asmify strncpy

src/library.js

@@ -4350,14 +4350,18 @@ LibraryManager.library = {
     return pdest + i - 1;
   },
 
+  strncpy__asm: 'true',
+  strncpy__sig: 'iiii',
   strncpy: function(pdest, psrc, num) {
-    var padding = false, curr;
+    pdest = pdest|0; psrc = psrc|0; num = num|0;
-    for (var i = 0; i < num; i++) {
+    var padding = 0, curr = 0, i = 0;
-      curr = padding ? 0 : {{{ makeGetValue('psrc', 'i', 'i8') }}};
+    while ((i|0) < (num|0)) {
+      curr = padding ? 0 : {{{ makeGetValueAsm('psrc', 'i', 'i8') }}};
       {{{ makeSetValue('pdest', 'i', 'curr', 'i8') }}}
-      padding = padding || {{{ makeGetValue('psrc', 'i', 'i8') }}} == 0;
+      padding = padding | ({{{ makeGetValueAsm('psrc', 'i', 'i8') }}} == 0);
+      i = (i+1)|0;
     }
-    return pdest;
+    return pdest|0;
   },
   
   strlwr__deps:['tolower'],

tests/runner.py

@@ -1890,13 +1890,24 @@ Succeeded!
             printf("%s\\n", strdup_val);
             free(strdup_val);
 
+            {
+              char *one = "one 1 ONE !";
+              char *two = "two 2 TWO ?";
+              char three[1024];
+              memset(three, '.', 1024);
+              three[50] = 0;
+              strncpy(three + argc, one + (argc/2), argc+1);
+              strncpy(three + argc*3, two + (argc/3), argc+2);
+              printf("waka %s\\n", three);
+            }
+
             return 0;
           }
         '''
         for named in (0, 1):
           print named
           Settings.NAMED_GLOBALS = named
-          self.do_run(src, '4:10,177,543,def\n4\nwowie\ntoo\n76\n5\n(null)\n/* a comment */\n// another\ntest\n', ['wowie', 'too', '74'])
+          self.do_run(src, '4:10,177,543,def\n4\nwowie\ntoo\n76\n5\n(null)\n/* a comment */\n// another\ntest\nwaka ....e 1 O...wo 2 T................................\n', ['wowie', 'too', '74'])
           if self.emcc_args == []:
             gen = open(self.in_dir('src.cpp.o.js')).read()
             assert ('var __str1;' in gen) == named