+ /// Parameters that control the generic loop unrolling transformation.
+ struct UnrollingPreferences {
+ /// The cost threshold for the unrolled loop, compared to
+ /// CodeMetrics.NumInsts aggregated over all basic blocks in the loop body.
+ /// The unrolling factor is set such that the unrolled loop body does not
+ /// exceed this cost. Set this to UINT_MAX to disable the loop body cost
+ /// restriction.
+ unsigned Threshold;
+ /// The cost threshold for the unrolled loop when optimizing for size (set
+ /// to UINT_MAX to disable).
+ unsigned OptSizeThreshold;
+ /// A forced unrolling factor (the number of concatenated bodies of the
+ /// original loop in the unrolled loop body). When set to 0, the unrolling
+ /// transformation will select an unrolling factor based on the current cost
+ /// threshold and other factors.
+ unsigned Count;
+ /// Allow partial unrolling (unrolling of loops to expand the size of the
+ /// loop body, not only to eliminate small constant-trip-count loops).
+ bool Partial;
+ /// Allow runtime unrolling (unrolling of loops to expand the size of the
+ /// loop body even when the number of loop iterations is not known at compile
+ /// time).
+ bool Runtime;
+ };
+
+ /// \brief Get target-customized preferences for the generic loop unrolling
+ /// transformation. The caller will initialize UP with the current
+ /// target-independent defaults.
+ virtual void getUnrollingPreferences(Loop *L, UnrollingPreferences &UP) const;
+