From: "Patrick R. Michaud" <[EMAIL PROTECTED]>
Date: Sat, 4 Oct 2008 09:41:22 -0500
On Fri, Oct 03, 2008 at 09:47:38PM -0700, Larry Wall wrote:
> On Fri, Oct 03, 2008 at 11:57:30PM -0400, Michael G Schwern wrote:
> : What's the status of numeric upgrades in Perl 6? Is see the
> : docs say "Perl 6 intrinsically supports big integers and rationals
> : through its system of type declarations. Int automatically
> : supports promotion to arbitrary precision" but it looks like it's
> : doing the same thing as Perl 5.
>
> The status of numeric upgrades in Perl 6 is fine. It's rakudo that
> doesn't do so well. :)
Correct. I suspect that eventually the Rakudo developers will have
to develop a custom set of PMCs for Perl 6 behaviors rather than
relying on the Parrot ones.
The Parrot behavior in this case may be closer than you think. After
applying the patch below, I get the expected output from Rakudo:
[EMAIL PROTECTED]> ./perl6 -e 'say 2**40'
1099511627776
[EMAIL PROTECTED]> ./perl6 -e 'say 2**50'
1125899906842624
[EMAIL PROTECTED]> ./perl6 -e 'say 2**1100'
13582985290493858492773514283592667786034938469317445497485196697278130927542418487205392083207560592298578262953847383475038725543234929971155548342800628721885763499406390331782864144164680730766837160526223176512798435772129956553355286032203080380775759732320198985094884004069116123084147875437183658467465148948790552744165376
[EMAIL PROTECTED]>
It does produces >300 spectest_regression failures, though, so I don't
claim the patch is right.
Parrot doesn't currently downgrade BigInt PMCs to Integer when it
should, though.
-- Bob Rogers
http://rgrjr.dyndns.org/
Make <infix:**> and <infix:*> DTRT for Int => BigInt promotion. May
break other numeric behaviors.
Index: languages/perl6/src/builtins/op.pir
===================================================================
--- languages/perl6/src/builtins/op.pir (revision 31592)
+++ languages/perl6/src/builtins/op.pir (working copy)
@@ -59,21 +59,12 @@
## exponentiation
.sub 'infix:**' :multi(_,_)
- .param num base
- .param num exp
- $N0 = pow base, exp
- .return ($N0)
+ .param pmc base
+ .param pmc exp
+ $P0 = n_pow base, exp
+ .return ($P0)
.end
-
-.sub 'infix:**' :multi(Integer,Integer)
- .param num base
- .param num exp
- $N0 = pow base, exp
- .return '!upgrade_to_num_if_needed'($N0)
-.end
-
-
## symbolic unary
.sub 'prefix:!' :multi(_)
.param pmc a
@@ -140,21 +131,13 @@
## multiplicative
.sub 'infix:*' :multi(_,_)
- .param num a
- .param num b
- $N0 = a * b
- .return ($N0)
+ .param pmc a
+ .param pmc b
+ $P0 = n_mul a, b
+ .return ($P0)
.end
-.sub 'infix:*' :multi(Integer,Integer)
- .param num a
- .param num b
- $N0 = a * b
- .return '!upgrade_to_num_if_needed'($N0)
-.end
-
-
.sub 'infix:/' :multi(_,_)
.param num a
.param num b
