jones@ut-emx.uucp (William L. Jones) (02/19/91)
Since perl uses floating point arithmetic 20.0/5.0 != 4.0 on a cray.
This breaks lib/bigint.pl so that lib/big.t fails under perl 4.0 beta and
probably any other version of perl. There is a context diff that follows
that insures perl generates the correct answer for case like the above
on a cray. perl 4.0 beta passes all of the regression test on the cray with
this patch. (I hope cray fixes there floating point divide on the next machine).
I have not found any other problems with perl 4.0 beta. It installed
very cleanly under UNICOS 5.1.11.
Lary, would please incorporate this patch into perl 4.0.
I am sure that there will be other perl packages that will run
into this problem with floating point arithmetic on crays.
Bill Jones
----------------
*** eval.c Sun Feb 17 23:08:57 1991
--- orig/eval.c Sun Feb 17 22:38:56 1991
***************
*** 731,753 ****
case O_DIVIDE:
if ((value = str_gnum(st[2])) == 0.0)
fatal("Illegal division by zero");
- #ifdef cray
- /* insure that 20./5. == 4. */
- {
- double x;
- int k;
- x = str_gnum(st[1]);
- if ((double)(int)x == x &&
- (double)(int)value == value &&
- (k = (int)x/(int)value)*(int)value == (int)x) {
- value = k;
- } else {
- value = x/value;
- }
- }
- #else
value = str_gnum(st[1]) / value;
- #endif
goto donumset;
case O_MODULO:
tmplong = (long) str_gnum(st[2]);
--- 731,737 ----
*** orig/consarg.c Sun Feb 17 22:39:00 1991
--- consarg.c Sun Feb 17 23:15:36 1991
***************
*** 349,355 ****
if (value == 0.0)
yyerror("Illegal division by constant zero");
else
! str_numset(str,str_gnum(s1) / value);
break;
case O_MODULO:
tmplong = (unsigned long)str_gnum(s2);
--- 349,372 ----
if (value == 0.0)
yyerror("Illegal division by constant zero");
else
! #ifdef cray
! /* insure that 20./5. == 4. */
! {
! double x;
! int k;
! x = str_gnum(s1);
! if ((double)(int)x == x &&
! (double)(int)value == value &&
! (k = (int)x/(int)value)*(int)value == (int)x) {
! value = k;
! } else {
! value = x/value;
! }
! str_numset(str,value);
! }
! #else
! str_numset(str,str_gnum(s1) / value);
! #endif
break;
case O_MODULO:
tmplong = (unsigned long)str_gnum(s2);