This is a common operation that is executed many times in rep movs or rep stos loops. It can improve performance by several percentage points.
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> Link: https://lore.kernel.org/r/20241215090613.89588-13-pbonz...@redhat.com Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> --- target/i386/tcg/translate.c | 54 ++++++++++++++++++------------------- 1 file changed, 26 insertions(+), 28 deletions(-) diff --git a/target/i386/tcg/translate.c b/target/i386/tcg/translate.c index 991baf5d829..9f4d3ebbd95 100644 --- a/target/i386/tcg/translate.c +++ b/target/i386/tcg/translate.c @@ -832,16 +832,13 @@ static bool gen_check_io(DisasContext *s, MemOp ot, TCGv_i32 port, #endif } -static void gen_movs(DisasContext *s, MemOp ot) +static void gen_movs(DisasContext *s, MemOp ot, TCGv dshift) { - TCGv dshift; - gen_string_movl_A0_ESI(s); gen_op_ld_v(s, ot, s->T0, s->A0); gen_string_movl_A0_EDI(s); gen_op_st_v(s, ot, s->T0, s->A0); - dshift = gen_compute_Dshift(s, ot); gen_op_add_reg(s, s->aflag, R_ESI, dshift); gen_op_add_reg(s, s->aflag, R_EDI, dshift); } @@ -1246,22 +1243,22 @@ static inline void gen_jcc(DisasContext *s, int b, TCGLabel *l1) } } -static void gen_stos(DisasContext *s, MemOp ot) +static void gen_stos(DisasContext *s, MemOp ot, TCGv dshift) { gen_string_movl_A0_EDI(s); gen_op_st_v(s, ot, s->T0, s->A0); - gen_op_add_reg(s, s->aflag, R_EDI, gen_compute_Dshift(s, ot)); + gen_op_add_reg(s, s->aflag, R_EDI, dshift); } -static void gen_lods(DisasContext *s, MemOp ot) +static void gen_lods(DisasContext *s, MemOp ot, TCGv dshift) { gen_string_movl_A0_ESI(s); gen_op_ld_v(s, ot, s->T0, s->A0); gen_op_mov_reg_v(s, ot, R_EAX, s->T0); - gen_op_add_reg(s, s->aflag, R_ESI, gen_compute_Dshift(s, ot)); + gen_op_add_reg(s, s->aflag, R_ESI, dshift); } -static void gen_scas(DisasContext *s, MemOp ot) +static void gen_scas(DisasContext *s, MemOp ot, TCGv dshift) { gen_string_movl_A0_EDI(s); gen_op_ld_v(s, ot, s->T1, s->A0); @@ -1270,13 +1267,11 @@ static void gen_scas(DisasContext *s, MemOp ot) tcg_gen_sub_tl(cpu_cc_dst, s->T0, s->T1); set_cc_op(s, CC_OP_SUBB + ot); - gen_op_add_reg(s, s->aflag, R_EDI, gen_compute_Dshift(s, ot)); + gen_op_add_reg(s, s->aflag, R_EDI, dshift); } -static void gen_cmps(DisasContext *s, MemOp ot) +static void gen_cmps(DisasContext *s, MemOp ot, TCGv dshift) { - TCGv dshift; - gen_string_movl_A0_EDI(s); gen_op_ld_v(s, ot, s->T1, s->A0); gen_string_movl_A0_ESI(s); @@ -1286,7 +1281,6 @@ static void gen_cmps(DisasContext *s, MemOp ot) tcg_gen_sub_tl(cpu_cc_dst, s->T0, s->T1); set_cc_op(s, CC_OP_SUBB + ot); - dshift = gen_compute_Dshift(s, ot); gen_op_add_reg(s, s->aflag, R_ESI, dshift); gen_op_add_reg(s, s->aflag, R_EDI, dshift); } @@ -1305,7 +1299,7 @@ static void gen_bpt_io(DisasContext *s, TCGv_i32 t_port, int ot) } } -static void gen_ins(DisasContext *s, MemOp ot) +static void gen_ins(DisasContext *s, MemOp ot, TCGv dshift) { gen_string_movl_A0_EDI(s); /* Note: we must do this dummy write first to be restartable in @@ -1316,11 +1310,11 @@ static void gen_ins(DisasContext *s, MemOp ot) tcg_gen_andi_i32(s->tmp2_i32, s->tmp2_i32, 0xffff); gen_helper_in_func(ot, s->T0, s->tmp2_i32); gen_op_st_v(s, ot, s->T0, s->A0); - gen_op_add_reg(s, s->aflag, R_EDI, gen_compute_Dshift(s, ot)); + gen_op_add_reg(s, s->aflag, R_EDI, dshift); gen_bpt_io(s, s->tmp2_i32, ot); } -static void gen_outs(DisasContext *s, MemOp ot) +static void gen_outs(DisasContext *s, MemOp ot, TCGv dshift) { gen_string_movl_A0_ESI(s); gen_op_ld_v(s, ot, s->T0, s->A0); @@ -1329,14 +1323,14 @@ static void gen_outs(DisasContext *s, MemOp ot) tcg_gen_andi_i32(s->tmp2_i32, s->tmp2_i32, 0xffff); tcg_gen_trunc_tl_i32(s->tmp3_i32, s->T0); gen_helper_out_func(ot, s->tmp2_i32, s->tmp3_i32); - gen_op_add_reg(s, s->aflag, R_ESI, gen_compute_Dshift(s, ot)); + gen_op_add_reg(s, s->aflag, R_ESI, dshift); gen_bpt_io(s, s->tmp2_i32, ot); } #define REP_MAX 65535 -static void do_gen_rep(DisasContext *s, MemOp ot, - void (*fn)(DisasContext *s, MemOp ot), +static void do_gen_rep(DisasContext *s, MemOp ot, TCGv dshift, + void (*fn)(DisasContext *s, MemOp ot, TCGv dshift), bool is_repz_nz) { TCGLabel *last = gen_new_label(); @@ -1401,7 +1395,7 @@ static void do_gen_rep(DisasContext *s, MemOp ot, } gen_set_label(loop); - fn(s, ot); + fn(s, ot, dshift); tcg_gen_mov_tl(cpu_regs[R_ECX], cx_next); gen_update_cc_op(s); @@ -1438,7 +1432,7 @@ static void do_gen_rep(DisasContext *s, MemOp ot, */ gen_set_label(last); set_cc_op(s, CC_OP_DYNAMIC); - fn(s, ot); + fn(s, ot, dshift); tcg_gen_mov_tl(cpu_regs[R_ECX], cx_next); gen_update_cc_op(s); } @@ -1453,23 +1447,27 @@ static void do_gen_rep(DisasContext *s, MemOp ot, } static void gen_repz(DisasContext *s, MemOp ot, - void (*fn)(DisasContext *s, MemOp ot)) + void (*fn)(DisasContext *s, MemOp ot, TCGv dshift)) { + TCGv dshift = gen_compute_Dshift(s, ot); + if (s->prefix & (PREFIX_REPZ | PREFIX_REPNZ)) { - do_gen_rep(s, ot, fn, false); + do_gen_rep(s, ot, dshift, fn, false); } else { - fn(s, ot); + fn(s, ot, dshift); } } static void gen_repz_nz(DisasContext *s, MemOp ot, - void (*fn)(DisasContext *s, MemOp ot)) + void (*fn)(DisasContext *s, MemOp ot, TCGv dshift)) { + TCGv dshift = gen_compute_Dshift(s, ot); + if (s->prefix & (PREFIX_REPZ | PREFIX_REPNZ)) { - do_gen_rep(s, ot, fn, true); + do_gen_rep(s, ot, dshift, fn, true); } else { - fn(s, ot); + fn(s, ot, dshift); } } -- 2.48.1
