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No longer used hacked liveness_pass_1

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This hack was introduced in issue#287 which later becomes endless maintainance pain.

=====

Our previous check_exit_request use `brcond` in the middle of a TranslationBlock which

breaks the assumptions and thus a hack to liveness_pass_1 is used for _all_ brcond instructions

which causes issues for MIPS and many other scenarios.

=====

This patch also resolves PC not sync-ed when no memory hooks are installed, finally. Now

Unicorn will always have correct PC no matter what happens.
This commit is contained in:
mio
2025-04-12 21:38:14 +08:00
parent e89eb87d04
commit 7f48b1dd4a
28 changed files with 80 additions and 63 deletions
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26
qemu/tcg/tcg.c
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@@ -2243,17 +2243,6 @@ static inline void la_reset_pref(TCGContext *tcg_ctx, TCGTemp *ts)
= (ts->state == TS_DEAD ? 0 : tcg_ctx->tcg_target_available_regs[ts->type]);
}
/*
Unicorn: for brcond, we should refresh liveness states for TCG globals
*/
static void la_brcond_end(TCGContext *s, int ng)
{
int i;
for (i = 0; i < ng; i++) {
s->temps[i].state |= TS_MEM;
}
}
/* liveness analysis: end of function: all temps are dead, and globals
should be in memory. */
@@ -2581,20 +2570,7 @@ static void liveness_pass_1(TCGContext *s)
if (def->flags & TCG_OPF_BB_EXIT) {
la_func_end(s, nb_globals, nb_temps);
} else if (def->flags & TCG_OPF_BB_END) {
// Unicorn: do not optimize dead temps on brcond,
// this causes problem because check_exit_request() inserts
// brcond instruction in the middle of the TB,
// which incorrectly flags end-of-block
if (opc != INDEX_op_brcond_i32) {
la_bb_end(s, nb_globals, nb_temps);
} else {
// Unicorn: we do not touch dead temps for brcond,
// but we should refresh TCG globals In-Memory states,
// otherwise, important CPU states(especially conditional flags) might be forgotten,
// result in wrongly generated host code that run into wrong branch.
// Refer to https://github.com/unicorn-engine/unicorn/issues/287 for further information
la_brcond_end(s, nb_globals);
}
la_bb_end(s, nb_globals, nb_temps);
} else if (def->flags & TCG_OPF_SIDE_EFFECTS) {
la_global_sync(s, nb_globals);
if (def->flags & TCG_OPF_CALL_CLOBBER) {