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

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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
This commit is contained in:
Denis Vlasenko 2008-07-28 15:17:44 +00:00
parent 12acec5ad4
commit cf22c89f9a
1 changed files with 15 additions and 15 deletions
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30
shell/hush.c
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@ -2016,7 +2016,7 @@ static int run_list(struct pipe *pi)
char *case_word = NULL; char *case_word = NULL;
#endif #endif
#if ENABLE_HUSH_LOOPS #if ENABLE_HUSH_LOOPS
struct pipe *loop_top; struct pipe *loop_top = loop_top; /* just for compiler */
char *for_varname = NULL; char *for_varname = NULL;
char **for_lcur = NULL; char **for_lcur = NULL;
char **for_list = NULL; char **for_list = NULL;
@ -2024,7 +2024,7 @@ static int run_list(struct pipe *pi)
smallint flag_goto_looptop = 0; smallint flag_goto_looptop = 0;
#endif #endif
smallint flag_skip = 1; smallint flag_skip = 1;
smalluint rcode = 0; /* probably for gcc only */ smalluint rcode = 0; /* probably just for compiler */
#if ENABLE_HUSH_IF #if ENABLE_HUSH_IF
smalluint cond_code = 0; smalluint cond_code = 0;
///experimentally off: last_cond_code seems to be bogus ///experimentally off: last_cond_code seems to be bogus
@ -2039,21 +2039,21 @@ static int run_list(struct pipe *pi)
#if ENABLE_HUSH_LOOPS #if ENABLE_HUSH_LOOPS
/* check syntax for "for" */ /* check syntax for "for" */
for (loop_top = pi; loop_top; loop_top = loop_top->next) { for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
if (loop_top->res_word != RES_FOR && loop_top->res_word != RES_IN) if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
continue; continue;
/* current word is FOR or IN (BOLD in comments below) */ /* current word is FOR or IN (BOLD in comments below) */
if (loop_top->next == NULL) { if (cpipe->next == NULL) {
syntax("malformed for"); syntax("malformed for");
debug_printf_exec("run_list lvl %d return 1\n", run_list_level); debug_printf_exec("run_list lvl %d return 1\n", run_list_level);
return 1; return 1;
} }
/* "FOR v; do ..." and "for v IN a b; do..." are ok */ /* "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; continue;
/* next word is not "do". It must be "in" then ("FOR v in ...") */ /* 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..."? */ if (cpipe->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..."? */ || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
) { ) {
syntax("malformed for"); syntax("malformed for");
debug_printf_exec("run_list lvl %d return 1\n", run_list_level); 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) { if (rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR) {
/* start of a loop: remember it */ /* start of a loop: remember it */
flag_goto_looptop = 0; /* not yet reached final "done" */ flag_goto_looptop = 0; /* not yet reached final "done" */
if (!loop_top) { /* hmm why this check is needed? */ // if (!loop_top) { /* hmm why this check is needed? */
flag_run_loop = 0; /* suppose loop condition is false (for now) */ // flag_run_loop = 0; /* suppose loop condition is false (for now) */
loop_top = pi; /* remember where loop starts */ loop_top = pi; /* remember where loop starts */
} // }
} }
#endif #endif
if (rword == skip_more_for_this_rword && flag_skip) { 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 */ break; /* "if <true> then ... ELIF cmd": skip cmd and all following ones */
#endif #endif
#if ENABLE_HUSH_LOOPS #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) { if (!for_lcur) {
/* first loop through for */ /* first loop through for */
@ -2158,7 +2158,7 @@ static int run_list(struct pipe *pi)
char **vals; char **vals;
vals = (char**)encoded_dollar_at_argv; 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 no variable values after "in" we skip "for" */
if (!pi->next->progs->argv) if (!pi->next->progs->argv)
continue; continue;
@ -2196,8 +2196,8 @@ static int run_list(struct pipe *pi)
if (rword == RES_DONE) { /* end of loop? */ if (rword == RES_DONE) { /* end of loop? */
if (flag_run_loop) { if (flag_run_loop) {
flag_goto_looptop = 1; flag_goto_looptop = 1;
} else { // } else {
loop_top = NULL; // loop_top = NULL;
} }
continue; //TEST /* "done" has no cmd anyway */ continue; //TEST /* "done" has no cmd anyway */
} }