Handle more cases in APInt::getLowBitsSet's fast path.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145249 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/ADT/APInt.h b/include/llvm/ADT/APInt.h
index 707e0dbb6b91e5fd5ef821620d652c926e64d571..78119bce2ac4a64b545145cb6bddd307fa4b54ab 100644 (file)
--- a/include/llvm/ADT/APInt.h
+++ b/include/llvm/ADT/APInt.h
@@ -497,8 +497,8 @@ public:
     if (loBitsSet == APINT_BITS_PER_WORD)
       return APInt(numBits, -1ULL);
     // For small values, return quickly.
-    if (numBits < APINT_BITS_PER_WORD)
-      return APInt(numBits, (1ULL << loBitsSet) - 1);
+    if (loBitsSet <= APINT_BITS_PER_WORD)
+      return APInt(numBits, -1ULL >> (APINT_BITS_PER_WORD - loBitsSet));
     return getAllOnesValue(numBits).lshr(numBits - loBitsSet);
   }