Add MathExtras.h OffsetToAlignment, like RoundUpToAlignment but returns the

offset to the next aligned integer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80339 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/Support/MathExtras.h b/include/llvm/Support/MathExtras.h
index 7ba5d8661cccdc5721606ca1da08725f875cb3af..6fa618eb1af85c7bd23f0dc6c4d07eb3cdb026b0 100644 (file)
--- a/include/llvm/Support/MathExtras.h
+++ b/include/llvm/Support/MathExtras.h
@@ -435,6 +435,13 @@ inline uint64_t RoundUpToAlignment(uint64_t Value, uint64_t Align) {
   return ((Value + Align - 1) / Align) * Align;
 }
 
+/// OffsetToAlignment - Return the offset to the next integer (mod 2**64) that
+/// is greater than or equal to \arg Value and is a multiple of \arg
+/// Align. Align must be non-zero.
+inline uint64_t OffsetToAlignment(uint64_t Value, uint64_t Align) {
+  return RoundUpToAlignment(Value, Align) - Value;
+}
+
 /// abs64 - absolute value of a 64-bit int.  Not all environments support
 /// "abs" on whatever their name for the 64-bit int type is.  The absolute
 /// value of the largest negative number is undefined, as with "abs".