shithub: femtolisp

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some micro-optimizations

--- a/femtolisp/flisp.c

+++ b/femtolisp/flisp.c

@@ -615,13 +615,13 @@

   is that a vararg lambda often needs to recur by applying itself to the

   tail of its argument list, so copying the list would be unacceptable.

 */

-static void list(value_t *pv, int nargs, value_t *plastcdr)

+static void list(value_t *pv, uint32_t nargs, value_t *plastcdr)

 {

     cons_t *c;

-    int i;

+    uint32_t i;

     *pv = cons_reserve(nargs);

     c = (cons_t*)ptr(*pv);

-    for(i=SP-nargs; i < (int)SP; i++) {

+    for(i=SP-nargs; i < SP; i++) {

         c->car = Stack[i];

         c->cdr = tagptr(c+1, TAG_CONS);

         c++;

@@ -683,8 +683,8 @@

     value_t f, v, *pv, *argsyms, *body;

     cons_t *c;

     symbol_t *sym;

-    uint32_t saveSP, envsz, lenv;

-    int i, nargs=0, noeval=0;

+    uint32_t saveSP, envsz, lenv, nargs;

+    int i, noeval=0;

     fixnum_t s, lo, hi;

     cvalue_t *cv;

     int64_t accum;

@@ -700,8 +700,10 @@

                 if (car_(v)==e) return *pv;

                 v = cdr_(v); pv++;

             }

-            if (v == e) return *pv;  // dotted list

-            if (v != NIL) pv++;

+            if (v != NIL) {

+                if (v == e) return *pv;  // dotted list

+                pv++;

+            }

             if (*pv == NIL) break;

             pv = &vector_elt(*pv, 0);

         }

@@ -758,12 +760,14 @@

                     }

                     f = cdr_(f); pv++;

                 }

-                if (f == e) {

-                    *pv = v;

-                    SP = saveSP;

-                    return v;

+                if (f != NIL) {

+                    if (f == e) {

+                        *pv = v;

+                        SP = saveSP;

+                        return v;

+                    }

+                    pv++;

                 }

-                if (f != NIL) pv++;

                 if (*pv == NIL) break;

                 pv = &vector_elt(*pv, 0);

             }

@@ -792,19 +796,29 @@

                 PUSH(Stack[penv+1]); // env has already been captured; share

             }

             c = (cons_t*)ptr(v=cons_reserve(3));

+            e = Stack[saveSP];

+            if (!iscons(e)) goto notpair;

             c->car = LAMBDA;

             c->cdr = tagptr(c+1, TAG_CONS); c++;

-            c->car = car(Stack[saveSP]); //argsyms

+            c->car = car_(e);      //argsyms

             c->cdr = tagptr(c+1, TAG_CONS); c++;

-            c->car = car(cdr_(Stack[saveSP])); //body

-            c->cdr = Stack[SP-1]; //env

+            if (!iscons(e=cdr_(e))) goto notpair;

+            c->car = car_(e);      //body

+            c->cdr = Stack[SP-1];  //env

             break;

         case F_IF:

-            v = car(Stack[saveSP]);

-            if (eval(v) != NIL)

-                v = car(cdr_(Stack[saveSP]));

-            else

-                v = car(cdr(cdr_(Stack[saveSP])));

+            if (!iscons(Stack[saveSP])) goto notpair;

+            v = car_(Stack[saveSP]);

+            if (eval(v) != NIL) {

+                v = cdr_(Stack[saveSP]);

+                if (!iscons(v)) goto notpair;

+                v = car_(v);

+            }

+            else {

+                v = cdr_(Stack[saveSP]);

+                if (!iscons(v) || !iscons(v=cdr_(v))) goto notpair;

+                v = car_(v);

+            }

             tail_eval(v);

             break;

         case F_COND:

@@ -913,11 +927,15 @@

             break;

         case F_CAR:

             argcount("car", nargs, 1);

-            v = car(Stack[SP-1]);

+            v = Stack[SP-1];

+            if (!iscons(v)) goto notpair;

+            v = car_(v);

             break;

         case F_CDR:

             argcount("cdr", nargs, 1);

-            v = cdr(Stack[SP-1]);

+            v = Stack[SP-1];

+            if (!iscons(v)) goto notpair;

+            v = cdr_(v);

             break;

         case F_RPLACA:

             argcount("rplaca", nargs, 2);

@@ -1250,7 +1268,8 @@

         // apply lambda expression

         f = cdr_(f);

         PUSH(f);

-        PUSH(car(f)); // arglist

+        if (!iscons(f)) goto notpair;

+        PUSH(car_(f)); // arglist

         argsyms = &Stack[SP-1];

         // build a calling environment for the lambda

         // the environment is the argument binds on top of the captured

@@ -1303,7 +1322,8 @@

             lerror(ArgError, "apply: too few arguments");

         }

         f = cdr_(Stack[saveSP+1]);

-        e = car(f);

+        if (!iscons(f)) goto notpair;

+        e = car_(f);

         if (selfevaluating(e)) { SP=saveSP; return(e); }

         PUSH(cdr_(f));                     // add closed environment

         *argsyms = car_(Stack[saveSP+1]);  // put lambda list

@@ -1339,6 +1359,8 @@

         // not reached

     }

     type_error("apply", "function", f);

+ notpair:

+    lerror(TypeError, "expected cons");

     return NIL;

 }

--- a/femtolisp/flisp.h

+++ b/femtolisp/flisp.h

@@ -150,7 +150,7 @@

 void type_error(char *fname, char *expected, value_t got) __attribute__ ((__noreturn__));

 void bounds_error(char *fname, value_t arr, value_t ind) __attribute__ ((__noreturn__));

 extern value_t ArgError, IOError, KeyError;

-static inline void argcount(char *fname, int nargs, int c)

+static inline void argcount(char *fname, uint32_t nargs, uint32_t c)

 {

     if (__unlikely(nargs != c))

         lerror(ArgError,"%s: too %s arguments", fname, nargs<c ? "few":"many");