Experimental "slab" allocator for ops.

To try it -DPL_OP_SLAB_ALLOC for op.c 
This is for proof of concept only, it leaks memory 
(ops are not free'd) so don't use in embedded apps.
If this minimalist version does not show performance 
gain then whole idea is worthless. 
Nick see's approx 12% speed up vs perlmalloc running
  perl -Ilib -MCPAN -e '' 
Solaris2.6, gcc-2.8.1 but numbers are not repeatable.

p4raw-id: //depot/perl@3424

1 files changed, 59 insertions, 20 deletions

diff --git a/op.c b/op.c
index 919d9d8170..94c0b392d1 100644
--- a/op.c
+++ b/op.c
@@ -22,8 +22,31 @@
 #define CHECKCALL this->*PL_check
 #else
 #define CHECKCALL *PL_check
+#endif              
+
+/* #define PL_OP_SLAB_ALLOC */
+                                                            
+#ifdef PL_OP_SLAB_ALLOC 
+#define SLAB_SIZE 8192
+static char    *PL_OpPtr  = NULL;
+static int     PL_OpSpace = 0;
+#define NewOp(m,var,c,type) do { if ((PL_OpSpace -= c*sizeof(type)) >= 0)     \
+                              var =  (type *)(PL_OpPtr -= c*sizeof(type));    \
+                             else                                             \
+                              var = (type *) Slab_Alloc(m,c*sizeof(type));    \
+                           } while (0)
+
+static void *           
+Slab_Alloc(int m, size_t sz)
+{ 
+ Newz(m,PL_OpPtr,SLAB_SIZE,char);
+ PL_OpSpace = SLAB_SIZE - sz;
+ return PL_OpPtr += PL_OpSpace;
+}
+
+#else 
+#define NewOp(m, var, c, type) Newz(m, var, c, type)
 #endif
-
 /*
  * In the following definition, the ", Nullop" is just to make the compiler
  * think the expression is of the right type: croak actually does a Siglongjmp.
@@ -706,7 +729,13 @@ op_free(OP *o)
     if (o->op_targ > 0)
 	pad_free(o->op_targ);
 
+#ifdef PL_OP_SLAB_ALLOC
+    if ((char *) o == PL_OpPtr)
+     {
+     }
+#else
     Safefree(o);
+#endif
 }
 
 STATIC void
@@ -1999,8 +2028,11 @@ append_list(I32 type, LISTOP *first, LISTOP *last)
     first->op_children += last->op_children;
     if (first->op_children)
 	first->op_flags |= OPf_KIDS;
-
-    Safefree(last);
+    
+#ifdef PL_OP_SLAB_ALLOC
+#else
+    Safefree(last);     
+#endif
     return (OP*)first;
 }
 
@@ -2055,7 +2087,7 @@ newLISTOP(I32 type, I32 flags, OP *first, OP *last)
 {
     LISTOP *listop;
 
-    Newz(1101, listop, 1, LISTOP);
+    NewOp(1101, listop, 1, LISTOP);
 
     listop->op_type = type;
     listop->op_ppaddr = PL_ppaddr[type];
@@ -2089,7 +2121,7 @@ OP *
 newOP(I32 type, I32 flags)
 {
     OP *o;
-    Newz(1101, o, 1, OP);
+    NewOp(1101, o, 1, OP);
     o->op_type = type;
     o->op_ppaddr = PL_ppaddr[type];
     o->op_flags = flags;
@@ -2113,7 +2145,7 @@ newUNOP(I32 type, I32 flags, OP *first)
     if (PL_opargs[type] & OA_MARK)
 	first = force_list(first);
 
-    Newz(1101, unop, 1, UNOP);
+    NewOp(1101, unop, 1, UNOP);
     unop->op_type = type;
     unop->op_ppaddr = PL_ppaddr[type];
     unop->op_first = first;
@@ -2130,7 +2162,7 @@ OP *
 newBINOP(I32 type, I32 flags, OP *first, OP *last)
 {
     BINOP *binop;
-    Newz(1101, binop, 1, BINOP);
+    NewOp(1101, binop, 1, BINOP);
 
     if (!first)
 	first = newOP(OP_NULL, 0);
@@ -2427,7 +2459,7 @@ newPMOP(I32 type, I32 flags)
     dTHR;
     PMOP *pmop;
 
-    Newz(1101, pmop, 1, PMOP);
+    NewOp(1101, pmop, 1, PMOP);
     pmop->op_type = type;
     pmop->op_ppaddr = PL_ppaddr[type];
     pmop->op_flags = flags;
@@ -2482,7 +2514,7 @@ pmruntime(OP *o, OP *expr, OP *repl)
 			    ? OP_REGCRESET
 			    : OP_REGCMAYBE),0,expr);
 
-	Newz(1101, rcop, 1, LOGOP);
+	NewOp(1101, rcop, 1, LOGOP);
 	rcop->op_type = OP_REGCOMP;
 	rcop->op_ppaddr = PL_ppaddr[OP_REGCOMP];
 	rcop->op_first = scalar(expr);
@@ -2577,7 +2609,7 @@ pmruntime(OP *o, OP *expr, OP *repl)
 		pm->op_pmflags |= PMf_MAYBE_CONST;
 		pm->op_pmpermflags |= PMf_MAYBE_CONST;
 	    }
-	    Newz(1101, rcop, 1, LOGOP);
+	    NewOp(1101, rcop, 1, LOGOP);
 	    rcop->op_type = OP_SUBSTCONT;
 	    rcop->op_ppaddr = PL_ppaddr[OP_SUBSTCONT];
 	    rcop->op_first = scalar(repl);
@@ -2602,7 +2634,7 @@ OP *
 newSVOP(I32 type, I32 flags, SV *sv)
 {
     SVOP *svop;
-    Newz(1101, svop, 1, SVOP);
+    NewOp(1101, svop, 1, SVOP);
     svop->op_type = type;
     svop->op_ppaddr = PL_ppaddr[type];
     svop->op_sv = sv;
@@ -2620,7 +2652,7 @@ newGVOP(I32 type, I32 flags, GV *gv)
 {
     dTHR;
     GVOP *gvop;
-    Newz(1101, gvop, 1, GVOP);
+    NewOp(1101, gvop, 1, GVOP);
     gvop->op_type = type;
     gvop->op_ppaddr = PL_ppaddr[type];
     gvop->op_gv = (GV*)SvREFCNT_inc(gv);
@@ -2637,7 +2669,7 @@ OP *
 newPVOP(I32 type, I32 flags, char *pv)
 {
     PVOP *pvop;
-    Newz(1101, pvop, 1, PVOP);
+    NewOp(1101, pvop, 1, PVOP);
     pvop->op_type = type;
     pvop->op_ppaddr = PL_ppaddr[type];
     pvop->op_pv = pv;
@@ -2975,7 +3007,7 @@ newSTATEOP(I32 flags, char *label, OP *o)
     U32 seq = intro_my();
     register COP *cop;
 
-    Newz(1101, cop, 1, COP);
+    NewOp(1101, cop, 1, COP);
     if (PERLDB_LINE && PL_curcop->cop_line && PL_curstash != PL_debstash) {
 	cop->op_type = OP_DBSTATE;
 	cop->op_ppaddr = PL_ppaddr[ OP_DBSTATE ];
@@ -3142,7 +3174,7 @@ new_logop(I32 type, I32 flags, OP** firstp, OP** otherp)
     if (type == OP_ANDASSIGN || type == OP_ORASSIGN)
 	other->op_private |= OPpASSIGN_BACKWARDS;  /* other is an OP_SASSIGN */
 
-    Newz(1101, logop, 1, LOGOP);
+    NewOp(1101, logop, 1, LOGOP);
 
     logop->op_type = type;
     logop->op_ppaddr = PL_ppaddr[type];
@@ -3191,7 +3223,7 @@ newCONDOP(I32 flags, OP *first, OP *trueop, OP *falseop)
 	list(trueop);
 	scalar(falseop);
     }
-    Newz(1101, condop, 1, CONDOP);
+    NewOp(1101, condop, 1, CONDOP);
 
     condop->op_type = OP_COND_EXPR;
     condop->op_ppaddr = PL_ppaddr[OP_COND_EXPR];
@@ -3224,7 +3256,7 @@ newRANGE(I32 flags, OP *left, OP *right)
     OP *flop;
     OP *o;
 
-    Newz(1101, condop, 1, CONDOP);
+    NewOp(1101, condop, 1, CONDOP);
 
     condop->op_type = OP_RANGE;
     condop->op_ppaddr = PL_ppaddr[OP_RANGE];
@@ -3385,7 +3417,7 @@ newWHILEOP(I32 flags, I32 debuggable, LOOP *loop, I32 whileline, OP *expr, OP *b
 	o = listop;
 
     if (!loop) {
-	Newz(1101,loop,1,LOOP);
+	NewOp(1101,loop,1,LOOP);
 	loop->op_type = OP_ENTERLOOP;
 	loop->op_ppaddr = PL_ppaddr[OP_ENTERLOOP];
 	loop->op_private = 0;
@@ -3411,6 +3443,7 @@ OP *
 newFOROP(I32 flags,char *label,line_t forline,OP *sv,OP *expr,OP *block,OP *cont)
 {
     LOOP *loop;
+    LOOP *tmp;
     OP *wop;
     int padoff = 0;
     I32 iterflags = 0;
@@ -3482,7 +3515,13 @@ newFOROP(I32 flags,char *label,line_t forline,OP *sv,OP *expr,OP *block,OP *cont
     loop = (LOOP*)list(convert(OP_ENTERITER, iterflags,
 			       append_elem(OP_LIST, expr, scalar(sv))));
     assert(!loop->op_next);
+#ifdef PL_OP_SLAB_ALLOC
+    NewOp(1234,tmp,1,LOOP);
+    Copy(loop,tmp,1,LOOP);
+    loop = tmp;
+#else
     Renew(loop, 1, LOOP);
+#endif 
     loop->op_targ = padoff;
     wop = newWHILEOP(flags, 1, loop, forline, newOP(OP_ITER, 0), block, cont);
     PL_copline = forline;
@@ -4466,7 +4505,7 @@ ck_eval(OP *o)
 	    cUNOPo->op_first = 0;
 	    op_free(o);
 
-	    Newz(1101, enter, 1, LOGOP);
+	    NewOp(1101, enter, 1, LOGOP);
 	    enter->op_type = OP_ENTERTRY;
 	    enter->op_ppaddr = PL_ppaddr[OP_ENTERTRY];
 	    enter->op_private = 0;
@@ -4877,7 +4916,7 @@ ck_grep(OP *o)
     OPCODE type = o->op_type == OP_GREPSTART ? OP_GREPWHILE : OP_MAPWHILE;
 
     o->op_ppaddr = PL_ppaddr[OP_GREPSTART];
-    Newz(1101, gwop, 1, LOGOP);
+    NewOp(1101, gwop, 1, LOGOP);
 
     if (o->op_flags & OPf_STACKED) {
 	OP* k;