hush: in run_list(), some loop_top ops seems to be superfluous.

 comment them out. Also, use separate temp variable
 for verification loop, helps gcc to optimize better.

function                                             old     new   delta
run_list                                            2039    1984     -55

diff --git a/shell/hush.c b/shell/hush.c
index 98a69c1b138beb75ac2ea73a1574d32ddd4d45ce..ca2a1d21fd8e3a06450e6ca6524754b99f2cda79 100644 (file)
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -2016,7 +2016,7 @@ static int run_list(struct pipe *pi)
        char *case_word = NULL;
 #endif
 #if ENABLE_HUSH_LOOPS
-       struct pipe *loop_top;
+       struct pipe *loop_top = loop_top; /* just for compiler */
        char *for_varname = NULL;
        char **for_lcur = NULL;
        char **for_list = NULL;
@@ -2024,7 +2024,7 @@ static int run_list(struct pipe *pi)
        smallint flag_goto_looptop = 0;
 #endif
        smallint flag_skip = 1;
-       smalluint rcode = 0; /* probably for gcc only */
+       smalluint rcode = 0; /* probably just for compiler */
 #if ENABLE_HUSH_IF
        smalluint cond_code = 0;
 ///experimentally off: last_cond_code seems to be bogus
@@ -2039,21 +2039,21 @@ static int run_list(struct pipe *pi)
 
 #if ENABLE_HUSH_LOOPS
        /* check syntax for "for" */
-       for (loop_top = pi; loop_top; loop_top = loop_top->next) {
-               if (loop_top->res_word != RES_FOR && loop_top->res_word != RES_IN)
+       for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
+               if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
                        continue;
                /* current word is FOR or IN (BOLD in comments below) */
-               if (loop_top->next == NULL) {
+               if (cpipe->next == NULL) {
                        syntax("malformed for");
                        debug_printf_exec("run_list lvl %d return 1\n", run_list_level);
                        return 1;
                }
                /* "FOR v; do ..." and "for v IN a b; do..." are ok */
-               if (loop_top->next->res_word == RES_DO)
+               if (cpipe->next->res_word == RES_DO)
                        continue;
                /* next word is not "do". It must be "in" then ("FOR v in ...") */
-               if (loop_top->res_word == RES_IN /* "for v IN a b; not_do..."? */
-                || loop_top->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
+               if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
+                || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
                ) {
                        syntax("malformed for");
                        debug_printf_exec("run_list lvl %d return 1\n", run_list_level);
@@ -2118,10 +2118,10 @@ static int run_list(struct pipe *pi)
                if (rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR) {
                        /* start of a loop: remember it */
                        flag_goto_looptop = 0; /* not yet reached final "done" */
-                       if (!loop_top) { /* hmm why this check is needed? */
-                               flag_run_loop = 0; /* suppose loop condition is false (for now) */
+//                     if (!loop_top) { /* hmm why this check is needed? */
+//                             flag_run_loop = 0; /* suppose loop condition is false (for now) */
                                loop_top = pi; /* remember where loop starts */
-                       }
+//                     }
                }
 #endif
                if (rword == skip_more_for_this_rword && flag_skip) {
@@ -2145,7 +2145,7 @@ static int run_list(struct pipe *pi)
                        break; /* "if <true> then ... ELIF cmd": skip cmd and all following ones */
 #endif
 #if ENABLE_HUSH_LOOPS
-               if (rword == RES_FOR && pi->num_progs) {
+               if (rword == RES_FOR && pi->num_progs) { /* hmm why "&& pi->num_progs"? */
                        if (!for_lcur) {
                                /* first loop through for */
 
@@ -2158,7 +2158,7 @@ static int run_list(struct pipe *pi)
                                char **vals;
 
                                vals = (char**)encoded_dollar_at_argv;
-                               if (loop_top->next->res_word == RES_IN) {
+                               if (pi->next->res_word == RES_IN) {
                                        /* if no variable values after "in" we skip "for" */
                                        if (!pi->next->progs->argv)
                                                continue;
@@ -2196,8 +2196,8 @@ static int run_list(struct pipe *pi)
                if (rword == RES_DONE) { /* end of loop? */
                        if (flag_run_loop) {
                                flag_goto_looptop = 1;
-                       } else {
-                               loop_top = NULL;
+//                     } else {
+//                             loop_top = NULL;
                        }
                        continue; //TEST /* "done" has no cmd anyway */
                }