summaryrefslogtreecommitdiff
path: root/lvm.c
diff options
context:
space:
mode:
authorRoberto Ierusalimschy <roberto@inf.puc-rio.br>2015-01-16 14:54:37 -0200
committerRoberto Ierusalimschy <roberto@inf.puc-rio.br>2015-01-16 14:54:37 -0200
commit7e2015a46df7976bddee313b994742e49e420714 (patch)
tree0b2db30f1214a478ccb3664d165c8a431f0d5850 /lvm.c
parent5b01cb39b5ec36c544152351c35c43149d9bbfec (diff)
downloadlua-7e2015a46df7976bddee313b994742e49e420714.tar.gz
lua-7e2015a46df7976bddee313b994742e49e420714.tar.bz2
lua-7e2015a46df7976bddee313b994742e49e420714.zip
size of short strings stored in a single byte, to reduce the size
of struct 'TString'
Diffstat (limited to '')
-rw-r--r--lvm.c32
1 files changed, 19 insertions, 13 deletions
diff --git a/lvm.c b/lvm.c
index 1b4357fd..06fc60a4 100644
--- a/lvm.c
+++ b/lvm.c
@@ -1,5 +1,5 @@
1/* 1/*
2** $Id: lvm.c,v 2.231 2014/12/19 13:36:32 roberto Exp roberto $ 2** $Id: lvm.c,v 2.232 2014/12/27 20:30:38 roberto Exp roberto $
3** Lua virtual machine 3** Lua virtual machine
4** See Copyright Notice in lua.h 4** See Copyright Notice in lua.h
5*/ 5*/
@@ -73,7 +73,7 @@ int luaV_tonumber_ (const TValue *obj, lua_Number *n) {
73 return 1; 73 return 1;
74 } 74 }
75 else if (cvt2num(obj) && /* string convertible to number? */ 75 else if (cvt2num(obj) && /* string convertible to number? */
76 luaO_str2num(svalue(obj), &v) == tsvalue(obj)->len + 1) { 76 luaO_str2num(svalue(obj), &v) == vslen(obj) + 1) {
77 *n = nvalue(&v); /* convert result of 'luaO_str2num' to a float */ 77 *n = nvalue(&v); /* convert result of 'luaO_str2num' to a float */
78 return 1; 78 return 1;
79 } 79 }
@@ -106,7 +106,7 @@ static int tointeger_aux (const TValue *obj, lua_Integer *p, int mode) {
106 return 1; 106 return 1;
107 } 107 }
108 else if (cvt2num(obj) && 108 else if (cvt2num(obj) &&
109 luaO_str2num(svalue(obj), &v) == tsvalue(obj)->len + 1) { 109 luaO_str2num(svalue(obj), &v) == vslen(obj) + 1) {
110 obj = &v; 110 obj = &v;
111 goto again; /* convert result from 'luaO_str2num' to an integer */ 111 goto again; /* convert result from 'luaO_str2num' to an integer */
112 } 112 }
@@ -239,9 +239,9 @@ void luaV_settable (lua_State *L, const TValue *t, TValue *key, StkId val) {
239*/ 239*/
240static int l_strcmp (const TString *ls, const TString *rs) { 240static int l_strcmp (const TString *ls, const TString *rs) {
241 const char *l = getstr(ls); 241 const char *l = getstr(ls);
242 size_t ll = ls->len; 242 size_t ll = tsslen(ls);
243 const char *r = getstr(rs); 243 const char *r = getstr(rs);
244 size_t lr = rs->len; 244 size_t lr = tsslen(rs);
245 for (;;) { /* for each segment */ 245 for (;;) { /* for each segment */
246 int temp = strcoll(l, r); 246 int temp = strcoll(l, r);
247 if (temp != 0) /* not equal? */ 247 if (temp != 0) /* not equal? */
@@ -354,6 +354,8 @@ int luaV_equalobj (lua_State *L, const TValue *t1, const TValue *t2) {
354#define tostring(L,o) \ 354#define tostring(L,o) \
355 (ttisstring(o) || (cvt2str(o) && (luaO_tostring(L, o), 1))) 355 (ttisstring(o) || (cvt2str(o) && (luaO_tostring(L, o), 1)))
356 356
357#define isemptystr(o) (ttisshrstring(o) && tsvalue(o)->shrlen == 0)
358
357/* 359/*
358** Main operation for concatenation: concat 'total' values in the stack, 360** Main operation for concatenation: concat 'total' values in the stack,
359** from 'L->top - total' up to 'L->top - 1'. 361** from 'L->top - total' up to 'L->top - 1'.
@@ -365,19 +367,19 @@ void luaV_concat (lua_State *L, int total) {
365 int n = 2; /* number of elements handled in this pass (at least 2) */ 367 int n = 2; /* number of elements handled in this pass (at least 2) */
366 if (!(ttisstring(top-2) || cvt2str(top-2)) || !tostring(L, top-1)) 368 if (!(ttisstring(top-2) || cvt2str(top-2)) || !tostring(L, top-1))
367 luaT_trybinTM(L, top-2, top-1, top-2, TM_CONCAT); 369 luaT_trybinTM(L, top-2, top-1, top-2, TM_CONCAT);
368 else if (tsvalue(top-1)->len == 0) /* second operand is empty? */ 370 else if (isemptystr(top - 1)) /* second operand is empty? */
369 cast_void(tostring(L, top - 2)); /* result is first operand */ 371 cast_void(tostring(L, top - 2)); /* result is first operand */
370 else if (ttisstring(top-2) && tsvalue(top-2)->len == 0) { 372 else if (isemptystr(top - 2)) { /* first operand is an empty string? */
371 setobjs2s(L, top - 2, top - 1); /* result is second op. */ 373 setobjs2s(L, top - 2, top - 1); /* result is second op. */
372 } 374 }
373 else { 375 else {
374 /* at least two non-empty string values; get as many as possible */ 376 /* at least two non-empty string values; get as many as possible */
375 size_t tl = tsvalue(top-1)->len; 377 size_t tl = vslen(top - 1);
376 char *buffer; 378 char *buffer;
377 int i; 379 int i;
378 /* collect total length */ 380 /* collect total length */
379 for (i = 1; i < total && tostring(L, top-i-1); i++) { 381 for (i = 1; i < total && tostring(L, top-i-1); i++) {
380 size_t l = tsvalue(top-i-1)->len; 382 size_t l = vslen(top - i - 1);
381 if (l >= (MAX_SIZE/sizeof(char)) - tl) 383 if (l >= (MAX_SIZE/sizeof(char)) - tl)
382 luaG_runerror(L, "string length overflow"); 384 luaG_runerror(L, "string length overflow");
383 tl += l; 385 tl += l;
@@ -386,7 +388,7 @@ void luaV_concat (lua_State *L, int total) {
386 tl = 0; 388 tl = 0;
387 n = i; 389 n = i;
388 do { /* copy all strings to buffer */ 390 do { /* copy all strings to buffer */
389 size_t l = tsvalue(top-i)->len; 391 size_t l = vslen(top - i);
390 memcpy(buffer+tl, svalue(top-i), l * sizeof(char)); 392 memcpy(buffer+tl, svalue(top-i), l * sizeof(char));
391 tl += l; 393 tl += l;
392 } while (--i > 0); 394 } while (--i > 0);
@@ -403,7 +405,7 @@ void luaV_concat (lua_State *L, int total) {
403*/ 405*/
404void luaV_objlen (lua_State *L, StkId ra, const TValue *rb) { 406void luaV_objlen (lua_State *L, StkId ra, const TValue *rb) {
405 const TValue *tm; 407 const TValue *tm;
406 switch (ttnov(rb)) { 408 switch (ttype(rb)) {
407 case LUA_TTABLE: { 409 case LUA_TTABLE: {
408 Table *h = hvalue(rb); 410 Table *h = hvalue(rb);
409 tm = fasttm(L, h->metatable, TM_LEN); 411 tm = fasttm(L, h->metatable, TM_LEN);
@@ -411,8 +413,12 @@ void luaV_objlen (lua_State *L, StkId ra, const TValue *rb) {
411 setivalue(ra, luaH_getn(h)); /* else primitive len */ 413 setivalue(ra, luaH_getn(h)); /* else primitive len */
412 return; 414 return;
413 } 415 }
414 case LUA_TSTRING: { 416 case LUA_TSHRSTR: {
415 setivalue(ra, tsvalue(rb)->len); 417 setivalue(ra, tsvalue(rb)->shrlen);
418 return;
419 }
420 case LUA_TLNGSTR: {
421 setivalue(ra, tsvalue(rb)->u.lnglen);
416 return; 422 return;
417 } 423 }
418 default: { /* try metamethod */ 424 default: { /* try metamethod */
generated by cgit v1.2.3-55-g6feb (git 2.39.1) at 2025-03-17 08:31:49 +0000