From cf9e07dea8aad32c5e7e2631d135566b20e1763c Mon Sep 17 00:00:00 2001
From: Nick Lewycky <nicholas@mxc.ca>
Date: Mon, 13 Jul 2009 02:49:08 +0000
Subject: [PATCH] Fix a bug summing two full sets. The overflow checking
doesn't handle sets as large as the full set, only those one size smaller.
Thanks to Daniel Dunbar who found this bug using Klee!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75443 91177308-0d34-0410-b5e6-96231b3b80d8
---
lib/Support/ConstantRange.cpp | 2 ++
unittests/Support/ConstantRangeTest.cpp | 1 +
2 files changed, 3 insertions(+)
diff --git a/lib/Support/ConstantRange.cpp b/lib/Support/ConstantRange.cpp
index 04a1b68e072..8bab5377952 100644
--- a/lib/Support/ConstantRange.cpp
+++ b/lib/Support/ConstantRange.cpp
@@ -533,6 +533,8 @@ ConstantRange
ConstantRange::add(const ConstantRange &Other) const {
if (isEmptySet() || Other.isEmptySet())
return ConstantRange(getBitWidth(), /*isFullSet=*/false);
+ if (isFullSet() || Other.isFullSet())
+ return ConstantRange(getBitWidth(), /*isFullSet=*/true);
APInt Spread_X = getSetSize(), Spread_Y = Other.getSetSize();
APInt NewLower = getLower() + Other.getLower();
diff --git a/unittests/Support/ConstantRangeTest.cpp b/unittests/Support/ConstantRangeTest.cpp
index 891c209f11c..cd91a9e103c 100644
--- a/unittests/Support/ConstantRangeTest.cpp
+++ b/unittests/Support/ConstantRangeTest.cpp
@@ -239,6 +239,7 @@ TEST_F(ConstantRangeTest, SubtractAPInt) {
TEST_F(ConstantRangeTest, Add) {
EXPECT_TRUE(Full.add(APInt(16, 4)).isFullSet());
+ EXPECT_EQ(Full.add(Full), Full);
EXPECT_EQ(Full.add(Empty), Empty);
EXPECT_EQ(Full.add(One), Full);
EXPECT_EQ(Full.add(Some), Full);