From e661cb9a62428e610918bac9c0ba6ff9cd1449fc Mon Sep 17 00:00:00 2001
From: Benjamin Oldenburg <benjamin.oldenburg@ordis.co.th>
Date: Sun, 15 Mar 2026 23:47:09 +0700
Subject: [PATCH] Restrict arm64 old-style vararg handling to PE

---
 arm64-gen.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/arm64-gen.c b/arm64-gen.c
index 438a2205..9ec32cab 100644
--- a/arm64-gen.c
+++ b/arm64-gen.c
@@ -862,13 +862,6 @@ static unsigned long arm64_pcs_aux(int variadic, int n, CType **type, unsigned l
     unsigned long ns = 32; // next stack offset
     int i;
 
-#if defined(TCC_TARGET_MACHO)
-    /* Old-style / unprototyped calls must follow the variadic stack rules
-       from the first argument on Darwin. */
-    if (variadic < 0)
-        nx = 8, nv = 8;
-#endif
-
     for (i = 0; i < n; i++) {
         int hfa = arm64_hfa(type[i], 0);
         int win_vararg_float = 0;
@@ -1111,8 +1104,10 @@ ST_FUNC void gfunc_call(int nb_args)
 
     if (variadic)
         pcs_variadic = var_nb_arg;
+#ifdef TCC_TARGET_PE
     else if (old_style)
         pcs_variadic = ARM64_PCS_ALL_VARARGS;
+#endif
     stack = arm64_pcs(pcs_variadic, nb_args, t, a);
 
     // Allocate space for structs replaced by pointer: