Commit 36f0399d authored by Richard Henderson's avatar Richard Henderson Committed by Laurent Vivier
Browse files

target-m68k: Optimize gen_flush_flags 



Signed-off-by: default avatarRichard Henderson <rth@twiddle.net>
Signed-off-by: default avatarLaurent Vivier <laurent@vivier.eu>
parent 9d896621

target-m68k/translate.c

+52 −4
Original line number Diff line number Diff line
@@ -458,18 +458,66 @@ static TCGv gen_lea_indexed(CPUM68KState *env, DisasContext *s, TCGv base) 


static void gen_flush_flags(DisasContext *s)

{

    TCGv tmp;

    TCGv t0, t1;



    switch (s->cc_op) {

    case CC_OP_FLAGS:

        return;



    case CC_OP_ADD:

        tcg_gen_mov_i32(QREG_CC_C, QREG_CC_X);

        tcg_gen_mov_i32(QREG_CC_Z, QREG_CC_N);

        /* Compute signed overflow for addition.  */

        t0 = tcg_temp_new();

        t1 = tcg_temp_new();

        tcg_gen_sub_i32(t0, QREG_CC_N, QREG_CC_V);

        tcg_gen_xor_i32(t1, QREG_CC_N, QREG_CC_V);

        tcg_gen_xor_i32(QREG_CC_V, QREG_CC_V, t0);

        tcg_temp_free(t0);

        tcg_gen_andc_i32(QREG_CC_V, t1, QREG_CC_V);

        tcg_temp_free(t1);

        break;



    case CC_OP_SUB:

        tcg_gen_mov_i32(QREG_CC_C, QREG_CC_X);

        tcg_gen_mov_i32(QREG_CC_Z, QREG_CC_N);

        /* Compute signed overflow for subtraction.  */

        t0 = tcg_temp_new();

        t1 = tcg_temp_new();

        tcg_gen_add_i32(t0, QREG_CC_N, QREG_CC_V);

        tcg_gen_xor_i32(t1, QREG_CC_N, QREG_CC_V);

        tcg_gen_xor_i32(QREG_CC_V, QREG_CC_V, t0);

        tcg_temp_free(t0);

        tcg_gen_and_i32(QREG_CC_V, QREG_CC_V, t1);

        tcg_temp_free(t1);

        break;



    case CC_OP_CMP:

        tcg_gen_setcond_i32(TCG_COND_LTU, QREG_CC_C, QREG_CC_N, QREG_CC_V);

        tcg_gen_sub_i32(QREG_CC_Z, QREG_CC_N, QREG_CC_V);

        /* Compute signed overflow for subtraction.  */

        t0 = tcg_temp_new();

        tcg_gen_xor_i32(t0, QREG_CC_Z, QREG_CC_N);

        tcg_gen_xor_i32(QREG_CC_V, QREG_CC_V, QREG_CC_N);

        tcg_gen_and_i32(QREG_CC_V, QREG_CC_V, t0);

        tcg_temp_free(t0);

        tcg_gen_mov_i32(QREG_CC_N, QREG_CC_Z);

        break;



    case CC_OP_LOGIC:

        tcg_gen_mov_i32(QREG_CC_Z, QREG_CC_N);

        tcg_gen_movi_i32(QREG_CC_C, 0);

        tcg_gen_movi_i32(QREG_CC_V, 0);

        break;



    case CC_OP_DYNAMIC:

        gen_helper_flush_flags(cpu_env, QREG_CC_OP);

        break;



    default:

        tmp = tcg_const_i32(s->cc_op);

        gen_helper_flush_flags(cpu_env, tmp);

        tcg_temp_free(tmp);

        t0 = tcg_const_i32(s->cc_op);

        gen_helper_flush_flags(cpu_env, t0);

        tcg_temp_free(t0);

        break;

    }