2 files changed, 11 insertions, 7 deletions

diff --git a/lgc.c b/lgc.c
index c93b5994..c2b0535d 100644
--- a/lgc.c
+++ b/lgc.c
@@ -1614,12 +1614,16 @@ static void incstep (lua_State *L, global_State *g) {
 }
 
 /*
-** performs a basic GC step if collector is running
+** Performs a basic GC step if collector is running. (If collector is
+** not running, set a reasonable debt to avoid it being called at
+** every single check.)
 */
 void luaC_step (lua_State *L) {
   global_State *g = G(L);
   lua_assert(!g->gcemergency);
-  if (gcrunning(g)) {  /* running? */
+  if (!gcrunning(g))  /* not running? */
+    luaE_setdebt(g, -2000);
+  else {
     switch (g->gckind) {
       case KGC_INC:
         incstep(L, g);
diff --git a/lmathlib.c b/lmathlib.c
index e0c61a16..d0b1e1e5 100644
--- a/lmathlib.c
+++ b/lmathlib.c
@@ -267,7 +267,7 @@ static int math_type (lua_State *L) {
 
 /* try to find an integer type with at least 64 bits */
 
-#if (ULONG_MAX >> 31 >> 31) >= 3
+#if ((ULONG_MAX >> 31) >> 31) >= 3
 
 /* 'long' has at least 64 bits */
 #define Rand64          unsigned long
@@ -277,9 +277,9 @@ static int math_type (lua_State *L) {
 /* there is a 'long long' type (which must have at least 64 bits) */
 #define Rand64          unsigned long long
 
-#elif (LUA_MAXUNSIGNED >> 31 >> 31) >= 3
+#elif ((LUA_MAXUNSIGNED >> 31) >> 31) >= 3
 
-/* 'lua_Integer' has at least 64 bits */
+/* 'lua_Unsigned' has at least 64 bits */
 #define Rand64          lua_Unsigned
 
 #endif
@@ -500,12 +500,12 @@ static lua_Number I2d (Rand64 x) {
 
 /* convert a 'Rand64' to a 'lua_Unsigned' */
 static lua_Unsigned I2UInt (Rand64 x) {
-  return ((lua_Unsigned)trim32(x.h) << 31 << 1) | (lua_Unsigned)trim32(x.l);
+  return (((lua_Unsigned)trim32(x.h) << 31) << 1) | (lua_Unsigned)trim32(x.l);
 }
 
 /* convert a 'lua_Unsigned' to a 'Rand64' */
 static Rand64 Int2I (lua_Unsigned n) {
-  return packI((lu_int32)(n >> 31 >> 1), (lu_int32)n);
+  return packI((lu_int32)((n >> 31) >> 1), (lu_int32)n);
 }
 
 #endif  /* } */