diff options
| -rw-r--r-- | tcg/tcg.c | 103 |
1 files changed, 81 insertions, 22 deletions
@@ -1887,6 +1887,20 @@ static const char * const alignment_name[(MO_AMASK >> MO_ASHIFT) + 1] = { [MO_ALIGN_64 >> MO_ASHIFT] = "al64+", }; +static inline bool tcg_regset_single(TCGRegSet d) +{ + return (d & (d - 1)) == 0; +} + +static inline TCGReg tcg_regset_first(TCGRegSet d) +{ + if (TCG_TARGET_NB_REGS <= 32) { + return ctz32(d); + } else { + return ctz64(d); + } +} + void tcg_dump_ops(TCGContext *s) { char buf[128]; @@ -1902,6 +1916,7 @@ void tcg_dump_ops(TCGContext *s) def = &tcg_op_defs[c]; if (c == INDEX_op_insn_start) { + nb_oargs = 0; col += qemu_log("\n ----"); for (i = 0; i < TARGET_INSN_START_WORDS; ++i) { @@ -2902,31 +2917,72 @@ static void tcg_reg_free(TCGContext *s, TCGReg reg, TCGRegSet allocated_regs) } } -/* Allocate a register belonging to reg1 & ~reg2 */ -static TCGReg tcg_reg_alloc(TCGContext *s, TCGRegSet desired_regs, - TCGRegSet allocated_regs, bool rev) +/** + * tcg_reg_alloc: + * @required_regs: Set of registers in which we must allocate. + * @allocated_regs: Set of registers which must be avoided. + * @preferred_regs: Set of registers we should prefer. + * @rev: True if we search the registers in "indirect" order. + * + * The allocated register must be in @required_regs & ~@allocated_regs, + * but if we can put it in @preferred_regs we may save a move later. + */ +static TCGReg tcg_reg_alloc(TCGContext *s, TCGRegSet required_regs, + TCGRegSet allocated_regs, + TCGRegSet preferred_regs, bool rev) { - int i, n = ARRAY_SIZE(tcg_target_reg_alloc_order); + int i, j, f, n = ARRAY_SIZE(tcg_target_reg_alloc_order); + TCGRegSet reg_ct[2]; const int *order; - TCGReg reg; - TCGRegSet reg_ct; - reg_ct = desired_regs & ~allocated_regs; + reg_ct[1] = required_regs & ~allocated_regs; + tcg_debug_assert(reg_ct[1] != 0); + reg_ct[0] = reg_ct[1] & preferred_regs; + + /* Skip the preferred_regs option if it cannot be satisfied, + or if the preference made no difference. */ + f = reg_ct[0] == 0 || reg_ct[0] == reg_ct[1]; + order = rev ? indirect_reg_alloc_order : tcg_target_reg_alloc_order; - /* first try free registers */ - for(i = 0; i < n; i++) { - reg = order[i]; - if (tcg_regset_test_reg(reg_ct, reg) && s->reg_to_temp[reg] == NULL) - return reg; + /* Try free registers, preferences first. */ + for (j = f; j < 2; j++) { + TCGRegSet set = reg_ct[j]; + + if (tcg_regset_single(set)) { + /* One register in the set. */ + TCGReg reg = tcg_regset_first(set); + if (s->reg_to_temp[reg] == NULL) { + return reg; + } + } else { + for (i = 0; i < n; i++) { + TCGReg reg = order[i]; + if (s->reg_to_temp[reg] == NULL && + tcg_regset_test_reg(set, reg)) { + return reg; + } + } + } } - /* XXX: do better spill choice */ - for(i = 0; i < n; i++) { - reg = order[i]; - if (tcg_regset_test_reg(reg_ct, reg)) { + /* We must spill something. */ + for (j = f; j < 2; j++) { + TCGRegSet set = reg_ct[j]; + + if (tcg_regset_single(set)) { + /* One register in the set. */ + TCGReg reg = tcg_regset_first(set); tcg_reg_free(s, reg, allocated_regs); return reg; + } else { + for (i = 0; i < n; i++) { + TCGReg reg = order[i]; + if (tcg_regset_test_reg(set, reg)) { + tcg_reg_free(s, reg, allocated_regs); + return reg; + } + } } } @@ -2944,12 +3000,14 @@ static void temp_load(TCGContext *s, TCGTemp *ts, TCGRegSet desired_regs, case TEMP_VAL_REG: return; case TEMP_VAL_CONST: - reg = tcg_reg_alloc(s, desired_regs, allocated_regs, ts->indirect_base); + reg = tcg_reg_alloc(s, desired_regs, allocated_regs, + 0, ts->indirect_base); tcg_out_movi(s, ts->type, reg, ts->val); ts->mem_coherent = 0; break; case TEMP_VAL_MEM: - reg = tcg_reg_alloc(s, desired_regs, allocated_regs, ts->indirect_base); + reg = tcg_reg_alloc(s, desired_regs, allocated_regs, + 0, ts->indirect_base); tcg_out_ld(s, ts->type, reg, ts->mem_base->reg, ts->mem_offset); ts->mem_coherent = 1; break; @@ -3109,7 +3167,8 @@ static void tcg_reg_alloc_mov(TCGContext *s, const TCGOp *op) input one. */ tcg_regset_set_reg(allocated_regs, ts->reg); ots->reg = tcg_reg_alloc(s, tcg_target_available_regs[otype], - allocated_regs, ots->indirect_base); + allocated_regs, 0, + ots->indirect_base); } tcg_out_mov(s, otype, ots->reg, ts->reg); } @@ -3197,7 +3256,7 @@ static void tcg_reg_alloc_op(TCGContext *s, const TCGOp *op) /* allocate a new register matching the constraint and move the temporary register into it */ reg = tcg_reg_alloc(s, arg_ct->u.regs, i_allocated_regs, - ts->indirect_base); + 0, ts->indirect_base); tcg_out_mov(s, ts->type, reg, ts->reg); } new_args[i] = reg; @@ -3242,7 +3301,7 @@ static void tcg_reg_alloc_op(TCGContext *s, const TCGOp *op) } else if (arg_ct->ct & TCG_CT_NEWREG) { reg = tcg_reg_alloc(s, arg_ct->u.regs, i_allocated_regs | o_allocated_regs, - ts->indirect_base); + 0, ts->indirect_base); } else { /* if fixed register, we try to use it */ reg = ts->reg; @@ -3251,7 +3310,7 @@ static void tcg_reg_alloc_op(TCGContext *s, const TCGOp *op) goto oarg_end; } reg = tcg_reg_alloc(s, arg_ct->u.regs, o_allocated_regs, - ts->indirect_base); + 0, ts->indirect_base); } tcg_regset_set_reg(o_allocated_regs, reg); /* if a fixed register is used, then a move will be done afterwards */ |