nik/lush
1
1
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

a better way to control optimizations.

Browse Source
This commit is contained in:
Roberto Ierusalimschy
2000-03-04 17:18:15 -03:00
parent 29e0193425
commit 563de491be
6 changed files with 220 additions and 194 deletions
Download Patch File Download Diff File Expand all files Collapse all files

160
lcode.c
View File

@@ -1,5 +1,5 @@
/*
** $Id: lcode.c,v 1.4 2000/03/03 18:53:17 roberto Exp roberto $
** $Id: lcode.c,v 1.5 2000/03/03 20:30:47 roberto Exp roberto $
** Code generator for Lua
** See Copyright Notice in lua.h
*/
@@ -20,10 +20,19 @@ void luaK_error (LexState *ls, const char *msg) {
}
static Instruction *last_i (LexState *ls, expdesc *v) {
/*
** Returns the address of the previous instruction, for optimizations.
** If there is a jump target between this and the current instruction,
** returns the address of a dummy instruction to avoid wrong optimizations.
*/
static Instruction *previous_instruction (LexState *ls) {
FuncState *fs = ls->fs;
int last_pc = (v->info != NOJUMPS) ? v->info : fs->pc-1;
return &fs->f->code[last_pc];
if (fs->pc > fs->lasttarget) /* no jumps to current position? */
return &fs->f->code[fs->pc-1]; /* returns previous instruction */
else {
static Instruction dummy = CREATE_0(ENDCODE);
return &dummy; /* no optimizations after an `ENDCODE' */
}
}
@@ -35,61 +44,74 @@ int luaK_primitivecode (LexState *ls, Instruction i) {
}
static void luaK_minus (LexState *ls, expdesc *v) {
Instruction *last = last_i(ls, v);
switch(GET_OPCODE(*last)) {
case PUSHINT: *last = SETARG_S(*last, -GETARG_S(*last)); return;
case PUSHNUM: *last = SET_OPCODE(*last, PUSHNEGNUM); return;
case PUSHNEGNUM: *last = SET_OPCODE(*last, PUSHNUM); return;
static void luaK_minus (LexState *ls) {
Instruction *previous = previous_instruction(ls);
switch(GET_OPCODE(*previous)) {
case PUSHINT: *previous = SETARG_S(*previous, -GETARG_S(*previous)); return;
case PUSHNUM: *previous = SET_OPCODE(*previous, PUSHNEGNUM); return;
case PUSHNEGNUM: *previous = SET_OPCODE(*previous, PUSHNUM); return;
default: luaK_primitivecode(ls, CREATE_0(MINUSOP));
}
}
static void luaK_gettable (LexState *ls, expdesc *v) {
Instruction *last = last_i(ls, v);
static void luaK_gettable (LexState *ls) {
Instruction *previous = previous_instruction(ls);
luaK_deltastack(ls, -1);
switch(GET_OPCODE(*last)) {
case PUSHSTRING: *last = SET_OPCODE(*last, GETDOTTED); break;
switch(GET_OPCODE(*previous)) {
case PUSHSTRING: *previous = SET_OPCODE(*previous, GETDOTTED); break;
default: luaK_primitivecode(ls, CREATE_0(GETTABLE));
}
}
static void luaK_add (LexState *ls, expdesc *v) {
Instruction *last = last_i(ls, v);
static void luaK_add (LexState *ls) {
Instruction *previous = previous_instruction(ls);
luaK_deltastack(ls, -1);
switch(GET_OPCODE(*last)) {
case PUSHINT: *last = SET_OPCODE(*last, ADDI); break;
switch(GET_OPCODE(*previous)) {
case PUSHINT: *previous = SET_OPCODE(*previous, ADDI); break;
default: luaK_primitivecode(ls, CREATE_0(ADDOP));
}
}
static void luaK_sub (LexState *ls, expdesc *v) {
Instruction *last = last_i(ls, v);
static void luaK_sub (LexState *ls) {
Instruction *previous = previous_instruction(ls);
luaK_deltastack(ls, -1);
switch(GET_OPCODE(*last)) {
switch(GET_OPCODE(*previous)) {
case PUSHINT:
*last = SET_OPCODE(*last, ADDI);
*last = SETARG_S(*last, -GETARG_S(*last));
*previous = SET_OPCODE(*previous, ADDI);
*previous = SETARG_S(*previous, -GETARG_S(*previous));
break;
default: luaK_primitivecode(ls, CREATE_0(SUBOP));
}
}
void luaK_retcode (LexState *ls, int nlocals, listdesc *e) {
if (e->n > 0 && luaK_iscall(ls, e->info)) {
Instruction *last = &ls->fs->f->code[ls->fs->pc-1];
*last = SET_OPCODE(*last, TAILCALL);
*last = SETARG_B(*last, nlocals);
void luaK_retcode (LexState *ls, int nlocals, int nexps) {
Instruction *previous = previous_instruction(ls);
if (nexps > 0 && GET_OPCODE(*previous) == CALL) {
LUA_ASSERT(ls->L, GETARG_B(*previous) == MULT_RET, "call should be open");
*previous = SET_OPCODE(*previous, TAILCALL);
*previous = SETARG_B(*previous, nlocals);
}
else
luaK_primitivecode(ls, CREATE_U(RETCODE, nlocals));
}
static void luaK_pushnil (LexState *ls, int n) {
Instruction *previous = previous_instruction(ls);
luaK_deltastack(ls, n);
switch(GET_OPCODE(*previous)) {
case PUSHNIL:
*previous = SETARG_U(*previous, GETARG_U(*previous)+n);
break;
default: luaK_primitivecode(ls, CREATE_U(PUSHNIL, n));
}
}
int luaK_code (LexState *ls, Instruction i, int delta) {
luaK_deltastack(ls, delta);
return luaK_primitivecode(ls, i);
@@ -104,6 +126,17 @@ void luaK_fixjump (LexState *ls, int pc, int dest) {
}
/*
** returns current `pc' and marks it as a jump target (to avoid wrong
** optimizations with consecutive instructions not in the same basic block).
*/
int luaK_getlabel (LexState *ls) {
FuncState *fs = ls->fs;
fs->lasttarget = fs->pc;
return fs->pc;
}
void luaK_deltastack (LexState *ls, int delta) {
FuncState *fs = ls->fs;
fs->stacksize += delta;
@@ -151,28 +184,27 @@ void luaK_adjuststack (LexState *ls, int n) {
if (n > 0)
luaK_U(ls, POP, n, -n);
else if (n < 0)
luaK_U(ls, PUSHNIL, (-n)-1, -n);
luaK_pushnil(ls, -n);
}
int luaK_iscall (LexState *ls, int hasjumps) {
if (hasjumps) return 0; /* a call cannot have internal jumps */
else /* check whether last instruction is a function call */
return (GET_OPCODE(ls->fs->f->code[ls->fs->pc-1]) == CALL);
int luaK_lastisopen (LexState *ls) {
/* check whether last instruction is an (open) function call */
Instruction *i = previous_instruction(ls);
if (GET_OPCODE(*i) == CALL) {
LUA_ASSERT(ls->L, GETARG_B(*i) == MULT_RET, "call should be open");
return 1;
}
else return 0;
}
void luaK_setcallreturns (LexState *ls, int hasjumps, int nresults) {
if (!hasjumps) { /* if `hasjumps' cannot be a function call */
Instruction *i = &ls->fs->f->code[ls->fs->pc-1];
if (GET_OPCODE(*i) == CALL) { /* expression is a function call? */
int old_nresults = GETARG_B(*i);
if (old_nresults != MULT_RET)
luaK_deltastack(ls, -old_nresults); /* pop old nresults */
*i = SETARG_B(*i, nresults); /* set nresults */
if (nresults != MULT_RET)
luaK_deltastack(ls, nresults); /* push results */
}
void luaK_setcallreturns (LexState *ls, int nresults) {
Instruction *i = previous_instruction(ls);
if (GET_OPCODE(*i) == CALL) { /* expression is a function call? */
LUA_ASSERT(ls->L, GETARG_B(*i) == MULT_RET, "call should be open");
*i = SETARG_B(*i, nresults); /* set nresults */
luaK_deltastack(ls, nresults); /* push results */
}
}
@@ -182,7 +214,7 @@ static void assertglobal (LexState *ls, int index) {
}
void luaK_2stack (LexState *ls, expdesc *var) {
void luaK_tostack (LexState *ls, expdesc *var) {
switch (var->k) {
case VLOCAL:
luaK_U(ls, PUSHLOCAL, var->info, 1);
@@ -192,14 +224,20 @@ void luaK_2stack (LexState *ls, expdesc *var) {
assertglobal(ls, var->info); /* make sure that there is a global */
break;
case VINDEXED:
luaK_gettable(ls, var);
luaK_gettable(ls);
break;
case VEXP:
luaK_setcallreturns(ls, var->info, 1); /* call must return 1 value */
return; /* does not change var->info */
return; /* exp result is already on stack */
}
var->k = VEXP;
var->info = NOJUMPS;
}
void luaK_1tostack (LexState *ls, expdesc *var) {
if (var->k == VEXP)
luaK_setcallreturns(ls, 1); /* call must return 1 value */
else
luaK_tostack(ls, var);
}
@@ -222,30 +260,29 @@ void luaK_storevar (LexState *ls, const expdesc *var) {
void luaK_prefix (LexState *ls, int op, expdesc *v) {
luaK_2stack(ls, v);
if (op == '-') luaK_minus(ls, v);
luaK_1tostack(ls, v);
if (op == '-') luaK_minus(ls);
else luaK_0(ls, NOTOP, 0);
v->info = NOJUMPS;
}
void luaK_infix (LexState *ls, expdesc *v) {
luaK_2stack(ls, v);
if (ls->token == AND)
void luaK_infix (LexState *ls, int op, expdesc *v) {
luaK_1tostack(ls, v);
if (op == AND)
v->info = luaK_0(ls, ONFJMP, -1);
else if (ls->token == OR)
else if (op == OR)
v->info = luaK_0(ls, ONTJMP, -1);
}
void luaK_posfix (LexState *ls, int op, expdesc *v1, expdesc *v2) {
luaK_2stack(ls, v2);
luaK_1tostack(ls, v2);
switch (op) {
case AND: case OR:
luaK_fixjump(ls, v1->info, ls->fs->pc);
return; /* keep v1->info != NOJUMPS */
case '+': luaK_add(ls, v2); break;
case '-': luaK_sub(ls, v2); break;
luaK_fixjump(ls, v1->info, luaK_getlabel(ls));
break;
case '+': luaK_add(ls); break;
case '-': luaK_sub(ls); break;
case '*': luaK_0(ls, MULTOP, -1); break;
case '/': luaK_0(ls, DIVOP, -1); break;
case '^': luaK_0(ls, POWOP, -1); break;
@@ -257,6 +294,5 @@ void luaK_posfix (LexState *ls, int op, expdesc *v1, expdesc *v2) {
case GE: luaK_0(ls, GEOP, -1); break;
case LE: luaK_0(ls, LEOP, -1); break;
}
v1->info = NOJUMPS;
}