an error and return NULL here, // so we can fail more gracefully if (cb->write_pos + 1024 >= cb->mem_size) { rb_bug("out of executable memory"); } if (ocb->write_pos + 1024 >= ocb->mem_size) { rb_bug("out of executable memory (outlined block)"); } // Align the current write positon to cache line boundaries cb_align_pos(cb, 64); // Get a pointer to the current write position in the code block uint8_t *code_ptr = &cb->mem_block[cb->write_pos]; //printf("write pos: %ld\n", cb->write_pos); // Get the first opcode in the sequence int first_opcode = opcode_at_pc(iseq, &encoded[insn_idx]); // Create codegen context ctx_t ctx; ctx.pc = NULL; ctx.stack_diff = 0; ctx.iseq = iseq; // For each instruction to compile size_t num_instrs; for (num_instrs = 0;; ++num_instrs) { // Set the current PC ctx.pc = &encoded[insn_idx]; // Get the current opcode int opcode = ctx_get_opcode(&ctx); // Lookup the codegen function for this instruction st_data_t st_gen_fn; if (!rb_st_lookup(gen_fns, opcode, &st_gen_fn)) { //print_int(cb, imm_opnd(num_instrs)); //print_str(cb, insn_name(opcode)); break; } // Write the pre call bytes before the first instruction if (num_instrs == 0) { ujit_gen_entry(cb); // Load the current SP from the CFP into RSI mov(cb, RSI, mem_opnd(64, RDI, 8)); } // Call the code generation function codegen_fn gen_fn = (codegen_fn)st_gen_fn; if (!gen_fn(cb, ocb, &ctx)) { break; } // Move to the next instruction insn_idx += insn_len(opcode); } // Let the caller know how many instructions ujit compiled *next_ujit_idx = insn_idx; // If no instructions were compiled if (num_instrs == 0) { return NULL; } // Generate code to exit to the interpreter ujit_gen_exit(cb, &ctx, ctx.pc); addr2insn_bookkeeping(code_ptr, first_opcode); return code_ptr; } bool gen_dup(codeblock_t* cb, codeblock_t* ocb, ctx_t* ctx) { x86opnd_t dup_val = ctx_stack_pop(ctx, 1); x86opnd_t loc0 = ctx_stack_push(ctx, 1); x86opnd_t loc1 = ctx_stack_push(ctx, 1); mov(cb, RAX, dup_val); mov(cb, loc0, RAX); mov(cb, loc1, RAX); return true; } bool gen_nop(codeblock_t* cb, codeblock_t* ocb, ctx_t* ctx) { // Do nothing return true; } bool gen_pop(codeblock_t* cb, codeblock_t* ocb, ctx_t* ctx) { // Decrement SP ctx_stack_pop(ctx, 1); return true; } bool gen_putnil(codeblock_t* cb, codeblock_t* ocb, ctx_t* ctx) { // Write constant at SP x86opnd_t stack_top = ctx_stack_push(ctx, 1); mov(cb, stack_top, imm_opnd(Qnil)); return true; } bool gen_putobject(codeblock_t* cb, codeblock_t* ocb, ctx_t* ctx) { // Load the argument from the bytecode sequence. // We need to do this as the argument can chanage due to GC compaction. x86opnd_t pc_imm = const_ptr_opnd((void*)ctx->pc); mov(cb, RAX, pc_imm); mov(cb, RAX, mem_opnd(64, RAX, 8)); // One after the opcode // Write argument at SP x86opnd_t stack_top = ctx_stack_push(ctx, 1); mov(cb, stack_top, RAX); return true; } bool gen_putobject_int2fix(codeblock_t* cb, codeblock_t* ocb, ctx_t* ctx) { int opcode = ctx_get_opcode(ctx); int cst_val = (opcode == BIN(putobject_INT2FIX_0_))? 0:1; // Write constant at SP x86opnd_t stack_top = ctx_stack_push(ctx, 1); mov(cb, stack_top, imm_opnd(INT2FIX(cst_val))); return true; } bool gen_putself(codeblock_t* cb, codeblock_t* ocb, ctx_t* ctx) { // Load self from CFP mov(cb, RAX, mem_opnd(64, RDI, 24)); // Write it on the stack x86opnd_t stack_top = ctx_stack_push(ctx, 1); mov(cb, stack_top, RAX); return true; } bool gen_getlocal_wc0(codeblock_t* cb, codeblock_t* ocb, ctx_t* ctx) { // Load environment pointer EP from CFP mov(cb, RDX, member_opnd(RDI, rb_control_frame_t, ep)); // Compute the offset from BP to the local int32_t local_idx = (int32_t)ctx_get_arg(ctx, 0); const int32_t offs = -8 * local_idx; // Load the local from the block mov(cb, RCX, mem_opnd(64, RDX, offs)); // Write the local at SP x86opnd_t stack_top = ctx_stack_push(ctx, 1); mov(cb, stack_top, RCX); return true; } bool gen_setlocal_wc0(codeblock_t* cb, codeblock_t* ocb, ctx_t* ctx) { /* vm_env_write(const VALUE *ep, int index, VALUE v) { VALUE flags = ep[VM_ENV_DATA_INDEX_FLAGS]; if (LIKELY((flags & VM_ENV_FLAG_WB_REQUIRED) == 0)) { VM_STACK_ENV_WRITE(ep, index, v); } else { vm_env_write_slowpath(ep, index, v); } } */ // Load environment pointer EP from CFP mov(cb, RDX, member_opnd(RDI, rb_control_frame_t, ep)); // flags & VM_ENV_FLAG_WB_REQUIRED x86opnd_t flags_opnd = mem_opnd(64, RDX, 8 * VM_ENV_DATA_INDEX_FLAGS); test(cb, flags_opnd, imm_opnd(VM_ENV_FLAG_WB_REQUIRED)); // Create a size-exit to fall back to the interpreter uint8_t* side_exit = ujit_side_exit(ocb, ctx, ctx->pc); // if (flags & VM_ENV_FLAG_WB_REQUIRED) != 0 jnz_ptr(cb, side_exit); // Pop the value to write from the stack x86opnd_t stack_top = ctx_stack_pop(ctx, 1); mov(cb, RCX, stack_top); // Write the value at the environment pointer int32_t local_idx = (int32_t)ctx_get_arg(ctx, 0); const int32_t offs = -8 * local_idx; mov(cb, mem_opnd(64, RDX, offs), RCX); return true; } bool gen_opt_minus(codeblock_t* cb, codeblock_t* ocb, ctx_t* ctx) { // Create a size-exit to fall back to the interpreter // Note: we generate the side-exit before popping operands from the stack uint8_t* side_exit = ujit_side_exit(ocb, ctx, ctx->pc); // TODO: make a helper function for this // Make sure that minus isn't redefined for integers mov(cb, RAX, const_ptr_opnd(ruby_current_vm_ptr)); test( cb, member_opnd_idx(RAX, rb_vm_t, redefined_flag, BOP_MINUS), imm_opnd(INTEGER_REDEFINED_OP_FLAG) ); jnz_ptr(cb, side_exit); // Get the operands and destination from the stack x86opnd_t arg1 = ctx_stack_pop(ctx, 1); x86opnd_t arg0 = ctx_stack_pop(ctx, 1); // If not fixnums, fall back test(cb, arg0, imm_opnd(RUBY_FIXNUM_FLAG)); jz_ptr(cb, side_exit); test(cb, arg1, imm_opnd(RUBY_FIXNUM_FLAG)); jz_ptr(cb, side_exit); // Subtract arg0 - arg1 and test for overflow mov(cb, RAX, arg0); sub(cb, RAX, arg1); jo_ptr(cb, side_exit); add(cb, RAX, imm_opnd(1)); // Push the output on the stack x86opnd_t dst = ctx_stack_push(ctx, 1); mov(cb, dst, RAX); return true; } bool gen_opt_send_without_block(codeblock_t* cb, codeblock_t* ocb, ctx_t* ctx) { // Definitions relevant to the call cache are in vm_callinfo.h struct rb_call_data * cd = (struct rb_call_data *)ctx_get_arg(ctx, 0); int32_t argc = (int32_t)vm_ci_argc(cd->ci); const struct rb_callcache *cc = cd->cc; // Callee method ID ID mid = vm_ci_mid(cd->ci); //printf("jitting call to \"%s\", argc: %lu\n", rb_id2name(mid), argc); // Don't JIT calls with keyword splat if (vm_ci_flag(cd->ci) & VM_CALL_KW_SPLAT) { return false; } // Don't JIT calls that aren't simple if (!(vm_ci_flag(cd->ci) & VM_CALL_ARGS_SIMPLE)) { return false; } // Don't JIT if the inline cache is not set if (cd->cc == vm_cc_empty()) { //printf("call cache is empty\n"); return false; } // Don't JIT if this is not a C call if (vm_cc_cme(cd->cc)->def->type != VM_METHOD_TYPE_CFUNC) { return false; } //printf("call to C function \"%s\", argc: %lu\n", rb_id2name(mid), argc); // Things we need to do at run-time: // - Check that the cached klass matches // - Check that method entry is not invalidated // - ??? // - Create a new frame // - copy function arguments? // - Call the C function // - Remove the frame // Create a size-exit to fall back to the interpreter uint8_t* side_exit = ujit_side_exit(ocb, ctx, ctx->pc); // Points to the receiver operand on the stack x86opnd_t recv = ctx_stack_opnd(ctx, argc); mov(cb, RCX, recv); //print_str(cb, rb_id2name(mid)); //print_ptr(cb, RCX); // IDEA: may be able to eliminate this in some cases if we know the previous instruction? // TODO: guard_is_object() helper function? // FIXME: an object can have QNil bit 1000 set // need to check for immediate mask, Qnil and Qfalse // Check that the receiver is an object test(cb, RCX, imm_opnd(RUBY_IMMEDIATE_MASK)); jnz_ptr(cb, side_exit); cmp(cb, RCX, imm_opnd(Qfalse)); je_ptr(cb, side_exit); cmp(cb, RCX, imm_opnd(Qnil)); je_ptr(cb, side_exit); // Pointer to the klass field of the receiver &(recv->klass) x86opnd_t klass_opnd = mem_opnd(64, RCX, offsetof(struct RBasic, klass)); // IDEA: Aaron suggested we could possibly treat a changed // class pointer as a cache miss // Check if we have a cache hit mov(cb, RAX, const_ptr_opnd((void*)cd->cc->klass)); cmp(cb, RAX, klass_opnd); jne_ptr(cb, side_exit); //print_str(cb, "cache klass hit"); jmp_ptr(cb, side_exit); return true; /* // Create a size-exit to fall back to the interpreter uint8_t* side_exit = ujit_side_exit(ocb, ctx, ctx->pc); struct rb_calling_info *calling = (struct rb_calling_info*)malloc(sizeof(struct rb_calling_info)); calling->block_handler = VM_BLOCK_HANDLER_NONE; calling->kw_splat = 0; calling->argc = argc; mov(cb, RAX, const_ptr_opnd(cd)); x86opnd_t ptr_to_cc = member_opnd(RAX, struct rb_call_data, cc); mov(cb, RAX, ptr_to_cc); x86opnd_t ptr_to_klass = mem_opnd(64, RAX, offsetof(struct rb_callcache, klass)); x86opnd_t ptr_to_cme_ = mem_opnd(64, RAX, offsetof(struct rb_callcache, cme_)); x86opnd_t ptr_to_call_ = mem_opnd(64, RAX, offsetof(struct rb_callcache, call_)); mov(cb, R9, ptr_to_klass); mov(cb, RCX, ptr_to_cme_); // Points to the receiver operand on the stack x86opnd_t recv = ctx_stack_opnd(ctx, argc); mov(cb, RDX, recv); //print_int(cb, recv); // Store calling->recv mov(cb, R8, const_ptr_opnd(calling)); x86opnd_t recv_opnd = mem_opnd(64, R8, offsetof(struct rb_calling_info, recv)); mov(cb, recv_opnd, RDX); // Pointer to the klass field of the receiver x86opnd_t klass_opnd = mem_opnd(64, RDX, offsetof(struct RBasic, klass)); // IDEA: Aaron suggested we could possibly treat a changed // class pointer as a cache miss // Check if we have a cache hit cmp(cb, R9, klass_opnd); jne_ptr(cb, side_exit); //print_int(cb, klass_opnd); print_str(cb, "cache klass hit"); //#define METHOD_ENTRY_INVALIDATED(me) ((me)->flags & IMEMO_FL_USER5) x86opnd_t flags_opnd = mem_opnd(64, RCX, offsetof( rb_callable_method_entry_t, flags)); test(cb, flags_opnd, imm_opnd(IMEMO_FL_USER5)); jnz_ptr(cb, side_exit); push(cb, RDI); push(cb, RSI); x86opnd_t ptr_to_pc = mem_opnd(64, RDI, offsetof(rb_control_frame_t, pc)); mov(cb, ptr_to_pc, const_ptr_opnd(ctx->pc + insn_len(BIN(opt_send_without_block)))); // Write the adjusted SP back into the CFP if (ctx->stack_diff != 0) { x86opnd_t stack_pointer = ctx_sp_opnd(ctx, 1); lea(cb, RSI, stack_pointer); mov(cb, mem_opnd(64, RDI, 8), RSI); } // val = vm_cc_call(cc)(ec, GET_CFP(), &calling, cd); mov(cb, RSI, RDI); mov(cb, RDI, const_ptr_opnd(rb_current_execution_context())); mov(cb, RDX, R8); print_int(cb, RDX); mov(cb, RCX, const_ptr_opnd(cd)); call(cb, ptr_to_call_); pop(cb, RSI); pop(cb, RDI); size_t continue_in_jit = cb_new_label(cb, "continue_in_jit"); cmp(cb, RAX, imm_opnd(Qundef)); jne(cb, continue_in_jit); //print_str(cb, "method entry not invalidated!!!1"); mov(cb, RDI, const_ptr_opnd(rb_current_execution_context())); mov(cb, RDI, mem_opnd(64, RDI, offsetof(rb_execution_context_t, cfp))); // Read the PC from the CFP mov(cb, RAX, mem_opnd(64, RDI, 0)); // Write the post call bytes for (size_t i = 0; i < sizeof(ujit_post_call_bytes); ++i) cb_write_byte(cb, ujit_post_call_bytes[i]); cb_write_label(cb, continue_in_jit); cb_link_labels(cb); return true; */ } void rb_ujit_compile_iseq(const rb_iseq_t *iseq) { #if OPT_DIRECT_THREADED_CODE || OPT_CALL_THREADED_CODE RB_VM_LOCK(); VALUE *encoded = (VALUE *)iseq->body->iseq_encoded; unsigned int insn_idx; unsigned int next_ujit_idx = 0; for (insn_idx = 0; insn_idx < iseq->body->iseq_size; /* */) { int insn = opcode_at_pc(iseq, &encoded[insn_idx]); int len = insn_len(insn); uint8_t *native_code_ptr = NULL; // If ujit hasn't already compiled this instruction if (insn_idx >= next_ujit_idx) { native_code_ptr = ujit_compile_insn(iseq, insn_idx, &next_ujit_idx); } if (native_code_ptr) { encoded[insn_idx] = (VALUE)native_code_ptr; } insn_idx += len; } RB_VM_UNLOCK(); #endif } void rb_ujit_init(void) { if (!ujit_scrape_successful || !PLATFORM_SUPPORTED_P) { return; } rb_ujit_enabled = true; // Initialize the code blocks size_t mem_size = 128 * 1024 * 1024; uint8_t* mem_block = alloc_exec_mem(mem_size); cb = █ cb_init(cb, mem_block, mem_size/2); ocb = &outline_block; cb_init(ocb, mem_block + mem_size/2, mem_size/2); // Initialize the codegen function table gen_fns = rb_st_init_numtable(); // Map YARV opcodes to the corresponding codegen functions st_insert(gen_fns, (st_data_t)BIN(dup), (st_data_t)&gen_dup); st_insert(gen_fns, (st_data_t)BIN(nop), (st_data_t)&gen_nop); st_insert(gen_fns, (st_data_t)BIN(pop), (st_data_t)&gen_pop); st_insert(gen_fns, (st_data_t)BIN(putnil), (st_data_t)&gen_putnil); st_insert(gen_fns, (st_data_t)BIN(putobject), (st_data_t)&gen_putobject); st_insert(gen_fns, (st_data_t)BIN(putobject_INT2FIX_0_), (st_data_t)&gen_putobject_int2fix); st_insert(gen_fns, (st_data_t)BIN(putobject_INT2FIX_1_), (st_data_t)&gen_putobject_int2fix); st_insert(gen_fns, (st_data_t)BIN(putself), (st_data_t)&gen_putself); st_insert(gen_fns, (st_data_t)BIN(getlocal_WC_0), (st_data_t)&gen_getlocal_wc0); st_insert(gen_fns, (st_data_t)BIN(setlocal_WC_0), (st_data_t)&gen_setlocal_wc0); st_insert(gen_fns, (st_data_t)BIN(opt_minus), (st_data_t)&gen_opt_minus); st_insert(gen_fns, (st_data_t)BIN(opt_send_without_block), (st_data_t)&gen_opt_send_without_block); }