[LV] Use VF from selected plan when creating InnerLoopVectorizer.

Summary:
This makes sure the same VF is used when executing the plan and in the
functions in InnerLoopVectorizer when the assertion is disabled (e.g.
release builds).

No tests added as they would trigger an assertion.

Test Plan: 

Reviewers: 

Subscribers: 

Tasks: 

Tags: 


Differential Revision: https://phabricator.intern.facebook.com/D60251701

Author: fhahn

llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

@@ -10402,10 +10402,6 @@ bool LoopVectorizePass::processLoop(Loop *L) {
         if (!MainILV.areSafetyChecksAdded())
           DisableRuntimeUnroll = true;
       } else {
-        InnerLoopVectorizer LB(L, PSE, LI, DT, TLI, TTI, AC, ORE, VF.Width,
-                               VF.MinProfitableTripCount, IC, &LVL, &CM, BFI,
-                               PSI, Checks);
-
         VPlan &BestPlan = LVP.getBestPlan();
         assert(size(BestPlan.vectorFactors()) == 1 &&
                "Plan should have a single VF");
@@ -10414,6 +10410,9 @@ bool LoopVectorizePass::processLoop(Loop *L) {
                           << "\n");
         assert(VF.Width == Width &&
                "VPlan cost model and legacy cost model disagreed");
+        InnerLoopVectorizer LB(L, PSE, LI, DT, TLI, TTI, AC, ORE, Width,
+                               VF.MinProfitableTripCount, IC, &LVL, &CM, BFI,
+                               PSI, Checks);
         LVP.executePlan(Width, IC, BestPlan, LB, DT, false);
         ++LoopsVectorized;