Cleanup some -Wundef warnings in include/llvm/Support/MathExtras.h

[tkelman]

Summary

e.g.

include/llvm/Support/MathExtras.h:74:7: warning: "_MSC_VER" is not defined [-Wundef]
#elif _MSC_VER

^

[ArchDRobison]

Looks right to me.

[Bigcheese]

lgtm

[tkelman]

Thanks! On a similar note, should the instances of __GNUC__ >= 4 probably be changed to LLVM_GNUC_PREREQ(4, 0, 0)? Can be dealt with in a separate patch since I don't build under MSVC with the equivalent warning levels.

[Bigcheese]

looks like it should be.

[tkelman]

committed by Arch as r253614

include/llvm/Support/MathExtras.h

while (Shift) {
       }
       Shift >>= 1;
       Mask >>= Shift;
     }
     return ZeroBits;
   }
 };
 
-#if __GNUC__ >= 4 || _MSC_VER
+#if __GNUC__ >= 4 || defined(_MSC_VER)
 template <typename T> struct TrailingZerosCounter<T, 4> {
   static std::size_t count(T Val, ZeroBehavior ZB) {
     if (ZB != ZB_Undefined && Val == 0)
       return 32;
 
 #if __has_builtin(__builtin_ctz) || LLVM_GNUC_PREREQ(4, 0, 0)
     return __builtin_ctz(Val);
-#elif _MSC_VER
+#elif defined(_MSC_VER)
     unsigned long Index;
     _BitScanForward(&Index, Val);
     return Index;
 #endif
   }
 };
 
 #if !defined(_MSC_VER) || defined(_M_X64)
 template <typename T> struct TrailingZerosCounter<T, 8> {
   static std::size_t count(T Val, ZeroBehavior ZB) {
     if (ZB != ZB_Undefined && Val == 0)
       return 64;
 
 #if __has_builtin(__builtin_ctzll) || LLVM_GNUC_PREREQ(4, 0, 0)
     return __builtin_ctzll(Val);
-#elif _MSC_VER
+#elif defined(_MSC_VER)
     unsigned long Index;
     _BitScanForward64(&Index, Val);
     return Index;
 #endif
   }
 };
 #endif
 #endif
for (T Shift = std::numeric_limits<T>::digits >> 1; Shift; Shift >>= 1) {
         Val = Tmp;
       else
         ZeroBits |= Shift;
     }
     return ZeroBits;
   }
 };
 
-#if __GNUC__ >= 4 || _MSC_VER
+#if __GNUC__ >= 4 || defined(_MSC_VER)
 template <typename T> struct LeadingZerosCounter<T, 4> {
   static std::size_t count(T Val, ZeroBehavior ZB) {
     if (ZB != ZB_Undefined && Val == 0)
       return 32;
 
 #if __has_builtin(__builtin_clz) || LLVM_GNUC_PREREQ(4, 0, 0)
     return __builtin_clz(Val);
-#elif _MSC_VER
+#elif defined(_MSC_VER)
     unsigned long Index;
     _BitScanReverse(&Index, Val);
     return Index ^ 31;
 #endif
   }
 };
 
 #if !defined(_MSC_VER) || defined(_M_X64)
 template <typename T> struct LeadingZerosCounter<T, 8> {
   static std::size_t count(T Val, ZeroBehavior ZB) {
     if (ZB != ZB_Undefined && Val == 0)
       return 64;
 
 #if __has_builtin(__builtin_clzll) || LLVM_GNUC_PREREQ(4, 0, 0)
     return __builtin_clzll(Val);
-#elif _MSC_VER
+#elif defined(_MSC_VER)
     unsigned long Index;
     _BitScanReverse64(&Index, Val);
     return Index ^ 63;
 #endif
   }
 };
 #endif
 #endif