diff --git a/gcc/genemit.c b/gcc/genemit.c
index 84d07d388ee..23c89dbf4e9 100644
--- a/gcc/genemit.c
+++ b/gcc/genemit.c
@@ -857,6 +857,9 @@ main (int argc, const char **argv)
 
 #define DEF_INTERNAL_OPTAB_FN(NAME, FLAGS, OPTAB, TYPE) \
   nofail_optabs[OPTAB##_optab] = true;
+
+#define DEF_INTERNAL_OPTAB_CAN_FAIL(OPTAB) \
+  nofail_optabs[OPTAB##_optab] = false;
 #include "internal-fn.def"
 
   /* Assign sequential codes to all entries in the machine description
diff --git a/gcc/internal-fn.def b/gcc/internal-fn.def
index 0c6fc371190..373273de2c2 100644
--- a/gcc/internal-fn.def
+++ b/gcc/internal-fn.def
@@ -34,6 +34,7 @@ along with GCC; see the file COPYING3.  If not see
 				   UNSIGNED_OPTAB, TYPE)
      DEF_INTERNAL_FLT_FN (NAME, FLAGS, OPTAB, TYPE)
      DEF_INTERNAL_INT_FN (NAME, FLAGS, OPTAB, TYPE)
+     DEF_INTERNAL_OPTAB_CAN_FAIL (OPTAB)
 
    where NAME is the name of the function, FLAGS is a set of
    ECF_* flags and FNSPEC is a string describing functions fnspec.
@@ -86,7 +87,10 @@ along with GCC; see the file COPYING3.  If not see
 
    where STMT is the statement that performs the call.  These are generated
    automatically for optab functions and call out to a function or macro
-   called expand_<TYPE>_optab_fn.  */
+   called expand_<TYPE>_optab_fn.
+
+   DEF_INTERNAL_OPTAB_CAN_FAIL defines tables that are used for GIMPLE
+   instruction selection and do not map directly to instructions.  */
 
 #ifndef DEF_INTERNAL_FN
 #define DEF_INTERNAL_FN(CODE, FLAGS, FNSPEC)
@@ -118,6 +122,10 @@ along with GCC; see the file COPYING3.  If not see
   DEF_INTERNAL_OPTAB_FN (NAME, FLAGS, OPTAB, TYPE)
 #endif
 
+#ifndef DEF_INTERNAL_OPTAB_CAN_FAIL
+#define DEF_INTERNAL_OPTAB_CAN_FAIL(OPTAB)
+#endif
+
 DEF_INTERNAL_OPTAB_FN (MASK_LOAD, ECF_PURE, maskload, mask_load)
 DEF_INTERNAL_OPTAB_FN (LOAD_LANES, ECF_CONST, vec_load_lanes, load_lanes)
 DEF_INTERNAL_OPTAB_FN (MASK_LOAD_LANES, ECF_PURE,
@@ -141,6 +149,11 @@ DEF_INTERNAL_OPTAB_FN (VCONDU, 0, vcondu, vec_condu)
 DEF_INTERNAL_OPTAB_FN (VCONDEQ, 0, vcondeq, vec_condeq)
 DEF_INTERNAL_OPTAB_FN (VCOND_MASK, 0, vcond_mask, vec_cond_mask)
 
+DEF_INTERNAL_OPTAB_CAN_FAIL (vcond)
+DEF_INTERNAL_OPTAB_CAN_FAIL (vcondu)
+DEF_INTERNAL_OPTAB_CAN_FAIL (vcondeq)
+DEF_INTERNAL_OPTAB_CAN_FAIL (vcond_mask)
+
 DEF_INTERNAL_OPTAB_FN (WHILE_ULT, ECF_CONST | ECF_NOTHROW, while_ult, while)
 DEF_INTERNAL_OPTAB_FN (CHECK_RAW_PTRS, ECF_CONST | ECF_NOTHROW,
 		       check_raw_ptrs, check_ptrs)
@@ -385,4 +398,5 @@ DEF_INTERNAL_FN (NOP, ECF_CONST | ECF_LEAF | ECF_NOTHROW, NULL)
 #undef DEF_INTERNAL_FLT_FLOATN_FN
 #undef DEF_INTERNAL_SIGNED_OPTAB_FN
 #undef DEF_INTERNAL_OPTAB_FN
+#undef DEF_INTERNAL_OPTAB_CAN_FAIL
 #undef DEF_INTERNAL_FN