--- a/opcodes/ppc-svp64-dis.c
+++ b/opcodes/ppc-svp64-dis.c
@@ -45,19 +45,17 @@ static const struct powerpc_opcode *
 svp64_lookup (uint64_t insn, ppc_cpu_t dialect,
     struct svp64_ctx *svp64)
 {
-  uint32_t rm;
   unsigned long op;
-  struct svp64_prefix svp64_prefix;
+  struct svp64_insn svp64_insn;
   const struct powerpc_opcode *opcode;
   const struct svp64_record *record;
   const struct svp64_record *record_end;
-  uint32_t prefix = PPC_GET_PREFIX (insn);
   uint32_t suffix = PPC_GET_SUFFIX (insn);

-  memset (&svp64_prefix, 0, sizeof (svp64_prefix));
-  svp64_prefix_set (&svp64_prefix, SVP64_PREFIX_INSN, prefix);
-  if ((svp64_prefix_get (svp64_prefix, SVP64_PREFIX_MAJOR) != 0x1) ||
-      (svp64_prefix_get (svp64_prefix, SVP64_PREFIX_PID) != 0x3))
+  svp64_insn_set (&svp64_insn, insn);
+
+  if ((svp64_insn_get_prefix_PO (&svp64_insn) != 0x1) ||
+      (svp64_insn_get_prefix_id (&svp64_insn) != 0x3))
     return NULL;

   opcode = lookup_powerpc (suffix, dialect & ~PPC_OPCODE_ANY);
@@ -81,8 +79,6 @@ svp64_lookup (uint64_t insn, ppc_cpu_t dialect,
   if (record == record_end)
     return NULL;

-  rm = svp64_prefix_get (svp64_prefix, SVP64_PREFIX_RM);
-  svp64_rm_set (&svp64->rm, SVP64_RM_SPR, rm);
   svp64->desc = &record->desc;

   return opcode;