[llvm-commits] CVS: llvm/include/llvm/ADT/APInt.h

[Reid Spencer]

Changes in directory llvm/include/llvm/ADT:

APInt.h updated: 1.54 -> 1.55
---
Log message:

Make it illegal to set 0 bits in getHighBitsSet and getLowBitsSet. For that
they should have used the uint64_t constructor. This avoids causing 
undefined results via shifts by the word size when the bit width is an 
exact multiple of the word size.


---
Diffs of the changes:  (+2 -0)

 APInt.h |    2 ++
 1 files changed, 2 insertions(+)


Index: llvm/include/llvm/ADT/APInt.h
diff -u llvm/include/llvm/ADT/APInt.h:1.54 llvm/include/llvm/ADT/APInt.h:1.55
--- llvm/include/llvm/ADT/APInt.h:1.54	Sat Mar 24 18:42:47 2007
+++ llvm/include/llvm/ADT/APInt.h	Sat Mar 24 18:47:58 2007
@@ -355,6 +355,7 @@
   /// @brief Get a value with high bits set
   static APInt getHighBitsSet(uint32_t numBits, uint32_t hiBitsSet) {
     assert(hiBitsSet <= numBits && "Too many bits to set!");
+    assert(hiBitsSet > 0 && "You must set SOME bits");
     uint32_t shiftAmt = numBits - hiBitsSet;
     // For small values, return quickly
     if (numBits <= APINT_BITS_PER_WORD)
@@ -368,6 +369,7 @@
   /// @brief Get a value with low bits set
   static APInt getLowBitsSet(uint32_t numBits, uint32_t loBitsSet) {
     assert(loBitsSet <= numBits && "Too many bits to set!");
+    assert(loBitsSet > 0 && "You must set SOME bits");
     uint32_t shiftAmt = numBits - loBitsSet;
     // For small values, return quickly
     if (numBits <= APINT_BITS_PER_WORD)