[llvm] r247993 - Simplify SmallBitVector::applyMask by consolidating common code for 32- and 64-bit builds

[Yaron Keren via llvm-commits]

Author: yrnkrn
Date: Fri Sep 18 10:08:24 2015
New Revision: 247993

URL: http://llvm.org/viewvc/llvm-project?rev=247993&view=rev
Log:
Simplify SmallBitVector::applyMask by consolidating common code for 32- and 64-bit builds
and assert when mask is too large to apply in the small case,
previously the extra words were silently ignored.
clang-format the entire function to match current code standards.

This is a rewrite of r247972 which was reverted in r247983 due to
warning and possible UB on 32-bits hosts.


Modified:
    llvm/trunk/include/llvm/ADT/SmallBitVector.h
    llvm/trunk/unittests/ADT/BitVectorTest.cpp

Modified: llvm/trunk/include/llvm/ADT/SmallBitVector.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ADT/SmallBitVector.h?rev=247993&r1=247992&r2=247993&view=diff
==============================================================================
--- llvm/trunk/include/llvm/ADT/SmallBitVector.h (original)
+++ llvm/trunk/include/llvm/ADT/SmallBitVector.h Fri Sep 18 10:08:24 2015
@@ -551,19 +551,18 @@ public:
   }
 
 private:
-  template<bool AddBits, bool InvertMask>
+  template <bool AddBits, bool InvertMask>
   void applyMask(const uint32_t *Mask, unsigned MaskWords) {
-    if (NumBaseBits == 64 && MaskWords >= 2) {
-      uint64_t M = Mask[0] | (uint64_t(Mask[1]) << 32);
-      if (InvertMask) M = ~M;
-      if (AddBits) setSmallBits(getSmallBits() | M);
-      else         setSmallBits(getSmallBits() & ~M);
-    } else {
-      uint32_t M = Mask[0];
-      if (InvertMask) M = ~M;
-      if (AddBits) setSmallBits(getSmallBits() | M);
-      else         setSmallBits(getSmallBits() & ~M);
-    }
+    assert(MaskWords <= sizeof(uintptr_t) && "Mask is larger than base!");
+    uintptr_t M = Mask[0];
+    if (NumBaseBits == 64)
+      M |= uint64_t(Mask[1]) << 32;
+    if (InvertMask)
+      M = ~M;
+    if (AddBits)
+      setSmallBits(getSmallBits() | M);
+    else
+      setSmallBits(getSmallBits() & ~M);
   }
 };
 

Modified: llvm/trunk/unittests/ADT/BitVectorTest.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/ADT/BitVectorTest.cpp?rev=247993&r1=247992&r2=247993&view=diff
==============================================================================
--- llvm/trunk/unittests/ADT/BitVectorTest.cpp (original)
+++ llvm/trunk/unittests/ADT/BitVectorTest.cpp Fri Sep 18 10:08:24 2015
@@ -235,12 +235,12 @@ TYPED_TEST(BitVectorTest, PortableBitMas
   const uint32_t Mask1[] = { 0x80000000, 6, 5 };
 
   A.resize(10);
-  A.setBitsInMask(Mask1, 3);
+  A.setBitsInMask(Mask1, 1);
   EXPECT_EQ(10u, A.size());
   EXPECT_FALSE(A.test(0));
 
   A.resize(32);
-  A.setBitsInMask(Mask1, 3);
+  A.setBitsInMask(Mask1, 1);
   EXPECT_FALSE(A.test(0));
   EXPECT_TRUE(A.test(31));
   EXPECT_EQ(1u, A.count());