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-rw-r--r--lcode.c65
1 files changed, 28 insertions, 37 deletions
diff --git a/lcode.c b/lcode.c
index f72bcdb3..26a90430 100644
--- a/lcode.c
+++ b/lcode.c
@@ -1,5 +1,5 @@
1/* 1/*
2** $Id: lcode.c,v 1.100 2002/05/09 14:14:34 roberto Exp roberto $ 2** $Id: lcode.c,v 1.101 2002/05/10 17:02:32 roberto Exp roberto $
3** Code generator for Lua 3** Code generator for Lua
4** See Copyright Notice in lua.h 4** See Copyright Notice in lua.h
5*/ 5*/
@@ -39,58 +39,48 @@ void luaK_nil (FuncState *fs, int from, int n) {
39} 39}
40 40
41 41
42void luaK_moveexp (expdesc *e, int offset) {
43 if (e->t != NO_JUMP) e->t += offset;
44 if (e->f != NO_JUMP) e->f += offset;
45 if (e->k == VRELOCABLE || e->k == VJMP) e->info += offset;
46}
47
48
49int luaK_jump (FuncState *fs) { 42int luaK_jump (FuncState *fs) {
50 int j = luaK_codeAsBx(fs, OP_JMP, 0, NO_JUMP); 43 int jpc = fs->jpc; /* save list of jumps to here */
51 if (j == fs->lasttarget) { /* possible jumps to this jump? */ 44 int j;
52 luaK_concat(fs, &j, fs->jlt); /* keep them on hold */ 45 fs->jpc = NO_JUMP;
53 fs->jlt = NO_JUMP; 46 j = luaK_codeAsBx(fs, OP_JMP, 0, NO_JUMP);
54 } 47 luaK_concat(fs, &j, jpc); /* keep them on hold */
55 return j; 48 return j;
56} 49}
57 50
58 51
59static int luaK_condjump (FuncState *fs, OpCode op, int A, int B, int C) { 52static int luaK_condjump (FuncState *fs, OpCode op, int A, int B, int C) {
60 luaK_codeABC(fs, op, A, B, C); 53 luaK_codeABC(fs, op, A, B, C);
61 return luaK_codeAsBx(fs, OP_JMP, 0, NO_JUMP); 54 return luaK_jump(fs);
62} 55}
63 56
64 57
65static void luaK_fixjump (FuncState *fs, int pc, int dest) { 58static void luaK_fixjump (FuncState *fs, int pc, int dest) {
66 Instruction *jmp = &fs->f->code[pc]; 59 Instruction *jmp = &fs->f->code[pc];
67 if (dest == NO_JUMP) 60 int offset = dest-(pc+1);
68 SETARG_sBx(*jmp, NO_JUMP); /* point to itself to represent end of list */ 61 lua_assert(dest != NO_JUMP);
69 else { /* jump is relative to position following jump instruction */ 62 if (abs(offset) > MAXARG_sBx)
70 int offset = dest-(pc+1); 63 luaX_syntaxerror(fs->ls, "control structure too long");
71 if (abs(offset) > MAXARG_sBx) 64 SETARG_sBx(*jmp, offset);
72 luaX_syntaxerror(fs->ls, "control structure too long");
73 SETARG_sBx(*jmp, offset);
74 }
75} 65}
76 66
77 67
78/* 68/*
79** returns current `pc' and marks it as a jump target (to avoid wrong 69** returns current `pc' and marks it as a jump target (to avoid wrong
80** optimizations with consecutive instructions not in the same basic block). 70** optimizations with consecutive instructions not in the same basic block).
81** discharge list of jumps to last target.
82*/ 71*/
83int luaK_getlabel (FuncState *fs) { 72int luaK_getlabel (FuncState *fs) {
84 if (fs->pc != fs->lasttarget) { 73 fs->lasttarget = fs->pc;
85 int lasttarget = fs->lasttarget;
86 fs->lasttarget = fs->pc;
87 luaK_patchlist(fs, fs->jlt, lasttarget); /* discharge old list `jlt' */
88 fs->jlt = NO_JUMP; /* nobody jumps to this new label (yet) */
89 }
90 return fs->pc; 74 return fs->pc;
91} 75}
92 76
93 77
78void luaK_dischargejpc (FuncState *fs) {
79 luaK_patchlist(fs, fs->jpc, fs->pc); /* discharge old list `jpc' */
80 fs->jpc = NO_JUMP;
81}
82
83
94static int luaK_getjump (FuncState *fs, int pc) { 84static int luaK_getjump (FuncState *fs, int pc) {
95 int offset = GETARG_sBx(fs->f->code[pc]); 85 int offset = GETARG_sBx(fs->f->code[pc]);
96 if (offset == NO_JUMP) /* point to itself represents end of list */ 86 if (offset == NO_JUMP) /* point to itself represents end of list */
@@ -155,20 +145,20 @@ static void luaK_patchlistaux (FuncState *fs, int list,
155 145
156 146
157void luaK_patchlist (FuncState *fs, int list, int target) { 147void luaK_patchlist (FuncState *fs, int list, int target) {
158 if (target == fs->lasttarget) /* same target that list `jlt'? */ 148 lua_assert(target <= fs->pc);
159 luaK_concat(fs, &fs->jlt, list); /* delay fixing */ 149 luaK_patchlistaux(fs, list, target, NO_REG, target, NO_REG, target);
160 else
161 luaK_patchlistaux(fs, list, target, NO_REG, target, NO_REG, target);
162} 150}
163 151
164 152
165void luaK_patchtohere (FuncState *fs, int list) { 153void luaK_patchtohere (FuncState *fs, int list) {
166 luaK_patchlist(fs, list, luaK_getlabel(fs)); 154 luaK_getlabel(fs);
155 luaK_concat(fs, &fs->jpc, list);
167} 156}
168 157
169 158
170void luaK_concat (FuncState *fs, int *l1, int l2) { 159void luaK_concat (FuncState *fs, int *l1, int l2) {
171 if (*l1 == NO_JUMP) 160 if (l2 == NO_JUMP) return;
161 else if (*l1 == NO_JUMP)
172 *l1 = l2; 162 *l1 = l2;
173 else { 163 else {
174 int list = *l1; 164 int list = *l1;
@@ -508,7 +498,7 @@ void luaK_goiftrue (FuncState *fs, expdesc *e) {
508 break; 498 break;
509 } 499 }
510 case VFALSE: { 500 case VFALSE: {
511 pc = luaK_codeAsBx(fs, OP_JMP, 0, NO_JUMP); /* always jump */ 501 pc = luaK_jump(fs); /* always jump */
512 break; 502 break;
513 } 503 }
514 case VJMP: { 504 case VJMP: {
@@ -534,7 +524,7 @@ void luaK_goiffalse (FuncState *fs, expdesc *e) {
534 break; 524 break;
535 } 525 }
536 case VTRUE: { 526 case VTRUE: {
537 pc = luaK_codeAsBx(fs, OP_JMP, 0, NO_JUMP); /* always jump */ 527 pc = luaK_jump(fs); /* always jump */
538 break; 528 break;
539 } 529 }
540 case VJMP: { 530 case VJMP: {
@@ -737,6 +727,7 @@ void luaK_posfix (FuncState *fs, BinOpr op, expdesc *e1, expdesc *e2) {
737int luaK_code (FuncState *fs, Instruction i, int line) { 727int luaK_code (FuncState *fs, Instruction i, int line) {
738 Proto *f = fs->f; 728 Proto *f = fs->f;
739 int oldsize = f->sizecode; 729 int oldsize = f->sizecode;
730 luaK_dischargejpc(fs); /* `pc' will change */
740 /* put new instruction in code array */ 731 /* put new instruction in code array */
741 luaM_growvector(fs->L, f->code, fs->pc, f->sizecode, Instruction, 732 luaM_growvector(fs->L, f->code, fs->pc, f->sizecode, Instruction,
742 MAX_INT, "code size overflow"); 733 MAX_INT, "code size overflow");