Module Name: src
Committed By: kre
Date: Mon Mar 20 11:31:00 UTC 2017
Modified Files:
src/bin/sh: arith_token.c
Log Message:
Alternative way of writing (part of) the arithmetic lexical analyzer
- committed separately to make it easier to swap back if desired.
This version avoids open coding is_name() and isdigit() - measurements
show it is perhaps fractionally faster (though the difference is so small
as to probably be statistically insignifigant - if I were a statician
I might understand that) and just a little larger than the previous version.
To generate a diff of this commit:
cvs rdiff -u -r1.1 -r1.2 src/bin/sh/arith_token.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/bin/sh/arith_token.c
diff -u src/bin/sh/arith_token.c:1.1 src/bin/sh/arith_token.c:1.2
--- src/bin/sh/arith_token.c:1.1 Mon Mar 20 11:26:07 2017
+++ src/bin/sh/arith_token.c Mon Mar 20 11:31:00 2017
@@ -1,4 +1,4 @@
-/* $NetBSD: arith_token.c,v 1.1 2017/03/20 11:26:07 kre Exp $ */
+/* $NetBSD: arith_token.c,v 1.2 2017/03/20 11:31:00 kre Exp $ */
/*-
* Copyright (c) 2002
@@ -39,7 +39,7 @@
#include <sys/cdefs.h>
#ifndef lint
-__RCSID("$NetBSD: arith_token.c,v 1.1 2017/03/20 11:26:07 kre Exp $");
+__RCSID("$NetBSD: arith_token.c,v 1.2 2017/03/20 11:31:00 kre Exp $");
#endif /* not lint */
#include <inttypes.h>
@@ -79,35 +79,22 @@ arith_token(void)
for (;;) {
token = *buf;
- switch (token) {
- case ' ':
- case '\t':
- case '\n':
- buf++;
- continue;
-
- default:
- error("arithmetic: unexpected '%c' (%#x) in expression",
- token, token);
- /* NOTREACHED */
-
- case '0': case '1': case '2': case '3': case '4':
- case '5': case '6': case '7': case '8': case '9':
+ if (isdigit(token)) {
+ /*
+ * Numbers all start with a digit, and nothing
+ * else does, the number ends wherever
+ * strtoimax() stops...
+ */
a_t_val.val = strtoimax(buf, &end, 0);
arith_buf = end;
return ARITH_NUM;
- case 'A': case 'B': case 'C': case 'D': case 'E':
- case 'F': case 'G': case 'H': case 'I': case 'J':
- case 'K': case 'L': case 'M': case 'N': case 'O':
- case 'P': case 'Q': case 'R': case 'S': case 'T':
- case 'U': case 'V': case 'W': case 'X': case 'Y': case 'Z':
- case 'a': case 'b': case 'c': case 'd': case 'e':
- case 'f': case 'g': case 'h': case 'i': case 'j':
- case 'k': case 'l': case 'm': case 'n': case 'o':
- case 'p': case 'q': case 'r': case 's': case 't':
- case 'u': case 'v': case 'w': case 'x': case 'y': case 'z':
- case '_':
+ } else if (is_name(token) {
+ /*
+ * Variable names all start with an alpha (or '_')
+ * and nothing else does. They continue for the
+ * longest unbroken sequence of alphanumerics ( + _ )
+ */
p = buf;
while (buf++, is_in_name(*buf))
;
@@ -117,6 +104,22 @@ arith_token(void)
arith_buf = buf;
return ARITH_VAR;
+ } else switch (token) {
+ /*
+ * everything else must be some kind of
+ * operator, white space, or an error.
+ */
+ case ' ':
+ case '\t':
+ case '\n':
+ buf++;
+ continue;
+
+ default:
+ error("arithmetic: unexpected '%c' (%#x) in expression",
+ token, token);
+ /* NOTREACHED */
+
case '=':
token = ARITH_ASS;
checkeq:
