[VPlan] Determine Vector Width programmatically.

With this change, the VPlan native path is triggered with the directive:

   #pragma clang loop vectorize(enable)

There is no need to specify the vectorize_width(N) clause.

Patch by Francesco Petrogalli <francesco.petrogalli@arm.com>

Differential Revision: https://reviews.llvm.org/D57598

llvm-svn: 357156

1 files changed, 4 insertions, 0 deletions

diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorizationPlanner.h b/llvm/lib/Transforms/Vectorize/LoopVectorizationPlanner.h
index 7264eb97e1b..8b7cf300eef 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorizationPlanner.h
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorizationPlanner.h
@@ -174,6 +174,10 @@ struct VectorizationFactor {
 
   // Width 1 means no vectorization, cost 0 means uncomputed cost.
   static VectorizationFactor Disabled() { return {1, 0}; }
+
+  bool operator==(const VectorizationFactor &rhs) const {
+    return Width == rhs.Width && Cost == rhs.Cost;
+  }
 };
 
 /// Planner drives the vectorization process after having passed