tcg: Simplify logic using TCG_OPF_NOT_PRESENT

Expand the definition of "not present" to include "should not be present".
This means we can simplify the logic surrounding the generic tcg opcodes
for which the host backend ought not be providing definitions.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>

1 files changed, 2 insertions, 1 deletions

diff --git a/tcg/tcg.h b/tcg/tcg.h
index 28ca1bd976..f3f9889694 100644
--- a/tcg/tcg.h
+++ b/tcg/tcg.h
@@ -596,7 +596,8 @@ enum {
     TCG_OPF_SIDE_EFFECTS = 0x04,
     /* Instruction operands are 64-bits (otherwise 32-bits).  */
     TCG_OPF_64BIT        = 0x08,
-    /* Instruction is optional and not implemented by the host.  */
+    /* Instruction is optional and not implemented by the host, or insn
+       is generic and should not be implemened by the host.  */
     TCG_OPF_NOT_PRESENT  = 0x10,
 };