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-rw-r--r--lib/Transforms/Scalar/Reassociate.cpp18
1 files changed, 7 insertions, 11 deletions
diff --git a/lib/Transforms/Scalar/Reassociate.cpp b/lib/Transforms/Scalar/Reassociate.cpp
index b572f4eb07..69cdc0f799 100644
--- a/lib/Transforms/Scalar/Reassociate.cpp
+++ b/lib/Transforms/Scalar/Reassociate.cpp
@@ -673,16 +673,10 @@ void Reassociate::RewriteExprTree(BinaryOperator *I,
// original in some non-trivial way, requiring the clearing of optional flags.
// Flags are cleared from the operator in ExpressionChanged up to I inclusive.
BinaryOperator *ExpressionChanged = 0;
- BinaryOperator *Previous;
- BinaryOperator *Op = 0;
- for (unsigned i = 0, e = Ops.size(); i != e; ++i) {
+ for (unsigned i = 0; ; ++i) {
assert(!NodesToRewrite.empty() &&
"Optimized expressions has more nodes than original!");
- Previous = Op; Op = NodesToRewrite.pop_back_val();
- if (ExpressionChanged)
- // Compactify the tree instructions together with each other to guarantee
- // that the expression tree is dominated by all of Ops.
- Op->moveBefore(Previous);
+ BinaryOperator *Op = NodesToRewrite.pop_back_val();
// The last operation (which comes earliest in the IR) is special as both
// operands will come from Ops, rather than just one with the other being
@@ -771,15 +765,17 @@ void Reassociate::RewriteExprTree(BinaryOperator *I,
}
// If the expression changed non-trivially then clear out all subclass data
- // starting from the operator specified in ExpressionChanged.
- if (ExpressionChanged) {
+ // starting from the operator specified in ExpressionChanged, and compactify
+ // the operators to just before the expression root to guarantee that the
+ // expression tree is dominated by all of Ops.
+ if (ExpressionChanged)
do {
ExpressionChanged->clearSubclassOptionalData();
if (ExpressionChanged == I)
break;
+ ExpressionChanged->moveBefore(I);
ExpressionChanged = cast<BinaryOperator>(*ExpressionChanged->use_begin());
} while (1);
- }
// Throw away any left over nodes from the original expression.
for (unsigned i = 0, e = NodesToRewrite.size(); i != e; ++i)