1 files changed, 86 insertions, 240 deletions

diff --git a/src/luac/opt.c b/src/luac/opt.c
index e2becc2a..e51a0868 100644
--- a/src/luac/opt.c
+++ b/src/luac/opt.c
@@ -1,5 +1,5 @@
 /*
-** $Id: opt.c,v 1.12 1999/07/02 19:34:26 lhf Exp $
+** $Id: opt.c,v 1.22 2000/10/31 16:57:23 lhf Exp $
 ** optimize bytecodes
 ** See Copyright Notice in lua.h
 */
@@ -7,275 +7,121 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include "luac.h"
 
-static void FixArg(Byte* p, int i, int j, int isconst)
-{
- if (j==i)
-  ;
- else if (i<=MAX_BYTE)		/* j<i, so j fits where i did */
-  p[1]=j;
- else if (i<=MAX_WORD)
- {
-  if (isconst && j<=MAX_BYTE)	/* may use byte variant instead */
-  {
-   p[0]++;			/* byte variant follows word variant */
-   p[1]=j;
-   p[2]=NOP;
-  }
-  else 				/* stuck with word variant */
-  {
-   p[1]=j>>8;
-   p[2]=j;
-  }
- }
- else 				/* previous instruction must've been LONGARG */
- {
-  if (isconst && j<=MAX_WORD) p[-2]=p[-1]=NOP; else p[-1]=j>>16;
-  p[1]=j>>8;
-  p[2]=j;
- }
-}
+#include "luac.h"
 
-static void FixConstants(TProtoFunc* tf, int* C)
+static int MapConstant(Hash* t, int j, const TObject* key)
 {
- Byte* code=tf->code;
- Byte* p=code;
- int longarg=0;
- for (;;)
+ const TObject* o=luaH_get(L,t,key);
+ if (ttype(o)==LUA_TNUMBER)
+  return (int) nvalue(o);
+ else
  {
-  Opcode OP;
-  int n=INFO(tf,p,&OP);
-  int op=OP.class;
-  int i=OP.arg+longarg;
-  longarg=0;
-  if (op==PUSHCONSTANT || op==GETGLOBAL || op==GETDOTTED ||
-      op==PUSHSELF     || op==SETGLOBAL || op==CLOSURE)
-   FixArg(p,i,C[i],1);
-  else if (op==LONGARG) longarg=i<<16;
-  else if (op==ENDCODE) break;
-  p+=n;
+  TObject val;
+  ttype(&val)=LUA_TNUMBER;
+  nvalue(&val)=j;
+  *luaH_set(L,t,key)=val;
+  LUA_ASSERT(j>=0,"MapConstant returns negative!");
+  return j;
  }
 }
 
-#define	UNREF	1			/* "type" of unused constants */
-#define	BIAS	128			/* mark for used constants */
-
-static void NoUnrefs(TProtoFunc* tf)
+static int MapConstants(Proto* tf, Hash* map)
 {
- int i,n=tf->nconsts;
- Byte* code=tf->code;
- Byte* p=code;
- int longarg=0;
- for (;;)				/* mark all used constants */
- {
-  Opcode OP;
-  int n=INFO(tf,p,&OP);
-  int op=OP.class;
-  int i=OP.arg+longarg;
-  longarg=0;
-  if (op==PUSHCONSTANT || op==GETGLOBAL || op==GETDOTTED ||
-      op==PUSHSELF     || op==SETGLOBAL || op==CLOSURE)
-  {
-   TObject* o=tf->consts+i;
-   if (ttype(o)<=0) ttype(o)+=BIAS;	/* mark as used */
-  }
-  else if (op==LONGARG) longarg=i<<16;
-  else if (op==ENDCODE) break;
-  p+=n;
- }
- for (i=0; i<n; i++)			/* mark all unused constants */
+ int i,j,k,n,m=0;
+ TObject o;
+ j=0; n=tf->nknum; ttype(&o)=LUA_TNUMBER;
+ for (i=0; i<n; i++)
  {
-  TObject* o=tf->consts+i;
-  if (ttype(o)<=0)
-   ttype(o)=UNREF;			/* mark as unused */
-  else
-   ttype(o)-=BIAS;			/* unmark used constant */
+  nvalue(&o)=tf->knum[i];
+  k=MapConstant(map,j,&o);
+  if (k==j) j++;
  }
-}
-
-#define CMP(oa,ob,f)	memcmp(&f(oa),&f(ob),sizeof(f(oa)))
-
-static int compare(TProtoFunc* tf, int ia, int ib)
-{
- TObject* oa=tf->consts+ia;
- TObject* ob=tf->consts+ib;
- int t=ttype(oa)-ttype(ob);
- if (t) return t;
- switch (ttype(oa))
+ m=j;
+ j=0; n=tf->nkstr; ttype(&o)=LUA_TSTRING;
+ for (i=0; i<n; i++)
  {
-  case LUA_T_NUMBER:	return CMP(oa,ob,nvalue);
-  case LUA_T_STRING:	return CMP(oa,ob,tsvalue);
-  case LUA_T_PROTO:	return CMP(oa,ob,tfvalue);
-  case LUA_T_NIL:	return 0;
-  case UNREF:		return 0;
-  default:		return ia-ib;	/* cannot happen */
+  tsvalue(&o)=tf->kstr[i];
+  k=MapConstant(map,j,&o);
+  if (k==j) j++;
  }
+ return m+j;
 }
 
-static TProtoFunc* TF;			/* for sort */
-
-static int compare1(const void* a, const void* b)
-{
- int ia=*(int*)a;
- int ib=*(int*)b;
- int t=compare(TF,ia,ib);
- return (t) ? t : ia-ib;
-}
-
-static void OptConstants(TProtoFunc* tf)
+static void PackConstants(Proto* tf, Hash* map)
 {
- static int* C=NULL;
- static int* D=NULL;
- int i,k;
- int n=tf->nconsts;
- if (n==0) return;
- luaM_reallocvector(C,n,int);
- luaM_reallocvector(D,n,int);
- NoUnrefs(tf);
- for (i=0; i<n; i++) C[i]=D[i]=i;	/* group duplicates */
- TF=tf; qsort(C,n,sizeof(C[0]),compare1);
- k=C[0];				/* build duplicate table */
- for (i=1; i<n; i++)
- {
-  int j=C[i];
-  if (compare(tf,k,j)==0) D[j]=k; else k=j;
- }
- k=0;					/* build rename map & pack constants */
+ int i,j,k,n;
+ TObject o;
+#ifdef DEBUG
+ printf("%p before pack nknum=%d nkstr=%d\n",tf,tf->nknum,tf->nkstr);
+#endif
+ j=0; n=tf->nknum; ttype(&o)=LUA_TNUMBER;
  for (i=0; i<n; i++)
  {
-  if (D[i]==i)				/* new value */
-  {
-   TObject* o=tf->consts+i;
-   if (ttype(o)!=UNREF)
-   {
-    tf->consts[k]=tf->consts[i];
-    C[i]=k++;
-   }
-  }
-  else C[i]=C[D[i]];
+  nvalue(&o)=tf->knum[i];
+  k=MapConstant(map,-1,&o);
+  if (k==j) tf->knum[j++]=tf->knum[i];
  }
- if (k<n)
+ tf->nknum=j;
+ j=0; n=tf->nkstr; ttype(&o)=LUA_TSTRING;
+ for (i=0; i<n; i++)
  {
-printf("\t" SOURCE " reduced constants from %d to %d\n",
-	 tf->source->str,tf->lineDefined,n,k);
-  FixConstants(tf,C);
-  tf->nconsts=k;
+  tsvalue(&o)=tf->kstr[i];
+  k=MapConstant(map,-1,&o);
+  if (k==j) tf->kstr[j++]=tf->kstr[i];
  }
+ tf->nkstr=j;
+#ifdef DEBUG
+ printf("%p after  pack nknum=%d nkstr=%d\n",tf,tf->nknum,tf->nkstr);
+#endif
 }
 
-static int NoDebug(TProtoFunc* tf)
+static void OptConstants(Proto* tf)
 {
- Byte* code=tf->code;
- Byte* p=code;
- int lop=NOP;				/* last opcode */
- int nop=0;
- for (;;)				/* change SETLINE to NOP */
+ Instruction* p;
+ int n=tf->nknum+tf->nkstr;
+ Hash* map=luaH_new(L,n);
+ int m=MapConstants(tf,map);
+#ifdef DEBUG
+ printf("%p n=%d m=%d %s\n",tf,n,m,(m==n)?"nothing to optimize":"yes!");
+#endif
+ if (m==n) return;
+ for (p=tf->code;; p++)
  {
-  Opcode OP;
-  int n=INFO(tf,p,&OP);
-  int op=OP.class;
-  if (op==NOP) ++nop;
-  else if (op==SETLINE)
+  Instruction i=*p;
+  int op=GET_OPCODE(i);
+  switch (op)
   {
-   int m;
-   if (lop==LONGARG) m=2; else if (lop==LONGARGW) m=3; else m=0;
-   nop+=n+m; memset(p-m,NOP,n+m);
+   TObject o;
+   int j,k;
+   case OP_PUSHNUM: case OP_PUSHNEGNUM:
+    j=GETARG_U(i);
+    ttype(&o)=LUA_TNUMBER; nvalue(&o)=tf->knum[j];
+    k=MapConstant(map,-1,&o);
+    if (k!=j) *p=CREATE_U(op,k);
+    break;
+   case OP_PUSHSTRING: case OP_GETGLOBAL: case OP_GETDOTTED:
+   case OP_PUSHSELF:   case OP_SETGLOBAL:
+    j=GETARG_U(i);
+    ttype(&o)=LUA_TSTRING; tsvalue(&o)=tf->kstr[j];
+    k=MapConstant(map,-1,&o);
+    if (k!=j) *p=CREATE_U(op,k);
+    break;
+   case OP_END:
+    PackConstants(tf,map);
+    luaH_free(L,map);
+    return;
+   default:
+    break;
   }
-  else if (op==ENDCODE) break;
-  lop=OP.op;
-  p+=n;
  }
- return nop;
 }
 
-static int FixJump(TProtoFunc* tf, Byte* a, Byte* b)
-{
- Byte* p;
- int nop=0;
- for (p=a; p<b; )
- {
-  Opcode OP;
-  int n=INFO(tf,p,&OP);
-  int op=OP.class;
-  if (op==NOP) ++nop;
-  else if (op==ENDCODE) break;
-  p+=n;
- }
- return nop;
-}
+#define OptFunction luaU_optchunk
 
-static void FixJumps(TProtoFunc* tf)
-{
- Byte* code=tf->code;
- Byte* p=code;
- int longarg=0;
- for (;;)
- {
-  Opcode OP;
-  int n=INFO(tf,p,&OP);
-  int op=OP.class;
-  int i=OP.arg+longarg;
-  int nop=0;
-  longarg=0;
-  if (op==ENDCODE) break;
-  else if (op==IFTUPJMP || op==IFFUPJMP)
-   nop=FixJump(tf,p-i+n,p);
-  else if (op==ONTJMP || op==ONFJMP || op==JMP || op==IFFJMP)
-   nop=FixJump(tf,p,p+i+n);
-  else if (op==LONGARG) longarg=i<<16;
-  if (nop>0) FixArg(p,i,i-nop,0);
-  p+=n;
- }
-}
-
-static void PackCode(TProtoFunc* tf)
-{
- Byte* code=tf->code;
- Byte* p=code;
- Byte* q=code;
- for (;;)
- {
-  Opcode OP;
-  int n=INFO(tf,p,&OP);
-  int op=OP.class;
-  if (op!=NOP) { memcpy(q,p,n); q+=n; }
-  p+=n;
-  if (op==ENDCODE) break;
- }
-printf("\t" SOURCE " reduced code from %d to %d\n",
-	tf->source->str,tf->lineDefined,(int)(p-code),(int)(q-code));
-}
-
-static void OptCode(TProtoFunc* tf)
-{
- if (NoDebug(tf)==0) return;		/* cannot improve code */
- FixJumps(tf);
- PackCode(tf);
-}
-
-static void OptFunction(TProtoFunc* tf);
-
-static void OptFunctions(TProtoFunc* tf)
-{
- int i,n=tf->nconsts;
- for (i=0; i<n; i++)
- {
-  TObject* o=tf->consts+i;
-  if (ttype(o)==LUA_T_PROTO) OptFunction(tfvalue(o));
- }
-}
-
-static void OptFunction(TProtoFunc* tf)
+void OptFunction(Proto* tf)
 {
+ int i,n=tf->nkproto;
  OptConstants(tf);
- OptCode(tf);
- OptFunctions(tf);
- tf->source=luaS_new("");
- tf->locvars=NULL;
-}
-
-void luaU_optchunk(TProtoFunc* Main)
-{
- OptFunction(Main);
+ for (i=0; i<n; i++) OptFunction(tf->kproto[i]);
 }