diff options
| -rw-r--r-- | lib/Analysis/IVUsers.cpp | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/lib/Analysis/IVUsers.cpp b/lib/Analysis/IVUsers.cpp index cf52320d1f..efe40e4c6d 100644 --- a/lib/Analysis/IVUsers.cpp +++ b/lib/Analysis/IVUsers.cpp @@ -24,6 +24,7 @@ #include "llvm/ADT/STLExtras.h" #include "llvm/Support/Debug.h" #include "llvm/Support/raw_ostream.h" +#include "llvm/Support/CommandLine.h" #include <algorithm> using namespace llvm; @@ -31,6 +32,10 @@ char IVUsers::ID = 0; static RegisterPass<IVUsers> X("iv-users", "Induction Variable Users", false, true); +static cl::opt<bool> +SimplifyIVUsers("simplify-iv-users", cl::Hidden, cl::init(false), + cl::desc("Restrict IV Users to loop-invariant strides")); + Pass *llvm::createIVUsersPass() { return new IVUsers(); } @@ -208,6 +213,11 @@ bool IVUsers::AddUsersIfInteresting(Instruction *I) { if (!getSCEVStartAndStride(ISE, L, UseLoop, Start, Stride, SE, DT)) return false; // Non-reducible symbolic expression, bail out. + // Keep things simple. Don't touch loop-variant strides. + if (SimplifyIVUsers && !Stride->isLoopInvariant(L) + && L->contains(I->getParent())) + return false; + SmallPtrSet<Instruction *, 4> UniqueUsers; for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); UI != E; ++UI) { |