diff --git a/gcc/config/aarch64/aarch64-protos.h b/gcc/config/aarch64/aarch64-protos.h
index c4c1817..2abee03 100644
--- a/gcc/config/aarch64/aarch64-protos.h
+++ b/gcc/config/aarch64/aarch64-protos.h
@@ -231,8 +231,19 @@ enum aarch64_fusion_pairs
 };
 #undef AARCH64_FUSION_PAIR
 
-#define AARCH64_EXTRA_TUNING_OPTION(x, name, index) \
-  AARCH64_EXTRA_TUNE_##name = (1 << index),
+#define AARCH64_EXTRA_TUNING_OPTION(x, name) \
+  AARCH64_EXTRA_TUNE_##name##_index,
+/* Supported tuning flags indexes.  */
+enum aarch64_extra_tuning_flags_index
+{
+#include "aarch64-tuning-flags.def"
+  AARCH64_EXTRA_TUNE_index_END
+};
+#undef AARCH64_EXTRA_TUNING_OPTION
+
+
+#define AARCH64_EXTRA_TUNING_OPTION(x, name) \
+  AARCH64_EXTRA_TUNE_##name = (1 << AARCH64_EXTRA_TUNE_##name##_index),
 /* Supported tuning flags.  */
 enum aarch64_extra_tuning_flags
 {
@@ -242,7 +253,7 @@ enum aarch64_extra_tuning_flags
 /* Hacky macro to build the "all" flag mask.
    Expands to 0 | AARCH64_TUNE_index0 | AARCH64_TUNE_index1 , etc.  */
 #undef AARCH64_EXTRA_TUNING_OPTION
-#define AARCH64_EXTRA_TUNING_OPTION(x, name, y) \
+#define AARCH64_EXTRA_TUNING_OPTION(x, name) \
   | AARCH64_EXTRA_TUNE_##name
   AARCH64_EXTRA_TUNE_ALL = 0
 #include "aarch64-tuning-flags.def"
diff --git a/gcc/config/aarch64/aarch64-tuning-flags.def b/gcc/config/aarch64/aarch64-tuning-flags.def
index 01aaca8..628386b 100644
--- a/gcc/config/aarch64/aarch64-tuning-flags.def
+++ b/gcc/config/aarch64/aarch64-tuning-flags.def
@@ -20,15 +20,13 @@
 /* Additional control over certain tuning parameters.  Before including
    this file, define a macro:
 
-     AARCH64_EXTRA_TUNING_OPTION (name, internal_name, index_bit)
+     AARCH64_EXTRA_TUNING_OPTION (name, internal_name)
 
    Where:
 
      NAME is a string giving a friendly name for the tuning flag.
      INTERNAL_NAME gives the internal name suitable for appending to
-     AARCH64_TUNE_ to give an enum name.
-     INDEX_BIT is the bit to set in the bitmask of supported tuning
-     flags.  */
+     AARCH64_TUNE_ to give an enum name. */
 
-AARCH64_EXTRA_TUNING_OPTION ("rename_fma_regs", RENAME_FMA_REGS, 0)
+AARCH64_EXTRA_TUNING_OPTION ("rename_fma_regs", RENAME_FMA_REGS)
 
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 162e25e..ad144fe 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -183,7 +183,7 @@ static const struct aarch64_flag_desc aarch64_fusible_pairs[] =
 };
 #undef AARCH64_FUION_PAIR
 
-#define AARCH64_EXTRA_TUNING_OPTION(name, internal_name, y) \
+#define AARCH64_EXTRA_TUNING_OPTION(name, internal_name) \
   { name, AARCH64_EXTRA_TUNE_##internal_name },
 static const struct aarch64_flag_desc aarch64_tuning_flags[] =
 {