-fno-type-redefinition-check

    don't catch redefinition for local vars. With this option on
    tcc accepts the following code:
    int main()
    {
        int a = 0;
        long a = 0;
    }
    But if you shure there is no problem with your local variables,
    then a compilation speed can be improved if you have a lots of
    the local variables (50000+)

1 files changed, 7 insertions, 5 deletions

diff --git a/tccgen.c b/tccgen.c
index b9681df..898856c 100644
--- a/tccgen.c
+++ b/tccgen.c
@@ -166,11 +166,13 @@ ST_INLN void sym_free(Sym *sym)
 ST_FUNC Sym *sym_push2(Sym **ps, int v, int t, long c)
 {
     Sym *s;
-    if (ps == &local_stack) {
-        for (s = *ps; s && s != scope_stack_bottom; s = s->prev)
-            if (!(v & SYM_FIELD) && (v & ~SYM_STRUCT) < SYM_FIRST_ANOM && s->v == v)
-                tcc_error("incompatible types for redefinition of '%s'",
-                          get_tok_str(v, NULL));
+    if (!tcc_state->no_type_redef_check) {
+        if (ps == &local_stack) {
+            for (s = *ps; s && s != scope_stack_bottom; s = s->prev)
+                if (!(v & SYM_FIELD) && (v & ~SYM_STRUCT) < SYM_FIRST_ANOM && s->v == v)
+                    tcc_error("incompatible types for redefinition of '%s'",
+                              get_tok_str(v, NULL));
+        }
     }
     s = sym_malloc();
     s->asm_label = 0;