Index: /trunk/include/iprt/x86.h
===================================================================
--- /trunk/include/iprt/x86.h	(revision 66055)
+++ /trunk/include/iprt/x86.h	(revision 66056)
@@ -4098,4 +4098,9 @@
 AssertCompile((X86_MODRM_REG_MASK >> X86_MODRM_REG_SHIFT) == X86_MODRM_REG_SMASK);
 AssertCompile((X86_MODRM_MOD_MASK >> X86_MODRM_MOD_SHIFT) == X86_MODRM_MOD_SMASK);
+/** @def X86_MODRM_MAKE
+ * @param   a_Mod       The mod value (0..3).
+ * @param   a_Reg       The register value (0..7).
+ * @param   a_RegMem    The register or memory value (0..7). */
+# define X86_MODRM_MAKE(a_Mod, a_Reg, a_RegMem) (((a_Mod) << X86_MODRM_MOD_SHIFT) | ((a_Reg) << X86_MODRM_REG_SHIFT) | (a_RegMem))
 #endif
 /** @} */