From 9773e45a1e97f5098905bac26b8b8b7c844473f0 Mon Sep 17 00:00:00 2001
From: Owen Anderson <resistor@mac.com>
Date: Sat, 7 Aug 2010 05:47:46 +0000
Subject: [PATCH] Add an inverse() method to ConstantRange.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110504 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/Support/ConstantRange.h    |  3 +++
 lib/Support/ConstantRange.cpp           | 11 +++++++++++
 unittests/Support/ConstantRangeTest.cpp |  3 +++
 3 files changed, 17 insertions(+)

diff --git a/include/llvm/Support/ConstantRange.h b/include/llvm/Support/ConstantRange.h
index d767bd36b0c..c3a6dd03fdf 100644
--- a/include/llvm/Support/ConstantRange.h
+++ b/include/llvm/Support/ConstantRange.h
@@ -232,6 +232,9 @@ public:
   /// from a logical right shift of a value in this range by the Amount value.
   ConstantRange lshr(const ConstantRange &Amount) const;
 
+  /// inverse - Return a new range that is the logical not of the current set.
+  ConstantRange inverse() const;
+  
   /// print - Print out the bounds to a stream...
   ///
   void print(raw_ostream &OS) const;
diff --git a/lib/Support/ConstantRange.cpp b/lib/Support/ConstantRange.cpp
index fb0442823c4..26a23efe031 100644
--- a/lib/Support/ConstantRange.cpp
+++ b/lib/Support/ConstantRange.cpp
@@ -655,6 +655,17 @@ ConstantRange::lshr(const ConstantRange &Amount) const {
   return ConstantRange(min, max);
 }
 
+ConstantRange ConstantRange::inverse() const {
+  if (isFullSet()) {
+    return ConstantRange(APInt::getNullValue(Lower.getBitWidth()),
+      APInt::getNullValue(Lower.getBitWidth()));
+  } else if (isEmptySet()) {
+    return ConstantRange(APInt::getAllOnesValue(Lower.getBitWidth()),
+      APInt::getAllOnesValue(Lower.getBitWidth()));
+  }
+  return ConstantRange(Upper, Lower);
+}
+
 /// print - Print out the bounds to a stream...
 ///
 void ConstantRange::print(raw_ostream &OS) const {
diff --git a/unittests/Support/ConstantRangeTest.cpp b/unittests/Support/ConstantRangeTest.cpp
index 6b8d01d553f..fc1f5b8d06c 100644
--- a/unittests/Support/ConstantRangeTest.cpp
+++ b/unittests/Support/ConstantRangeTest.cpp
@@ -33,6 +33,7 @@ ConstantRange ConstantRangeTest::Wrap(APInt(16, 0xaaa), APInt(16, 0xa));
 TEST_F(ConstantRangeTest, Basics) {
   EXPECT_TRUE(Full.isFullSet());
   EXPECT_FALSE(Full.isEmptySet());
+  EXPECT_TRUE(Full.inverse().isEmptySet());
   EXPECT_FALSE(Full.isWrappedSet());
   EXPECT_TRUE(Full.contains(APInt(16, 0x0)));
   EXPECT_TRUE(Full.contains(APInt(16, 0x9)));
@@ -42,6 +43,7 @@ TEST_F(ConstantRangeTest, Basics) {
 
   EXPECT_FALSE(Empty.isFullSet());
   EXPECT_TRUE(Empty.isEmptySet());
+  EXPECT_TRUE(Empty.inverse().isFullSet());
   EXPECT_FALSE(Empty.isWrappedSet());
   EXPECT_FALSE(Empty.contains(APInt(16, 0x0)));
   EXPECT_FALSE(Empty.contains(APInt(16, 0x9)));
@@ -57,6 +59,7 @@ TEST_F(ConstantRangeTest, Basics) {
   EXPECT_TRUE(One.contains(APInt(16, 0xa)));
   EXPECT_FALSE(One.contains(APInt(16, 0xaa9)));
   EXPECT_FALSE(One.contains(APInt(16, 0xaaa)));
+  EXPECT_FALSE(One.inverse().contains(APInt(16, 0xa)));
 
   EXPECT_FALSE(Some.isFullSet());
   EXPECT_FALSE(Some.isEmptySet());
-- 
2.34.1