From: Craig Topper <craig.topper@gmail.com>
Date: Sun, 26 Feb 2017 19:28:45 +0000 (+0000)
Subject: [APInt] Remove unnecessary early out from getLowBitsSet. The same case is handled... 
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=d1973fd95b817badea760efc3f43bd625916c1dd;p=llvm

[APInt] Remove unnecessary early out from getLowBitsSet. The same case is handled equally well by the next check.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296299 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/llvm/ADT/APInt.h b/include/llvm/ADT/APInt.h
index fa4233a0aa9..21be50aa49c 100644
--- a/include/llvm/ADT/APInt.h
+++ b/include/llvm/ADT/APInt.h
@@ -538,8 +538,6 @@ public:
     // Handle a degenerate case, to avoid shifting by word size
     if (loBitsSet == 0)
       return APInt(numBits, 0);
-    if (loBitsSet == APINT_BITS_PER_WORD)
-      return APInt(numBits, UINT64_MAX);
     // For small values, return quickly.
     if (loBitsSet <= APINT_BITS_PER_WORD)
       return APInt(numBits, UINT64_MAX >> (APINT_BITS_PER_WORD - loBitsSet));
diff --git a/unittests/ADT/APIntTest.cpp b/unittests/ADT/APIntTest.cpp
index 30da181a105..fa499bdf22b 100644
--- a/unittests/ADT/APIntTest.cpp
+++ b/unittests/ADT/APIntTest.cpp
@@ -1521,3 +1521,13 @@ TEST(APIntTest, extractBits) {
   EXPECT_EQ(static_cast<int64_t>(0xFFFFFFFFFF80007Full),
             i257.extractBits(129, 1).getSExtValue());
 }
+
+TEST(APIntTest, getLowBitsSet) {
+  APInt i128lo64 = APInt::getLowBitsSet(128, 64);
+  EXPECT_EQ(0u, i128lo64.countLeadingOnes());
+  EXPECT_EQ(64u, i128lo64.countLeadingZeros());
+  EXPECT_EQ(64u, i128lo64.getActiveBits());
+  EXPECT_EQ(0u, i128lo64.countTrailingZeros());
+  EXPECT_EQ(64u, i128lo64.countTrailingOnes());
+  EXPECT_EQ(64u, i128lo64.countPopulation());
+}