From: Amara Emerson <aemerson@apple.com>
Date: Fri, 10 May 2019 17:29:35 +0000 (+0000)
Subject: [LSR] Tweak setup cost depth threshold to 10.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=3ff5f06bc05741030255aa05b284617714128e69;p=llvm

[LSR] Tweak setup cost depth threshold to 10.

The original change introduced a depth limit of 7 which caused a 22% regression
in the Swift MapReduceLazyCollection & Ackermann benchmarks. This new threshold
still ensures that the original test case doesn't hang.

rdar://50359639

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@360444 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index 768860140e6..9247ae35adb 100644
--- a/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -165,7 +165,7 @@ static cl::opt<unsigned> ComplexityLimit(
   cl::desc("LSR search space complexity limit"));
 
 static cl::opt<unsigned> SetupCostDepthLimit(
-    "lsr-setupcost-depth-limit", cl::Hidden, cl::init(7),
+    "lsr-setupcost-depth-limit", cl::Hidden, cl::init(10),
     cl::desc("The limit on recursion depth for LSRs setup cost"));
 
 #ifndef NDEBUG