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/*
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* Optimizations for Tiny Code Generator for QEMU
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*
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* Copyright (c) 2010 Samsung Electronics.
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* Contributed by Kirill Batuzov <batuzovk@ispras.ru>
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "config.h" |
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#include <stdlib.h> |
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#include <stdio.h> |
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#include "qemu-common.h" |
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#include "tcg-op.h" |
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#define CASE_OP_32_64(x) \
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glue(glue(case INDEX_op_, x), _i32): \
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glue(glue(case INDEX_op_, x), _i64)
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typedef enum { |
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TCG_TEMP_UNDEF = 0,
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TCG_TEMP_CONST, |
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TCG_TEMP_COPY, |
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TCG_TEMP_HAS_COPY, |
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TCG_TEMP_ANY |
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} tcg_temp_state; |
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struct tcg_temp_info {
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tcg_temp_state state; |
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uint16_t prev_copy; |
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uint16_t next_copy; |
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tcg_target_ulong val; |
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}; |
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static struct tcg_temp_info temps[TCG_MAX_TEMPS]; |
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/* Reset TEMP's state to TCG_TEMP_ANY. If TEMP was a representative of some
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class of equivalent temp's, a new representative should be chosen in this
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class. */
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static void reset_temp(TCGArg temp, int nb_temps, int nb_globals) |
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{ |
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int i;
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TCGArg new_base = (TCGArg)-1;
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if (temps[temp].state == TCG_TEMP_HAS_COPY) {
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for (i = temps[temp].next_copy; i != temp; i = temps[i].next_copy) {
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if (i >= nb_globals) {
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temps[i].state = TCG_TEMP_HAS_COPY; |
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new_base = i; |
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break;
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} |
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} |
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for (i = temps[temp].next_copy; i != temp; i = temps[i].next_copy) {
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if (new_base == (TCGArg)-1) { |
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temps[i].state = TCG_TEMP_ANY; |
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} else {
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temps[i].val = new_base; |
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} |
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} |
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temps[temps[temp].next_copy].prev_copy = temps[temp].prev_copy; |
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temps[temps[temp].prev_copy].next_copy = temps[temp].next_copy; |
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} else if (temps[temp].state == TCG_TEMP_COPY) { |
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temps[temps[temp].next_copy].prev_copy = temps[temp].prev_copy; |
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temps[temps[temp].prev_copy].next_copy = temps[temp].next_copy; |
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new_base = temps[temp].val; |
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} |
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temps[temp].state = TCG_TEMP_ANY; |
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if (new_base != (TCGArg)-1 && temps[new_base].next_copy == new_base) { |
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temps[new_base].state = TCG_TEMP_ANY; |
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} |
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} |
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static int op_bits(enum TCGOpcode op) |
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{ |
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const TCGOpDef *def = &tcg_op_defs[op];
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return def->flags & TCG_OPF_64BIT ? 64 : 32; |
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} |
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static int op_to_movi(int op) |
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{ |
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switch (op_bits(op)) {
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case 32: |
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return INDEX_op_movi_i32;
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case 64: |
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return INDEX_op_movi_i64;
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default:
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fprintf(stderr, "op_to_movi: unexpected return value of "
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"function op_bits.\n");
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tcg_abort(); |
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} |
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} |
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static void tcg_opt_gen_mov(TCGContext *s, TCGArg *gen_args, TCGArg dst, |
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TCGArg src, int nb_temps, int nb_globals) |
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{ |
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reset_temp(dst, nb_temps, nb_globals); |
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assert(temps[src].state != TCG_TEMP_COPY); |
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/* Don't try to copy if one of temps is a global or either one
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is local and another is register */
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if (src >= nb_globals && dst >= nb_globals &&
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tcg_arg_is_local(s, src) == tcg_arg_is_local(s, dst)) { |
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assert(temps[src].state != TCG_TEMP_CONST); |
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if (temps[src].state != TCG_TEMP_HAS_COPY) {
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temps[src].state = TCG_TEMP_HAS_COPY; |
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temps[src].next_copy = src; |
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temps[src].prev_copy = src; |
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} |
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temps[dst].state = TCG_TEMP_COPY; |
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temps[dst].val = src; |
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temps[dst].next_copy = temps[src].next_copy; |
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temps[dst].prev_copy = src; |
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temps[temps[dst].next_copy].prev_copy = dst; |
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temps[src].next_copy = dst; |
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} |
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gen_args[0] = dst;
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gen_args[1] = src;
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} |
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static void tcg_opt_gen_movi(TCGArg *gen_args, TCGArg dst, TCGArg val, |
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int nb_temps, int nb_globals) |
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{ |
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reset_temp(dst, nb_temps, nb_globals); |
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temps[dst].state = TCG_TEMP_CONST; |
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temps[dst].val = val; |
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gen_args[0] = dst;
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gen_args[1] = val;
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} |
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static int op_to_mov(int op) |
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{ |
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switch (op_bits(op)) {
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case 32: |
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return INDEX_op_mov_i32;
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case 64: |
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return INDEX_op_mov_i64;
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default:
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fprintf(stderr, "op_to_mov: unexpected return value of "
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"function op_bits.\n");
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tcg_abort(); |
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} |
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} |
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static TCGArg do_constant_folding_2(int op, TCGArg x, TCGArg y) |
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{ |
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switch (op) {
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CASE_OP_32_64(add): |
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return x + y;
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CASE_OP_32_64(sub): |
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return x - y;
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CASE_OP_32_64(mul): |
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return x * y;
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CASE_OP_32_64(and): |
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return x & y;
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CASE_OP_32_64(or): |
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return x | y;
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CASE_OP_32_64(xor): |
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return x ^ y;
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case INDEX_op_shl_i32:
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return (uint32_t)x << (uint32_t)y;
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case INDEX_op_shl_i64:
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return (uint64_t)x << (uint64_t)y;
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case INDEX_op_shr_i32:
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return (uint32_t)x >> (uint32_t)y;
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case INDEX_op_shr_i64:
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return (uint64_t)x >> (uint64_t)y;
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case INDEX_op_sar_i32:
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return (int32_t)x >> (int32_t)y;
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case INDEX_op_sar_i64:
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return (int64_t)x >> (int64_t)y;
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case INDEX_op_rotr_i32:
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x = ((uint32_t)x << (32 - y)) | ((uint32_t)x >> y);
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return x;
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case INDEX_op_rotr_i64:
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x = ((uint64_t)x << (64 - y)) | ((uint64_t)x >> y);
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return x;
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case INDEX_op_rotl_i32:
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x = ((uint32_t)x << y) | ((uint32_t)x >> (32 - y));
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return x;
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case INDEX_op_rotl_i64:
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x = ((uint64_t)x << y) | ((uint64_t)x >> (64 - y));
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return x;
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CASE_OP_32_64(not): |
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return ~x;
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CASE_OP_32_64(neg): |
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return -x;
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CASE_OP_32_64(andc): |
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return x & ~y;
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CASE_OP_32_64(orc): |
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return x | ~y;
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CASE_OP_32_64(eqv): |
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return ~(x ^ y);
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CASE_OP_32_64(nand): |
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return ~(x & y);
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CASE_OP_32_64(nor): |
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return ~(x | y);
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CASE_OP_32_64(ext8s): |
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return (int8_t)x;
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CASE_OP_32_64(ext16s): |
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return (int16_t)x;
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CASE_OP_32_64(ext8u): |
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return (uint8_t)x;
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CASE_OP_32_64(ext16u): |
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return (uint16_t)x;
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case INDEX_op_ext32s_i64:
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return (int32_t)x;
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case INDEX_op_ext32u_i64:
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return (uint32_t)x;
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default:
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fprintf(stderr, |
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"Unrecognized operation %d in do_constant_folding.\n", op);
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tcg_abort(); |
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} |
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} |
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static TCGArg do_constant_folding(int op, TCGArg x, TCGArg y) |
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{ |
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TCGArg res = do_constant_folding_2(op, x, y); |
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if (op_bits(op) == 32) { |
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res &= 0xffffffff;
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} |
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return res;
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} |
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/* Propagate constants and copies, fold constant expressions. */
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static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
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TCGArg *args, TCGOpDef *tcg_op_defs) |
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{ |
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int i, nb_ops, op_index, op, nb_temps, nb_globals, nb_call_args;
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const TCGOpDef *def;
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TCGArg *gen_args; |
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TCGArg tmp; |
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/* Array VALS has an element for each temp.
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If this temp holds a constant then its value is kept in VALS' element.
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If this temp is a copy of other ones then this equivalence class'
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representative is kept in VALS' element.
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If this temp is neither copy nor constant then corresponding VALS'
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element is unused. */
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nb_temps = s->nb_temps; |
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nb_globals = s->nb_globals; |
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memset(temps, 0, nb_temps * sizeof(struct tcg_temp_info)); |
288 |
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nb_ops = tcg_opc_ptr - gen_opc_buf; |
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gen_args = args; |
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for (op_index = 0; op_index < nb_ops; op_index++) { |
292 |
op = gen_opc_buf[op_index]; |
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def = &tcg_op_defs[op]; |
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/* Do copy propagation */
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if (!(def->flags & (TCG_OPF_CALL_CLOBBER | TCG_OPF_SIDE_EFFECTS))) {
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assert(op != INDEX_op_call); |
297 |
for (i = def->nb_oargs; i < def->nb_oargs + def->nb_iargs; i++) {
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if (temps[args[i]].state == TCG_TEMP_COPY) {
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args[i] = temps[args[i]].val; |
300 |
} |
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} |
302 |
} |
303 |
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/* For commutative operations make constant second argument */
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switch (op) {
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CASE_OP_32_64(add): |
307 |
CASE_OP_32_64(mul): |
308 |
CASE_OP_32_64(and): |
309 |
CASE_OP_32_64(or): |
310 |
CASE_OP_32_64(xor): |
311 |
CASE_OP_32_64(eqv): |
312 |
CASE_OP_32_64(nand): |
313 |
CASE_OP_32_64(nor): |
314 |
if (temps[args[1]].state == TCG_TEMP_CONST) { |
315 |
tmp = args[1];
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316 |
args[1] = args[2]; |
317 |
args[2] = tmp;
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} |
319 |
break;
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320 |
default:
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321 |
break;
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322 |
} |
323 |
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324 |
/* Simplify expression if possible. */
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325 |
switch (op) {
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326 |
CASE_OP_32_64(add): |
327 |
CASE_OP_32_64(sub): |
328 |
CASE_OP_32_64(shl): |
329 |
CASE_OP_32_64(shr): |
330 |
CASE_OP_32_64(sar): |
331 |
CASE_OP_32_64(rotl): |
332 |
CASE_OP_32_64(rotr): |
333 |
if (temps[args[1]].state == TCG_TEMP_CONST) { |
334 |
/* Proceed with possible constant folding. */
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335 |
break;
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336 |
} |
337 |
if (temps[args[2]].state == TCG_TEMP_CONST |
338 |
&& temps[args[2]].val == 0) { |
339 |
if ((temps[args[0]].state == TCG_TEMP_COPY |
340 |
&& temps[args[0]].val == args[1]) |
341 |
|| args[0] == args[1]) { |
342 |
args += 3;
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343 |
gen_opc_buf[op_index] = INDEX_op_nop; |
344 |
} else {
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345 |
gen_opc_buf[op_index] = op_to_mov(op); |
346 |
tcg_opt_gen_mov(s, gen_args, args[0], args[1], |
347 |
nb_temps, nb_globals); |
348 |
gen_args += 2;
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349 |
args += 3;
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350 |
} |
351 |
continue;
|
352 |
} |
353 |
break;
|
354 |
CASE_OP_32_64(mul): |
355 |
if ((temps[args[2]].state == TCG_TEMP_CONST |
356 |
&& temps[args[2]].val == 0)) { |
357 |
gen_opc_buf[op_index] = op_to_movi(op); |
358 |
tcg_opt_gen_movi(gen_args, args[0], 0, nb_temps, nb_globals); |
359 |
args += 3;
|
360 |
gen_args += 2;
|
361 |
continue;
|
362 |
} |
363 |
break;
|
364 |
CASE_OP_32_64(or): |
365 |
CASE_OP_32_64(and): |
366 |
if (args[1] == args[2]) { |
367 |
if (args[1] == args[0]) { |
368 |
args += 3;
|
369 |
gen_opc_buf[op_index] = INDEX_op_nop; |
370 |
} else {
|
371 |
gen_opc_buf[op_index] = op_to_mov(op); |
372 |
tcg_opt_gen_mov(s, gen_args, args[0], args[1], nb_temps, |
373 |
nb_globals); |
374 |
gen_args += 2;
|
375 |
args += 3;
|
376 |
} |
377 |
continue;
|
378 |
} |
379 |
break;
|
380 |
} |
381 |
|
382 |
/* Propagate constants through copy operations and do constant
|
383 |
folding. Constants will be substituted to arguments by register
|
384 |
allocator where needed and possible. Also detect copies. */
|
385 |
switch (op) {
|
386 |
CASE_OP_32_64(mov): |
387 |
if ((temps[args[1]].state == TCG_TEMP_COPY |
388 |
&& temps[args[1]].val == args[0]) |
389 |
|| args[0] == args[1]) { |
390 |
args += 2;
|
391 |
gen_opc_buf[op_index] = INDEX_op_nop; |
392 |
break;
|
393 |
} |
394 |
if (temps[args[1]].state != TCG_TEMP_CONST) { |
395 |
tcg_opt_gen_mov(s, gen_args, args[0], args[1], |
396 |
nb_temps, nb_globals); |
397 |
gen_args += 2;
|
398 |
args += 2;
|
399 |
break;
|
400 |
} |
401 |
/* Source argument is constant. Rewrite the operation and
|
402 |
let movi case handle it. */
|
403 |
op = op_to_movi(op); |
404 |
gen_opc_buf[op_index] = op; |
405 |
args[1] = temps[args[1]].val; |
406 |
/* fallthrough */
|
407 |
CASE_OP_32_64(movi): |
408 |
tcg_opt_gen_movi(gen_args, args[0], args[1], nb_temps, nb_globals); |
409 |
gen_args += 2;
|
410 |
args += 2;
|
411 |
break;
|
412 |
CASE_OP_32_64(not): |
413 |
CASE_OP_32_64(neg): |
414 |
CASE_OP_32_64(ext8s): |
415 |
CASE_OP_32_64(ext8u): |
416 |
CASE_OP_32_64(ext16s): |
417 |
CASE_OP_32_64(ext16u): |
418 |
case INDEX_op_ext32s_i64:
|
419 |
case INDEX_op_ext32u_i64:
|
420 |
if (temps[args[1]].state == TCG_TEMP_CONST) { |
421 |
gen_opc_buf[op_index] = op_to_movi(op); |
422 |
tmp = do_constant_folding(op, temps[args[1]].val, 0); |
423 |
tcg_opt_gen_movi(gen_args, args[0], tmp, nb_temps, nb_globals);
|
424 |
gen_args += 2;
|
425 |
args += 2;
|
426 |
break;
|
427 |
} else {
|
428 |
reset_temp(args[0], nb_temps, nb_globals);
|
429 |
gen_args[0] = args[0]; |
430 |
gen_args[1] = args[1]; |
431 |
gen_args += 2;
|
432 |
args += 2;
|
433 |
break;
|
434 |
} |
435 |
CASE_OP_32_64(add): |
436 |
CASE_OP_32_64(sub): |
437 |
CASE_OP_32_64(mul): |
438 |
CASE_OP_32_64(or): |
439 |
CASE_OP_32_64(and): |
440 |
CASE_OP_32_64(xor): |
441 |
CASE_OP_32_64(shl): |
442 |
CASE_OP_32_64(shr): |
443 |
CASE_OP_32_64(sar): |
444 |
CASE_OP_32_64(rotl): |
445 |
CASE_OP_32_64(rotr): |
446 |
CASE_OP_32_64(andc): |
447 |
CASE_OP_32_64(orc): |
448 |
CASE_OP_32_64(eqv): |
449 |
CASE_OP_32_64(nand): |
450 |
CASE_OP_32_64(nor): |
451 |
if (temps[args[1]].state == TCG_TEMP_CONST |
452 |
&& temps[args[2]].state == TCG_TEMP_CONST) {
|
453 |
gen_opc_buf[op_index] = op_to_movi(op); |
454 |
tmp = do_constant_folding(op, temps[args[1]].val,
|
455 |
temps[args[2]].val);
|
456 |
tcg_opt_gen_movi(gen_args, args[0], tmp, nb_temps, nb_globals);
|
457 |
gen_args += 2;
|
458 |
args += 3;
|
459 |
break;
|
460 |
} else {
|
461 |
reset_temp(args[0], nb_temps, nb_globals);
|
462 |
gen_args[0] = args[0]; |
463 |
gen_args[1] = args[1]; |
464 |
gen_args[2] = args[2]; |
465 |
gen_args += 3;
|
466 |
args += 3;
|
467 |
break;
|
468 |
} |
469 |
case INDEX_op_call:
|
470 |
nb_call_args = (args[0] >> 16) + (args[0] & 0xffff); |
471 |
if (!(args[nb_call_args + 1] & (TCG_CALL_CONST | TCG_CALL_PURE))) { |
472 |
for (i = 0; i < nb_globals; i++) { |
473 |
reset_temp(i, nb_temps, nb_globals); |
474 |
} |
475 |
} |
476 |
for (i = 0; i < (args[0] >> 16); i++) { |
477 |
reset_temp(args[i + 1], nb_temps, nb_globals);
|
478 |
} |
479 |
i = nb_call_args + 3;
|
480 |
while (i) {
|
481 |
*gen_args = *args; |
482 |
args++; |
483 |
gen_args++; |
484 |
i--; |
485 |
} |
486 |
break;
|
487 |
case INDEX_op_set_label:
|
488 |
case INDEX_op_jmp:
|
489 |
case INDEX_op_br:
|
490 |
CASE_OP_32_64(brcond): |
491 |
memset(temps, 0, nb_temps * sizeof(struct tcg_temp_info)); |
492 |
for (i = 0; i < def->nb_args; i++) { |
493 |
*gen_args = *args; |
494 |
args++; |
495 |
gen_args++; |
496 |
} |
497 |
break;
|
498 |
default:
|
499 |
/* Default case: we do know nothing about operation so no
|
500 |
propagation is done. We only trash output args. */
|
501 |
for (i = 0; i < def->nb_oargs; i++) { |
502 |
reset_temp(args[i], nb_temps, nb_globals); |
503 |
} |
504 |
for (i = 0; i < def->nb_args; i++) { |
505 |
gen_args[i] = args[i]; |
506 |
} |
507 |
args += def->nb_args; |
508 |
gen_args += def->nb_args; |
509 |
break;
|
510 |
} |
511 |
} |
512 |
|
513 |
return gen_args;
|
514 |
} |
515 |
|
516 |
TCGArg *tcg_optimize(TCGContext *s, uint16_t *tcg_opc_ptr, |
517 |
TCGArg *args, TCGOpDef *tcg_op_defs) |
518 |
{ |
519 |
TCGArg *res; |
520 |
res = tcg_constant_folding(s, tcg_opc_ptr, args, tcg_op_defs); |
521 |
return res;
|
522 |
} |