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Broadening the use of branch hints
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More uses of macros 'likely'/'unlikely' (renamed to
'l_likely'/'l_unlikely'), both in range (extended to the
libraries) and in scope (extended to hooks, stack growth).
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@roberto-ieru
roberto-ieru committed Feb 24, 2021
1 parent c03c527 commit 59c88f8
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Showing 24 changed files with 162 additions and 141 deletions.
22 changes: 11 additions & 11 deletions lauxlib.c
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Original file line number Diff line number Diff line change
Expand Up @@ -190,7 +190,7 @@ LUALIB_API int luaL_argerror (lua_State *L, int arg, const char *extramsg) {
}


int luaL_typeerror (lua_State *L, int arg, const char *tname) {
LUALIB_API int luaL_typeerror (lua_State *L, int arg, const char *tname) {
const char *msg;
const char *typearg; /* name for the type of the actual argument */
if (luaL_getmetafield(L, arg, "__name") == LUA_TSTRING)
Expand Down Expand Up @@ -378,7 +378,7 @@ LUALIB_API int luaL_checkoption (lua_State *L, int arg, const char *def,
** but without 'msg'.)
*/
LUALIB_API void luaL_checkstack (lua_State *L, int space, const char *msg) {
if (!lua_checkstack(L, space)) {
if (l_unlikely(!lua_checkstack(L, space))) {
if (msg)
luaL_error(L, "stack overflow (%s)", msg);
else
Expand All @@ -388,20 +388,20 @@ LUALIB_API void luaL_checkstack (lua_State *L, int space, const char *msg) {


LUALIB_API void luaL_checktype (lua_State *L, int arg, int t) {
if (lua_type(L, arg) != t)
if (l_unlikely(lua_type(L, arg) != t))
tag_error(L, arg, t);
}


LUALIB_API void luaL_checkany (lua_State *L, int arg) {
if (lua_type(L, arg) == LUA_TNONE)
if (l_unlikely(lua_type(L, arg) == LUA_TNONE))
luaL_argerror(L, arg, "value expected");
}


LUALIB_API const char *luaL_checklstring (lua_State *L, int arg, size_t *len) {
const char *s = lua_tolstring(L, arg, len);
if (!s) tag_error(L, arg, LUA_TSTRING);
if (l_unlikely(!s)) tag_error(L, arg, LUA_TSTRING);
return s;
}

Expand All @@ -420,7 +420,7 @@ LUALIB_API const char *luaL_optlstring (lua_State *L, int arg,
LUALIB_API lua_Number luaL_checknumber (lua_State *L, int arg) {
int isnum;
lua_Number d = lua_tonumberx(L, arg, &isnum);
if (!isnum)
if (l_unlikely(!isnum))
tag_error(L, arg, LUA_TNUMBER);
return d;
}
Expand All @@ -442,7 +442,7 @@ static void interror (lua_State *L, int arg) {
LUALIB_API lua_Integer luaL_checkinteger (lua_State *L, int arg) {
int isnum;
lua_Integer d = lua_tointegerx(L, arg, &isnum);
if (!isnum) {
if (l_unlikely(!isnum)) {
interror(L, arg);
}
return d;
Expand Down Expand Up @@ -475,7 +475,7 @@ static void *resizebox (lua_State *L, int idx, size_t newsize) {
lua_Alloc allocf = lua_getallocf(L, &ud);
UBox *box = (UBox *)lua_touserdata(L, idx);
void *temp = allocf(ud, box->box, box->bsize, newsize);
if (temp == NULL && newsize > 0) { /* allocation error? */
if (l_unlikely(temp == NULL && newsize > 0)) { /* allocation error? */
lua_pushliteral(L, "not enough memory");
lua_error(L); /* raise a memory error */
}
Expand Down Expand Up @@ -521,7 +521,7 @@ static void newbox (lua_State *L) {
*/
static size_t newbuffsize (luaL_Buffer *B, size_t sz) {
size_t newsize = B->size * 2; /* double buffer size */
if (MAX_SIZET - sz < B->n) /* overflow in (B->n + sz)? */
if (l_unlikely(MAX_SIZET - sz < B->n)) /* overflow in (B->n + sz)? */
return luaL_error(B->L, "buffer too large");
if (newsize < B->n + sz) /* double is not big enough? */
newsize = B->n + sz;
Expand Down Expand Up @@ -861,7 +861,7 @@ LUALIB_API lua_Integer luaL_len (lua_State *L, int idx) {
int isnum;
lua_len(L, idx);
l = lua_tointegerx(L, -1, &isnum);
if (!isnum)
if (l_unlikely(!isnum))
luaL_error(L, "object length is not an integer");
lua_pop(L, 1); /* remove object */
return l;
Expand Down Expand Up @@ -1074,7 +1074,7 @@ static void warnfon (void *ud, const char *message, int tocont) {

LUALIB_API lua_State *luaL_newstate (void) {
lua_State *L = lua_newstate(l_alloc, NULL);
if (L) {
if (l_likely(L)) {
lua_atpanic(L, &panic);
lua_setwarnf(L, warnfoff, L); /* default is warnings off */
}
Expand Down
8 changes: 6 additions & 2 deletions lauxlib.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -122,6 +122,10 @@ LUALIB_API void (luaL_requiref) (lua_State *L, const char *modname,
** ===============================================================
*/

#if !defined(l_likely)
#define l_likely(x) x
#endif


#define luaL_newlibtable(L,l) \
lua_createtable(L, 0, sizeof(l)/sizeof((l)[0]) - 1)
Expand All @@ -130,10 +134,10 @@ LUALIB_API void (luaL_requiref) (lua_State *L, const char *modname,
(luaL_checkversion(L), luaL_newlibtable(L,l), luaL_setfuncs(L,l,0))

#define luaL_argcheck(L, cond,arg,extramsg) \
((void)((cond) || luaL_argerror(L, (arg), (extramsg))))
((void)(l_likely(cond) || luaL_argerror(L, (arg), (extramsg))))

#define luaL_argexpected(L,cond,arg,tname) \
((void)((cond) || luaL_typeerror(L, (arg), (tname))))
((void)(l_likely(cond) || luaL_typeerror(L, (arg), (tname))))

#define luaL_checkstring(L,n) (luaL_checklstring(L, (n), NULL))
#define luaL_optstring(L,n,d) (luaL_optlstring(L, (n), (d), NULL))
Expand Down
12 changes: 6 additions & 6 deletions lbaselib.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -138,7 +138,7 @@ static int luaB_setmetatable (lua_State *L) {
int t = lua_type(L, 2);
luaL_checktype(L, 1, LUA_TTABLE);
luaL_argexpected(L, t == LUA_TNIL || t == LUA_TTABLE, 2, "nil or table");
if (luaL_getmetafield(L, 1, "__metatable") != LUA_TNIL)
if (l_unlikely(luaL_getmetafield(L, 1, "__metatable") != LUA_TNIL))
return luaL_error(L, "cannot change a protected metatable");
lua_settop(L, 2);
lua_setmetatable(L, 1);
Expand Down Expand Up @@ -300,7 +300,7 @@ static int luaB_ipairs (lua_State *L) {


static int load_aux (lua_State *L, int status, int envidx) {
if (status == LUA_OK) {
if (l_likely(status == LUA_OK)) {
if (envidx != 0) { /* 'env' parameter? */
lua_pushvalue(L, envidx); /* environment for loaded function */
if (!lua_setupvalue(L, -2, 1)) /* set it as 1st upvalue */
Expand Down Expand Up @@ -356,7 +356,7 @@ static const char *generic_reader (lua_State *L, void *ud, size_t *size) {
*size = 0;
return NULL;
}
else if (!lua_isstring(L, -1))
else if (l_unlikely(!lua_isstring(L, -1)))
luaL_error(L, "reader function must return a string");
lua_replace(L, RESERVEDSLOT); /* save string in reserved slot */
return lua_tolstring(L, RESERVEDSLOT, size);
Expand Down Expand Up @@ -394,15 +394,15 @@ static int dofilecont (lua_State *L, int d1, lua_KContext d2) {
static int luaB_dofile (lua_State *L) {
const char *fname = luaL_optstring(L, 1, NULL);
lua_settop(L, 1);
if (luaL_loadfile(L, fname) != LUA_OK)
if (l_unlikely(luaL_loadfile(L, fname) != LUA_OK))
return lua_error(L);
lua_callk(L, 0, LUA_MULTRET, 0, dofilecont);
return dofilecont(L, 0, 0);
}


static int luaB_assert (lua_State *L) {
if (lua_toboolean(L, 1)) /* condition is true? */
if (l_likely(lua_toboolean(L, 1))) /* condition is true? */
return lua_gettop(L); /* return all arguments */
else { /* error */
luaL_checkany(L, 1); /* there must be a condition */
Expand Down Expand Up @@ -438,7 +438,7 @@ static int luaB_select (lua_State *L) {
** ignored).
*/
static int finishpcall (lua_State *L, int status, lua_KContext extra) {
if (status != LUA_OK && status != LUA_YIELD) { /* error? */
if (l_unlikely(status != LUA_OK && status != LUA_YIELD)) { /* error? */
lua_pushboolean(L, 0); /* first result (false) */
lua_pushvalue(L, -2); /* error message */
return 2; /* return false, msg */
Expand Down
10 changes: 5 additions & 5 deletions lcorolib.c
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Original file line number Diff line number Diff line change
Expand Up @@ -31,14 +31,14 @@ static lua_State *getco (lua_State *L) {
*/
static int auxresume (lua_State *L, lua_State *co, int narg) {
int status, nres;
if (!lua_checkstack(co, narg)) {
if (l_unlikely(!lua_checkstack(co, narg))) {
lua_pushliteral(L, "too many arguments to resume");
return -1; /* error flag */
}
lua_xmove(L, co, narg);
status = lua_resume(co, L, narg, &nres);
if (status == LUA_OK || status == LUA_YIELD) {
if (!lua_checkstack(L, nres + 1)) {
if (l_likely(status == LUA_OK || status == LUA_YIELD)) {
if (l_unlikely(!lua_checkstack(L, nres + 1))) {
lua_pop(co, nres); /* remove results anyway */
lua_pushliteral(L, "too many results to resume");
return -1; /* error flag */
Expand All @@ -57,7 +57,7 @@ static int luaB_coresume (lua_State *L) {
lua_State *co = getco(L);
int r;
r = auxresume(L, co, lua_gettop(L) - 1);
if (r < 0) {
if (l_unlikely(r < 0)) {
lua_pushboolean(L, 0);
lua_insert(L, -2);
return 2; /* return false + error message */
Expand All @@ -73,7 +73,7 @@ static int luaB_coresume (lua_State *L) {
static int luaB_auxwrap (lua_State *L) {
lua_State *co = lua_tothread(L, lua_upvalueindex(1));
int r = auxresume(L, co, lua_gettop(L));
if (r < 0) { /* error? */
if (l_unlikely(r < 0)) { /* error? */
int stat = lua_status(co);
if (stat != LUA_OK && stat != LUA_YIELD) { /* error in the coroutine? */
stat = lua_resetthread(co); /* close its tbc variables */
Expand Down
6 changes: 3 additions & 3 deletions ldblib.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -33,7 +33,7 @@ static const char *const HOOKKEY = "_HOOKKEY";
** checked.
*/
static void checkstack (lua_State *L, lua_State *L1, int n) {
if (L != L1 && !lua_checkstack(L1, n))
if (l_unlikely(L != L1 && !lua_checkstack(L1, n)))
luaL_error(L, "stack overflow");
}

Expand Down Expand Up @@ -213,7 +213,7 @@ static int db_getlocal (lua_State *L) {
lua_Debug ar;
const char *name;
int level = (int)luaL_checkinteger(L, arg + 1);
if (!lua_getstack(L1, level, &ar)) /* out of range? */
if (l_unlikely(!lua_getstack(L1, level, &ar))) /* out of range? */
return luaL_argerror(L, arg+1, "level out of range");
checkstack(L, L1, 1);
name = lua_getlocal(L1, &ar, nvar);
Expand All @@ -238,7 +238,7 @@ static int db_setlocal (lua_State *L) {
lua_Debug ar;
int level = (int)luaL_checkinteger(L, arg + 1);
int nvar = (int)luaL_checkinteger(L, arg + 2);
if (!lua_getstack(L1, level, &ar)) /* out of range? */
if (l_unlikely(!lua_getstack(L1, level, &ar))) /* out of range? */
return luaL_argerror(L, arg+1, "level out of range");
luaL_checkany(L, arg+3);
lua_settop(L, arg+3);
Expand Down
24 changes: 12 additions & 12 deletions ldo.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -184,7 +184,7 @@ int luaD_reallocstack (lua_State *L, int newsize, int raiseerror) {
StkId newstack = luaM_reallocvector(L, L->stack,
lim + EXTRA_STACK, newsize + EXTRA_STACK, StackValue);
lua_assert(newsize <= LUAI_MAXSTACK || newsize == ERRORSTACKSIZE);
if (unlikely(newstack == NULL)) { /* reallocation failed? */
if (l_unlikely(newstack == NULL)) { /* reallocation failed? */
if (raiseerror)
luaM_error(L);
else return 0; /* do not raise an error */
Expand All @@ -204,7 +204,7 @@ int luaD_reallocstack (lua_State *L, int newsize, int raiseerror) {
*/
int luaD_growstack (lua_State *L, int n, int raiseerror) {
int size = stacksize(L);
if (unlikely(size > LUAI_MAXSTACK)) {
if (l_unlikely(size > LUAI_MAXSTACK)) {
/* if stack is larger than maximum, thread is already using the
extra space reserved for errors, that is, thread is handling
a stack error; cannot grow further than that. */
Expand All @@ -220,7 +220,7 @@ int luaD_growstack (lua_State *L, int n, int raiseerror) {
newsize = LUAI_MAXSTACK;
if (newsize < needed) /* but must respect what was asked for */
newsize = needed;
if (likely(newsize <= LUAI_MAXSTACK))
if (l_likely(newsize <= LUAI_MAXSTACK))
return luaD_reallocstack(L, newsize, raiseerror);
else { /* stack overflow */
/* add extra size to be able to handle the error message */
Expand Down Expand Up @@ -376,7 +376,7 @@ static void rethook (lua_State *L, CallInfo *ci, int nres) {
void luaD_tryfuncTM (lua_State *L, StkId func) {
const TValue *tm = luaT_gettmbyobj(L, s2v(func), TM_CALL);
StkId p;
if (unlikely(ttisnil(tm)))
if (l_unlikely(ttisnil(tm)))
luaG_callerror(L, s2v(func)); /* nothing to call */
for (p = L->top; p > func; p--) /* open space for metamethod */
setobjs2s(L, p, p-1);
Expand Down Expand Up @@ -444,7 +444,7 @@ static void moveresults (lua_State *L, StkId res, int nres, int wanted) {
*/
void luaD_poscall (lua_State *L, CallInfo *ci, int nres) {
int wanted = ci->nresults;
if (L->hookmask && !hastocloseCfunc(wanted))
if (l_unlikely(L->hookmask && !hastocloseCfunc(wanted)))
rethook(L, ci, nres);
/* move results to proper place */
moveresults(L, ci->func, nres, wanted);
Expand Down Expand Up @@ -510,7 +510,7 @@ CallInfo *luaD_precall (lua_State *L, StkId func, int nresults) {
ci->top = L->top + LUA_MINSTACK;
ci->func = func;
lua_assert(ci->top <= L->stack_last);
if (L->hookmask & LUA_MASKCALL) {
if (l_unlikely(L->hookmask & LUA_MASKCALL)) {
int narg = cast_int(L->top - func) - 1;
luaD_hook(L, LUA_HOOKCALL, -1, 1, narg);
}
Expand Down Expand Up @@ -556,7 +556,7 @@ CallInfo *luaD_precall (lua_State *L, StkId func, int nresults) {
static void ccall (lua_State *L, StkId func, int nResults, int inc) {
CallInfo *ci;
L->nCcalls += inc;
if (unlikely(getCcalls(L) >= LUAI_MAXCCALLS))
if (l_unlikely(getCcalls(L) >= LUAI_MAXCCALLS))
luaE_checkcstack(L);
if ((ci = luaD_precall(L, func, nResults)) != NULL) { /* Lua function? */
ci->callstatus = CIST_FRESH; /* mark that it is a "fresh" execute */
Expand Down Expand Up @@ -600,7 +600,7 @@ void luaD_callnoyield (lua_State *L, StkId func, int nResults) {
*/
static int finishpcallk (lua_State *L, CallInfo *ci) {
int status = getcistrecst(ci); /* get original status */
if (status == LUA_OK) /* no error? */
if (l_likely(status == LUA_OK)) /* no error? */
status = LUA_YIELD; /* was interrupted by an yield */
else { /* error */
StkId func = restorestack(L, ci->u2.funcidx);
Expand Down Expand Up @@ -774,7 +774,7 @@ LUA_API int lua_resume (lua_State *L, lua_State *from, int nargs,
status = luaD_rawrunprotected(L, resume, &nargs);
/* continue running after recoverable errors */
status = precover(L, status);
if (likely(!errorstatus(status)))
if (l_likely(!errorstatus(status)))
lua_assert(status == L->status); /* normal end or yield */
else { /* unrecoverable error */
L->status = cast_byte(status); /* mark thread as 'dead' */
Expand All @@ -800,7 +800,7 @@ LUA_API int lua_yieldk (lua_State *L, int nresults, lua_KContext ctx,
lua_lock(L);
ci = L->ci;
api_checknelems(L, nresults);
if (unlikely(!yieldable(L))) {
if (l_unlikely(!yieldable(L))) {
if (L != G(L)->mainthread)
luaG_runerror(L, "attempt to yield across a C-call boundary");
else
Expand Down Expand Up @@ -853,7 +853,7 @@ int luaD_closeprotected (lua_State *L, ptrdiff_t level, int status) {
struct CloseP pcl;
pcl.level = restorestack(L, level); pcl.status = status;
status = luaD_rawrunprotected(L, &closepaux, &pcl);
if (likely(status == LUA_OK)) /* no more errors? */
if (l_likely(status == LUA_OK)) /* no more errors? */
return pcl.status;
else { /* an error occurred; restore saved state and repeat */
L->ci = old_ci;
Expand All @@ -876,7 +876,7 @@ int luaD_pcall (lua_State *L, Pfunc func, void *u,
ptrdiff_t old_errfunc = L->errfunc;
L->errfunc = ef;
status = luaD_rawrunprotected(L, func, u);
if (unlikely(status != LUA_OK)) { /* an error occurred? */
if (l_unlikely(status != LUA_OK)) { /* an error occurred? */
L->ci = old_ci;
L->allowhook = old_allowhooks;
status = luaD_closeprotected(L, old_top, status);
Expand Down
2 changes: 1 addition & 1 deletion ldo.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -23,7 +23,7 @@
** at every check.
*/
#define luaD_checkstackaux(L,n,pre,pos) \
if (L->stack_last - L->top <= (n)) \
if (l_unlikely(L->stack_last - L->top <= (n))) \
{ pre; luaD_growstack(L, n, 1); pos; } \
else { condmovestack(L,pre,pos); }

Expand Down
2 changes: 1 addition & 1 deletion lgc.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -916,7 +916,7 @@ static void GCTM (lua_State *L) {
L->ci->callstatus &= ~CIST_FIN; /* not running a finalizer anymore */
L->allowhook = oldah; /* restore hooks */
g->gcrunning = running; /* restore state */
if (unlikely(status != LUA_OK)) { /* error while running __gc? */
if (l_unlikely(status != LUA_OK)) { /* error while running __gc? */
luaE_warnerror(L, "__gc metamethod");
L->top--; /* pops error object */
}
Expand Down
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