[LoopUnroll] Move a simple check earlier. NFC.

Move the check of CallInst earlier to skip expensive recursive operations.

Differential Revision: https://reviews.llvm.org/D23611

llvm-svn: 278998

1 files changed, 5 insertions, 5 deletions

diff --git a/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp b/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
index 0a45732a892..f53ac86b14c 100644
--- a/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
@@ -431,16 +431,16 @@ analyzeLoopUnrollCost(const Loop *L, unsigned TripCount, DominatorTree &DT,
         if (IsFree)
           continue;
 
-        // If the instruction might have a side-effect recursively account for
-        // the cost of it and all the instructions leading up to it.
-        if (I.mayHaveSideEffects())
-          AddCostRecursively(I, Iteration);
-
         // Can't properly model a cost of a call.
         // FIXME: With a proper cost model we should be able to do it.
         if(isa<CallInst>(&I))
           return None;
 
+        // If the instruction might have a side-effect recursively account for
+        // the cost of it and all the instructions leading up to it.
+        if (I.mayHaveSideEffects())
+          AddCostRecursively(I, Iteration);
+
         // If unrolled body turns out to be too big, bail out.
         if (UnrolledCost > MaxUnrolledLoopSize) {
           DEBUG(dbgs() << "  Exceeded threshold.. exiting.\n"