commit ac65bab25f1eaaf70e1826a6937a74b3a55b521b
parent f185c0132e09a5e0a32782c674de75b510f887d8
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Mon, 14 Aug 2017 15:32:47 -0300
jumps in 'for' loops don't need to be signed
Diffstat:
4 files changed, 38 insertions(+), 20 deletions(-)
diff --git a/lopcodes.c b/lopcodes.c
@@ -1,5 +1,5 @@
/*
-** $Id: lopcodes.c,v 1.58 2017/04/28 20:57:45 roberto Exp roberto $
+** $Id: lopcodes.c,v 1.59 2017/06/29 15:38:41 roberto Exp roberto $
** Opcodes for Lua virtual machine
** See Copyright Notice in lua.h
*/
@@ -124,10 +124,10 @@ LUAI_DDEF const lu_byte luaP_opmodes[NUM_OPCODES] = {
,opmode(0, 1, OpArgU, OpArgU, iABC) /* OP_CALL */
,opmode(0, 1, OpArgU, OpArgU, iABC) /* OP_TAILCALL */
,opmode(0, 0, OpArgU, OpArgN, iABC) /* OP_RETURN */
- ,opmode(0, 1, OpArgR, OpArgN, iAsBx) /* OP_FORLOOP */
- ,opmode(0, 1, OpArgR, OpArgN, iAsBx) /* OP_FORPREP */
+ ,opmode(0, 1, OpArgR, OpArgN, iABx) /* OP_FORLOOP */
+ ,opmode(0, 1, OpArgR, OpArgN, iABx) /* OP_FORPREP */
,opmode(0, 0, OpArgN, OpArgU, iABC) /* OP_TFORCALL */
- ,opmode(0, 1, OpArgR, OpArgN, iAsBx) /* OP_TFORLOOP */
+ ,opmode(0, 1, OpArgR, OpArgN, iABx) /* OP_TFORLOOP */
,opmode(0, 0, OpArgU, OpArgU, iABC) /* OP_SETLIST */
,opmode(0, 1, OpArgU, OpArgN, iABx) /* OP_CLOSURE */
,opmode(0, 1, OpArgU, OpArgR, iABC) /* OP_VARARG */
diff --git a/lopcodes.h b/lopcodes.h
@@ -1,5 +1,5 @@
/*
-** $Id: lopcodes.h,v 1.154 2017/05/08 16:08:01 roberto Exp roberto $
+** $Id: lopcodes.h,v 1.155 2017/06/29 15:38:41 roberto Exp roberto $
** Opcodes for Lua virtual machine
** See Copyright Notice in lua.h
*/
@@ -229,12 +229,12 @@ OP_CALL,/* A B C R(A), ... ,R(A+C-2) := R(A)(R(A+1), ... ,R(A+B-1)) */
OP_TAILCALL,/* A B C return R(A)(R(A+1), ... ,R(A+B-1)) */
OP_RETURN,/* A B return R(A), ... ,R(A+B-2) (see note) */
-OP_FORLOOP,/* A sBx R(A)+=R(A+2);
- if R(A) <?= R(A+1) then { pc+=sBx; R(A+3)=R(A) }*/
-OP_FORPREP,/* A sBx R(A)-=R(A+2); pc+=sBx */
+OP_FORLOOP,/* A Bx R(A)+=R(A+2);
+ if R(A) <?= R(A+1) then { pc-=Bx; R(A+3)=R(A) }*/
+OP_FORPREP,/* A Bx R(A)-=R(A+2); pc+=Bx */
OP_TFORCALL,/* A C R(A+3), ... ,R(A+2+C) := R(A)(R(A+1), R(A+2)); */
-OP_TFORLOOP,/* A sBx if R(A+1) ~= nil then { R(A)=R(A+1); pc += sBx }*/
+OP_TFORLOOP,/* A Bx if R(A+1) ~= nil then { R(A)=R(A+1); pc -= Bx }*/
OP_SETLIST,/* A B C R(A)[(C-1)*FPF+i] := R(A+i), 1 <= i <= B */
diff --git a/lparser.c b/lparser.c
@@ -1,5 +1,5 @@
/*
-** $Id: lparser.c,v 2.162 2017/06/29 15:38:41 roberto Exp roberto $
+** $Id: lparser.c,v 2.163 2017/08/12 13:12:21 roberto Exp roberto $
** Lua Parser
** See Copyright Notice in lua.h
*/
@@ -1307,6 +1307,22 @@ static int exp1 (LexState *ls) {
}
+/*
+** Fix for instruction at position 'pc' to jump to 'dest'.
+** (Jump addresses are relative in Lua). 'back' true means
+** a back jump.
+*/
+static void fixforjump (FuncState *fs, int pc, int dest, int back) {
+ Instruction *jmp = &fs->f->code[pc];
+ int offset = dest - (pc + 1);
+ if (back)
+ offset = -offset;
+ if (offset > MAXARG_Bx)
+ luaX_syntaxerror(fs->ls, "control structure too long");
+ SETARG_Bx(*jmp, offset);
+}
+
+
static void forbody (LexState *ls, int base, int line, int nvars, int isnum) {
/* forbody -> DO block */
BlockCnt bl;
@@ -1314,21 +1330,23 @@ static void forbody (LexState *ls, int base, int line, int nvars, int isnum) {
int prep, endfor;
adjustlocalvars(ls, 3); /* control variables */
checknext(ls, TK_DO);
- prep = isnum ? luaK_codeAsBx(fs, OP_FORPREP, base, NO_JUMP) : luaK_jump(fs);
+ prep = isnum ? luaK_codeABx(fs, OP_FORPREP, base, 0) : luaK_jump(fs);
enterblock(fs, &bl, 0); /* scope for declared variables */
adjustlocalvars(ls, nvars);
luaK_reserveregs(fs, nvars);
block(ls);
leaveblock(fs); /* end of scope for declared variables */
- luaK_patchtohere(fs, prep);
- if (isnum) /* numeric for? */
- endfor = luaK_codeAsBx(fs, OP_FORLOOP, base, NO_JUMP);
+ if (isnum) { /* numeric for? */
+ fixforjump(fs, prep, luaK_getlabel(fs), 0);
+ endfor = luaK_codeABx(fs, OP_FORLOOP, base, 0);
+ }
else { /* generic for */
+ luaK_patchtohere(fs, prep);
luaK_codeABC(fs, OP_TFORCALL, base, 0, nvars);
luaK_fixline(fs, line);
endfor = luaK_codeAsBx(fs, OP_TFORLOOP, base + 2, NO_JUMP);
}
- luaK_patchlist(fs, endfor, prep + 1);
+ fixforjump(fs, endfor, prep + 1, 1);
luaK_fixline(fs, line);
}
diff --git a/lvm.c b/lvm.c
@@ -1,5 +1,5 @@
/*
-** $Id: lvm.c,v 2.289 2017/06/29 15:38:41 roberto Exp roberto $
+** $Id: lvm.c,v 2.290 2017/07/07 16:34:32 roberto Exp roberto $
** Lua virtual machine
** See Copyright Notice in lua.h
*/
@@ -1335,7 +1335,7 @@ void luaV_execute (lua_State *L) {
lua_Integer idx = intop(+, ivalue(s2v(ra)), step); /* increment index */
lua_Integer limit = ivalue(s2v(ra + 1));
if ((0 < step) ? (idx <= limit) : (limit <= idx)) {
- pc += GETARG_sBx(i); /* jump back */
+ pc -= GETARG_Bx(i); /* jump back */
chgivalue(s2v(ra), idx); /* update internal index... */
setivalue(s2v(ra + 3), idx); /* ...and external index */
}
@@ -1347,7 +1347,7 @@ void luaV_execute (lua_State *L) {
idx = luai_numadd(L, idx, step); /* inc. index */
if (luai_numlt(0, step) ? luai_numle(idx, limit)
: luai_numle(limit, idx)) {
- pc += GETARG_sBx(i); /* jump back */
+ pc -= GETARG_Bx(i); /* jump back */
chgfltvalue(s2v(ra), idx); /* update internal index... */
setfltvalue(s2v(ra + 3), idx); /* ...and external index */
}
@@ -1381,7 +1381,7 @@ void luaV_execute (lua_State *L) {
luaG_runerror(L, "'for' initial value must be a number");
setfltvalue(init, luai_numsub(L, ninit, nstep));
}
- pc += GETARG_sBx(i);
+ pc += GETARG_Bx(i);
vmbreak;
}
vmcase(OP_TFORCALL) {
@@ -1401,7 +1401,7 @@ void luaV_execute (lua_State *L) {
l_tforloop:
if (!ttisnil(s2v(ra + 1))) { /* continue loop? */
setobjs2s(L, ra, ra + 1); /* save control variable */
- pc += GETARG_sBx(i); /* jump back */
+ pc -= GETARG_Bx(i); /* jump back */
}
vmbreak;
}
