Commit ae36a246 authored by Richard Henderson's avatar Richard Henderson
Browse files

tcg: Add TCG_OPF_BB_EXIT 



Use this to notice the opcodes that exit the TB, which implies
that local temps are really dead and need not be synced.

Previously we so marked the true end of the TB, but that was
immediately overwritten by the la_bb_end invoked by any
TCG_OPF_BB_END opcode, like exit_tb.

Reviewed-by: default avatarEmilio G. Cota <cota@braap.org>
Signed-off-by: default avatarRichard Henderson <richard.henderson@linaro.org>
parent f65a061c

tcg/tcg-opc.h

+4 −3
Original line number Diff line number Diff line
@@ -191,9 +191,10 @@ DEF(mulsh_i64, 1, 2, 0, IMPL64 | IMPL(TCG_TARGET_HAS_mulsh_i64)) 
/* QEMU specific */

DEF(insn_start, 0, 0, TLADDR_ARGS * TARGET_INSN_START_WORDS,

    TCG_OPF_NOT_PRESENT)

DEF(exit_tb, 0, 0, 1, TCG_OPF_BB_END)

DEF(goto_tb, 0, 0, 1, TCG_OPF_BB_END)

DEF(goto_ptr, 0, 1, 0, TCG_OPF_BB_END | IMPL(TCG_TARGET_HAS_goto_ptr))

DEF(exit_tb, 0, 0, 1, TCG_OPF_BB_EXIT | TCG_OPF_BB_END)

DEF(goto_tb, 0, 0, 1, TCG_OPF_BB_EXIT | TCG_OPF_BB_END)

DEF(goto_ptr, 0, 1, 0,

    TCG_OPF_BB_EXIT | TCG_OPF_BB_END | IMPL(TCG_TARGET_HAS_goto_ptr))



DEF(qemu_ld_i32, 1, TLADDR_ARGS, 1,

    TCG_OPF_CALL_CLOBBER | TCG_OPF_SIDE_EFFECTS)

tcg/tcg.c

+4 −1
Original line number Diff line number Diff line
@@ -2424,6 +2424,7 @@ static void liveness_pass_1(TCGContext *s) 
    int nb_temps = s->nb_temps;

    TCGOp *op, *op_prev;



    /* ??? Should be redundant with the exit_tb that ends the TB.  */

    la_func_end(s, nb_globals, nb_temps);



    QTAILQ_FOREACH_REVERSE_SAFE(op, &s->ops, TCGOpHead, link, op_prev) {
@@ -2612,7 +2613,9 @@ static void liveness_pass_1(TCGContext *s) 
            }



            /* if end of basic block, update */

            if (def->flags & TCG_OPF_BB_END) {

            if (def->flags & TCG_OPF_BB_EXIT) {

                la_func_end(s, nb_globals, nb_temps);

            } else if (def->flags & TCG_OPF_BB_END) {

                la_bb_end(s, nb_globals, nb_temps);

            } else if (def->flags & TCG_OPF_SIDE_EFFECTS) {

                la_global_sync(s, nb_globals);

tcg/tcg.h

+8 −6
Original line number Diff line number Diff line
@@ -1030,20 +1030,22 @@ typedef struct TCGArgConstraint { 


/* Bits for TCGOpDef->flags, 8 bits available.  */

enum {

    /* Instruction exits the translation block.  */

    TCG_OPF_BB_EXIT      = 0x01,

    /* Instruction defines the end of a basic block.  */

    TCG_OPF_BB_END       = 0x01,

    TCG_OPF_BB_END       = 0x02,

    /* Instruction clobbers call registers and potentially update globals.  */

    TCG_OPF_CALL_CLOBBER = 0x02,

    TCG_OPF_CALL_CLOBBER = 0x04,

    /* Instruction has side effects: it cannot be removed if its outputs

       are not used, and might trigger exceptions.  */

    TCG_OPF_SIDE_EFFECTS = 0x04,

    TCG_OPF_SIDE_EFFECTS = 0x08,

    /* Instruction operands are 64-bits (otherwise 32-bits).  */

    TCG_OPF_64BIT        = 0x08,

    TCG_OPF_64BIT        = 0x10,

    /* Instruction is optional and not implemented by the host, or insn

       is generic and should not be implemened by the host.  */

    TCG_OPF_NOT_PRESENT  = 0x10,

    TCG_OPF_NOT_PRESENT  = 0x20,

    /* Instruction operands are vectors.  */

    TCG_OPF_VECTOR       = 0x20,

    TCG_OPF_VECTOR       = 0x40,

};



typedef struct TCGOpDef {