lua

commit 8a0acf0898fc9bd990fc10275e72c89a6ca829a6
parent e2be310a85df0b8eb5c406aa0397088a66b98c47
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date:   Tue, 20 May 2014 11:12:34 -0300

comments

Diffstat:
M
lvm.c
 | 
10
++++++----

1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/lvm.c b/lvm.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lvm.c,v 2.210 2014/05/14 19:47:11 roberto Exp roberto $
+** $Id: lvm.c,v 2.211 2014/05/15 20:08:32 roberto Exp roberto $
 ** Lua virtual machine
 ** See Copyright Notice in lua.h
 */
@@ -452,7 +452,8 @@ void luaV_objlen (lua_State *L, StkId ra, const TValue *rb) {
 
 
 /*
-** Integer division; return 'm // n'.
+** Integer division; return 'm // n'. (Assume that C division with
+** negative operands follows C99 behavior.)
 */
 lua_Integer luaV_div (lua_State *L, lua_Integer m, lua_Integer n) {
   if (l_castS2U(n) + 1u <= 1u) {  /* special cases: -1 or 0 */
@@ -471,7 +472,8 @@ lua_Integer luaV_div (lua_State *L, lua_Integer m, lua_Integer n) {
 
 
 /*
-** Integer modulus; return 'm % n'.
+** Integer modulus; return 'm % n'. (Assume that C '%' with 
+** negative operands follows C99 behavior.)
 */
 lua_Integer luaV_mod (lua_State *L, lua_Integer m, lua_Integer n) {
   if (l_castS2U(n) + 1u <= 1u) {  /* special cases: -1 or 0 */
@@ -481,7 +483,7 @@ lua_Integer luaV_mod (lua_State *L, lua_Integer m, lua_Integer n) {
   }
   else {
     lua_Integer r = m % n;
-    if (r == 0 || (m ^ n) >= 0)
+    if (r == 0 || (m ^ n) >= 0)  /* no rest or same signal? */
       return r;
     else
       return r + n;  /* correct 'mod' for negative case */