Use an explicit table for tolower() to avoid a function call

On some platforms, tolower() is implemented as a function call, in
order to handle locale support.  We never change locales, so can the
result of tolower() into a table, so we don't have to sit through the
function call every time.

~1.3% overall performance improvement on a macro-heavy benchmark under
Linux x86-64.

1 files changed, 2 insertions, 0 deletions

diff --git a/nasm.c b/nasm.c
index a8efbb2..416cee8 100644
--- a/nasm.c
+++ b/nasm.c
@@ -298,6 +298,8 @@ int main(int argc, char **argv)
 
     error_file = stderr;
 
+    tolower_init();
+
     nasm_set_malloc_error(report_error);
     offsets = raa_init();
     forwrefs = saa_init((int32_t)sizeof(struct forwrefinfo));