tcg: Pass number of arguments to tcg_emit_op() / tcg_op_insert_*()

In order to have variable size allocated TCGOp, pass the number
of arguments we use (and would allocate) up to tcg_op_alloc().

This alters tcg_emit_op(), tcg_op_insert_before() and
tcg_op_insert_after() prototypes.

In tcg_op_alloc() ensure the number of arguments is in range.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
[PMD: Extracted from bigger patch]
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20221218211832.73312-2-philmd@linaro.org>

1 files changed, 17 insertions, 13 deletions

diff --git a/tcg/tcg.c b/tcg/tcg.c
index 0b29c1b..ecbbe99 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -1479,7 +1479,7 @@ bool tcg_op_supported(TCGOpcode op)
    and endian swap in tcg_reg_alloc_call(). */
 void tcg_gen_callN(void *func, TCGTemp *ret, int nargs, TCGTemp **args)
 {
-    int i, real_args, nb_rets, pi;
+    int i, real_args, nb_rets, pi, max_args;
     unsigned typemask;
     const TCGHelperInfo *info;
     TCGOp *op;
@@ -1513,7 +1513,8 @@ void tcg_gen_callN(void *func, TCGTemp *ret, int nargs, TCGTemp **args)
         }
     }
 
-    op = tcg_emit_op(INDEX_op_call);
+    max_args = ARRAY_SIZE(op->args);
+    op = tcg_emit_op(INDEX_op_call, max_args);
 
     pi = 0;
     if (ret != NULL) {
@@ -1590,7 +1591,7 @@ void tcg_gen_callN(void *func, TCGTemp *ret, int nargs, TCGTemp **args)
 
     /* Make sure the fields didn't overflow.  */
     tcg_debug_assert(TCGOP_CALLI(op) == real_args);
-    tcg_debug_assert(pi <= ARRAY_SIZE(op->args));
+    tcg_debug_assert(pi <= max_args);
 
     if (TCG_TARGET_CALL_ARG_I32 == TCG_CALL_ARG_EXTEND) {
         for (i = 0; i < nargs; ++i) {
@@ -2294,11 +2295,12 @@ void tcg_remove_ops_after(TCGOp *op)
     }
 }
 
-static TCGOp *tcg_op_alloc(TCGOpcode opc)
+static TCGOp *tcg_op_alloc(TCGOpcode opc, unsigned nargs)
 {
     TCGContext *s = tcg_ctx;
     TCGOp *op;
 
+    assert(nargs < ARRAY_SIZE(op->args));
     if (likely(QTAILQ_EMPTY(&s->free_ops))) {
         op = tcg_malloc(sizeof(TCGOp));
     } else {
@@ -2312,23 +2314,25 @@ static TCGOp *tcg_op_alloc(TCGOpcode opc)
     return op;
 }
 
-TCGOp *tcg_emit_op(TCGOpcode opc)
+TCGOp *tcg_emit_op(TCGOpcode opc, unsigned nargs)
 {
-    TCGOp *op = tcg_op_alloc(opc);
+    TCGOp *op = tcg_op_alloc(opc, nargs);
     QTAILQ_INSERT_TAIL(&tcg_ctx->ops, op, link);
     return op;
 }
 
-TCGOp *tcg_op_insert_before(TCGContext *s, TCGOp *old_op, TCGOpcode opc)
+TCGOp *tcg_op_insert_before(TCGContext *s, TCGOp *old_op,
+                            TCGOpcode opc, unsigned nargs)
 {
-    TCGOp *new_op = tcg_op_alloc(opc);
+    TCGOp *new_op = tcg_op_alloc(opc, nargs);
     QTAILQ_INSERT_BEFORE(old_op, new_op, link);
     return new_op;
 }
 
-TCGOp *tcg_op_insert_after(TCGContext *s, TCGOp *old_op, TCGOpcode opc)
+TCGOp *tcg_op_insert_after(TCGContext *s, TCGOp *old_op,
+                           TCGOpcode opc, unsigned nargs)
 {
-    TCGOp *new_op = tcg_op_alloc(opc);
+    TCGOp *new_op = tcg_op_alloc(opc, nargs);
     QTAILQ_INSERT_AFTER(&s->ops, old_op, new_op, link);
     return new_op;
 }
@@ -2937,7 +2941,7 @@ static bool liveness_pass_2(TCGContext *s)
                     TCGOpcode lopc = (arg_ts->type == TCG_TYPE_I32
                                       ? INDEX_op_ld_i32
                                       : INDEX_op_ld_i64);
-                    TCGOp *lop = tcg_op_insert_before(s, op, lopc);
+                    TCGOp *lop = tcg_op_insert_before(s, op, lopc, 3);
 
                     lop->args[0] = temp_arg(dir_ts);
                     lop->args[1] = temp_arg(arg_ts->mem_base);
@@ -3003,7 +3007,7 @@ static bool liveness_pass_2(TCGContext *s)
                     TCGOpcode sopc = (arg_ts->type == TCG_TYPE_I32
                                       ? INDEX_op_st_i32
                                       : INDEX_op_st_i64);
-                    TCGOp *sop = tcg_op_insert_after(s, op, sopc);
+                    TCGOp *sop = tcg_op_insert_after(s, op, sopc, 3);
                     TCGTemp *out_ts = dir_ts;
 
                     if (IS_DEAD_ARG(0)) {
@@ -3039,7 +3043,7 @@ static bool liveness_pass_2(TCGContext *s)
                     TCGOpcode sopc = (arg_ts->type == TCG_TYPE_I32
                                       ? INDEX_op_st_i32
                                       : INDEX_op_st_i64);
-                    TCGOp *sop = tcg_op_insert_after(s, op, sopc);
+                    TCGOp *sop = tcg_op_insert_after(s, op, sopc, 3);
 
                     sop->args[0] = temp_arg(dir_ts);
                     sop->args[1] = temp_arg(arg_ts->mem_base);