[Guile-commits] 06/06: Minor evaluator tweaks

[Andy Wingo]

wingo pushed a commit to branch wip-closure-conversion
in repository guile.

commit 5bfc0653d6361ab29ed2da68eeba14cce1ec8f6c
Author: Andy Wingo <address@hidden>
Date:   Sun Dec 7 19:03:19 2014 +0100

    Minor evaluator tweaks
    
    * libguile/eval.c (eval): Remove unused variable.
    * libguile/memoize.c (unmemoize): Fix unmemoization.
    * module/ice-9/eval.scm: Attempt to speed up common box-ref cases.
---
 libguile/eval.c       |    2 +-
 libguile/memoize.c    |   13 +++++++++----
 module/ice-9/eval.scm |   15 +++++++++++++--
 3 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/libguile/eval.c b/libguile/eval.c
index b69b5b2..72f1531 100644
--- a/libguile/eval.c
+++ b/libguile/eval.c
@@ -413,7 +413,7 @@ eval (SCM x, SCM env)
         return mx;
       else
         {
-          SCM mod, var;
+          SCM var;
 
           var = scm_sys_resolve_variable (mx, env_tail (env));
           scm_set_cdr_x (x, var);
diff --git a/libguile/memoize.c b/libguile/memoize.c
index cefb269..88a168f 100644
--- a/libguile/memoize.c
+++ b/libguile/memoize.c
@@ -750,10 +750,15 @@ unmemoize (const SCM expr)
                          unmemoize (CAR (args)),
                          unmemoize (CDR (args)));
     case SCM_M_RESOLVE:
-      return (SCM_VARIABLEP (args) || scm_is_symbol (args)) ? args
-        : scm_list_3 (scm_is_true (CDDR (args)) ? scm_sym_at : scm_sym_atat,
-                      scm_i_finite_list_copy (CAR (args)),
-                      CADR (args));
+      if (SCM_VARIABLEP (args))
+        return args;
+      else if (scm_is_symbol (CDR (args)))
+        return CDR (args);
+      else
+        return scm_list_3
+          (scm_is_true (CDDDR (args)) ? scm_sym_at : scm_sym_atat,
+           scm_i_finite_list_copy (CADR (args)),
+           CADDR (args));
     case SCM_M_CALL_WITH_PROMPT:
       return scm_list_4 (scm_from_latin1_symbol ("call-with-prompt"),
                          unmemoize (CAR (args)),
diff --git a/module/ice-9/eval.scm b/module/ice-9/eval.scm
index f3f0899..a1398f6 100644
--- a/module/ice-9/eval.scm
+++ b/module/ice-9/eval.scm
@@ -279,9 +279,11 @@
   ;; we compile `case' effectively, this situation will improve.
   (define-syntax mx-match
     (lambda (x)
-      (syntax-case x (quote)
+      (syntax-case x (quote else)
         ((_ mx data tag)
          #'(error "what" mx))
+        ((_ mx data tag (else body))
+         #'body)
         ((_ mx data tag (('type pat) body) c* ...)
          #`(if (eqv? tag #,(or (memoized-typecode (syntax->datum #'type))
                                (error "not a typecode" #'type)))
@@ -464,7 +466,16 @@
            (call eval proc nargs args env)))
         
         (('box-ref box)
-         (variable-ref (eval box env)))
+         (memoized-expression-case box
+           ;; Accelerate common cases.
+           (('resolve var-or-loc)
+            (if (variable? var-or-loc)
+                (variable-ref var-or-loc)
+                (variable-ref (eval box env))))
+           (('lexical-ref (depth . width))
+            (variable-ref (env-ref env depth width)))
+           (else
+            (variable-ref (eval box env)))))
 
         (('resolve var-or-loc)
          (if (variable? var-or-loc)