From 8ac06726b92fff66714ceee8af89068ac876875a Mon Sep 17 00:00:00 2001 From: Eelco Dolstra Date: Sat, 23 Oct 2010 20:07:47 +0000 Subject: [PATCH] * Make Value smaller by not storing redundant PrimOp info. * Clear pointers in Values after overwriting them to make sure that no objects are kept alive unnecessarily. --- src/libexpr/eval.cc | 37 +++++++++++++++++++++---------------- src/libexpr/eval.hh | 32 +++++++++++++++++++++++--------- 2 files changed, 44 insertions(+), 25 deletions(-) diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc index faf18cb7f4..72a3bf9b9c 100644 --- a/src/libexpr/eval.cc +++ b/src/libexpr/eval.cc @@ -153,15 +153,14 @@ void EvalState::addConstant(const string & name, Value & v) void EvalState::addPrimOp(const string & name, - unsigned int arity, PrimOp primOp) + unsigned int arity, PrimOpFun primOp) { Value * v = allocValue(); string name2 = string(name, 0, 2) == "__" ? string(name, 2) : name; + Symbol sym = symbols.create(name); v->type = tPrimOp; - v->primOp.arity = arity; - v->primOp.fun = primOp; - v->primOp.name = GC_STRDUP(name2.c_str()); - staticBaseEnv.vars[symbols.create(name)] = baseEnvDispl; + v->primOp = new (UseGC) PrimOp(primOp, arity, sym); + staticBaseEnv.vars[sym] = baseEnvDispl; baseEnv.values[baseEnvDispl++] = v; (*baseEnv.values[0]->attrs)[symbols.create(name2)].value = v; } @@ -252,6 +251,7 @@ void mkString(Value & v, const string & s, const PathSet & context) void mkPath(Value & v, const char * s) { + clearValue(v); v.type = tPath; v.path = GC_STRDUP(s); } @@ -310,6 +310,7 @@ void EvalState::mkList(Value & v, unsigned int length) void EvalState::mkAttrs(Value & v) { + clearValue(v); v.type = tAttrs; #if HAVE_BOEHMGC v.attrs = new (UseGC) Bindings; @@ -595,15 +596,20 @@ void ExprApp::eval(EvalState & state, Env & env, Value & v) void EvalState::callFunction(Value & fun, Value & arg, Value & v) { if (fun.type == tPrimOp || fun.type == tPrimOpApp) { - unsigned int argsLeft = - fun.type == tPrimOp ? fun.primOp.arity : fun.primOpApp.argsLeft; + + /* Figure out the number of arguments still needed. */ + unsigned int argsDone = 0; + Value * primOp = &fun; + while (primOp->type == tPrimOpApp) { + argsDone++; + primOp = primOp->primOpApp.left; + } + assert(primOp->type == tPrimOp); + unsigned int arity = primOp->primOp->arity; + unsigned int argsLeft = arity - argsDone; + if (argsLeft == 1) { - /* We have all the arguments, so call the primop. First - find the primop. */ - Value * primOp = &fun; - while (primOp->type == tPrimOpApp) primOp = primOp->primOpApp.left; - assert(primOp->type == tPrimOp); - unsigned int arity = primOp->primOp.arity; + /* We have all the arguments, so call the primop. */ /* Put all the arguments in an array. */ Value * vArgs[arity]; @@ -614,9 +620,9 @@ void EvalState::callFunction(Value & fun, Value & arg, Value & v) /* And call the primop. */ try { - primOp->primOp.fun(*this, vArgs, v); + primOp->primOp->fun(*this, vArgs, v); } catch (Error & e) { - addErrorPrefix(e, "while evaluating the builtin function `%1%':\n", primOp->primOp.name); + addErrorPrefix(e, "while evaluating the builtin function `%1%':\n", primOp->primOp->name); throw; } } else { @@ -624,7 +630,6 @@ void EvalState::callFunction(Value & fun, Value & arg, Value & v) v.primOpApp.left = allocValue(); *v.primOpApp.left = fun; v.primOpApp.right = &arg; - v.primOpApp.argsLeft = argsLeft - 1; } return; } diff --git a/src/libexpr/eval.hh b/src/libexpr/eval.hh index 5f5966930f..ec49394425 100644 --- a/src/libexpr/eval.hh +++ b/src/libexpr/eval.hh @@ -44,7 +44,17 @@ typedef enum { } ValueType; -typedef void (* PrimOp) (EvalState & state, Value * * args, Value & v); +typedef void (* PrimOpFun) (EvalState & state, Value * * args, Value & v); + + +struct PrimOp +{ + PrimOpFun fun; + unsigned int arity; + Symbol name; + PrimOp(PrimOpFun fun, unsigned int arity, Symbol name) + : fun(fun), arity(arity), name(name) { } +}; struct Value @@ -97,15 +107,9 @@ struct Value Env * env; ExprLambda * fun; } lambda; - Value * val; - struct { - PrimOp fun; - char * name; - unsigned int arity; - } primOp; + PrimOp * primOp; struct { Value * left, * right; - unsigned int argsLeft; } primOpApp; }; }; @@ -127,8 +131,17 @@ struct Attr }; +/* After overwriting an app node, be sure to clear pointers in the + Value to ensure that the target isn't kept alive unnecessarily. */ +static inline void clearValue(Value & v) +{ + v.app.right = 0; +} + + static inline void mkInt(Value & v, int n) { + clearValue(v); v.type = tInt; v.integer = n; } @@ -136,6 +149,7 @@ static inline void mkInt(Value & v, int n) static inline void mkBool(Value & v, bool b) { + clearValue(v); v.type = tBool; v.boolean = b; } @@ -268,7 +282,7 @@ private: void addConstant(const string & name, Value & v); void addPrimOp(const string & name, - unsigned int arity, PrimOp primOp); + unsigned int arity, PrimOpFun primOp); Value * lookupVar(Env * env, const VarRef & var);