On 11/20/24 19:49, Anton Johansson wrote:
Adds a function pointer to the TCGContext which may be set by targets via
the TARGET_HELPER_DISPATCHER macro. The dispatcher is function
(void *func, TCGTemp *ret, int nargs, TCGTemp **args) -> bool
which allows targets to hook the generation of helper calls in TCG and
take over translation. Specifically, this will be used by helper-to-tcg
to replace helper function translation, without having to modify frontends.
Signed-off-by: Anton Johansson <a...@rev.ng>
---
accel/tcg/translate-all.c | 4 ++++
include/tcg/tcg.h | 4 ++++
tcg/tcg.c | 5 +++++
3 files changed, 13 insertions(+)
I guess I'll have to read further to understand this, but my first reaction is: why would
we not modify how the gen_helper_* functions are defined instead?
r~
diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c
index fdf6d8ac19..814aae93ae 100644
--- a/accel/tcg/translate-all.c
+++ b/accel/tcg/translate-all.c
@@ -352,6 +352,10 @@ TranslationBlock *tb_gen_code(CPUState *cpu,
tcg_ctx->guest_mo = TCG_MO_ALL;
#endif
+#if defined(CONFIG_HELPER_TO_TCG) && defined(TARGET_HELPER_DISPATCHER)
+ tcg_ctx->helper_dispatcher = TARGET_HELPER_DISPATCHER;
+#endif
+
restart_translate:
trace_translate_block(tb, pc, tb->tc.ptr);
diff --git a/include/tcg/tcg.h b/include/tcg/tcg.h
index a77ed12b9d..d3e820568f 100644
--- a/include/tcg/tcg.h
+++ b/include/tcg/tcg.h
@@ -549,6 +549,10 @@ struct TCGContext {
/* Exit to translator on overflow. */
sigjmp_buf jmp_trans;
+
+
+ bool (*helper_dispatcher)(void *func, TCGTemp *ret_temp,
+ int nargs, TCGTemp **args);
};
static inline bool temp_readonly(TCGTemp *ts)
diff --git a/tcg/tcg.c b/tcg/tcg.c
index 0babae1b88..5f03bef688 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -2252,6 +2252,11 @@ static void tcg_gen_callN(void *func, TCGHelperInfo
*info,
}
total_args = info->nr_out + info->nr_in + 2;
+ if (unlikely(tcg_ctx->helper_dispatcher) &&
+ tcg_ctx->helper_dispatcher(info->func, ret, total_args, args)) {
+ return;
+ }
+
op = tcg_op_alloc(INDEX_op_call, total_args);
#ifdef CONFIG_PLUGIN
