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Postings from January 2001
Re: [PATCH: perl@8342] lib/bigfloat.t FAILED at test 351
From:
Peter Prymmer
Date:
January 12, 2001 16:25
Subject:
Re: [PATCH: perl@8342] lib/bigfloat.t FAILED at test 351
Message ID:
Pine.OSF.4.10.10101121623130.478096-100000@aspara.forte.com
On Fri, 12 Jan 2001, Jarkko Hietaniemi wrote:
> > OK the variable alluded to above would have been better name
> > fp_multiply_broken, but in order to be both terse and explicit how about
> > fp_snm_broken? As in this snippet that could fit into Configure after the
> > value of $i_math is determined (the eval and rm lines have been #commented
> > out so that I could play with this script standalone, the echo >&4 line
> > is commented too since I have not done the approriate exec in my login
> > shell):
>
> I feel that this is too specific an error with too specific parameters
> to warrant a separate Configure test. How about a BEGIN test in the
> library files?
OK so we back away from doing the test in C and revert to perl. Do you
want for the BEGIN{} block to be a test done as part of a:
lib/bigint_pl.PL -> lib/bigint.pl
lib/Math/BigInt_pm.PL -> lib/Math/BigInt.pm
file extraction? Or would this do (it tests lib/big*.t tests ok with the
8375 kit on os/390 and with the 8404 kit on Tru 64 4.0D)?
diff -ru perl.8404.orig/lib/Math/BigInt.pm perl.8404/lib/Math/BigInt.pm
--- perl.8404.orig/lib/Math/BigInt.pm Sat Jan 6 21:32:28 2001
+++ perl.8404/lib/Math/BigInt.pm Fri Jan 12 15:55:25 2001
@@ -52,6 +52,11 @@
$zero = 0;
+# overcome a floating point problem on certain osnames (posix-bc, os390)
+BEGIN {
+ my $x = 100000.0;
+ my $use_mult = int($x*1e-5)*1e5 == $x ? 1 : 0;
+}
# normalize string form of number. Strip leading zeros. Strip any
# white space and add a sign, if missing.
@@ -228,8 +233,14 @@
($car, $cty) = (0, $[);
for $y (@y) {
$prod = $x * $y + ($prod[$cty] || 0) + $car;
+ if ($use_mult) {
$prod[$cty++] =
$prod - ($car = int($prod * 1e-5)) * 1e5;
+ }
+ else {
+ $prod[$cty++] =
+ $prod - ($car = int($prod / 1e5)) * 1e5;
+ }
}
$prod[$cty] += $car if $car;
$x = shift @prod;
@@ -254,12 +265,22 @@
if (($dd = int(1e5/($y[$#y]+1))) != 1) {
for $x (@x) {
$x = $x * $dd + $car;
+ if ($use_mult) {
$x -= ($car = int($x * 1e-5)) * 1e5;
+ }
+ else {
+ $x -= ($car = int($x / 1e5)) * 1e5;
+ }
}
push(@x, $car); $car = 0;
for $y (@y) {
$y = $y * $dd + $car;
+ if ($use_mult) {
$y -= ($car = int($y * 1e-5)) * 1e5;
+ }
+ else {
+ $y -= ($car = int($y / 1e5)) * 1e5;
+ }
}
}
else {
@@ -276,7 +297,12 @@
($car, $bar) = (0,0);
for ($y = $[, $x = $#x-$#y+$[-1; $y <= $#y; ++$y,++$x) {
$prd = $q * $y[$y] + $car;
+ if ($use_mult) {
$prd -= ($car = int($prd * 1e-5)) * 1e5;
+ }
+ else {
+ $prd -= ($car = int($prd / 1e5)) * 1e5;
+ }
$x[$x] += 1e5 if ($bar = (($x[$x] -= $prd + $bar) < 0));
}
if ($x[$#x] < $car + $bar) {
diff -ru perl.8404.orig/lib/bigint.pl perl.8404/lib/bigint.pl
--- perl.8404.orig/lib/bigint.pl Sat Jan 6 21:32:33 2001
+++ perl.8404/lib/bigint.pl Fri Jan 12 15:55:13 2001
@@ -42,6 +42,12 @@
# bnorm(BINT) return BINT normalization
#
+# overcome a floating point problem on certain osnames (posix-bc, os390)
+BEGIN {
+ my $x = 100000.0;
+ my $use_mult = int($x*1e-5)*1e5 == $x ? 1 : 0;
+}
+
$zero = 0;
@@ -212,8 +218,14 @@
($car, $cty) = (0, $[);
for $y (@y) {
$prod = $x * $y + $prod[$cty] + $car;
- $prod[$cty++] =
- $prod - ($car = int($prod * 1e-5)) * 1e5;
+ if ($use_mult) {
+ $prod[$cty++] =
+ $prod - ($car = int($prod * 1e-5)) * 1e5;
+ }
+ else {
+ $prod[$cty++] =
+ $prod - ($car = int($prod / 1e5)) * 1e5;
+ }
}
$prod[$cty] += $car if $car;
$x = shift @prod;
@@ -239,12 +251,22 @@
if (($dd = int(1e5/($y[$#y]+1))) != 1) {
for $x (@x) {
$x = $x * $dd + $car;
+ if ($use_mult) {
$x -= ($car = int($x * 1e-5)) * 1e5;
+ }
+ else {
+ $x -= ($car = int($x / 1e5)) * 1e5;
+ }
}
push(@x, $car); $car = 0;
for $y (@y) {
$y = $y * $dd + $car;
+ if ($use_mult) {
$y -= ($car = int($y * 1e-5)) * 1e5;
+ }
+ else {
+ $y -= ($car = int($y / 1e5)) * 1e5;
+ }
}
}
else {
@@ -259,7 +281,12 @@
($car, $bar) = (0,0);
for ($y = $[, $x = $#x-$#y+$[-1; $y <= $#y; ++$y,++$x) {
$prd = $q * $y[$y] + $car;
+ if ($use_mult) {
$prd -= ($car = int($prd * 1e-5)) * 1e5;
+ }
+ else {
+ $prd -= ($car = int($prd / 1e5)) * 1e5;
+ }
$x[$x] += 1e5 if ($bar = (($x[$x] -= $prd + $bar) < 0));
}
if ($x[$#x] < $car + $bar) {
End of Patch.
Peter Prymmer