When computing the value on an edge, in certain cases LVI would fail to compute the value range

in the predecessor block, leading to an incorrect conclusion for the edge value.  Found by inspection.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122908 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Owen Anderson 2011-01-05 21:37:18 +00:00
parent bfb7dd9e9e
commit be41901d5a

View File

@ -817,6 +817,11 @@ bool LazyValueInfoCache::getEdgeValue(Value *Val, BasicBlock *BBFrom,
if (!isTrueDest) TrueValues = TrueValues.inverse();
// Figure out the possible values of the query BEFORE this branch.
if (!hasBlockValue(Val, BBFrom)) {
block_value_stack.push(std::make_pair(BBFrom, Val));
return false;
}
LVILatticeVal InBlock = getBlockValue(Val, BBFrom);
if (!InBlock.isConstantRange()) {
Result = LVILatticeVal::getRange(TrueValues);