From 9ad679573c99b62e751d827be2d6b391cae52b6e Mon Sep 17 00:00:00 2001
From: hjp <hjp>
Date: Thu, 1 Oct 2009 17:29:22 +0000
Subject: [PATCH] script to compute ulp+ and ulp-

---
 ieeefloat/ulp | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)
 create mode 100755 ieeefloat/ulp

diff --git a/ieeefloat/ulp b/ieeefloat/ulp
new file mode 100755
index 0000000..4b2660d
--- /dev/null
+++ b/ieeefloat/ulp
@@ -0,0 +1,26 @@
+#!/usr/bin/perl
+
+use warnings;
+use strict;
+
+my $x = $ARGV[0] + 0;
+
+my $d = 1;
+while ($x + $d == $x) {
+    $d *= 2;
+}
+while ($x + $d/2 != $x) {
+    $d /= 2;
+}
+
+printf "ulp+ = %.17e %.17e %.17e\n", $d, $x, $x + $d;
+
+$d = 1;
+while ($x - $d == $x) {
+    $d *= 2;
+}
+while ($x - $d/2 != $x) {
+    $d /= 2;
+}
+
+printf "ulp- = %.17e %.17e %.17e\n", $d, $x, $x - $d;