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| author | Denys Vlasenko | 2019-05-09 15:58:46 +0200 |
|---|---|---|
| committer | Denys Vlasenko | 2019-05-09 15:58:46 +0200 |
| commit | 89023b167fad897fb6c0d2cdd24f0140beea7df3 (patch) | |
| tree | 76a330b35745d7c67b59d6ea551272eb42ca9630 | |
| parent | 3106784e654e7443ab724d927f9de0230adbe5ac (diff) | |
| download | busybox-89023b167fad897fb6c0d2cdd24f0140beea7df3.zip busybox-89023b167fad897fb6c0d2cdd24f0140beea7df3.tar.gz | |
dc: code shrink
function old new delta
check_under 20 21 +1
print_no_pop 32 27 -5
pop 24 18 -6
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/2 up/down: 1/-11) Total: -10 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
| -rw-r--r-- | miscutils/dc.c | 22 |
1 files changed, 16 insertions, 6 deletions
diff --git a/miscutils/dc.c b/miscutils/dc.c index 17fdda8..5119c13 100644 --- a/miscutils/dc.c +++ b/miscutils/dc.c @@ -35,10 +35,12 @@ enum { STACK_SIZE = (COMMON_BUFSIZE - offsetof(struct globals, stack)) / sizeof( base = 10; \ } while (0) -static void check_under(void) +static unsigned check_under(void) { - if (pointer == 0) + unsigned p = pointer; + if (p == 0) bb_error_msg_and_die("stack underflow"); + return p - 1; } static void push(double a) @@ -50,8 +52,9 @@ static void push(double a) static double pop(void) { - check_under(); - return stack[--pointer]; + unsigned p = check_under(); + pointer = p; + return stack[p]; } static void add(void) @@ -91,6 +94,14 @@ static void mod(void) { data_t d = pop(); + //if (d == 0) { + // bb_error_msg("remainder by zero"); + // pop(); + // push(0); + // return; + //} + //^^^^ without this, we simply get SIGFPE and die + push((data_t) pop() % d); } @@ -171,8 +182,7 @@ static void print_stack_no_pop(void) static void print_no_pop(void) { - check_under(); - print_base(stack[pointer-1]); + print_base(stack[check_under()]); } struct op { |