Re: [PATCH: perl@8342] lib/bigfloat.t FAILED at test 351

Message-ID: <Pine.OSF.4.10.10101121623130.478096-100000@aspara.forte.com>

Add a BEGIN guard for sloppy floating point division.

p4raw-id: //depot/perl@8428

diff --git a/lib/Math/BigInt.pm b/lib/Math/BigInt.pm
index 808e552..066577d 100644 (file)
--- a/lib/Math/BigInt.pm
+++ b/lib/Math/BigInt.pm
@@ -52,6 +52,11 @@ sub import {
 
 $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 @@ sub mul { #(*int_num_array, *int_num_array) return int_num_array
       ($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;
       $x = shift @prod;
@@ -254,12 +265,22 @@ sub bdiv { #(dividend: num_str, divisor: num_str) return num_str
     if (($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($y / 1e5)) * 1e5;
+            }
        }
     }
     else {
@@ -276,7 +297,12 @@ sub bdiv { #(dividend: num_str, divisor: num_str) return num_str
            ($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 --git a/lib/bigint.pl b/lib/bigint.pl
index 4044f7f..9a3d50d 100644 (file)
--- a/lib/bigint.pl
+++ b/lib/bigint.pl
@@ -42,6 +42,12 @@ package bigint;
 #   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;
 
 \f
@@ -212,8 +218,14 @@ sub main'bmul { #(num_str, num_str) return num_str
            ($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;
            $x = shift @prod;
@@ -239,12 +251,22 @@ sub main'bdiv { #(dividend: num_str, divisor: num_str) return num_str
     if (($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($y / 1e5)) * 1e5;
+            }
        }
     }
     else {
@@ -259,7 +281,12 @@ sub main'bdiv { #(dividend: num_str, divisor: num_str) return num_str
            ($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) {