p->next = NULL;
 }
 
+static int is_fixed(const char *s)
+{
+       while (*s && !is_regex_special(*s))
+               s++;
+       return !*s;
+}
+
 static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
 {
-       int err = regcomp(&p->regexp, p->pattern, opt->regflags);
+       int err;
+
+       if (opt->fixed || is_fixed(p->pattern))
+               p->fixed = 1;
+       if (opt->regflags & REG_ICASE)
+               p->fixed = 0;
+       if (p->fixed)
+               return;
+
+       err = regcomp(&p->regexp, p->pattern, opt->regflags);
        if (err) {
                char errbuf[1024];
                char where[1024];
                case GREP_PATTERN: /* atom */
                case GREP_PATTERN_HEAD:
                case GREP_PATTERN_BODY:
-                       if (!opt->fixed)
-                               compile_regexp(p, opt);
+                       compile_regexp(p, opt);
                        break;
                default:
                        opt->extended = 1;
        }
 
  again:
-       if (!opt->fixed) {
+       if (!p->fixed) {
                regex_t *exp = &p->regexp;
                hit = !regexec(exp, bol, ARRAY_SIZE(pmatch),
                               pmatch, 0);