From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:40059) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hHkWR-0008KO-Ur for qemu-devel@nongnu.org; Sat, 20 Apr 2019 03:34:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hHkWQ-0007em-HA for qemu-devel@nongnu.org; Sat, 20 Apr 2019 03:34:51 -0400 Received: from mail-pg1-x544.google.com ([2607:f8b0:4864:20::544]:39734) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1hHkWQ-0007eQ-B4 for qemu-devel@nongnu.org; Sat, 20 Apr 2019 03:34:50 -0400 Received: by mail-pg1-x544.google.com with SMTP id l18so3459315pgj.6 for ; Sat, 20 Apr 2019 00:34:50 -0700 (PDT) From: Richard Henderson Date: Fri, 19 Apr 2019 21:34:06 -1000 Message-Id: <20190420073442.7488-3-richard.henderson@linaro.org> In-Reply-To: <20190420073442.7488-1-richard.henderson@linaro.org> References: <20190420073442.7488-1-richard.henderson@linaro.org> Subject: [Qemu-devel] [PATCH 02/38] tcg: Assert fixed_reg is read-only List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: david@redhat.com The only fixed_reg is cpu_env, and it should not be modified during any TB. Therefore code that tries to special-case moves into a fixed_reg is dead. Remove it. Signed-off-by: Richard Henderson --- tcg/tcg.c | 85 +++++++++++++++++++++++++------------------------------ 1 file changed, 38 insertions(+), 47 deletions(-) diff --git a/tcg/tcg.c b/tcg/tcg.c index ade6050982..4f77a957b0 100644 --- a/tcg/tcg.c +++ b/tcg/tcg.c @@ -3279,11 +3279,8 @@ static void tcg_reg_alloc_do_movi(TCGContext *s, TCGTemp *ots, tcg_target_ulong val, TCGLifeData arg_life, TCGRegSet preferred_regs) { - if (ots->fixed_reg) { - /* For fixed registers, we do not do any constant propagation. */ - tcg_out_movi(s, ots->type, ots->reg, val); - return; - } + /* ENV should not be modified. */ + tcg_debug_assert(!ots->fixed_reg); /* The movi is not explicitly generated here. */ if (ots->val_type == TEMP_VAL_REG) { @@ -3319,6 +3316,9 @@ static void tcg_reg_alloc_mov(TCGContext *s, const TCGOp *op) ots = arg_temp(op->args[0]); ts = arg_temp(op->args[1]); + /* ENV should not be modified. */ + tcg_debug_assert(!ots->fixed_reg); + /* Note that otype != itype for no-op truncation. */ otype = ots->type; itype = ts->type; @@ -3343,7 +3343,7 @@ static void tcg_reg_alloc_mov(TCGContext *s, const TCGOp *op) } tcg_debug_assert(ts->val_type == TEMP_VAL_REG); - if (IS_DEAD_ARG(0) && !ots->fixed_reg) { + if (IS_DEAD_ARG(0)) { /* mov to a non-saved dead register makes no sense (even with liveness analysis disabled). */ tcg_debug_assert(NEED_SYNC_ARG(0)); @@ -3356,7 +3356,7 @@ static void tcg_reg_alloc_mov(TCGContext *s, const TCGOp *op) } temp_dead(s, ots); } else { - if (IS_DEAD_ARG(1) && !ts->fixed_reg && !ots->fixed_reg) { + if (IS_DEAD_ARG(1) && !ts->fixed_reg) { /* the mov can be suppressed */ if (ots->val_type == TEMP_VAL_REG) { s->reg_to_temp[ots->reg] = NULL; @@ -3509,6 +3509,10 @@ static void tcg_reg_alloc_op(TCGContext *s, const TCGOp *op) arg = op->args[i]; arg_ct = &def->args_ct[i]; ts = arg_temp(arg); + + /* ENV should not be modified. */ + tcg_debug_assert(!ts->fixed_reg); + if ((arg_ct->ct & TCG_CT_ALIAS) && !const_args[arg_ct->alias_index]) { reg = new_args[arg_ct->alias_index]; @@ -3517,29 +3521,19 @@ static void tcg_reg_alloc_op(TCGContext *s, const TCGOp *op) i_allocated_regs | o_allocated_regs, op->output_pref[k], ts->indirect_base); } else { - /* if fixed register, we try to use it */ - reg = ts->reg; - if (ts->fixed_reg && - tcg_regset_test_reg(arg_ct->u.regs, reg)) { - goto oarg_end; - } reg = tcg_reg_alloc(s, arg_ct->u.regs, o_allocated_regs, op->output_pref[k], ts->indirect_base); } tcg_regset_set_reg(o_allocated_regs, reg); - /* if a fixed register is used, then a move will be done afterwards */ - if (!ts->fixed_reg) { - if (ts->val_type == TEMP_VAL_REG) { - s->reg_to_temp[ts->reg] = NULL; - } - ts->val_type = TEMP_VAL_REG; - ts->reg = reg; - /* temp value is modified, so the value kept in memory is - potentially not the same */ - ts->mem_coherent = 0; - s->reg_to_temp[reg] = ts; + if (ts->val_type == TEMP_VAL_REG) { + s->reg_to_temp[ts->reg] = NULL; } - oarg_end: + ts->val_type = TEMP_VAL_REG; + ts->reg = reg; + /* temp value is modified, so the value kept in memory is + potentially not the same */ + ts->mem_coherent = 0; + s->reg_to_temp[reg] = ts; new_args[i] = reg; } } @@ -3555,10 +3549,10 @@ static void tcg_reg_alloc_op(TCGContext *s, const TCGOp *op) /* move the outputs in the correct register if needed */ for(i = 0; i < nb_oargs; i++) { ts = arg_temp(op->args[i]); - reg = new_args[i]; - if (ts->fixed_reg && ts->reg != reg) { - tcg_out_mov(s, ts->type, ts->reg, reg); - } + + /* ENV should not be modified. */ + tcg_debug_assert(!ts->fixed_reg); + if (NEED_SYNC_ARG(i)) { temp_sync(s, ts, o_allocated_regs, 0, IS_DEAD_ARG(i)); } else if (IS_DEAD_ARG(i)) { @@ -3679,26 +3673,23 @@ static void tcg_reg_alloc_call(TCGContext *s, TCGOp *op) for(i = 0; i < nb_oargs; i++) { arg = op->args[i]; ts = arg_temp(arg); + + /* ENV should not be modified. */ + tcg_debug_assert(!ts->fixed_reg); + reg = tcg_target_call_oarg_regs[i]; tcg_debug_assert(s->reg_to_temp[reg] == NULL); - - if (ts->fixed_reg) { - if (ts->reg != reg) { - tcg_out_mov(s, ts->type, ts->reg, reg); - } - } else { - if (ts->val_type == TEMP_VAL_REG) { - s->reg_to_temp[ts->reg] = NULL; - } - ts->val_type = TEMP_VAL_REG; - ts->reg = reg; - ts->mem_coherent = 0; - s->reg_to_temp[reg] = ts; - if (NEED_SYNC_ARG(i)) { - temp_sync(s, ts, allocated_regs, 0, IS_DEAD_ARG(i)); - } else if (IS_DEAD_ARG(i)) { - temp_dead(s, ts); - } + if (ts->val_type == TEMP_VAL_REG) { + s->reg_to_temp[ts->reg] = NULL; + } + ts->val_type = TEMP_VAL_REG; + ts->reg = reg; + ts->mem_coherent = 0; + s->reg_to_temp[reg] = ts; + if (NEED_SYNC_ARG(i)) { + temp_sync(s, ts, allocated_regs, 0, IS_DEAD_ARG(i)); + } else if (IS_DEAD_ARG(i)) { + temp_dead(s, ts); } } } -- 2.17.1