bc: shrink zbc_vm_stdin()

function                                             old     new   delta
bc_vm_run                                            592     534     -58

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 13 insertions, 11 deletions

diff --git a/miscutils/bc.c b/miscutils/bc.c
index 47acd7fc3..7ab320a4d 100644
--- a/miscutils/bc.c
+++ b/miscutils/bc.c
@@ -758,6 +758,7 @@ struct globals {
 # define G_exiting 0
 #endif
 #define IS_BC (ENABLE_BC && (!ENABLE_DC || applet_name[0] == 'b'))
+#define IS_DC (ENABLE_DC && (!ENABLE_BC || applet_name[0] != 'b'))
 
 #if ENABLE_BC
 
@@ -7070,27 +7071,28 @@ static BC_STATUS zbc_vm_stdin(void)
                                 str -= 1;
                         else if (buf.v[0] == G.sbgn)
                                 str += 1;
-                }
-                else if (len > 1 || comment) {
+                } else {
                         size_t i;
                         for (i = 0; i < len; ++i) {
-                                bool notend = len > i + 1;
                                 char c = string[i];
 
                                 if (i - 1 > len || string[i - 1] != '\\') {
-                                        if (G.sbgn == G.send)
-                                                str ^= c == G.sbgn;
-                                        else if (c == G.send)
-                                                str -= 1;
-                                        else if (c == G.sbgn)
-                                                str += 1;
+                                        // checking applet type is cheaper than accessing sbgn/send
+                                        if (IS_DC) // dc: sbgn = send = '"'
+                                                str ^= (c == '"');
+                                        else { // bc: sbgn = '[', send = ']'
+                                                if (c == ']')
+                                                        str -= 1;
+                                                else if (c == '[')
+                                                        str += 1;
+                                        }
                                 }
 
-                                if (c == '/' && notend && !comment && string[i + 1] == '*') {
+                                if (c == '/' && !comment && string[i + 1] == '*') {
                                         comment = true;
                                         break;
                                 }
-                                else if (c == '*' && notend && comment && string[i + 1] == '/')
+                                else if (c == '*' && comment && string[i + 1] == '/')
                                         comment = false;
                         }