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Fix FOLD rules for appending to string buffers.

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Mike Pall 2013-04-26 00:26:44 +02:00
parent 7c28448730
commit eeb204cd87
1 changed files with 21 additions and 6 deletions
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27
src/lj_opt_fold.c
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@ -533,6 +533,7 @@ LJFOLDF(bufput_append)
fleft->op1 == IR(fright->op1)->op1) {
IRRef ref = fins->op1;
IR(ref)->op2 = (fleft->op2 | IRBUFHDR_APPEND); /* Modify BUFHDR. */
IR(ref)->op1 = fright->op2;
return ref;
}
return EMITFOLD; /* This is a store and always emitted. */
@ -572,27 +573,41 @@ LJFOLDF(bufstr_kfold_cse)
lua_assert(fright->o == IR_BUFHDR || fright->o == IR_BUFPUT);
if (LJ_LIKELY(J->flags & JIT_F_OPT_FOLD)) {
if (fright->o == IR_BUFHDR) { /* No put operations? */
if (!(fright->op2 & IRBUFHDR_APPEND)) /* Empty buffer? */
if (!(fright->op2 & IRBUFHDR_APPEND)) { /* Empty buffer? */
lj_ir_rollback(J, fins->op1); /* Eliminate the current chain. */
return lj_ir_kstr(J, &J2G(J)->strempty);
}
fins->op2 = fright->prev; /* Relies on checks in bufput_append. */
return CSEFOLD;
} else {
IRIns *irb = IR(fright->op1);
if (irb->o == IR_BUFHDR && !(irb->op2 & IRBUFHDR_APPEND))
if (irb->o == IR_BUFHDR && !(irb->op2 & IRBUFHDR_APPEND)) {
lj_ir_rollback(J, fins->op1); /* Eliminate the current chain. */
return fright->op2; /* Shortcut for a single put operation. */
}
}
}
/* Try to CSE the whole chain. */
if (LJ_LIKELY(J->flags & JIT_F_OPT_CSE) && !(fleft->op2 & IRBUFHDR_APPEND)) {
if (LJ_LIKELY(J->flags & JIT_F_OPT_CSE)) {
IRRef ref = J->chain[IR_BUFSTR];
while (ref) {
IRRef last = fins->op2;
IRIns *irs = IR(ref), *ira = fright, *irb = IR(irs->op2);
while (ira->o == irb->o && ira->op2 == irb->op2) {
if (ira->o == IR_BUFHDR) {
lj_ir_rollback(J, fins->op1); /* Eliminate the current chain. */
if (ira->o == IR_BUFHDR && !(ira->op2 & IRBUFHDR_APPEND)) {
IRIns *irh;
for (irh = IR(ira->prev); irh != irb; irh = IR(irh->prev))
if (irh->op1 == irs->op2)
return ref; /* Do CSE, but avoid rollback if append follows. */
lj_ir_rollback(J, last); /* Eliminate the current chain. */
return ref; /* CSE succeeded. */
} else if (ira->o == IR_CALLS) {
ira = IR(ira->op1); irb = IR(irb->op1);
lua_assert(ira->o == IR_CARG && irb->o == IR_CARG);
if (ira->op2 != irb->op2) break;
}
ira = IR(ira->op1);
last = ira->op1;
ira = IR(last);
irb = IR(irb->op1);
}
ref = irs->prev;