Ensure KnownBits passed when calculating from range md has right size (#132985)

KnownBits passed to computeKnownBitsFromRangeMetadata must have the same
bit width as the range metadata bit width. Otherwise the calculated
results will be incorrect.

---------

Signed-off-by: John Lu <[email protected]>

Author: LU-JOHN

llvm/lib/Analysis/ValueTracking.cpp

@@ -430,6 +430,10 @@ void llvm::computeKnownBitsFromRangeMetadata(const MDNode &Ranges,
     ConstantInt *Upper =
         mdconst::extract<ConstantInt>(Ranges.getOperand(2 * i + 1));
     ConstantRange Range(Lower->getValue(), Upper->getValue());
+    // BitWidth must equal the Ranges BitWidth for the correct number of high
+    // bits to be set.
+    assert(BitWidth == Range.getBitWidth() &&
+           "Known bit width must match range bit width!");
 
     // The first CommonPrefixBits of all values in Range are equal.
     unsigned CommonPrefixBits =

llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp

@@ -9176,6 +9176,12 @@ SDValue SelectionDAG::getLoad(ISD::MemIndexedMode AM, ISD::LoadExtType ExtType,
            "Cannot use an ext load to change the number of vector elements!");
   }
 
+  assert((!MMO->getRanges() ||
+          (mdconst::extract<ConstantInt>(MMO->getRanges()->getOperand(0))
+                   ->getBitWidth() == MemVT.getScalarSizeInBits() &&
+           MemVT.isInteger())) &&
+         "Range metadata and load type must match!");
+
   bool Indexed = AM != ISD::UNINDEXED;
   assert((Indexed || Offset.isUndef()) && "Unindexed load with an offset!");