using 'A' for register instead of 'B' in relational opcodes

('R(A)' is already created by default for all instructions.)

lcode.c

@@ -1,5 +1,5 @@
 /*
-** $Id: lcode.c,v 2.133 2017/11/16 12:59:14 roberto Exp roberto $
+** $Id: lcode.c,v 2.134 2017/11/22 18:41:20 roberto Exp roberto $
 ** Code generator for Lua
 ** See Copyright Notice in lua.h
 */
@@ -969,7 +969,7 @@ static void negatecondition (FuncState *fs, expdesc *e) {
   Instruction *pc = getjumpcontrol(fs, e->u.info);
   lua_assert(testTMode(GET_OPCODE(*pc)) && GET_OPCODE(*pc) != OP_TESTSET &&
                                            GET_OPCODE(*pc) != OP_TEST);
-  SETARG_A(*pc, !(GETARG_A(*pc)));
+  SETARG_B(*pc, !(GETARG_B(*pc)));
 }
 
 
@@ -1286,12 +1286,12 @@ static void codeorder (FuncState *fs, BinOpr opr, expdesc *e1, expdesc *e2) {
     case OPR_GT: case OPR_GE: {
       /* '(a > b)' ==> '(b < a)';  '(a >= b)' ==> '(b <= a)' */
       OpCode op = cast(OpCode, (opr - OPR_NE) + OP_EQ);
-      e1->u.info = condjump(fs, op, 1, rk2, rk1);  /* invert operands */
+      e1->u.info = condjump(fs, op, rk2, 1, rk1);  /* invert operands */
       break;
     }
     default: {  /* '==', '<', '<=' use their own opcodes */
       OpCode op = cast(OpCode, (opr - OPR_EQ) + OP_EQ);
-      e1->u.info = condjump(fs, op, 1, rk1, rk2);
+      e1->u.info = condjump(fs, op, rk1, 1, rk2);
       break;
     }
   }
@@ -1325,7 +1325,7 @@ static void codeeq (FuncState *fs, BinOpr opr, expdesc *e1, expdesc *e2) {
     r2 = luaK_exp2anyreg(fs, e2);
   }
   freeexps(fs, e1, e2);
-  e1->u.info = condjump(fs, op, (opr == OPR_EQ), r1, r2);
+  e1->u.info = condjump(fs, op, r1, (opr == OPR_EQ), r2);
   e1->k = VJMP;
 }
 

lopcodes.h

@@ -1,5 +1,5 @@
 /*
-** $Id: lopcodes.h,v 1.168 2017/11/16 12:59:14 roberto Exp roberto $
+** $Id: lopcodes.h,v 1.169 2017/11/22 18:41:20 roberto Exp roberto $
 ** Opcodes for Lua virtual machine
 ** See Copyright Notice in lua.h
 */
@@ -236,12 +236,12 @@ OP_CONCAT,/*	A B C	R(A) := R(B).. ... ..R(C)			*/
 
 OP_CLOSE,/*	A	close all upvalues >= R(A)			*/
 OP_JMP,/*	k sJ	pc += sJ  (k is used in code generation)	*/
-OP_EQ,/*	A B C	if ((R(B) == R(C)) ~= A) then pc++		*/
-OP_LT,/*	A B C	if ((R(B) <  R(C)) ~= A) then pc++		*/
-OP_LE,/*	A B C	if ((R(B) <= R(C)) ~= A) then pc++		*/
+OP_EQ,/*	A B C	if ((R(A) == R(C)) ~= B) then pc++		*/
+OP_LT,/*	A B C	if ((R(A) <  R(C)) ~= B) then pc++		*/
+OP_LE,/*	A B C	if ((R(A) <= R(C)) ~= B) then pc++		*/
 
-OP_EQK,/*	A B C	if ((R(B) == K(C)) ~= A) then pc++		*/
-OP_EQI,/*	A B C	if ((R(B) == C) ~= A) then pc++			*/
+OP_EQK,/*	A B C	if ((R(A) == K(C)) ~= B) then pc++		*/
+OP_EQI,/*	A B C	if ((R(A) == C) ~= B) then pc++			*/
 
 OP_TEST,/*	A C	if not (R(A) <=> C) then pc++			*/
 OP_TESTSET,/*	A B C	if (R(B) <=> C) then R(A) := R(B) else pc++	*/

lvm.c

@@ -1,5 +1,5 @@
 /*
-** $Id: lvm.c,v 2.313 2017/11/21 14:17:35 roberto Exp $
+** $Id: lvm.c,v 2.314 2017/11/22 18:41:20 roberto Exp roberto $
 ** Lua virtual machine
 ** See Copyright Notice in lua.h
 */
@@ -715,7 +715,7 @@ void luaV_finishOp (lua_State *L) {
         res = !res;  /* negate result */
       }
       lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_JMP);
-      if (res != GETARG_A(inst))  /* condition failed? */
+      if (res != GETARG_B(inst))  /* condition failed? */
         ci->u.l.savedpc++;  /* skip jump instruction */
       break;
     }
@@ -1340,64 +1340,59 @@ void luaV_execute (lua_State *L) {
         vmbreak;
       }
       vmcase(OP_EQ) {
-        TValue *rb = vRB(i);
         TValue *rc = vRC(i);
         int res;
-        Protect(res = luaV_equalobj(L, rb, rc));
-        if (res != GETARG_A(i))
+        Protect(res = luaV_equalobj(L, s2v(ra), rc));
+        if (res != GETARG_B(i))
           pc++;
         else
           donextjump(ci);
         vmbreak;
       }
       vmcase(OP_LT) {
-        TValue *rb = vRB(i);
         TValue *rc = vRC(i);
         int res;
-        if (ttisinteger(rb) && ttisinteger(rc))
-          res = (ivalue(rb) < ivalue(rc));
-        else if (ttisnumber(rb) && ttisnumber(rc))
-          res = LTnum(rb, rc);
+        if (ttisinteger(s2v(ra)) && ttisinteger(rc))
+          res = (ivalue(s2v(ra)) < ivalue(rc));
+        else if (ttisnumber(s2v(ra)) && ttisnumber(rc))
+          res = LTnum(s2v(ra), rc);
         else
-          Protect(res = lessthanothers(L, rb, rc));
-        if (res != GETARG_A(i))
+          Protect(res = lessthanothers(L, s2v(ra), rc));
+        if (res != GETARG_B(i))
           pc++;
         else
           donextjump(ci);
         vmbreak;
       }
       vmcase(OP_LE) {
-        TValue *rb = vRB(i);
         TValue *rc = vRC(i);
         int res;
-        if (ttisinteger(rb) && ttisinteger(rc))
-          res = (ivalue(rb) <= ivalue(rc));
-        else if (ttisnumber(rb) && ttisnumber(rc))
-          res = LEnum(rb, rc);
+        if (ttisinteger(s2v(ra)) && ttisinteger(rc))
+          res = (ivalue(s2v(ra)) <= ivalue(rc));
+        else if (ttisnumber(s2v(ra)) && ttisnumber(rc))
+          res = LEnum(s2v(ra), rc);
         else
-          Protect(res = lessequalothers(L, rb, rc));
-        if (res != GETARG_A(i))
+          Protect(res = lessequalothers(L, s2v(ra), rc));
+        if (res != GETARG_B(i))
           pc++;
         else
           donextjump(ci);
         vmbreak;
       }
       vmcase(OP_EQK) {
-        TValue *rb = vRB(i);
         TValue *rc = KC(i);
         /* basic types do not use '__eq'; we can use raw equality */
-        if (luaV_equalobj(NULL, rb, rc) != GETARG_A(i))
+        if (luaV_equalobj(NULL, s2v(ra), rc) != GETARG_B(i))
           pc++;
         else
           donextjump(ci);
         vmbreak;
       }
       vmcase(OP_EQI) {
-        TValue *rb = vRB(i);
         int ic = GETARG_sC(i);
-        if ((ttisinteger(rb) ? (ivalue(rb) == ic)
-            :ttisfloat(rb) ? luai_numeq(fltvalue(rb), cast_num(ic))
-            : 0) != GETARG_A(i))
+        if ((ttisinteger(s2v(ra)) ? (ivalue(s2v(ra)) == ic)
+            :ttisfloat(s2v(ra)) ? luai_numeq(fltvalue(s2v(ra)), cast_num(ic))
+            : 0) != GETARG_B(i))
           pc++;
         else
           donextjump(ci);