Rewrite the handling of SAA's to allow random access

SAA's were never intended to allow random access, but several backends
do random or semirandom access via saa_fread() and saa_fwrite()
anyway.  Rewrite the SAA system to allow for efficient random access.

On "label.pl 10000000" this improves performance by a factor of 12.

1 files changed, 1 insertions, 1 deletions

diff --git a/nasm.c b/nasm.c
index 726fd09..12b51af 100644
--- a/nasm.c
+++ b/nasm.c
@@ -77,7 +77,7 @@ int32_t abs_offset;                /* ABSOLUTE offset */
 static struct RAA *offsets;
 
 static struct SAA *forwrefs;    /* keep track of forward references */
-static struct forwrefinfo *forwref;
+static const struct forwrefinfo *forwref;
 
 static Preproc *preproc;
 enum op_type {