commit 4758113043b6c362a0fdce77715c711332d909dc
parent a4e644add264b6bac3171a03aa6febcf61e89ae6
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Tue, 19 Apr 2011 13:21:49 -0300
change in opcode OP_LOADNIL: B is used as a counter instead of a
register. (Avoids an assignment to R(B), not present in any other
instruction.)
Diffstat:
5 files changed, 22 insertions(+), 18 deletions(-)
diff --git a/lcode.c b/lcode.c
@@ -1,5 +1,5 @@
/*
-** $Id: lcode.c,v 2.51 2011/02/01 18:03:10 roberto Exp roberto $
+** $Id: lcode.c,v 2.52 2011/04/07 18:14:12 roberto Exp roberto $
** Code generator for Lua
** See Copyright Notice in lua.h
*/
@@ -35,19 +35,23 @@ static int isnumeral(expdesc *e) {
void luaK_nil (FuncState *fs, int from, int n) {
Instruction *previous;
+ int l = from + n - 1; /* last register to set nil */
if (fs->pc > fs->lasttarget) { /* no jumps to current position? */
previous = &fs->f->code[fs->pc-1];
if (GET_OPCODE(*previous) == OP_LOADNIL) {
int pfrom = GETARG_A(*previous);
- int pto = GETARG_B(*previous);
- if (pfrom <= from && from <= pto+1) { /* can connect both? */
- if (from+n-1 > pto)
- SETARG_B(*previous, from+n-1);
+ int pl = pfrom + GETARG_B(*previous);
+ if ((pfrom <= from && from <= pl + 1) ||
+ (from <= pfrom && pfrom <= l + 1)) { /* can connect both? */
+ if (pfrom < from) from = pfrom; /* from = min(from, pfrom) */
+ if (pl > l) l = pl; /* l = max(l, pl) */
+ SETARG_A(*previous, from);
+ SETARG_B(*previous, l - from);
return;
}
- }
+ } /* else go through */
}
- luaK_codeABC(fs, OP_LOADNIL, from, from+n-1, 0); /* else no optimization */
+ luaK_codeABC(fs, OP_LOADNIL, from, n - 1, 0); /* else no optimization */
}
diff --git a/ldebug.c b/ldebug.c
@@ -1,5 +1,5 @@
/*
-** $Id: ldebug.c,v 2.78 2011/04/18 15:02:37 roberto Exp roberto $
+** $Id: ldebug.c,v 2.79 2011/04/18 19:49:13 roberto Exp roberto $
** Debug Interface
** See Copyright Notice in lua.h
*/
@@ -355,8 +355,8 @@ static const char *getobjname (lua_State *L, CallInfo *ci, int reg,
break;
}
case OP_LOADNIL: {
- int b = GETARG_B(i); /* move from 'b' to 'a' */
- if (a <= reg && reg <= b) /* set registers from 'a' to 'b' */
+ int b = GETARG_B(i);
+ if (a <= reg && reg <= a + b) /* set registers from 'a' to 'a+b' */
what = NULL;
break;
}
diff --git a/lopcodes.c b/lopcodes.c
@@ -1,5 +1,5 @@
/*
-** $Id: lopcodes.c,v 1.46 2011/04/07 18:14:12 roberto Exp roberto $
+** $Id: lopcodes.c,v 1.47 2011/04/12 17:27:35 roberto Exp roberto $
** See Copyright Notice in lua.h
*/
@@ -66,7 +66,7 @@ LUAI_DDEF const lu_byte luaP_opmodes[NUM_OPCODES] = {
,opmode(0, 1, OpArgK, OpArgN, iABx) /* OP_LOADK */
,opmode(0, 1, OpArgN, OpArgN, iABx) /* OP_LOADKX */
,opmode(0, 1, OpArgU, OpArgU, iABC) /* OP_LOADBOOL */
- ,opmode(0, 1, OpArgR, OpArgN, iABC) /* OP_LOADNIL */
+ ,opmode(0, 1, OpArgU, OpArgN, iABC) /* OP_LOADNIL */
,opmode(0, 1, OpArgU, OpArgN, iABC) /* OP_GETUPVAL */
,opmode(0, 1, OpArgU, OpArgK, iABC) /* OP_GETTABUP */
,opmode(0, 1, OpArgR, OpArgK, iABC) /* OP_GETTABLE */
diff --git a/lopcodes.h b/lopcodes.h
@@ -1,5 +1,5 @@
/*
-** $Id: lopcodes.h,v 1.139 2011/02/07 12:24:42 roberto Exp roberto $
+** $Id: lopcodes.h,v 1.140 2011/04/07 18:14:12 roberto Exp roberto $
** Opcodes for Lua virtual machine
** See Copyright Notice in lua.h
*/
@@ -170,7 +170,7 @@ OP_MOVE,/* A B R(A) := R(B) */
OP_LOADK,/* A Bx R(A) := Kst(Bx) */
OP_LOADKX,/* A R(A) := Kst(extra arg) */
OP_LOADBOOL,/* A B C R(A) := (Bool)B; if (C) pc++ */
-OP_LOADNIL,/* A B R(A) := ... := R(B) := nil */
+OP_LOADNIL,/* A B R(A), R(A+1), ..., R(A+B) := nil */
OP_GETUPVAL,/* A B R(A) := UpValue[B] */
OP_GETTABUP,/* A B C R(A) := UpValue[B][RK(C)] */
diff --git a/lvm.c b/lvm.c
@@ -1,5 +1,5 @@
/*
-** $Id: lvm.c,v 2.134 2011/04/07 18:14:12 roberto Exp roberto $
+** $Id: lvm.c,v 2.135 2011/04/18 19:48:53 roberto Exp roberto $
** Lua virtual machine
** See Copyright Notice in lua.h
*/
@@ -541,10 +541,10 @@ void luaV_execute (lua_State *L) {
if (GETARG_C(i)) ci->u.l.savedpc++; /* skip next instruction (if C) */
)
vmcase(OP_LOADNIL,
- TValue *rb = RB(i);
+ int b = GETARG_B(i);
do {
- setnilvalue(rb--);
- } while (rb >= ra);
+ setnilvalue(ra++);
+ } while (b--);
)
vmcase(OP_GETUPVAL,
int b = GETARG_B(i);