| /* |
| * 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 "qemu/osdep.h" |
| #include "qemu-common.h" |
| #include "exec/cpu-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) |
| |
| struct tcg_temp_info { |
| bool is_const; |
| uint16_t prev_copy; |
| uint16_t next_copy; |
| tcg_target_ulong val; |
| tcg_target_ulong mask; |
| }; |
| |
| static struct tcg_temp_info temps[TCG_MAX_TEMPS]; |
| static TCGTempSet temps_used; |
| |
| static inline bool temp_is_const(TCGArg arg) |
| { |
| return temps[arg].is_const; |
| } |
| |
| static inline bool temp_is_copy(TCGArg arg) |
| { |
| return temps[arg].next_copy != arg; |
| } |
| |
| /* Reset TEMP's state, possibly removing the temp for the list of copies. */ |
| static void reset_temp(TCGArg temp) |
| { |
| temps[temps[temp].next_copy].prev_copy = temps[temp].prev_copy; |
| temps[temps[temp].prev_copy].next_copy = temps[temp].next_copy; |
| temps[temp].next_copy = temp; |
| temps[temp].prev_copy = temp; |
| temps[temp].is_const = false; |
| temps[temp].mask = -1; |
| } |
| |
| /* Reset all temporaries, given that there are NB_TEMPS of them. */ |
| static void reset_all_temps(int nb_temps) |
| { |
| bitmap_zero(temps_used.l, nb_temps); |
| } |
| |
| /* Initialize and activate a temporary. */ |
| static void init_temp_info(TCGArg temp) |
| { |
| if (!test_bit(temp, temps_used.l)) { |
| temps[temp].next_copy = temp; |
| temps[temp].prev_copy = temp; |
| temps[temp].is_const = false; |
| temps[temp].mask = -1; |
| set_bit(temp, temps_used.l); |
| } |
| } |
| |
| static int op_bits(TCGOpcode op) |
| { |
| const TCGOpDef *def = &tcg_op_defs[op]; |
| return def->flags & TCG_OPF_64BIT ? 64 : 32; |
| } |
| |
| static TCGOpcode op_to_mov(TCGOpcode 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 TCGOpcode op_to_movi(TCGOpcode 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 TCGArg find_better_copy(TCGContext *s, TCGArg temp) |
| { |
| TCGArg i; |
| |
| /* If this is already a global, we can't do better. */ |
| if (temp < s->nb_globals) { |
| return temp; |
| } |
| |
| /* Search for a global first. */ |
| for (i = temps[temp].next_copy ; i != temp ; i = temps[i].next_copy) { |
| if (i < s->nb_globals) { |
| return i; |
| } |
| } |
| |
| /* If it is a temp, search for a temp local. */ |
| if (!s->temps[temp].temp_local) { |
| for (i = temps[temp].next_copy ; i != temp ; i = temps[i].next_copy) { |
| if (s->temps[i].temp_local) { |
| return i; |
| } |
| } |
| } |
| |
| /* Failure to find a better representation, return the same temp. */ |
| return temp; |
| } |
| |
| static bool temps_are_copies(TCGArg arg1, TCGArg arg2) |
| { |
| TCGArg i; |
| |
| if (arg1 == arg2) { |
| return true; |
| } |
| |
| if (!temp_is_copy(arg1) || !temp_is_copy(arg2)) { |
| return false; |
| } |
| |
| for (i = temps[arg1].next_copy ; i != arg1 ; i = temps[i].next_copy) { |
| if (i == arg2) { |
| return true; |
| } |
| } |
| |
| return false; |
| } |
| |
| static void tcg_opt_gen_movi(TCGContext *s, TCGOp *op, TCGArg *args, |
| TCGArg dst, TCGArg val) |
| { |
| TCGOpcode new_op = op_to_movi(op->opc); |
| tcg_target_ulong mask; |
| |
| op->opc = new_op; |
| |
| reset_temp(dst); |
| temps[dst].is_const = true; |
| temps[dst].val = val; |
| mask = val; |
| if (TCG_TARGET_REG_BITS > 32 && new_op == INDEX_op_movi_i32) { |
| /* High bits of the destination are now garbage. */ |
| mask |= ~0xffffffffull; |
| } |
| temps[dst].mask = mask; |
| |
| args[0] = dst; |
| args[1] = val; |
| } |
| |
| static void tcg_opt_gen_mov(TCGContext *s, TCGOp *op, TCGArg *args, |
| TCGArg dst, TCGArg src) |
| { |
| if (temps_are_copies(dst, src)) { |
| tcg_op_remove(s, op); |
| return; |
| } |
| |
| TCGOpcode new_op = op_to_mov(op->opc); |
| tcg_target_ulong mask; |
| |
| op->opc = new_op; |
| |
| reset_temp(dst); |
| mask = temps[src].mask; |
| if (TCG_TARGET_REG_BITS > 32 && new_op == INDEX_op_mov_i32) { |
| /* High bits of the destination are now garbage. */ |
| mask |= ~0xffffffffull; |
| } |
| temps[dst].mask = mask; |
| |
| if (s->temps[src].type == s->temps[dst].type) { |
| 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; |
| temps[dst].is_const = temps[src].is_const; |
| temps[dst].val = temps[src].val; |
| } |
| |
| args[0] = dst; |
| args[1] = src; |
| } |
| |
| static TCGArg do_constant_folding_2(TCGOpcode op, TCGArg x, TCGArg y) |
| { |
| uint64_t l64, h64; |
| |
| 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 << (y & 31); |
| |
| case INDEX_op_shl_i64: |
| return (uint64_t)x << (y & 63); |
| |
| case INDEX_op_shr_i32: |
| return (uint32_t)x >> (y & 31); |
| |
| case INDEX_op_shr_i64: |
| return (uint64_t)x >> (y & 63); |
| |
| case INDEX_op_sar_i32: |
| return (int32_t)x >> (y & 31); |
| |
| case INDEX_op_sar_i64: |
| return (int64_t)x >> (y & 63); |
| |
| case INDEX_op_rotr_i32: |
| return ror32(x, y & 31); |
| |
| case INDEX_op_rotr_i64: |
| return ror64(x, y & 63); |
| |
| case INDEX_op_rotl_i32: |
| return rol32(x, y & 31); |
| |
| case INDEX_op_rotl_i64: |
| return rol64(x, y & 63); |
| |
| 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_ext_i32_i64: |
| case INDEX_op_ext32s_i64: |
| return (int32_t)x; |
| |
| case INDEX_op_extu_i32_i64: |
| case INDEX_op_extrl_i64_i32: |
| case INDEX_op_ext32u_i64: |
| return (uint32_t)x; |
| |
| case INDEX_op_extrh_i64_i32: |
| return (uint64_t)x >> 32; |
| |
| case INDEX_op_muluh_i32: |
| return ((uint64_t)(uint32_t)x * (uint32_t)y) >> 32; |
| case INDEX_op_mulsh_i32: |
| return ((int64_t)(int32_t)x * (int32_t)y) >> 32; |
| |
| case INDEX_op_muluh_i64: |
| mulu64(&l64, &h64, x, y); |
| return h64; |
| case INDEX_op_mulsh_i64: |
| muls64(&l64, &h64, x, y); |
| return h64; |
| |
| case INDEX_op_div_i32: |
| /* Avoid crashing on divide by zero, otherwise undefined. */ |
| return (int32_t)x / ((int32_t)y ? : 1); |
| case INDEX_op_divu_i32: |
| return (uint32_t)x / ((uint32_t)y ? : 1); |
| case INDEX_op_div_i64: |
| return (int64_t)x / ((int64_t)y ? : 1); |
| case INDEX_op_divu_i64: |
| return (uint64_t)x / ((uint64_t)y ? : 1); |
| |
| case INDEX_op_rem_i32: |
| return (int32_t)x % ((int32_t)y ? : 1); |
| case INDEX_op_remu_i32: |
| return (uint32_t)x % ((uint32_t)y ? : 1); |
| case INDEX_op_rem_i64: |
| return (int64_t)x % ((int64_t)y ? : 1); |
| case INDEX_op_remu_i64: |
| return (uint64_t)x % ((uint64_t)y ? : 1); |
| |
| default: |
| fprintf(stderr, |
| "Unrecognized operation %d in do_constant_folding.\n", op); |
| tcg_abort(); |
| } |
| } |
| |
| static TCGArg do_constant_folding(TCGOpcode op, TCGArg x, TCGArg y) |
| { |
| TCGArg res = do_constant_folding_2(op, x, y); |
| if (op_bits(op) == 32) { |
| res = (int32_t)res; |
| } |
| return res; |
| } |
| |
| static bool do_constant_folding_cond_32(uint32_t x, uint32_t y, TCGCond c) |
| { |
| switch (c) { |
| case TCG_COND_EQ: |
| return x == y; |
| case TCG_COND_NE: |
| return x != y; |
| case TCG_COND_LT: |
| return (int32_t)x < (int32_t)y; |
| case TCG_COND_GE: |
| return (int32_t)x >= (int32_t)y; |
| case TCG_COND_LE: |
| return (int32_t)x <= (int32_t)y; |
| case TCG_COND_GT: |
| return (int32_t)x > (int32_t)y; |
| case TCG_COND_LTU: |
| return x < y; |
| case TCG_COND_GEU: |
| return x >= y; |
| case TCG_COND_LEU: |
| return x <= y; |
| case TCG_COND_GTU: |
| return x > y; |
| default: |
| tcg_abort(); |
| } |
| } |
| |
| static bool do_constant_folding_cond_64(uint64_t x, uint64_t y, TCGCond c) |
| { |
| switch (c) { |
| case TCG_COND_EQ: |
| return x == y; |
| case TCG_COND_NE: |
| return x != y; |
| case TCG_COND_LT: |
| return (int64_t)x < (int64_t)y; |
| case TCG_COND_GE: |
| return (int64_t)x >= (int64_t)y; |
| case TCG_COND_LE: |
| return (int64_t)x <= (int64_t)y; |
| case TCG_COND_GT: |
| return (int64_t)x > (int64_t)y; |
| case TCG_COND_LTU: |
| return x < y; |
| case TCG_COND_GEU: |
| return x >= y; |
| case TCG_COND_LEU: |
| return x <= y; |
| case TCG_COND_GTU: |
| return x > y; |
| default: |
| tcg_abort(); |
| } |
| } |
| |
| static bool do_constant_folding_cond_eq(TCGCond c) |
| { |
| switch (c) { |
| case TCG_COND_GT: |
| case TCG_COND_LTU: |
| case TCG_COND_LT: |
| case TCG_COND_GTU: |
| case TCG_COND_NE: |
| return 0; |
| case TCG_COND_GE: |
| case TCG_COND_GEU: |
| case TCG_COND_LE: |
| case TCG_COND_LEU: |
| case TCG_COND_EQ: |
| return 1; |
| default: |
| tcg_abort(); |
| } |
| } |
| |
| /* Return 2 if the condition can't be simplified, and the result |
| of the condition (0 or 1) if it can */ |
| static TCGArg do_constant_folding_cond(TCGOpcode op, TCGArg x, |
| TCGArg y, TCGCond c) |
| { |
| if (temp_is_const(x) && temp_is_const(y)) { |
| switch (op_bits(op)) { |
| case 32: |
| return do_constant_folding_cond_32(temps[x].val, temps[y].val, c); |
| case 64: |
| return do_constant_folding_cond_64(temps[x].val, temps[y].val, c); |
| default: |
| tcg_abort(); |
| } |
| } else if (temps_are_copies(x, y)) { |
| return do_constant_folding_cond_eq(c); |
| } else if (temp_is_const(y) && temps[y].val == 0) { |
| switch (c) { |
| case TCG_COND_LTU: |
| return 0; |
| case TCG_COND_GEU: |
| return 1; |
| default: |
| return 2; |
| } |
| } |
| return 2; |
| } |
| |
| /* Return 2 if the condition can't be simplified, and the result |
| of the condition (0 or 1) if it can */ |
| static TCGArg do_constant_folding_cond2(TCGArg *p1, TCGArg *p2, TCGCond c) |
| { |
| TCGArg al = p1[0], ah = p1[1]; |
| TCGArg bl = p2[0], bh = p2[1]; |
| |
| if (temp_is_const(bl) && temp_is_const(bh)) { |
| uint64_t b = ((uint64_t)temps[bh].val << 32) | (uint32_t)temps[bl].val; |
| |
| if (temp_is_const(al) && temp_is_const(ah)) { |
| uint64_t a; |
| a = ((uint64_t)temps[ah].val << 32) | (uint32_t)temps[al].val; |
| return do_constant_folding_cond_64(a, b, c); |
| } |
| if (b == 0) { |
| switch (c) { |
| case TCG_COND_LTU: |
| return 0; |
| case TCG_COND_GEU: |
| return 1; |
| default: |
| break; |
| } |
| } |
| } |
| if (temps_are_copies(al, bl) && temps_are_copies(ah, bh)) { |
| return do_constant_folding_cond_eq(c); |
| } |
| return 2; |
| } |
| |
| static bool swap_commutative(TCGArg dest, TCGArg *p1, TCGArg *p2) |
| { |
| TCGArg a1 = *p1, a2 = *p2; |
| int sum = 0; |
| sum += temp_is_const(a1); |
| sum -= temp_is_const(a2); |
| |
| /* Prefer the constant in second argument, and then the form |
| op a, a, b, which is better handled on non-RISC hosts. */ |
| if (sum > 0 || (sum == 0 && dest == a2)) { |
| *p1 = a2; |
| *p2 = a1; |
| return true; |
| } |
| return false; |
| } |
| |
| static bool swap_commutative2(TCGArg *p1, TCGArg *p2) |
| { |
| int sum = 0; |
| sum += temp_is_const(p1[0]); |
| sum += temp_is_const(p1[1]); |
| sum -= temp_is_const(p2[0]); |
| sum -= temp_is_const(p2[1]); |
| if (sum > 0) { |
| TCGArg t; |
| t = p1[0], p1[0] = p2[0], p2[0] = t; |
| t = p1[1], p1[1] = p2[1], p2[1] = t; |
| return true; |
| } |
| return false; |
| } |
| |
| /* Propagate constants and copies, fold constant expressions. */ |
| void tcg_optimize(TCGContext *s) |
| { |
| int oi, oi_next, nb_temps, nb_globals; |
| TCGArg *prev_mb_args = NULL; |
| |
| /* 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 the other copies are |
| available through the doubly linked circular list. */ |
| |
| nb_temps = s->nb_temps; |
| nb_globals = s->nb_globals; |
| reset_all_temps(nb_temps); |
| |
| for (oi = s->gen_op_buf[0].next; oi != 0; oi = oi_next) { |
| tcg_target_ulong mask, partmask, affected; |
| int nb_oargs, nb_iargs, i; |
| TCGArg tmp; |
| |
| TCGOp * const op = &s->gen_op_buf[oi]; |
| TCGArg * const args = &s->gen_opparam_buf[op->args]; |
| TCGOpcode opc = op->opc; |
| const TCGOpDef *def = &tcg_op_defs[opc]; |
| |
| oi_next = op->next; |
| |
| /* Count the arguments, and initialize the temps that are |
| going to be used */ |
| if (opc == INDEX_op_call) { |
| nb_oargs = op->callo; |
| nb_iargs = op->calli; |
| for (i = 0; i < nb_oargs + nb_iargs; i++) { |
| tmp = args[i]; |
| if (tmp != TCG_CALL_DUMMY_ARG) { |
| init_temp_info(tmp); |
| } |
| } |
| } else { |
| nb_oargs = def->nb_oargs; |
| nb_iargs = def->nb_iargs; |
| for (i = 0; i < nb_oargs + nb_iargs; i++) { |
| init_temp_info(args[i]); |
| } |
| } |
| |
| /* Do copy propagation */ |
| for (i = nb_oargs; i < nb_oargs + nb_iargs; i++) { |
| if (temp_is_copy(args[i])) { |
| args[i] = find_better_copy(s, args[i]); |
| } |
| } |
| |
| /* For commutative operations make constant second argument */ |
| switch (opc) { |
| 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): |
| CASE_OP_32_64(muluh): |
| CASE_OP_32_64(mulsh): |
| swap_commutative(args[0], &args[1], &args[2]); |
| break; |
| CASE_OP_32_64(brcond): |
| if (swap_commutative(-1, &args[0], &args[1])) { |
| args[2] = tcg_swap_cond(args[2]); |
| } |
| break; |
| CASE_OP_32_64(setcond): |
| if (swap_commutative(args[0], &args[1], &args[2])) { |
| args[3] = tcg_swap_cond(args[3]); |
| } |
| break; |
| CASE_OP_32_64(movcond): |
| if (swap_commutative(-1, &args[1], &args[2])) { |
| args[5] = tcg_swap_cond(args[5]); |
| } |
| /* For movcond, we canonicalize the "false" input reg to match |
| the destination reg so that the tcg backend can implement |
| a "move if true" operation. */ |
| if (swap_commutative(args[0], &args[4], &args[3])) { |
| args[5] = tcg_invert_cond(args[5]); |
| } |
| break; |
| CASE_OP_32_64(add2): |
| swap_commutative(args[0], &args[2], &args[4]); |
| swap_commutative(args[1], &args[3], &args[5]); |
| break; |
| CASE_OP_32_64(mulu2): |
| CASE_OP_32_64(muls2): |
| swap_commutative(args[0], &args[2], &args[3]); |
| break; |
| case INDEX_op_brcond2_i32: |
| if (swap_commutative2(&args[0], &args[2])) { |
| args[4] = tcg_swap_cond(args[4]); |
| } |
| break; |
| case INDEX_op_setcond2_i32: |
| if (swap_commutative2(&args[1], &args[3])) { |
| args[5] = tcg_swap_cond(args[5]); |
| } |
| break; |
| default: |
| break; |
| } |
| |
| /* Simplify expressions for "shift/rot r, 0, a => movi r, 0", |
| and "sub r, 0, a => neg r, a" case. */ |
| switch (opc) { |
| 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 (temp_is_const(args[1]) && temps[args[1]].val == 0) { |
| tcg_opt_gen_movi(s, op, args, args[0], 0); |
| continue; |
| } |
| break; |
| CASE_OP_32_64(sub): |
| { |
| TCGOpcode neg_op; |
| bool have_neg; |
| |
| if (temp_is_const(args[2])) { |
| /* Proceed with possible constant folding. */ |
| break; |
| } |
| if (opc == INDEX_op_sub_i32) { |
| neg_op = INDEX_op_neg_i32; |
| have_neg = TCG_TARGET_HAS_neg_i32; |
| } else { |
| neg_op = INDEX_op_neg_i64; |
| have_neg = TCG_TARGET_HAS_neg_i64; |
| } |
| if (!have_neg) { |
| break; |
| } |
| if (temp_is_const(args[1]) && temps[args[1]].val == 0) { |
| op->opc = neg_op; |
| reset_temp(args[0]); |
| args[1] = args[2]; |
| continue; |
| } |
| } |
| break; |
| CASE_OP_32_64(xor): |
| CASE_OP_32_64(nand): |
| if (!temp_is_const(args[1]) |
| && temp_is_const(args[2]) && temps[args[2]].val == -1) { |
| i = 1; |
| goto try_not; |
| } |
| break; |
| CASE_OP_32_64(nor): |
| if (!temp_is_const(args[1]) |
| && temp_is_const(args[2]) && temps[args[2]].val == 0) { |
| i = 1; |
| goto try_not; |
| } |
| break; |
| CASE_OP_32_64(andc): |
| if (!temp_is_const(args[2]) |
| && temp_is_const(args[1]) && temps[args[1]].val == -1) { |
| i = 2; |
| goto try_not; |
| } |
| break; |
| CASE_OP_32_64(orc): |
| CASE_OP_32_64(eqv): |
| if (!temp_is_const(args[2]) |
| && temp_is_const(args[1]) && temps[args[1]].val == 0) { |
| i = 2; |
| goto try_not; |
| } |
| break; |
| try_not: |
| { |
| TCGOpcode not_op; |
| bool have_not; |
| |
| if (def->flags & TCG_OPF_64BIT) { |
| not_op = INDEX_op_not_i64; |
| have_not = TCG_TARGET_HAS_not_i64; |
| } else { |
| not_op = INDEX_op_not_i32; |
| have_not = TCG_TARGET_HAS_not_i32; |
| } |
| if (!have_not) { |
| break; |
| } |
| op->opc = not_op; |
| reset_temp(args[0]); |
| args[1] = args[i]; |
| continue; |
| } |
| default: |
| break; |
| } |
| |
| /* Simplify expression for "op r, a, const => mov r, a" cases */ |
| switch (opc) { |
| 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): |
| CASE_OP_32_64(or): |
| CASE_OP_32_64(xor): |
| CASE_OP_32_64(andc): |
| if (!temp_is_const(args[1]) |
| && temp_is_const(args[2]) && temps[args[2]].val == 0) { |
| tcg_opt_gen_mov(s, op, args, args[0], args[1]); |
| continue; |
| } |
| break; |
| CASE_OP_32_64(and): |
| CASE_OP_32_64(orc): |
| CASE_OP_32_64(eqv): |
| if (!temp_is_const(args[1]) |
| && temp_is_const(args[2]) && temps[args[2]].val == -1) { |
| tcg_opt_gen_mov(s, op, args, args[0], args[1]); |
| continue; |
| } |
| break; |
| default: |
| break; |
| } |
| |
| /* Simplify using known-zero bits. Currently only ops with a single |
| output argument is supported. */ |
| mask = -1; |
| affected = -1; |
| switch (opc) { |
| CASE_OP_32_64(ext8s): |
| if ((temps[args[1]].mask & 0x80) != 0) { |
| break; |
| } |
| CASE_OP_32_64(ext8u): |
| mask = 0xff; |
| goto and_const; |
| CASE_OP_32_64(ext16s): |
| if ((temps[args[1]].mask & 0x8000) != 0) { |
| break; |
| } |
| CASE_OP_32_64(ext16u): |
| mask = 0xffff; |
| goto and_const; |
| case INDEX_op_ext32s_i64: |
| if ((temps[args[1]].mask & 0x80000000) != 0) { |
| break; |
| } |
| case INDEX_op_ext32u_i64: |
| mask = 0xffffffffU; |
| goto and_const; |
| |
| CASE_OP_32_64(and): |
| mask = temps[args[2]].mask; |
| if (temp_is_const(args[2])) { |
| and_const: |
| affected = temps[args[1]].mask & ~mask; |
| } |
| mask = temps[args[1]].mask & mask; |
| break; |
| |
| case INDEX_op_ext_i32_i64: |
| if ((temps[args[1]].mask & 0x80000000) != 0) { |
| break; |
| } |
| case INDEX_op_extu_i32_i64: |
| /* We do not compute affected as it is a size changing op. */ |
| mask = (uint32_t)temps[args[1]].mask; |
| break; |
| |
| CASE_OP_32_64(andc): |
| /* Known-zeros does not imply known-ones. Therefore unless |
| args[2] is constant, we can't infer anything from it. */ |
| if (temp_is_const(args[2])) { |
| mask = ~temps[args[2]].mask; |
| goto and_const; |
| } |
| /* But we certainly know nothing outside args[1] may be set. */ |
| mask = temps[args[1]].mask; |
| break; |
| |
| case INDEX_op_sar_i32: |
| if (temp_is_const(args[2])) { |
| tmp = temps[args[2]].val & 31; |
| mask = (int32_t)temps[args[1]].mask >> tmp; |
| } |
| break; |
| case INDEX_op_sar_i64: |
| if (temp_is_const(args[2])) { |
| tmp = temps[args[2]].val & 63; |
| mask = (int64_t)temps[args[1]].mask >> tmp; |
| } |
| break; |
| |
| case INDEX_op_shr_i32: |
| if (temp_is_const(args[2])) { |
| tmp = temps[args[2]].val & 31; |
| mask = (uint32_t)temps[args[1]].mask >> tmp; |
| } |
| break; |
| case INDEX_op_shr_i64: |
| if (temp_is_const(args[2])) { |
| tmp = temps[args[2]].val & 63; |
| mask = (uint64_t)temps[args[1]].mask >> tmp; |
| } |
| break; |
| |
| case INDEX_op_extrl_i64_i32: |
| mask = (uint32_t)temps[args[1]].mask; |
| break; |
| case INDEX_op_extrh_i64_i32: |
| mask = (uint64_t)temps[args[1]].mask >> 32; |
| break; |
| |
| CASE_OP_32_64(shl): |
| if (temp_is_const(args[2])) { |
| tmp = temps[args[2]].val & (TCG_TARGET_REG_BITS - 1); |
| mask = temps[args[1]].mask << tmp; |
| } |
| break; |
| |
| CASE_OP_32_64(neg): |
| /* Set to 1 all bits to the left of the rightmost. */ |
| mask = -(temps[args[1]].mask & -temps[args[1]].mask); |
| break; |
| |
| CASE_OP_32_64(deposit): |
| mask = deposit64(temps[args[1]].mask, args[3], args[4], |
| temps[args[2]].mask); |
| break; |
| |
| CASE_OP_32_64(or): |
| CASE_OP_32_64(xor): |
| mask = temps[args[1]].mask | temps[args[2]].mask; |
| break; |
| |
| CASE_OP_32_64(setcond): |
| case INDEX_op_setcond2_i32: |
| mask = 1; |
| break; |
| |
| CASE_OP_32_64(movcond): |
| mask = temps[args[3]].mask | temps[args[4]].mask; |
| break; |
| |
| CASE_OP_32_64(ld8u): |
| mask = 0xff; |
| break; |
| CASE_OP_32_64(ld16u): |
| mask = 0xffff; |
| break; |
| case INDEX_op_ld32u_i64: |
| mask = 0xffffffffu; |
| break; |
| |
| CASE_OP_32_64(qemu_ld): |
| { |
| TCGMemOpIdx oi = args[nb_oargs + nb_iargs]; |
| TCGMemOp mop = get_memop(oi); |
| if (!(mop & MO_SIGN)) { |
| mask = (2ULL << ((8 << (mop & MO_SIZE)) - 1)) - 1; |
| } |
| } |
| break; |
| |
| default: |
| break; |
| } |
| |
| /* 32-bit ops generate 32-bit results. For the result is zero test |
| below, we can ignore high bits, but for further optimizations we |
| need to record that the high bits contain garbage. */ |
| partmask = mask; |
| if (!(def->flags & TCG_OPF_64BIT)) { |
| mask |= ~(tcg_target_ulong)0xffffffffu; |
| partmask &= 0xffffffffu; |
| affected &= 0xffffffffu; |
| } |
| |
| if (partmask == 0) { |
| tcg_debug_assert(nb_oargs == 1); |
| tcg_opt_gen_movi(s, op, args, args[0], 0); |
| continue; |
| } |
| if (affected == 0) { |
| tcg_debug_assert(nb_oargs == 1); |
| tcg_opt_gen_mov(s, op, args, args[0], args[1]); |
| continue; |
| } |
| |
| /* Simplify expression for "op r, a, 0 => movi r, 0" cases */ |
| switch (opc) { |
| CASE_OP_32_64(and): |
| CASE_OP_32_64(mul): |
| CASE_OP_32_64(muluh): |
| CASE_OP_32_64(mulsh): |
| if ((temp_is_const(args[2]) && temps[args[2]].val == 0)) { |
| tcg_opt_gen_movi(s, op, args, args[0], 0); |
| continue; |
| } |
| break; |
| default: |
| break; |
| } |
| |
| /* Simplify expression for "op r, a, a => mov r, a" cases */ |
| switch (opc) { |
| CASE_OP_32_64(or): |
| CASE_OP_32_64(and): |
| if (temps_are_copies(args[1], args[2])) { |
| tcg_opt_gen_mov(s, op, args, args[0], args[1]); |
| continue; |
| } |
| break; |
| default: |
| break; |
| } |
| |
| /* Simplify expression for "op r, a, a => movi r, 0" cases */ |
| switch (opc) { |
| CASE_OP_32_64(andc): |
| CASE_OP_32_64(sub): |
| CASE_OP_32_64(xor): |
| if (temps_are_copies(args[1], args[2])) { |
| tcg_opt_gen_movi(s, op, args, args[0], 0); |
| continue; |
| } |
| break; |
| default: |
| 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 (opc) { |
| CASE_OP_32_64(mov): |
| tcg_opt_gen_mov(s, op, args, args[0], args[1]); |
| break; |
| CASE_OP_32_64(movi): |
| tcg_opt_gen_movi(s, op, args, args[0], args[1]); |
| 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: |
| case INDEX_op_ext_i32_i64: |
| case INDEX_op_extu_i32_i64: |
| case INDEX_op_extrl_i64_i32: |
| case INDEX_op_extrh_i64_i32: |
| if (temp_is_const(args[1])) { |
| tmp = do_constant_folding(opc, temps[args[1]].val, 0); |
| tcg_opt_gen_movi(s, op, args, args[0], tmp); |
| break; |
| } |
| goto do_default; |
| |
| 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): |
| CASE_OP_32_64(muluh): |
| CASE_OP_32_64(mulsh): |
| CASE_OP_32_64(div): |
| CASE_OP_32_64(divu): |
| CASE_OP_32_64(rem): |
| CASE_OP_32_64(remu): |
| if (temp_is_const(args[1]) && temp_is_const(args[2])) { |
| tmp = do_constant_folding(opc, temps[args[1]].val, |
| temps[args[2]].val); |
| tcg_opt_gen_movi(s, op, args, args[0], tmp); |
| break; |
| } |
| goto do_default; |
| |
| CASE_OP_32_64(deposit): |
| if (temp_is_const(args[1]) && temp_is_const(args[2])) { |
| tmp = deposit64(temps[args[1]].val, args[3], args[4], |
| temps[args[2]].val); |
| tcg_opt_gen_movi(s, op, args, args[0], tmp); |
| break; |
| } |
| goto do_default; |
| |
| CASE_OP_32_64(setcond): |
| tmp = do_constant_folding_cond(opc, args[1], args[2], args[3]); |
| if (tmp != 2) { |
| tcg_opt_gen_movi(s, op, args, args[0], tmp); |
| break; |
| } |
| goto do_default; |
| |
| CASE_OP_32_64(brcond): |
| tmp = do_constant_folding_cond(opc, args[0], args[1], args[2]); |
| if (tmp != 2) { |
| if (tmp) { |
| reset_all_temps(nb_temps); |
| op->opc = INDEX_op_br; |
| args[0] = args[3]; |
| } else { |
| tcg_op_remove(s, op); |
| } |
| break; |
| } |
| goto do_default; |
| |
| CASE_OP_32_64(movcond): |
| tmp = do_constant_folding_cond(opc, args[1], args[2], args[5]); |
| if (tmp != 2) { |
| tcg_opt_gen_mov(s, op, args, args[0], args[4-tmp]); |
| break; |
| } |
| goto do_default; |
| |
| case INDEX_op_add2_i32: |
| case INDEX_op_sub2_i32: |
| if (temp_is_const(args[2]) && temp_is_const(args[3]) |
| && temp_is_const(args[4]) && temp_is_const(args[5])) { |
| uint32_t al = temps[args[2]].val; |
| uint32_t ah = temps[args[3]].val; |
| uint32_t bl = temps[args[4]].val; |
| uint32_t bh = temps[args[5]].val; |
| uint64_t a = ((uint64_t)ah << 32) | al; |
| uint64_t b = ((uint64_t)bh << 32) | bl; |
| TCGArg rl, rh; |
| TCGOp *op2 = tcg_op_insert_before(s, op, INDEX_op_movi_i32, 2); |
| TCGArg *args2 = &s->gen_opparam_buf[op2->args]; |
| |
| if (opc == INDEX_op_add2_i32) { |
| a += b; |
| } else { |
| a -= b; |
| } |
| |
| rl = args[0]; |
| rh = args[1]; |
| tcg_opt_gen_movi(s, op, args, rl, (int32_t)a); |
| tcg_opt_gen_movi(s, op2, args2, rh, (int32_t)(a >> 32)); |
| |
| /* We've done all we need to do with the movi. Skip it. */ |
| oi_next = op2->next; |
| break; |
| } |
| goto do_default; |
| |
| case INDEX_op_mulu2_i32: |
| if (temp_is_const(args[2]) && temp_is_const(args[3])) { |
| uint32_t a = temps[args[2]].val; |
| uint32_t b = temps[args[3]].val; |
| uint64_t r = (uint64_t)a * b; |
| TCGArg rl, rh; |
| TCGOp *op2 = tcg_op_insert_before(s, op, INDEX_op_movi_i32, 2); |
| TCGArg *args2 = &s->gen_opparam_buf[op2->args]; |
| |
| rl = args[0]; |
| rh = args[1]; |
| tcg_opt_gen_movi(s, op, args, rl, (int32_t)r); |
| tcg_opt_gen_movi(s, op2, args2, rh, (int32_t)(r >> 32)); |
| |
| /* We've done all we need to do with the movi. Skip it. */ |
| oi_next = op2->next; |
| break; |
| } |
| goto do_default; |
| |
| case INDEX_op_brcond2_i32: |
| tmp = do_constant_folding_cond2(&args[0], &args[2], args[4]); |
| if (tmp != 2) { |
| if (tmp) { |
| do_brcond_true: |
| reset_all_temps(nb_temps); |
| op->opc = INDEX_op_br; |
| args[0] = args[5]; |
| } else { |
| do_brcond_false: |
| tcg_op_remove(s, op); |
| } |
| } else if ((args[4] == TCG_COND_LT || args[4] == TCG_COND_GE) |
| && temp_is_const(args[2]) && temps[args[2]].val == 0 |
| && temp_is_const(args[3]) && temps[args[3]].val == 0) { |
| /* Simplify LT/GE comparisons vs zero to a single compare |
| vs the high word of the input. */ |
| do_brcond_high: |
| reset_all_temps(nb_temps); |
| op->opc = INDEX_op_brcond_i32; |
| args[0] = args[1]; |
| args[1] = args[3]; |
| args[2] = args[4]; |
| args[3] = args[5]; |
| } else if (args[4] == TCG_COND_EQ) { |
| /* Simplify EQ comparisons where one of the pairs |
| can be simplified. */ |
| tmp = do_constant_folding_cond(INDEX_op_brcond_i32, |
| args[0], args[2], TCG_COND_EQ); |
| if (tmp == 0) { |
| goto do_brcond_false; |
| } else if (tmp == 1) { |
| goto do_brcond_high; |
| } |
| tmp = do_constant_folding_cond(INDEX_op_brcond_i32, |
| args[1], args[3], TCG_COND_EQ); |
| if (tmp == 0) { |
| goto do_brcond_false; |
| } else if (tmp != 1) { |
| goto do_default; |
| } |
| do_brcond_low: |
| reset_all_temps(nb_temps); |
| op->opc = INDEX_op_brcond_i32; |
| args[1] = args[2]; |
| args[2] = args[4]; |
| args[3] = args[5]; |
| } else if (args[4] == TCG_COND_NE) { |
| /* Simplify NE comparisons where one of the pairs |
| can be simplified. */ |
| tmp = do_constant_folding_cond(INDEX_op_brcond_i32, |
| args[0], args[2], TCG_COND_NE); |
| if (tmp == 0) { |
| goto do_brcond_high; |
| } else if (tmp == 1) { |
| goto do_brcond_true; |
| } |
| tmp = do_constant_folding_cond(INDEX_op_brcond_i32, |
| args[1], args[3], TCG_COND_NE); |
| if (tmp == 0) { |
| goto do_brcond_low; |
| } else if (tmp == 1) { |
| goto do_brcond_true; |
| } |
| goto do_default; |
| } else { |
| goto do_default; |
| } |
| break; |
| |
| case INDEX_op_setcond2_i32: |
| tmp = do_constant_folding_cond2(&args[1], &args[3], args[5]); |
| if (tmp != 2) { |
| do_setcond_const: |
| tcg_opt_gen_movi(s, op, args, args[0], tmp); |
| } else if ((args[5] == TCG_COND_LT || args[5] == TCG_COND_GE) |
| && temp_is_const(args[3]) && temps[args[3]].val == 0 |
| && temp_is_const(args[4]) && temps[args[4]].val == 0) { |
| /* Simplify LT/GE comparisons vs zero to a single compare |
| vs the high word of the input. */ |
| do_setcond_high: |
| reset_temp(args[0]); |
| temps[args[0]].mask = 1; |
| op->opc = INDEX_op_setcond_i32; |
| args[1] = args[2]; |
| args[2] = args[4]; |
| args[3] = args[5]; |
| } else if (args[5] == TCG_COND_EQ) { |
| /* Simplify EQ comparisons where one of the pairs |
| can be simplified. */ |
| tmp = do_constant_folding_cond(INDEX_op_setcond_i32, |
| args[1], args[3], TCG_COND_EQ); |
| if (tmp == 0) { |
| goto do_setcond_const; |
| } else if (tmp == 1) { |
| goto do_setcond_high; |
| } |
| tmp = do_constant_folding_cond(INDEX_op_setcond_i32, |
| args[2], args[4], TCG_COND_EQ); |
| if (tmp == 0) { |
| goto do_setcond_high; |
| } else if (tmp != 1) { |
| goto do_default; |
| } |
| do_setcond_low: |
| reset_temp(args[0]); |
| temps[args[0]].mask = 1; |
| op->opc = INDEX_op_setcond_i32; |
| args[2] = args[3]; |
| args[3] = args[5]; |
| } else if (args[5] == TCG_COND_NE) { |
| /* Simplify NE comparisons where one of the pairs |
| can be simplified. */ |
| tmp = do_constant_folding_cond(INDEX_op_setcond_i32, |
| args[1], args[3], TCG_COND_NE); |
| if (tmp == 0) { |
| goto do_setcond_high; |
| } else if (tmp == 1) { |
| goto do_setcond_const; |
| } |
| tmp = do_constant_folding_cond(INDEX_op_setcond_i32, |
| args[2], args[4], TCG_COND_NE); |
| if (tmp == 0) { |
| goto do_setcond_low; |
| } else if (tmp == 1) { |
| goto do_setcond_const; |
| } |
| goto do_default; |
| } else { |
| goto do_default; |
| } |
| break; |
| |
| case INDEX_op_call: |
| if (!(args[nb_oargs + nb_iargs + 1] |
| & (TCG_CALL_NO_READ_GLOBALS | TCG_CALL_NO_WRITE_GLOBALS))) { |
| for (i = 0; i < nb_globals; i++) { |
| if (test_bit(i, temps_used.l)) { |
| reset_temp(i); |
| } |
| } |
| } |
| goto do_reset_output; |
| |
| default: |
| do_default: |
| /* Default case: we know nothing about operation (or were unable |
| to compute the operation result) so no propagation is done. |
| We trash everything if the operation is the end of a basic |
| block, otherwise we only trash the output args. "mask" is |
| the non-zero bits mask for the first output arg. */ |
| if (def->flags & TCG_OPF_BB_END) { |
| reset_all_temps(nb_temps); |
| } else { |
| do_reset_output: |
| for (i = 0; i < nb_oargs; i++) { |
| reset_temp(args[i]); |
| /* Save the corresponding known-zero bits mask for the |
| first output argument (only one supported so far). */ |
| if (i == 0) { |
| temps[args[i]].mask = mask; |
| } |
| } |
| } |
| break; |
| } |
| |
| /* Eliminate duplicate and redundant fence instructions. */ |
| if (prev_mb_args) { |
| switch (opc) { |
| case INDEX_op_mb: |
| /* Merge two barriers of the same type into one, |
| * or a weaker barrier into a stronger one, |
| * or two weaker barriers into a stronger one. |
| * mb X; mb Y => mb X|Y |
| * mb; strl => mb; st |
| * ldaq; mb => ld; mb |
| * ldaq; strl => ld; mb; st |
| * Other combinations are also merged into a strong |
| * barrier. This is stricter than specified but for |
| * the purposes of TCG is better than not optimizing. |
| */ |
| prev_mb_args[0] |= args[0]; |
| tcg_op_remove(s, op); |
| break; |
| |
| default: |
| /* Opcodes that end the block stop the optimization. */ |
| if ((def->flags & TCG_OPF_BB_END) == 0) { |
| break; |
| } |
| /* fallthru */ |
| case INDEX_op_qemu_ld_i32: |
| case INDEX_op_qemu_ld_i64: |
| case INDEX_op_qemu_st_i32: |
| case INDEX_op_qemu_st_i64: |
| case INDEX_op_call: |
| /* Opcodes that touch guest memory stop the optimization. */ |
| prev_mb_args = NULL; |
| break; |
| } |
| } else if (opc == INDEX_op_mb) { |
| prev_mb_args = args; |
| } |
| } |
| } |
