target/m68k: introduce is_singlestepping() function

The m68k translator currently checks the DisasContextBase singlestep_enabled
boolean directly to determine whether to single-step execution. Soon
single-stepping may also be triggered by setting the appropriate bits in the
SR register so centralise the check into a single is_singlestepping()
function.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210519142917.16693-2-mark.cave-ayland@ilande.co.uk>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
This commit is contained in:
Mark Cave-Ayland 2021-05-19 15:29:14 +01:00 committed by Laurent Vivier
parent 0319ad22bd
commit f334bb2562

View file

@ -194,6 +194,17 @@ static void do_writebacks(DisasContext *s)
}
}
static bool is_singlestepping(DisasContext *s)
{
/*
* Return true if we are singlestepping either because of QEMU gdbstub
* singlestep. This does not include the command line '-singlestep' mode
* which is rather misnamed as it only means "one instruction per TB" and
* doesn't affect the code we generate.
*/
return s->base.singlestep_enabled;
}
/* is_jmp field values */
#define DISAS_JUMP DISAS_TARGET_0 /* only pc was modified dynamically */
#define DISAS_EXIT DISAS_TARGET_1 /* cpu state was modified dynamically */
@ -1506,7 +1517,7 @@ static inline bool use_goto_tb(DisasContext *s, uint32_t dest)
/* Generate a jump to an immediate address. */
static void gen_jmp_tb(DisasContext *s, int n, uint32_t dest)
{
if (unlikely(s->base.singlestep_enabled)) {
if (unlikely(is_singlestepping(s))) {
gen_exception(s, dest, EXCP_DEBUG);
} else if (use_goto_tb(s, dest)) {
tcg_gen_goto_tb(n);
@ -6245,7 +6256,7 @@ static void m68k_tr_tb_stop(DisasContextBase *dcbase, CPUState *cpu)
break;
case DISAS_TOO_MANY:
update_cc_op(dc);
if (dc->base.singlestep_enabled) {
if (is_singlestepping(dc)) {
tcg_gen_movi_i32(QREG_PC, dc->pc);
gen_raise_exception(EXCP_DEBUG);
} else {
@ -6254,7 +6265,7 @@ static void m68k_tr_tb_stop(DisasContextBase *dcbase, CPUState *cpu)
break;
case DISAS_JUMP:
/* We updated CC_OP and PC in gen_jmp/gen_jmp_im. */
if (dc->base.singlestep_enabled) {
if (is_singlestepping(dc)) {
gen_raise_exception(EXCP_DEBUG);
} else {
tcg_gen_lookup_and_goto_ptr();
@ -6265,7 +6276,7 @@ static void m68k_tr_tb_stop(DisasContextBase *dcbase, CPUState *cpu)
* We updated CC_OP and PC in gen_exit_tb, but also modified
* other state that may require returning to the main loop.
*/
if (dc->base.singlestep_enabled) {
if (is_singlestepping(dc)) {
gen_raise_exception(EXCP_DEBUG);
} else {
tcg_gen_exit_tb(NULL, 0);