[LoopStrengthReduce] ComplexityLimit as an option

Convert ComplexityLimit into a command line value.

Differential Revision: https://reviews.llvm.org/D54899

llvm-svn: 347843

1 files changed, 5 insertions, 3 deletions

diff --git a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index e9c24d61394..773ffb9df0a 100644
--- a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -155,6 +155,11 @@ static cl::opt<bool> FilterSameScaledReg(
     cl::desc("Narrow LSR search space by filtering non-optimal formulae"
              " with the same ScaledReg and Scale"));
 
+static cl::opt<unsigned> ComplexityLimit(
+  "lsr-complexity-limit", cl::Hidden,
+  cl::init(std::numeric_limits<uint16_t>::max()),
+  cl::desc("LSR search space complexity limit"));
+
 #ifndef NDEBUG
 // Stress test IV chain generation.
 static cl::opt<bool> StressIVChain(
@@ -4311,9 +4316,6 @@ void LSRInstance::FilterOutUndesirableDedicatedRegisters() {
   });
 }
 
-// This is a rough guess that seems to work fairly well.
-static const size_t ComplexityLimit = std::numeric_limits<uint16_t>::max();
-
 /// Estimate the worst-case number of solutions the solver might have to
 /// consider. It almost never considers this many solutions because it prune the
 /// search space, but the pruning isn't always sufficient.