commit c72ac048b989bea0f66f8532ab00a598da71e46d
parent b03dddf9e406f29e5d8bfa06ccb6db1dfad6e405
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Wed, 21 Feb 2018 16:43:17 -0300
conditional jumps "deunified"
(if a jump table is used, the unification may harm jump prediction.)
Diffstat:
M | lvm.c | | | 43 | ++++++++++++++++++++++++++++--------------- |
1 file changed, 28 insertions(+), 15 deletions(-)
diff --git a/lvm.c b/lvm.c
@@ -1,5 +1,5 @@
/*
-** $Id: lvm.c,v 2.344 2018/02/21 13:47:03 roberto Exp roberto $
+** $Id: lvm.c,v 2.345 2018/02/21 15:49:32 roberto Exp roberto $
** Lua virtual machine
** See Copyright Notice in lua.h
*/
@@ -805,6 +805,14 @@ void luaV_finishOp (lua_State *L) {
#define donextjump(ci) { i = *pc; dojump(ci, i, 1); }
/*
+** do a conditional jump: skip next instruction if 'cond' is not what
+** was expected (parameter 'k'), else do next instruction, which must
+** be a jump.
+*/
+#define docondjump() if (cond != GETARG_k(i)) pc++; else donextjump(ci);
+
+
+/*
** Correct global 'pc'.
*/
#define savepc(L) (ci->u.l.savedpc = pc)
@@ -1428,7 +1436,8 @@ void luaV_execute (lua_State *L, CallInfo *ci) {
vmcase(OP_EQ) {
TValue *rb = vRB(i);
Protect(cond = luaV_equalobj(L, vra, rb));
- goto condjump;
+ docondjump();
+ vmbreak;
}
vmcase(OP_LT) {
TValue *rb = vRB(i);
@@ -1438,7 +1447,8 @@ void luaV_execute (lua_State *L, CallInfo *ci) {
cond = LTnum(vra, rb);
else
Protect(cond = lessthanothers(L, vra, rb));
- goto condjump;
+ docondjump();
+ vmbreak;
}
vmcase(OP_LE) {
TValue *rb = vRB(i);
@@ -1448,13 +1458,15 @@ void luaV_execute (lua_State *L, CallInfo *ci) {
cond = LEnum(vra, rb);
else
Protect(cond = lessequalothers(L, vra, rb));
- goto condjump;
+ docondjump();
+ vmbreak;
}
vmcase(OP_EQK) {
TValue *rb = KB(i);
/* basic types do not use '__eq'; we can use raw equality */
cond = luaV_equalobj(NULL, vra, rb);
- goto condjump;
+ docondjump();
+ vmbreak;
}
vmcase(OP_EQI) {
int im = GETARG_sB(i);
@@ -1464,7 +1476,8 @@ void luaV_execute (lua_State *L, CallInfo *ci) {
cond = luai_numeq(fltvalue(vra), cast_num(im));
else
cond = 0; /* other types cannot be equal to a number */
- goto condjump;
+ docondjump();
+ vmbreak;
}
vmcase(OP_LTI) {
int im = GETARG_sB(i);
@@ -1474,7 +1487,8 @@ void luaV_execute (lua_State *L, CallInfo *ci) {
cond = luai_numlt(fltvalue(vra), cast_num(im));
else
Protect(cond = luaT_callorderiTM(L, vra, im, 0, TM_LT));
- goto condjump;
+ docondjump();
+ vmbreak;
}
vmcase(OP_LEI) {
int im = GETARG_sB(i);
@@ -1484,7 +1498,8 @@ void luaV_execute (lua_State *L, CallInfo *ci) {
cond = luai_numle(fltvalue(vra), cast_num(im));
else
Protect(cond = luaT_callorderiTM(L, vra, im, 0, TM_LE));
- goto condjump;
+ docondjump();
+ vmbreak;
}
vmcase(OP_GTI) {
int im = GETARG_sB(i);
@@ -1494,7 +1509,8 @@ void luaV_execute (lua_State *L, CallInfo *ci) {
cond = luai_numlt(cast_num(im), fltvalue(vra));
else
Protect(cond = luaT_callorderiTM(L, vra, im, 1, TM_LT));
- goto condjump;
+ docondjump();
+ vmbreak;
}
vmcase(OP_GEI) {
int im = GETARG_sB(i);
@@ -1504,15 +1520,12 @@ void luaV_execute (lua_State *L, CallInfo *ci) {
cond = luai_numle(cast_num(im), fltvalue(vra));
else
Protect(cond = luaT_callorderiTM(L, vra, im, 1, TM_LE));
- goto condjump;
+ docondjump();
+ vmbreak;
}
vmcase(OP_TEST) {
cond = !l_isfalse(vra);
- condjump:
- if (cond != GETARG_k(i))
- pc++; /* skip next jump */
- else
- donextjump(ci);
+ docondjump();
vmbreak;
}
vmcase(OP_TESTSET) {