diff options
| -rw-r--r-- | tcg/optimize.c | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/tcg/optimize.c b/tcg/optimize.c index f8afe7184..42a1bda66 100644 --- a/tcg/optimize.c +++ b/tcg/optimize.c @@ -96,9 +96,15 @@ static int op_bits(int op) { switch (op) { case INDEX_op_mov_i32: + case INDEX_op_add_i32: + case INDEX_op_sub_i32: + case INDEX_op_mul_i32: return 32; #if TCG_TARGET_REG_BITS == 64 case INDEX_op_mov_i64: + case INDEX_op_add_i64: + case INDEX_op_sub_i64: + case INDEX_op_mul_i64: return 64; #endif default: @@ -156,6 +162,52 @@ static void tcg_opt_gen_movi(TCGArg *gen_args, TCGArg dst, TCGArg val, gen_args[1] = val; } +static int op_to_mov(int op) +{ + switch (op_bits(op)) { + case 32: + return INDEX_op_mov_i32; +#if TCG_TARGET_REG_BITS == 64 + case 64: + return INDEX_op_mov_i64; +#endif + 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; + + 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 TCG_TARGET_REG_BITS == 64 + if (op_bits(op) == 32) { + res &= 0xffffffff; + } +#endif + 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) @@ -163,6 +215,7 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr, 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' @@ -189,6 +242,57 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr, } } + /* For commutative operations make constant second argument */ + switch (op) { + CASE_OP_32_64(add): + CASE_OP_32_64(mul): + 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): + 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(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; + } + /* 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. */ @@ -219,6 +323,27 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr, gen_args += 2; args += 2; break; + CASE_OP_32_64(add): + CASE_OP_32_64(sub): + CASE_OP_32_64(mul): + 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))) { |