From a7e6c5672e3169cdd81827a7f8282a1612b2e207 Mon Sep 17 00:00:00 2001
From: Vitor Santos Costa <vsc@dcc.fc.up.pt>
Date: Mon, 4 Jan 2010 21:16:42 -0200
Subject: [PATCH] try to speed up eval a bit.

---
 C/eval.c |  4 ++--
 H/eval.h | 14 +++++++++++---
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/C/eval.c b/C/eval.c
index f8f2ac491..bcc7721eb 100644
--- a/C/eval.c
+++ b/C/eval.c
@@ -120,9 +120,9 @@ Eval(Term t)
 }
 
 Term
-Yap_Eval(Term t)
+Yap_InnerEval(Term t)
 {
-  return Yap_FoundArithError(Eval(t), t);
+  return Eval(t);
 }
 
 #ifdef BEAM
diff --git a/H/eval.h b/H/eval.h
index 5e6bb8001..621047438 100644
--- a/H/eval.h
+++ b/H/eval.h
@@ -169,16 +169,24 @@ Term	STD_PROTO(Yap_eval_atom,(Int));
 Term	STD_PROTO(Yap_eval_unary,(Int,Term));
 Term	STD_PROTO(Yap_eval_binary,(Int,Term,Term));
 
-Term	STD_PROTO(Yap_Eval,(Term));
+Term	STD_PROTO(Yap_InnerEval,(Term));
 Int     STD_PROTO(Yap_ArithError,(yap_error_number,Term,char *msg, ...));
 
+inline EXTERN Term
+Yap_Eval(Term t)
+{
+  if (t == 0L || !IsVarTerm(t) || IsNumTerm(t))
+    return t;
+  return Yap_InnerEval(t);
+}
+
 inline static Term
 Yap_FoundArithError(Term t, Term inp)
 {
   if (Yap_Error_TYPE) {
     Yap_Error(Yap_Error_TYPE, (inp ? inp : Yap_Error_Term), Yap_ErrorMessage);
-     P = FAILCODE;
-     return 0L;
+    P = FAILCODE;
+    return 0L;
   }
   return t;
 }