1 files changed, 7 insertions, 0 deletions
diff --git a/gen_x86.h b/gen_x86.h
index d384107..6ff0da9 100644
--- a/gen_x86.h
+++ b/gen_x86.h
@@ -63,6 +63,13 @@ enum {
 #ifdef X86_64
 #define SZ_PTR SZ_Q
 #define MAX_INST_LEN 14
+#ifdef _WIN32
+#define FIRST_ARG_REG RCX
+#define SECOND_ARG_REG RDX
+#else
+#define FIRST_ARG_REG RDI
+#define SECOND_ARG_REG RSI
+#endif
 #else
 #define SZ_PTR SZ_D
 #define MAX_INST_LEN 11