| /* |
| * Optimizations for Tiny Code Generator for QEMU |
| * |
| * Copyright (c) 2010 Samsung Electronics. |
| * Contributed by Kirill Batuzov <batuzovk@ispras.ru> |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a copy |
| * of this software and associated documentation files (the "Software"), to deal |
| * in the Software without restriction, including without limitation the rights |
| * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| * copies of the Software, and to permit persons to whom the Software is |
| * furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice shall be included in |
| * all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| * THE SOFTWARE. |
| */ |
| |
| #include "config.h" |
| |
| #include <stdlib.h> |
| #include <stdio.h> |
| |
| #include "qemu-common.h" |
| #include "tcg-op.h" |
| |
| #define CASE_OP_32_64(x) \ |
| glue(glue(case INDEX_op_, x), _i32): \ |
| glue(glue(case INDEX_op_, x), _i64) |
| |
| typedef enum { |
| TCG_TEMP_UNDEF = 0, |
| TCG_TEMP_CONST, |
| TCG_TEMP_COPY, |
| TCG_TEMP_HAS_COPY, |
| TCG_TEMP_ANY |
| } tcg_temp_state; |
| |
| struct tcg_temp_info { |
| tcg_temp_state state; |
| uint16_t prev_copy; |
| uint16_t next_copy; |
| tcg_target_ulong val; |
| }; |
| |
| static struct tcg_temp_info temps[TCG_MAX_TEMPS]; |
| |
| /* Reset TEMP's state to TCG_TEMP_ANY. If TEMP was a representative of some |
| class of equivalent temp's, a new representative should be chosen in this |
| class. */ |
| static void reset_temp(TCGArg temp, int nb_temps, int nb_globals) |
| { |
| int i; |
| TCGArg new_base = (TCGArg)-1; |
| if (temps[temp].state == TCG_TEMP_HAS_COPY) { |
| for (i = temps[temp].next_copy; i != temp; i = temps[i].next_copy) { |
| if (i >= nb_globals) { |
| temps[i].state = TCG_TEMP_HAS_COPY; |
| new_base = i; |
| break; |
| } |
| } |
| for (i = temps[temp].next_copy; i != temp; i = temps[i].next_copy) { |
| if (new_base == (TCGArg)-1) { |
| temps[i].state = TCG_TEMP_ANY; |
| } else { |
| temps[i].val = new_base; |
| } |
| } |
| temps[temps[temp].next_copy].prev_copy = temps[temp].prev_copy; |
| temps[temps[temp].prev_copy].next_copy = temps[temp].next_copy; |
| } else if (temps[temp].state == TCG_TEMP_COPY) { |
| temps[temps[temp].next_copy].prev_copy = temps[temp].prev_copy; |
| temps[temps[temp].prev_copy].next_copy = temps[temp].next_copy; |
| new_base = temps[temp].val; |
| } |
| temps[temp].state = TCG_TEMP_ANY; |
| if (new_base != (TCGArg)-1 && temps[new_base].next_copy == new_base) { |
| temps[new_base].state = TCG_TEMP_ANY; |
| } |
| } |
| |
| static int op_bits(enum TCGOpcode op) |
| { |
| const TCGOpDef *def = &tcg_op_defs[op]; |
| return def->flags & TCG_OPF_64BIT ? 64 : 32; |
| } |
| |
| static int op_to_movi(int op) |
| { |
| switch (op_bits(op)) { |
| case 32: |
| return INDEX_op_movi_i32; |
| case 64: |
| return INDEX_op_movi_i64; |
| default: |
| fprintf(stderr, "op_to_movi: unexpected return value of " |
| "function op_bits.\n"); |
| tcg_abort(); |
| } |
| } |
| |
| static void tcg_opt_gen_mov(TCGContext *s, TCGArg *gen_args, TCGArg dst, |
| TCGArg src, int nb_temps, int nb_globals) |
| { |
| reset_temp(dst, nb_temps, nb_globals); |
| assert(temps[src].state != TCG_TEMP_COPY); |
| /* Don't try to copy if one of temps is a global or either one |
| is local and another is register */ |
| if (src >= nb_globals && dst >= nb_globals && |
| tcg_arg_is_local(s, src) == tcg_arg_is_local(s, dst)) { |
| assert(temps[src].state != TCG_TEMP_CONST); |
| if (temps[src].state != TCG_TEMP_HAS_COPY) { |
| temps[src].state = TCG_TEMP_HAS_COPY; |
| temps[src].next_copy = src; |
| temps[src].prev_copy = src; |
| } |
| temps[dst].state = TCG_TEMP_COPY; |
| temps[dst].val = src; |
| temps[dst].next_copy = temps[src].next_copy; |
| temps[dst].prev_copy = src; |
| temps[temps[dst].next_copy].prev_copy = dst; |
| temps[src].next_copy = dst; |
| } |
| gen_args[0] = dst; |
| gen_args[1] = src; |
| } |
| |
| static void tcg_opt_gen_movi(TCGArg *gen_args, TCGArg dst, TCGArg val, |
| int nb_temps, int nb_globals) |
| { |
| reset_temp(dst, nb_temps, nb_globals); |
| temps[dst].state = TCG_TEMP_CONST; |
| temps[dst].val = val; |
| gen_args[0] = dst; |
| gen_args[1] = val; |
| } |
| |
| static int op_to_mov(int op) |
| { |
| switch (op_bits(op)) { |
| case 32: |
| return INDEX_op_mov_i32; |
| case 64: |
| return INDEX_op_mov_i64; |
| default: |
| fprintf(stderr, "op_to_mov: unexpected return value of " |
| "function op_bits.\n"); |
| tcg_abort(); |
| } |
| } |
| |
| static TCGArg do_constant_folding_2(int op, TCGArg x, TCGArg y) |
| { |
| switch (op) { |
| CASE_OP_32_64(add): |
| return x + y; |
| |
| CASE_OP_32_64(sub): |
| return x - y; |
| |
| CASE_OP_32_64(mul): |
| return x * y; |
| |
| CASE_OP_32_64(and): |
| return x & y; |
| |
| CASE_OP_32_64(or): |
| return x | y; |
| |
| CASE_OP_32_64(xor): |
| return x ^ y; |
| |
| case INDEX_op_shl_i32: |
| return (uint32_t)x << (uint32_t)y; |
| |
| case INDEX_op_shl_i64: |
| return (uint64_t)x << (uint64_t)y; |
| |
| case INDEX_op_shr_i32: |
| return (uint32_t)x >> (uint32_t)y; |
| |
| case INDEX_op_shr_i64: |
| return (uint64_t)x >> (uint64_t)y; |
| |
| case INDEX_op_sar_i32: |
| return (int32_t)x >> (int32_t)y; |
| |
| case INDEX_op_sar_i64: |
| return (int64_t)x >> (int64_t)y; |
| |
| case INDEX_op_rotr_i32: |
| x = ((uint32_t)x << (32 - y)) | ((uint32_t)x >> y); |
| return x; |
| |
| case INDEX_op_rotr_i64: |
| x = ((uint64_t)x << (64 - y)) | ((uint64_t)x >> y); |
| return x; |
| |
| case INDEX_op_rotl_i32: |
| x = ((uint32_t)x << y) | ((uint32_t)x >> (32 - y)); |
| return x; |
| |
| case INDEX_op_rotl_i64: |
| x = ((uint64_t)x << y) | ((uint64_t)x >> (64 - y)); |
| return x; |
| |
| CASE_OP_32_64(not): |
| return ~x; |
| |
| CASE_OP_32_64(neg): |
| return -x; |
| |
| CASE_OP_32_64(andc): |
| return x & ~y; |
| |
| CASE_OP_32_64(orc): |
| return x | ~y; |
| |
| CASE_OP_32_64(eqv): |
| return ~(x ^ y); |
| |
| CASE_OP_32_64(nand): |
| return ~(x & y); |
| |
| CASE_OP_32_64(nor): |
| return ~(x | y); |
| |
| CASE_OP_32_64(ext8s): |
| return (int8_t)x; |
| |
| CASE_OP_32_64(ext16s): |
| return (int16_t)x; |
| |
| CASE_OP_32_64(ext8u): |
| return (uint8_t)x; |
| |
| CASE_OP_32_64(ext16u): |
| return (uint16_t)x; |
| |
| case INDEX_op_ext32s_i64: |
| return (int32_t)x; |
| |
| case INDEX_op_ext32u_i64: |
| return (uint32_t)x; |
| |
| default: |
| fprintf(stderr, |
| "Unrecognized operation %d in do_constant_folding.\n", op); |
| tcg_abort(); |
| } |
| } |
| |
| static TCGArg do_constant_folding(int op, TCGArg x, TCGArg y) |
| { |
| TCGArg res = do_constant_folding_2(op, x, y); |
| if (op_bits(op) == 32) { |
| res &= 0xffffffff; |
| } |
| return res; |
| } |
| |
| /* Propagate constants and copies, fold constant expressions. */ |
| static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr, |
| TCGArg *args, TCGOpDef *tcg_op_defs) |
| { |
| int i, nb_ops, op_index, op, nb_temps, nb_globals, nb_call_args; |
| const TCGOpDef *def; |
| TCGArg *gen_args; |
| TCGArg tmp; |
| /* Array VALS has an element for each temp. |
| If this temp holds a constant then its value is kept in VALS' element. |
| If this temp is a copy of other ones then this equivalence class' |
| representative is kept in VALS' element. |
| If this temp is neither copy nor constant then corresponding VALS' |
| element is unused. */ |
| |
| nb_temps = s->nb_temps; |
| nb_globals = s->nb_globals; |
| memset(temps, 0, nb_temps * sizeof(struct tcg_temp_info)); |
| |
| nb_ops = tcg_opc_ptr - gen_opc_buf; |
| gen_args = args; |
| for (op_index = 0; op_index < nb_ops; op_index++) { |
| op = gen_opc_buf[op_index]; |
| def = &tcg_op_defs[op]; |
| /* Do copy propagation */ |
| if (!(def->flags & (TCG_OPF_CALL_CLOBBER | TCG_OPF_SIDE_EFFECTS))) { |
| assert(op != INDEX_op_call); |
| for (i = def->nb_oargs; i < def->nb_oargs + def->nb_iargs; i++) { |
| if (temps[args[i]].state == TCG_TEMP_COPY) { |
| args[i] = temps[args[i]].val; |
| } |
| } |
| } |
| |
| /* For commutative operations make constant second argument */ |
| switch (op) { |
| CASE_OP_32_64(add): |
| CASE_OP_32_64(mul): |
| CASE_OP_32_64(and): |
| CASE_OP_32_64(or): |
| CASE_OP_32_64(xor): |
| CASE_OP_32_64(eqv): |
| CASE_OP_32_64(nand): |
| CASE_OP_32_64(nor): |
| if (temps[args[1]].state == TCG_TEMP_CONST) { |
| tmp = args[1]; |
| args[1] = args[2]; |
| args[2] = tmp; |
| } |
| break; |
| default: |
| break; |
| } |
| |
| /* Simplify expression if possible. */ |
| switch (op) { |
| CASE_OP_32_64(add): |
| CASE_OP_32_64(sub): |
| CASE_OP_32_64(shl): |
| CASE_OP_32_64(shr): |
| CASE_OP_32_64(sar): |
| CASE_OP_32_64(rotl): |
| CASE_OP_32_64(rotr): |
| if (temps[args[1]].state == TCG_TEMP_CONST) { |
| /* Proceed with possible constant folding. */ |
| break; |
| } |
| if (temps[args[2]].state == TCG_TEMP_CONST |
| && temps[args[2]].val == 0) { |
| if ((temps[args[0]].state == TCG_TEMP_COPY |
| && temps[args[0]].val == args[1]) |
| || args[0] == args[1]) { |
| args += 3; |
| gen_opc_buf[op_index] = INDEX_op_nop; |
| } else { |
| gen_opc_buf[op_index] = op_to_mov(op); |
| tcg_opt_gen_mov(s, gen_args, args[0], args[1], |
| nb_temps, nb_globals); |
| gen_args += 2; |
| args += 3; |
| } |
| continue; |
| } |
| break; |
| CASE_OP_32_64(mul): |
| if ((temps[args[2]].state == TCG_TEMP_CONST |
| && temps[args[2]].val == 0)) { |
| gen_opc_buf[op_index] = op_to_movi(op); |
| tcg_opt_gen_movi(gen_args, args[0], 0, nb_temps, nb_globals); |
| args += 3; |
| gen_args += 2; |
| continue; |
| } |
| break; |
| CASE_OP_32_64(or): |
| CASE_OP_32_64(and): |
| if (args[1] == args[2]) { |
| if (args[1] == args[0]) { |
| args += 3; |
| gen_opc_buf[op_index] = INDEX_op_nop; |
| } else { |
| gen_opc_buf[op_index] = op_to_mov(op); |
| tcg_opt_gen_mov(s, gen_args, args[0], args[1], nb_temps, |
| nb_globals); |
| gen_args += 2; |
| args += 3; |
| } |
| continue; |
| } |
| break; |
| } |
| |
| /* Propagate constants through copy operations and do constant |
| folding. Constants will be substituted to arguments by register |
| allocator where needed and possible. Also detect copies. */ |
| switch (op) { |
| CASE_OP_32_64(mov): |
| if ((temps[args[1]].state == TCG_TEMP_COPY |
| && temps[args[1]].val == args[0]) |
| || args[0] == args[1]) { |
| args += 2; |
| gen_opc_buf[op_index] = INDEX_op_nop; |
| break; |
| } |
| if (temps[args[1]].state != TCG_TEMP_CONST) { |
| tcg_opt_gen_mov(s, gen_args, args[0], args[1], |
| nb_temps, nb_globals); |
| gen_args += 2; |
| args += 2; |
| break; |
| } |
| /* Source argument is constant. Rewrite the operation and |
| let movi case handle it. */ |
| op = op_to_movi(op); |
| gen_opc_buf[op_index] = op; |
| args[1] = temps[args[1]].val; |
| /* fallthrough */ |
| CASE_OP_32_64(movi): |
| tcg_opt_gen_movi(gen_args, args[0], args[1], nb_temps, nb_globals); |
| gen_args += 2; |
| args += 2; |
| break; |
| CASE_OP_32_64(not): |
| CASE_OP_32_64(neg): |
| CASE_OP_32_64(ext8s): |
| CASE_OP_32_64(ext8u): |
| CASE_OP_32_64(ext16s): |
| CASE_OP_32_64(ext16u): |
| case INDEX_op_ext32s_i64: |
| case INDEX_op_ext32u_i64: |
| if (temps[args[1]].state == TCG_TEMP_CONST) { |
| gen_opc_buf[op_index] = op_to_movi(op); |
| tmp = do_constant_folding(op, temps[args[1]].val, 0); |
| tcg_opt_gen_movi(gen_args, args[0], tmp, nb_temps, nb_globals); |
| gen_args += 2; |
| args += 2; |
| break; |
| } else { |
| reset_temp(args[0], nb_temps, nb_globals); |
| gen_args[0] = args[0]; |
| gen_args[1] = args[1]; |
| gen_args += 2; |
| args += 2; |
| break; |
| } |
| CASE_OP_32_64(add): |
| CASE_OP_32_64(sub): |
| CASE_OP_32_64(mul): |
| CASE_OP_32_64(or): |
| CASE_OP_32_64(and): |
| CASE_OP_32_64(xor): |
| CASE_OP_32_64(shl): |
| CASE_OP_32_64(shr): |
| CASE_OP_32_64(sar): |
| CASE_OP_32_64(rotl): |
| CASE_OP_32_64(rotr): |
| CASE_OP_32_64(andc): |
| CASE_OP_32_64(orc): |
| CASE_OP_32_64(eqv): |
| CASE_OP_32_64(nand): |
| CASE_OP_32_64(nor): |
| if (temps[args[1]].state == TCG_TEMP_CONST |
| && temps[args[2]].state == TCG_TEMP_CONST) { |
| gen_opc_buf[op_index] = op_to_movi(op); |
| tmp = do_constant_folding(op, temps[args[1]].val, |
| temps[args[2]].val); |
| tcg_opt_gen_movi(gen_args, args[0], tmp, nb_temps, nb_globals); |
| gen_args += 2; |
| args += 3; |
| break; |
| } else { |
| reset_temp(args[0], nb_temps, nb_globals); |
| gen_args[0] = args[0]; |
| gen_args[1] = args[1]; |
| gen_args[2] = args[2]; |
| gen_args += 3; |
| args += 3; |
| break; |
| } |
| case INDEX_op_call: |
| nb_call_args = (args[0] >> 16) + (args[0] & 0xffff); |
| if (!(args[nb_call_args + 1] & (TCG_CALL_CONST | TCG_CALL_PURE))) { |
| for (i = 0; i < nb_globals; i++) { |
| reset_temp(i, nb_temps, nb_globals); |
| } |
| } |
| for (i = 0; i < (args[0] >> 16); i++) { |
| reset_temp(args[i + 1], nb_temps, nb_globals); |
| } |
| i = nb_call_args + 3; |
| while (i) { |
| *gen_args = *args; |
| args++; |
| gen_args++; |
| i--; |
| } |
| break; |
| case INDEX_op_set_label: |
| case INDEX_op_jmp: |
| case INDEX_op_br: |
| CASE_OP_32_64(brcond): |
| memset(temps, 0, nb_temps * sizeof(struct tcg_temp_info)); |
| for (i = 0; i < def->nb_args; i++) { |
| *gen_args = *args; |
| args++; |
| gen_args++; |
| } |
| break; |
| default: |
| /* Default case: we do know nothing about operation so no |
| propagation is done. We only trash output args. */ |
| for (i = 0; i < def->nb_oargs; i++) { |
| reset_temp(args[i], nb_temps, nb_globals); |
| } |
| for (i = 0; i < def->nb_args; i++) { |
| gen_args[i] = args[i]; |
| } |
| args += def->nb_args; |
| gen_args += def->nb_args; |
| break; |
| } |
| } |
| |
| return gen_args; |
| } |
| |
| TCGArg *tcg_optimize(TCGContext *s, uint16_t *tcg_opc_ptr, |
| TCGArg *args, TCGOpDef *tcg_op_defs) |
| { |
| TCGArg *res; |
| res = tcg_constant_folding(s, tcg_opc_ptr, args, tcg_op_defs); |
| return res; |
| } |
