Re: int/float comparison

[Daniel Gildea via]

> This seems like a bug:
> 
> GCL (GNU Common Lisp)  2.7.1 Thu Apr 10 09:38:27 PM EDT 2025  CLtL1    git: 
> Version_2_7_2pre20
> 
> >(< 1.0E16 10000000000000001) 
> NIL

Here is a proposed fix.


diff --git a/gcl/o/num_comp.c b/gcl/o/num_comp.c
index c4c364d54..e39f6b593 100644
--- a/gcl/o/num_comp.c
+++ b/gcl/o/num_comp.c
@@ -70,6 +70,8 @@ number_compare(object x, object y) {
       return(number_compare(x, y));
 
     case t_shortfloat:
+      if ((float)number_to_double((q=double_to_integer((double)sf(y))))==sf(y))
+       return(number_compare(x,q));
       {
        volatile float fx=fix(x);
        dx = fx;
@@ -78,6 +80,8 @@ number_compare(object x, object y) {
       goto LONGFLOAT;
 
     case t_longfloat:
+      if (number_to_double((q=double_to_integer(lf(y))))==lf(y))
+       return(number_compare(x,q));
       dx = fix(x);
       dy = lf(y);
       goto LONGFLOAT;
@@ -175,6 +179,8 @@ number_compare(object x, object y) {
     switch (ty) {
 
     case t_fixnum:
+      if (number_to_double((q=double_to_integer(dx)))==dx)
+       return(number_compare(q,y));
 
       if (tx==t_shortfloat) {
        volatile float fy=fix(y);