[llvm] b6088f7 - [ConstantRange] Handle wrapping range in binaryNot()

[Nikita Popov via llvm-commits]

Author: Nikita Popov
Date: 2021-02-20T21:45:59+01:00
New Revision: b6088f7465a9a6691d5d237e9c0eb002734da3bf

URL: https://github.com/llvm/llvm-project/commit/b6088f7465a9a6691d5d237e9c0eb002734da3bf
DIFF: https://github.com/llvm/llvm-project/commit/b6088f7465a9a6691d5d237e9c0eb002734da3bf.diff

LOG: [ConstantRange] Handle wrapping range in binaryNot()

We don't need any special handling for wrapping ranges (or empty
ranges for that matter). The sub() call will already compute a
correct and precise range.

We only need to adjust the test expectation: We're now computing
an optimal result, rather than an unsigned envelope.

Added: 
    

Modified: 
    llvm/lib/IR/ConstantRange.cpp
    llvm/unittests/IR/ConstantRangeTest.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/IR/ConstantRange.cpp b/llvm/lib/IR/ConstantRange.cpp
index 4b0ad1bd25a0..275996dd02d8 100644
--- a/llvm/lib/IR/ConstantRange.cpp
+++ b/llvm/lib/IR/ConstantRange.cpp
@@ -1256,12 +1256,6 @@ ConstantRange ConstantRange::srem(const ConstantRange &RHS) const {
 }
 
 ConstantRange ConstantRange::binaryNot() const {
-  if (isEmptySet())
-    return getEmpty();
-
-  if (isWrappedSet())
-    return getFull();
-
   return ConstantRange(APInt::getAllOnesValue(getBitWidth())).sub(*this);
 }
 

diff  --git a/llvm/unittests/IR/ConstantRangeTest.cpp b/llvm/unittests/IR/ConstantRangeTest.cpp
index 77f07a8729b3..2b9c56b4134f 100644
--- a/llvm/unittests/IR/ConstantRangeTest.cpp
+++ b/llvm/unittests/IR/ConstantRangeTest.cpp
@@ -2388,26 +2388,24 @@ TEST_F(ConstantRangeTest, binaryXor) {
 }
 
 TEST_F(ConstantRangeTest, binaryNot) {
-  // TODO: Improve binaryNot() implementation to remove the need for
-  // PreferSmallestUnsigned.
   TestUnaryOpExhaustive(
       [](const ConstantRange &CR) { return CR.binaryNot(); },
       [](const APInt &N) { return ~N; },
-      PreferSmallestUnsigned);
+      PreferSmallest);
   TestUnaryOpExhaustive(
       [](const ConstantRange &CR) {
         return CR.binaryXor(
             ConstantRange(APInt::getAllOnesValue(CR.getBitWidth())));
       },
       [](const APInt &N) { return ~N; },
-      PreferSmallestUnsigned);
+      PreferSmallest);
   TestUnaryOpExhaustive(
       [](const ConstantRange &CR) {
         return ConstantRange(APInt::getAllOnesValue(CR.getBitWidth()))
             .binaryXor(CR);
       },
       [](const APInt &N) { return ~N; },
-      PreferSmallestUnsigned);
+      PreferSmallest);
 }
 
 }  // anonymous namespace