diff --git a/include/llvm/ADT/SmallBitVector.h b/include/llvm/ADT/SmallBitVector.h
index 62620fa2678..652492a1538 100644
--- a/include/llvm/ADT/SmallBitVector.h
+++ b/include/llvm/ADT/SmallBitVector.h
@@ -178,9 +178,9 @@ public:
   unsigned count() const {
     if (isSmall()) {
       uintptr_t Bits = getSmallBits();
-      if (sizeof(uintptr_t) * CHAR_BIT == 32)
+      if (NumBaseBits == 32)
         return CountPopulation_32(Bits);
-      if (sizeof(uintptr_t) * CHAR_BIT == 64)
+      if (NumBaseBits == 64)
         return CountPopulation_64(Bits);
       llvm_unreachable("Unsupported!");
     }
@@ -215,9 +215,9 @@ public:
       uintptr_t Bits = getSmallBits();
       if (Bits == 0)
         return -1;
-      if (sizeof(uintptr_t) * CHAR_BIT == 32)
+      if (NumBaseBits == 32)
         return CountTrailingZeros_32(Bits);
-      if (sizeof(uintptr_t) * CHAR_BIT == 64)
+      if (NumBaseBits == 64)
         return CountTrailingZeros_64(Bits);
       llvm_unreachable("Unsupported!");
     }
@@ -233,9 +233,9 @@ public:
       Bits &= ~uintptr_t(0) << (Prev + 1);
       if (Bits == 0 || Prev + 1 >= getSmallSize())
         return -1;
-      if (sizeof(uintptr_t) * CHAR_BIT == 32)
+      if (NumBaseBits == 32)
         return CountTrailingZeros_32(Bits);
-      if (sizeof(uintptr_t) * CHAR_BIT == 64)
+      if (NumBaseBits == 64)
         return CountTrailingZeros_64(Bits);
       llvm_unreachable("Unsupported!");
     }