From abc4fd372d476821448dfb949bea4e28ab82ac26 Mon Sep 17 00:00:00 2001
From: Sverker Eriksson <sverker@erlang.org>
Date: Wed, 12 Jul 2017 17:09:10 +0200
Subject: erts: Fix bug in bxor of a big negative number

Wrong result for

(X bsl WS) bxor Y.

where
X is any negative integer
Y is any integer that does not require more words than X
WS is erlang:system_info(wordsize) or larger


Fix: The subtraction of 1 (for 2-complement conversion)
must be carried along all the way to the last words.
---
 erts/emulator/test/big_SUITE_data/borders.dat | 35 +++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

(limited to 'erts/emulator/test/big_SUITE_data')

diff --git a/erts/emulator/test/big_SUITE_data/borders.dat b/erts/emulator/test/big_SUITE_data/borders.dat
index 52e4f35861..c38ff93383 100644
--- a/erts/emulator/test/big_SUITE_data/borders.dat
+++ b/erts/emulator/test/big_SUITE_data/borders.dat
@@ -1114,3 +1114,38 @@
 1 = 16#800000000000001 rem (-16#800000000000000).
 0 = 16#FFFFFFFFFFFFFFF800000000 rem 16#FFFFFFFFFFFFFFF80.
 
+% ERL-450 bxor of big negative 2-pow
+-(1 bsl 8) bxor -1 = 16#ff.
+-(1 bsl 16) bxor -1 = 16#ffff.
+-(1 bsl 24) bxor -1 = 16#ffffff.
+-(1 bsl 32) bxor -1 = 16#ffffffff.
+-(1 bsl 40) bxor -1 = 16#ffffffffff.
+-(1 bsl 48) bxor -1 = 16#ffffffffffff.
+-(1 bsl 56) bxor -1 = 16#ffffffffffffff.
+-(1 bsl 64) bxor -1 = 16#ffffffffffffffff.
+-(1 bsl 72) bxor -1 = 16#ffffffffffffffffff.
+-(1 bsl 80) bxor -1 = 16#ffffffffffffffffffff.
+-(1 bsl 88) bxor -1 = 16#ffffffffffffffffffffff.
+-(1 bsl 96) bxor -1 = 16#ffffffffffffffffffffffff.
+-(1 bsl 104) bxor -1 = 16#ffffffffffffffffffffffffff.
+-(1 bsl 112) bxor -1 = 16#ffffffffffffffffffffffffffff.
+-(1 bsl 120) bxor -1 = 16#ffffffffffffffffffffffffffffff.
+-(1 bsl 128) bxor -1 = 16#ffffffffffffffffffffffffffffffff.
+-(1 bsl 136) bxor -1 = 16#ffffffffffffffffffffffffffffffffff.
+-(1 bsl 8) bxor 1 = -16#ff.
+-(1 bsl 16) bxor 1 = -16#ffff.
+-(1 bsl 24) bxor 1 = -16#ffffff.
+-(1 bsl 32) bxor 1 = -16#ffffffff.
+-(1 bsl 40) bxor 1 = -16#ffffffffff.
+-(1 bsl 48) bxor 1 = -16#ffffffffffff.
+-(1 bsl 56) bxor 1 = -16#ffffffffffffff.
+-(1 bsl 64) bxor 1 = -16#ffffffffffffffff.
+-(1 bsl 72) bxor 1 = -16#ffffffffffffffffff.
+-(1 bsl 80) bxor 1 = -16#ffffffffffffffffffff.
+-(1 bsl 88) bxor 1 = -16#ffffffffffffffffffffff.
+-(1 bsl 96) bxor 1 = -16#ffffffffffffffffffffffff.
+-(1 bsl 104) bxor 1 = -16#ffffffffffffffffffffffffff.
+-(1 bsl 112) bxor 1 = -16#ffffffffffffffffffffffffffff.
+-(1 bsl 120) bxor 1 = -16#ffffffffffffffffffffffffffffff.
+-(1 bsl 128) bxor 1 = -16#ffffffffffffffffffffffffffffffff.
+-(1 bsl 136) bxor 1 = -16#ffffffffffffffffffffffffffffffffff.
-- 
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